GMAW Fundamentals GMAW Fundamentals Gas Metal Arc Welding Metal Inert Gas
GMAW FundamentalsGMAW Fundamentals
Gas Metal Arc Welding
Metal Inert Gas
SafetySafety
1048708
Electrocution hazard1048708 Skin burns from flying metal1048708 Skin burns from direct light from arc1048708 Skin burns from indirect light from arc1048708 Cotton clothing and leather gloves1048708 Helmet to protect eyes from light1048708 Safety glasses when chipping slag
1048708 Ventilation to remove dangerous fumes1048708 Do not weld near water1048708 Do not weld near combustible materials1048708 Keep welding cables and jobs free grease1048708 Protect bystanders from arc rays
IntroductionIntroduction
GMAW is defined as arc welding using a continuously fed consumable electrode and a shielding gas
GMAW is also known as MIG (Metal Inert Gas)
Produces high-quality weldsYields high productivity
AdvantagesAdvantages
Large gaps filled or bridged easilyWelding can be done in all positionsNo slag removal requiredHigh welding speedsHigh weld qualityLess distortion of work piece
DisadvantagesDisadvantages
Hard to reach locations are less easily welded because of bulky torch and cables
Wind or air drafts may compromise gas shielding Reactive metals (ie titanium) may need special
shielding provisions High heat may be uncomfortable to welders Correct parameter selection learning needs
dedicated training Equipment is more complex and expensive than
that of alternative processes
Several tips must be consider in Several tips must be consider in selecting mode of transferselecting mode of transfer
Type intensity and polarity of welding current
Electrode size Electrode composition Electrode extension Shielding gas mix composition
Types of Metal TransferTypes of Metal Transfer
The basic GMAW process includes three distinctive process techniques
1 Short Circuit (Short Arc)
2 Globular Transfer
3 Spray Arc Transfer
Modes of GMAW TransferModes of GMAW Transfer
Short Circuit (Short Arc)Short Circuit (Short Arc)
Operates at low voltages and welding current Small fast-freezing weld puddle obtained Useful in joining thin materials in any position as
well as thick materials in vertical and overhead positions
Metal transfer occurs when an electrical short circuit is established
this cycle can repeat itself between 20 and as much as 250 times per second
Short CircuitShort CircuitA - Electrode is short circuited to base metal No arc and current is flowing through electrode wire and base metalB - Resistance increases in electrode wire causing it to heat melt and ldquoneck downrdquoC - Electrode wire separates from weld puddle creating an arc Small portion of electrode wireis deposited which forms a weld puddleD - Arc length and load voltage are at maximum Heat of arc is flattening the puddle and increasingthe diameter tip of electrodeE - Wire feed speed overcomes heat of arc and wire approaches base metal againF - Arc is off and the short circuit cycle starts again
AdvantagesAdvantages
All-position capability including flat horizontal vertical-up vertical-down and overhead
Handles poor fit-up extremely well and is capable of root pass work on pipe applications
Lower heat input reduces weldment distortion Higher operator appeal and ease of use Higher electrode efficiencies 93 or more
LimitationsLimitations
Restricted to sheet metal thickness range and open roots of groove joints on heavier sections of base material
Poor welding procedure control can result in incomplete fusion Cold lap and cold shut are additional terms that serve to describe incomplete fusion defects
Poor procedure control can result in excessive spatter and will increase weldment cleanup cost
To prevent the loss of shielding gas to the wind welding outdoors may require the use of a windscreen(s)
Globular TransferGlobular Transfer
Welding current and wire speed are increased above maximum for short arc
Droplets of metal have a greater diameter than the wire being used
Spatter present Welding is most effectively done in the flat
position when using globular transfer
Globular transfer is often a high voltage high amperage high wire feed speed transfer and is the result of using CO2 shielding gas (or 75 AR-25 CO2) with parameters higher than the short-circuiting range
AdvantagesAdvantages
Uses inexpensive CO2 shielding gas but is frequently used with argonCO2 blends
Is capable of making welds at very high travel speeds
Inexpensive solid or metal-cored electrodesWelding equipment is inexpensive
LimitationsLimitations
Higher spatter levels result in costly cleanup Prone to cold lap or cold shut incomplete fusion defects
which results in costly repairs Weld bead shape is convex and welds exhibit poor
wetting at the toes High spatter level reduces electrode efficiency to a range
of 87 ndash 93 Less desirable weld appearance than spray arc transfer Welding is limited to flat positions and horizontally fillet
welds Welding is limited to metal 18 inch (3 mm) or thicker
Spray Arc TransferSpray Arc Transfer
Occurs when the current and voltage settings are increased higher than that used for Globular Transfer
Used on thick sections of base material best suited for flat position due to large weld puddle
Spatter is minimal to none Uses 5 to 10 co2 mix with argon or oxygen
gtForms very small droplets of metalgtVery good stabilitygtVery little spatter
Spray arc transfer ldquospraysrdquo a streamof tiny molten droplets across thearc from the electrode wire to thebase metalSpray arc transfer uses relativelyhigh voltage wire feed speed andamperage values compared to shortcircuit transfer
AdvantagesAdvantages
High deposition rates High electrode efficiency of 98 or more Employs a wide range of filler metal types in an
equally wide range of electrode diameters Excellent weld bead appearance High operator appeal and ease of use Requires little post weld cleanup Absence of weld spatter Excellent weld fusion Lends itself to semiautomatic robotic and hard
automation applications
LimitationsLimitations
Restricted to the flat and horizontal welding positions
Welding fume generation is higher The higher-radiated heat and the generation of a
very bright arc require extra welder and bystander protection
The use of axial spray transfer outdoors requires the use of a windscreen(s)
The shielding used to support axial spray transfer costs more than 100 CO2
Pulse Spray Transfer Pulse Spray Transfer
GMAW-P was developed for two demanding reasons control of weld spatter and the elimination of incomplete fusion defects common to globular and short-circuiting transfer
The welding current alternates between a peak current and a lower background current
This faster-freezing weld puddle is what allows the pulsed-spray transfer to be used fort thinner metals
better control on out-of-position work allows for larger wire sizes to be used on varied metal
thicknesses
In pulse spray transfer (GMAW-P) the welding power sourcersquos pulse control pulses the welding output withhigh peak currents (amperage) which are set at levels which will cause the transfer to go into a spray The background current (amperage) is set at a level that will maintain the arcbut is too low for any metal transfer to occur
Pulsed arc transferPulsed arc transfer
AdvantagesAdvantages Absent or very low levels of spatter More resistant to lack of fusion defects than other modes of
GMAW metal transfer Excellent weld bead appearance and offers an engineered
solution for the control of weld fume generation Reduced levels of heat induced distortion and tendency for arc
blow Ability to weld out-of-position and handles poor fit-up When compared to FCAW SMAW and GMAW-S pulsed
spray transfer provides a low cost high-electrode efficiency of 98
Lends itself to robotic and hard automation applications Is combined for use with Tandem GMAW or other multiple arc
scenarios Capable of arc travel speeds greater than 50 inches per minute
(12 Mmin)
LimitationsLimitationsEquipment to support the process is more
expensive than traditional systemsBlends of argon based shielding gas are
more expensive than carbon dioxideHigher arc energy requires the use of
additional safety protection for welders and bystanders
Adds complexity to weldingRequires the use of windscreens outdoors
Manual GMAW EquipmentManual GMAW Equipment
Three major elements are
1) Welding torch and accessories
2) Welding control amp Wire feed motor
3) Power Source
GMAW equipment can be used either manually or automatically
GMAW Schematic DiagramGMAW Schematic Diagram
WIRE CONTROLamp
WIRE FEED MOTOR
POWER SOURCE
Welding Torch amp AccessoriesWelding Torch amp Accessories
The welding torch guides the wire and shielding gas to the weld zone
Brings welding power to the wire alsoMajor componentsparts of the torch are the
contact tip shielding gas nozzle gas diffuser and the wire conduit
Others types of torchOthers types of torch
TRIGGER
INSTALLED
COMPONENTS
NOZZLE
CONTACT TIP
GAS DIFFUSER
Welding Control amp Wire Welding Control amp Wire Feed MotorFeed Motor
Welding control amp Wire feed motor are combined into one unit
Main function is to pull the wire from the spool and feed it to the arc
Controls wire feed speed and regulates the starting and stopping of wire feed
Wire feed speed controls Amperage
Types of Wire Feed MotorTypes of Wire Feed Motor
Types of WFM RollerTypes of WFM Roller
Types of Wire FeederTypes of Wire Feeder
WIRE FEEDER
Power SourcePower Source
Almost all GMAW is done with reverse polarity also known as DCEP
Positive (+) lead is connected to the torchNegative (-) lead is connected to the work
pieceProvides a relatively consistent voltage to the
arcArc Voltage is the voltage between the end of
the wire and the work piece
Contact Tip To Work DistanceContact Tip To Work Distance
In constant current the CTWD (contact tip to work distance) determines the arc length
As the CTWD increases the arc length increases and as the
CTWD decreases the arc length decreases This presented a
problem for semiautomatic welding because it is difficult to
maintain the same CTWD To compensate for this problem an arc voltage controlled wire
Constant voltage power source designs provide a specific arc voltage for a given pre-selected wire feed speed The volt-amp curve or slope is comparatively flat As the CTWD increases with these types of power sources there is a decrease in the welding current As the CTWD decreases there is an increase in the welding current The arc in this case becomes a series circuit and the CTWD provides resistance to current In either scenario the voltage remains the same and the arc length remains the same
POSITIVETERMINAL
NEGATIVETERMINAL
Shielding GasesShielding Gases
Purpose of shielding gas is the protect the weld area from the contaminants in the atmosphere
Gas can be Inert Reactive or Mixtures of both
Gas flow rate is between 25-35 CFHArgon Helium and Carbon Dioxide are the
main three gases used in GMAW
Properties of GasesProperties of Gases
Affect the performance of the welding process include
1) Thermal properties at elevated temperatures 2) Chemical reaction of the gas with the various
elements in the base plate and welding wire 3) Effect of each gas on the mode of metal
transfer
Types of shielding gasesTypes of shielding gases
Inert Gas
1 Argon
2 Helium
3 Ar + HeActive Gas
1 Carbon Dioxide
2 Inert gas + any type of active gas
Argon is an inert gas which is used both singularly and in combination with other gases to achieve desired arc characteristics for the welding of both ferrous and non-ferrous metals
Carbon Dioxide Pure carbon dioxide is not an inert gas because the heat of the arc breaks down the CO2 into carbon monoxide and free oxygen This oxygen will combine with elements transferring across the arc to form oxides which are released from the weld puddle in the form of slag and scale
Helium is an inert gas which is used on weld applications requiring higher heat input for improved bead wetting deeper penetration and higher travel speed In GMAW it does not produce as stable an arc as argon Compared to argon helium has a higher thermal conductivity and voltage gradient
FLOW METER
CYLCINDERPRESSUREGAUGE
CFH PRESSURE ADJUSTMENT KNOB
Filler WireFiller Wire
Wire ChemistriesWire Chemistries
GMAW Operation techniquesGMAW Operation techniques
To setting WFS (Wire Feed Speed)
Voltage-bead ChangeVoltage-bead Change
Electrode Stick-outElectrode Stick-out
ESO SettingESO Setting
EOSEOS
Gun angles and techniquesGun angles and techniques
Direction of TravelDirection of Travel
THANK YOU
SafetySafety
1048708
Electrocution hazard1048708 Skin burns from flying metal1048708 Skin burns from direct light from arc1048708 Skin burns from indirect light from arc1048708 Cotton clothing and leather gloves1048708 Helmet to protect eyes from light1048708 Safety glasses when chipping slag
1048708 Ventilation to remove dangerous fumes1048708 Do not weld near water1048708 Do not weld near combustible materials1048708 Keep welding cables and jobs free grease1048708 Protect bystanders from arc rays
IntroductionIntroduction
GMAW is defined as arc welding using a continuously fed consumable electrode and a shielding gas
GMAW is also known as MIG (Metal Inert Gas)
Produces high-quality weldsYields high productivity
AdvantagesAdvantages
Large gaps filled or bridged easilyWelding can be done in all positionsNo slag removal requiredHigh welding speedsHigh weld qualityLess distortion of work piece
DisadvantagesDisadvantages
Hard to reach locations are less easily welded because of bulky torch and cables
Wind or air drafts may compromise gas shielding Reactive metals (ie titanium) may need special
shielding provisions High heat may be uncomfortable to welders Correct parameter selection learning needs
dedicated training Equipment is more complex and expensive than
that of alternative processes
Several tips must be consider in Several tips must be consider in selecting mode of transferselecting mode of transfer
Type intensity and polarity of welding current
Electrode size Electrode composition Electrode extension Shielding gas mix composition
Types of Metal TransferTypes of Metal Transfer
The basic GMAW process includes three distinctive process techniques
1 Short Circuit (Short Arc)
2 Globular Transfer
3 Spray Arc Transfer
Modes of GMAW TransferModes of GMAW Transfer
Short Circuit (Short Arc)Short Circuit (Short Arc)
Operates at low voltages and welding current Small fast-freezing weld puddle obtained Useful in joining thin materials in any position as
well as thick materials in vertical and overhead positions
Metal transfer occurs when an electrical short circuit is established
this cycle can repeat itself between 20 and as much as 250 times per second
Short CircuitShort CircuitA - Electrode is short circuited to base metal No arc and current is flowing through electrode wire and base metalB - Resistance increases in electrode wire causing it to heat melt and ldquoneck downrdquoC - Electrode wire separates from weld puddle creating an arc Small portion of electrode wireis deposited which forms a weld puddleD - Arc length and load voltage are at maximum Heat of arc is flattening the puddle and increasingthe diameter tip of electrodeE - Wire feed speed overcomes heat of arc and wire approaches base metal againF - Arc is off and the short circuit cycle starts again
AdvantagesAdvantages
All-position capability including flat horizontal vertical-up vertical-down and overhead
Handles poor fit-up extremely well and is capable of root pass work on pipe applications
Lower heat input reduces weldment distortion Higher operator appeal and ease of use Higher electrode efficiencies 93 or more
LimitationsLimitations
Restricted to sheet metal thickness range and open roots of groove joints on heavier sections of base material
Poor welding procedure control can result in incomplete fusion Cold lap and cold shut are additional terms that serve to describe incomplete fusion defects
Poor procedure control can result in excessive spatter and will increase weldment cleanup cost
To prevent the loss of shielding gas to the wind welding outdoors may require the use of a windscreen(s)
Globular TransferGlobular Transfer
Welding current and wire speed are increased above maximum for short arc
Droplets of metal have a greater diameter than the wire being used
Spatter present Welding is most effectively done in the flat
position when using globular transfer
Globular transfer is often a high voltage high amperage high wire feed speed transfer and is the result of using CO2 shielding gas (or 75 AR-25 CO2) with parameters higher than the short-circuiting range
AdvantagesAdvantages
Uses inexpensive CO2 shielding gas but is frequently used with argonCO2 blends
Is capable of making welds at very high travel speeds
Inexpensive solid or metal-cored electrodesWelding equipment is inexpensive
LimitationsLimitations
Higher spatter levels result in costly cleanup Prone to cold lap or cold shut incomplete fusion defects
which results in costly repairs Weld bead shape is convex and welds exhibit poor
wetting at the toes High spatter level reduces electrode efficiency to a range
of 87 ndash 93 Less desirable weld appearance than spray arc transfer Welding is limited to flat positions and horizontally fillet
welds Welding is limited to metal 18 inch (3 mm) or thicker
Spray Arc TransferSpray Arc Transfer
Occurs when the current and voltage settings are increased higher than that used for Globular Transfer
Used on thick sections of base material best suited for flat position due to large weld puddle
Spatter is minimal to none Uses 5 to 10 co2 mix with argon or oxygen
gtForms very small droplets of metalgtVery good stabilitygtVery little spatter
Spray arc transfer ldquospraysrdquo a streamof tiny molten droplets across thearc from the electrode wire to thebase metalSpray arc transfer uses relativelyhigh voltage wire feed speed andamperage values compared to shortcircuit transfer
AdvantagesAdvantages
High deposition rates High electrode efficiency of 98 or more Employs a wide range of filler metal types in an
equally wide range of electrode diameters Excellent weld bead appearance High operator appeal and ease of use Requires little post weld cleanup Absence of weld spatter Excellent weld fusion Lends itself to semiautomatic robotic and hard
automation applications
LimitationsLimitations
Restricted to the flat and horizontal welding positions
Welding fume generation is higher The higher-radiated heat and the generation of a
very bright arc require extra welder and bystander protection
The use of axial spray transfer outdoors requires the use of a windscreen(s)
The shielding used to support axial spray transfer costs more than 100 CO2
Pulse Spray Transfer Pulse Spray Transfer
GMAW-P was developed for two demanding reasons control of weld spatter and the elimination of incomplete fusion defects common to globular and short-circuiting transfer
The welding current alternates between a peak current and a lower background current
This faster-freezing weld puddle is what allows the pulsed-spray transfer to be used fort thinner metals
better control on out-of-position work allows for larger wire sizes to be used on varied metal
thicknesses
In pulse spray transfer (GMAW-P) the welding power sourcersquos pulse control pulses the welding output withhigh peak currents (amperage) which are set at levels which will cause the transfer to go into a spray The background current (amperage) is set at a level that will maintain the arcbut is too low for any metal transfer to occur
Pulsed arc transferPulsed arc transfer
AdvantagesAdvantages Absent or very low levels of spatter More resistant to lack of fusion defects than other modes of
GMAW metal transfer Excellent weld bead appearance and offers an engineered
solution for the control of weld fume generation Reduced levels of heat induced distortion and tendency for arc
blow Ability to weld out-of-position and handles poor fit-up When compared to FCAW SMAW and GMAW-S pulsed
spray transfer provides a low cost high-electrode efficiency of 98
Lends itself to robotic and hard automation applications Is combined for use with Tandem GMAW or other multiple arc
scenarios Capable of arc travel speeds greater than 50 inches per minute
(12 Mmin)
LimitationsLimitationsEquipment to support the process is more
expensive than traditional systemsBlends of argon based shielding gas are
more expensive than carbon dioxideHigher arc energy requires the use of
additional safety protection for welders and bystanders
Adds complexity to weldingRequires the use of windscreens outdoors
Manual GMAW EquipmentManual GMAW Equipment
Three major elements are
1) Welding torch and accessories
2) Welding control amp Wire feed motor
3) Power Source
GMAW equipment can be used either manually or automatically
GMAW Schematic DiagramGMAW Schematic Diagram
WIRE CONTROLamp
WIRE FEED MOTOR
POWER SOURCE
Welding Torch amp AccessoriesWelding Torch amp Accessories
The welding torch guides the wire and shielding gas to the weld zone
Brings welding power to the wire alsoMajor componentsparts of the torch are the
contact tip shielding gas nozzle gas diffuser and the wire conduit
Others types of torchOthers types of torch
TRIGGER
INSTALLED
COMPONENTS
NOZZLE
CONTACT TIP
GAS DIFFUSER
Welding Control amp Wire Welding Control amp Wire Feed MotorFeed Motor
Welding control amp Wire feed motor are combined into one unit
Main function is to pull the wire from the spool and feed it to the arc
Controls wire feed speed and regulates the starting and stopping of wire feed
Wire feed speed controls Amperage
Types of Wire Feed MotorTypes of Wire Feed Motor
Types of WFM RollerTypes of WFM Roller
Types of Wire FeederTypes of Wire Feeder
WIRE FEEDER
Power SourcePower Source
Almost all GMAW is done with reverse polarity also known as DCEP
Positive (+) lead is connected to the torchNegative (-) lead is connected to the work
pieceProvides a relatively consistent voltage to the
arcArc Voltage is the voltage between the end of
the wire and the work piece
Contact Tip To Work DistanceContact Tip To Work Distance
In constant current the CTWD (contact tip to work distance) determines the arc length
As the CTWD increases the arc length increases and as the
CTWD decreases the arc length decreases This presented a
problem for semiautomatic welding because it is difficult to
maintain the same CTWD To compensate for this problem an arc voltage controlled wire
Constant voltage power source designs provide a specific arc voltage for a given pre-selected wire feed speed The volt-amp curve or slope is comparatively flat As the CTWD increases with these types of power sources there is a decrease in the welding current As the CTWD decreases there is an increase in the welding current The arc in this case becomes a series circuit and the CTWD provides resistance to current In either scenario the voltage remains the same and the arc length remains the same
POSITIVETERMINAL
NEGATIVETERMINAL
Shielding GasesShielding Gases
Purpose of shielding gas is the protect the weld area from the contaminants in the atmosphere
Gas can be Inert Reactive or Mixtures of both
Gas flow rate is between 25-35 CFHArgon Helium and Carbon Dioxide are the
main three gases used in GMAW
Properties of GasesProperties of Gases
Affect the performance of the welding process include
1) Thermal properties at elevated temperatures 2) Chemical reaction of the gas with the various
elements in the base plate and welding wire 3) Effect of each gas on the mode of metal
transfer
Types of shielding gasesTypes of shielding gases
Inert Gas
1 Argon
2 Helium
3 Ar + HeActive Gas
1 Carbon Dioxide
2 Inert gas + any type of active gas
Argon is an inert gas which is used both singularly and in combination with other gases to achieve desired arc characteristics for the welding of both ferrous and non-ferrous metals
Carbon Dioxide Pure carbon dioxide is not an inert gas because the heat of the arc breaks down the CO2 into carbon monoxide and free oxygen This oxygen will combine with elements transferring across the arc to form oxides which are released from the weld puddle in the form of slag and scale
Helium is an inert gas which is used on weld applications requiring higher heat input for improved bead wetting deeper penetration and higher travel speed In GMAW it does not produce as stable an arc as argon Compared to argon helium has a higher thermal conductivity and voltage gradient
FLOW METER
CYLCINDERPRESSUREGAUGE
CFH PRESSURE ADJUSTMENT KNOB
Filler WireFiller Wire
Wire ChemistriesWire Chemistries
GMAW Operation techniquesGMAW Operation techniques
To setting WFS (Wire Feed Speed)
Voltage-bead ChangeVoltage-bead Change
Electrode Stick-outElectrode Stick-out
ESO SettingESO Setting
EOSEOS
Gun angles and techniquesGun angles and techniques
Direction of TravelDirection of Travel
THANK YOU
IntroductionIntroduction
GMAW is defined as arc welding using a continuously fed consumable electrode and a shielding gas
GMAW is also known as MIG (Metal Inert Gas)
Produces high-quality weldsYields high productivity
AdvantagesAdvantages
Large gaps filled or bridged easilyWelding can be done in all positionsNo slag removal requiredHigh welding speedsHigh weld qualityLess distortion of work piece
DisadvantagesDisadvantages
Hard to reach locations are less easily welded because of bulky torch and cables
Wind or air drafts may compromise gas shielding Reactive metals (ie titanium) may need special
shielding provisions High heat may be uncomfortable to welders Correct parameter selection learning needs
dedicated training Equipment is more complex and expensive than
that of alternative processes
Several tips must be consider in Several tips must be consider in selecting mode of transferselecting mode of transfer
Type intensity and polarity of welding current
Electrode size Electrode composition Electrode extension Shielding gas mix composition
Types of Metal TransferTypes of Metal Transfer
The basic GMAW process includes three distinctive process techniques
1 Short Circuit (Short Arc)
2 Globular Transfer
3 Spray Arc Transfer
Modes of GMAW TransferModes of GMAW Transfer
Short Circuit (Short Arc)Short Circuit (Short Arc)
Operates at low voltages and welding current Small fast-freezing weld puddle obtained Useful in joining thin materials in any position as
well as thick materials in vertical and overhead positions
Metal transfer occurs when an electrical short circuit is established
this cycle can repeat itself between 20 and as much as 250 times per second
Short CircuitShort CircuitA - Electrode is short circuited to base metal No arc and current is flowing through electrode wire and base metalB - Resistance increases in electrode wire causing it to heat melt and ldquoneck downrdquoC - Electrode wire separates from weld puddle creating an arc Small portion of electrode wireis deposited which forms a weld puddleD - Arc length and load voltage are at maximum Heat of arc is flattening the puddle and increasingthe diameter tip of electrodeE - Wire feed speed overcomes heat of arc and wire approaches base metal againF - Arc is off and the short circuit cycle starts again
AdvantagesAdvantages
All-position capability including flat horizontal vertical-up vertical-down and overhead
Handles poor fit-up extremely well and is capable of root pass work on pipe applications
Lower heat input reduces weldment distortion Higher operator appeal and ease of use Higher electrode efficiencies 93 or more
LimitationsLimitations
Restricted to sheet metal thickness range and open roots of groove joints on heavier sections of base material
Poor welding procedure control can result in incomplete fusion Cold lap and cold shut are additional terms that serve to describe incomplete fusion defects
Poor procedure control can result in excessive spatter and will increase weldment cleanup cost
To prevent the loss of shielding gas to the wind welding outdoors may require the use of a windscreen(s)
Globular TransferGlobular Transfer
Welding current and wire speed are increased above maximum for short arc
Droplets of metal have a greater diameter than the wire being used
Spatter present Welding is most effectively done in the flat
position when using globular transfer
Globular transfer is often a high voltage high amperage high wire feed speed transfer and is the result of using CO2 shielding gas (or 75 AR-25 CO2) with parameters higher than the short-circuiting range
AdvantagesAdvantages
Uses inexpensive CO2 shielding gas but is frequently used with argonCO2 blends
Is capable of making welds at very high travel speeds
Inexpensive solid or metal-cored electrodesWelding equipment is inexpensive
LimitationsLimitations
Higher spatter levels result in costly cleanup Prone to cold lap or cold shut incomplete fusion defects
which results in costly repairs Weld bead shape is convex and welds exhibit poor
wetting at the toes High spatter level reduces electrode efficiency to a range
of 87 ndash 93 Less desirable weld appearance than spray arc transfer Welding is limited to flat positions and horizontally fillet
welds Welding is limited to metal 18 inch (3 mm) or thicker
Spray Arc TransferSpray Arc Transfer
Occurs when the current and voltage settings are increased higher than that used for Globular Transfer
Used on thick sections of base material best suited for flat position due to large weld puddle
Spatter is minimal to none Uses 5 to 10 co2 mix with argon or oxygen
gtForms very small droplets of metalgtVery good stabilitygtVery little spatter
Spray arc transfer ldquospraysrdquo a streamof tiny molten droplets across thearc from the electrode wire to thebase metalSpray arc transfer uses relativelyhigh voltage wire feed speed andamperage values compared to shortcircuit transfer
AdvantagesAdvantages
High deposition rates High electrode efficiency of 98 or more Employs a wide range of filler metal types in an
equally wide range of electrode diameters Excellent weld bead appearance High operator appeal and ease of use Requires little post weld cleanup Absence of weld spatter Excellent weld fusion Lends itself to semiautomatic robotic and hard
automation applications
LimitationsLimitations
Restricted to the flat and horizontal welding positions
Welding fume generation is higher The higher-radiated heat and the generation of a
very bright arc require extra welder and bystander protection
The use of axial spray transfer outdoors requires the use of a windscreen(s)
The shielding used to support axial spray transfer costs more than 100 CO2
Pulse Spray Transfer Pulse Spray Transfer
GMAW-P was developed for two demanding reasons control of weld spatter and the elimination of incomplete fusion defects common to globular and short-circuiting transfer
The welding current alternates between a peak current and a lower background current
This faster-freezing weld puddle is what allows the pulsed-spray transfer to be used fort thinner metals
better control on out-of-position work allows for larger wire sizes to be used on varied metal
thicknesses
In pulse spray transfer (GMAW-P) the welding power sourcersquos pulse control pulses the welding output withhigh peak currents (amperage) which are set at levels which will cause the transfer to go into a spray The background current (amperage) is set at a level that will maintain the arcbut is too low for any metal transfer to occur
Pulsed arc transferPulsed arc transfer
AdvantagesAdvantages Absent or very low levels of spatter More resistant to lack of fusion defects than other modes of
GMAW metal transfer Excellent weld bead appearance and offers an engineered
solution for the control of weld fume generation Reduced levels of heat induced distortion and tendency for arc
blow Ability to weld out-of-position and handles poor fit-up When compared to FCAW SMAW and GMAW-S pulsed
spray transfer provides a low cost high-electrode efficiency of 98
Lends itself to robotic and hard automation applications Is combined for use with Tandem GMAW or other multiple arc
scenarios Capable of arc travel speeds greater than 50 inches per minute
(12 Mmin)
LimitationsLimitationsEquipment to support the process is more
expensive than traditional systemsBlends of argon based shielding gas are
more expensive than carbon dioxideHigher arc energy requires the use of
additional safety protection for welders and bystanders
Adds complexity to weldingRequires the use of windscreens outdoors
Manual GMAW EquipmentManual GMAW Equipment
Three major elements are
1) Welding torch and accessories
2) Welding control amp Wire feed motor
3) Power Source
GMAW equipment can be used either manually or automatically
GMAW Schematic DiagramGMAW Schematic Diagram
WIRE CONTROLamp
WIRE FEED MOTOR
POWER SOURCE
Welding Torch amp AccessoriesWelding Torch amp Accessories
The welding torch guides the wire and shielding gas to the weld zone
Brings welding power to the wire alsoMajor componentsparts of the torch are the
contact tip shielding gas nozzle gas diffuser and the wire conduit
Others types of torchOthers types of torch
TRIGGER
INSTALLED
COMPONENTS
NOZZLE
CONTACT TIP
GAS DIFFUSER
Welding Control amp Wire Welding Control amp Wire Feed MotorFeed Motor
Welding control amp Wire feed motor are combined into one unit
Main function is to pull the wire from the spool and feed it to the arc
Controls wire feed speed and regulates the starting and stopping of wire feed
Wire feed speed controls Amperage
Types of Wire Feed MotorTypes of Wire Feed Motor
Types of WFM RollerTypes of WFM Roller
Types of Wire FeederTypes of Wire Feeder
WIRE FEEDER
Power SourcePower Source
Almost all GMAW is done with reverse polarity also known as DCEP
Positive (+) lead is connected to the torchNegative (-) lead is connected to the work
pieceProvides a relatively consistent voltage to the
arcArc Voltage is the voltage between the end of
the wire and the work piece
Contact Tip To Work DistanceContact Tip To Work Distance
In constant current the CTWD (contact tip to work distance) determines the arc length
As the CTWD increases the arc length increases and as the
CTWD decreases the arc length decreases This presented a
problem for semiautomatic welding because it is difficult to
maintain the same CTWD To compensate for this problem an arc voltage controlled wire
Constant voltage power source designs provide a specific arc voltage for a given pre-selected wire feed speed The volt-amp curve or slope is comparatively flat As the CTWD increases with these types of power sources there is a decrease in the welding current As the CTWD decreases there is an increase in the welding current The arc in this case becomes a series circuit and the CTWD provides resistance to current In either scenario the voltage remains the same and the arc length remains the same
POSITIVETERMINAL
NEGATIVETERMINAL
Shielding GasesShielding Gases
Purpose of shielding gas is the protect the weld area from the contaminants in the atmosphere
Gas can be Inert Reactive or Mixtures of both
Gas flow rate is between 25-35 CFHArgon Helium and Carbon Dioxide are the
main three gases used in GMAW
Properties of GasesProperties of Gases
Affect the performance of the welding process include
1) Thermal properties at elevated temperatures 2) Chemical reaction of the gas with the various
elements in the base plate and welding wire 3) Effect of each gas on the mode of metal
transfer
Types of shielding gasesTypes of shielding gases
Inert Gas
1 Argon
2 Helium
3 Ar + HeActive Gas
1 Carbon Dioxide
2 Inert gas + any type of active gas
Argon is an inert gas which is used both singularly and in combination with other gases to achieve desired arc characteristics for the welding of both ferrous and non-ferrous metals
Carbon Dioxide Pure carbon dioxide is not an inert gas because the heat of the arc breaks down the CO2 into carbon monoxide and free oxygen This oxygen will combine with elements transferring across the arc to form oxides which are released from the weld puddle in the form of slag and scale
Helium is an inert gas which is used on weld applications requiring higher heat input for improved bead wetting deeper penetration and higher travel speed In GMAW it does not produce as stable an arc as argon Compared to argon helium has a higher thermal conductivity and voltage gradient
FLOW METER
CYLCINDERPRESSUREGAUGE
CFH PRESSURE ADJUSTMENT KNOB
Filler WireFiller Wire
Wire ChemistriesWire Chemistries
GMAW Operation techniquesGMAW Operation techniques
To setting WFS (Wire Feed Speed)
Voltage-bead ChangeVoltage-bead Change
Electrode Stick-outElectrode Stick-out
ESO SettingESO Setting
EOSEOS
Gun angles and techniquesGun angles and techniques
Direction of TravelDirection of Travel
THANK YOU
AdvantagesAdvantages
Large gaps filled or bridged easilyWelding can be done in all positionsNo slag removal requiredHigh welding speedsHigh weld qualityLess distortion of work piece
DisadvantagesDisadvantages
Hard to reach locations are less easily welded because of bulky torch and cables
Wind or air drafts may compromise gas shielding Reactive metals (ie titanium) may need special
shielding provisions High heat may be uncomfortable to welders Correct parameter selection learning needs
dedicated training Equipment is more complex and expensive than
that of alternative processes
Several tips must be consider in Several tips must be consider in selecting mode of transferselecting mode of transfer
Type intensity and polarity of welding current
Electrode size Electrode composition Electrode extension Shielding gas mix composition
Types of Metal TransferTypes of Metal Transfer
The basic GMAW process includes three distinctive process techniques
1 Short Circuit (Short Arc)
2 Globular Transfer
3 Spray Arc Transfer
Modes of GMAW TransferModes of GMAW Transfer
Short Circuit (Short Arc)Short Circuit (Short Arc)
Operates at low voltages and welding current Small fast-freezing weld puddle obtained Useful in joining thin materials in any position as
well as thick materials in vertical and overhead positions
Metal transfer occurs when an electrical short circuit is established
this cycle can repeat itself between 20 and as much as 250 times per second
Short CircuitShort CircuitA - Electrode is short circuited to base metal No arc and current is flowing through electrode wire and base metalB - Resistance increases in electrode wire causing it to heat melt and ldquoneck downrdquoC - Electrode wire separates from weld puddle creating an arc Small portion of electrode wireis deposited which forms a weld puddleD - Arc length and load voltage are at maximum Heat of arc is flattening the puddle and increasingthe diameter tip of electrodeE - Wire feed speed overcomes heat of arc and wire approaches base metal againF - Arc is off and the short circuit cycle starts again
AdvantagesAdvantages
All-position capability including flat horizontal vertical-up vertical-down and overhead
Handles poor fit-up extremely well and is capable of root pass work on pipe applications
Lower heat input reduces weldment distortion Higher operator appeal and ease of use Higher electrode efficiencies 93 or more
LimitationsLimitations
Restricted to sheet metal thickness range and open roots of groove joints on heavier sections of base material
Poor welding procedure control can result in incomplete fusion Cold lap and cold shut are additional terms that serve to describe incomplete fusion defects
Poor procedure control can result in excessive spatter and will increase weldment cleanup cost
To prevent the loss of shielding gas to the wind welding outdoors may require the use of a windscreen(s)
Globular TransferGlobular Transfer
Welding current and wire speed are increased above maximum for short arc
Droplets of metal have a greater diameter than the wire being used
Spatter present Welding is most effectively done in the flat
position when using globular transfer
Globular transfer is often a high voltage high amperage high wire feed speed transfer and is the result of using CO2 shielding gas (or 75 AR-25 CO2) with parameters higher than the short-circuiting range
AdvantagesAdvantages
Uses inexpensive CO2 shielding gas but is frequently used with argonCO2 blends
Is capable of making welds at very high travel speeds
Inexpensive solid or metal-cored electrodesWelding equipment is inexpensive
LimitationsLimitations
Higher spatter levels result in costly cleanup Prone to cold lap or cold shut incomplete fusion defects
which results in costly repairs Weld bead shape is convex and welds exhibit poor
wetting at the toes High spatter level reduces electrode efficiency to a range
of 87 ndash 93 Less desirable weld appearance than spray arc transfer Welding is limited to flat positions and horizontally fillet
welds Welding is limited to metal 18 inch (3 mm) or thicker
Spray Arc TransferSpray Arc Transfer
Occurs when the current and voltage settings are increased higher than that used for Globular Transfer
Used on thick sections of base material best suited for flat position due to large weld puddle
Spatter is minimal to none Uses 5 to 10 co2 mix with argon or oxygen
gtForms very small droplets of metalgtVery good stabilitygtVery little spatter
Spray arc transfer ldquospraysrdquo a streamof tiny molten droplets across thearc from the electrode wire to thebase metalSpray arc transfer uses relativelyhigh voltage wire feed speed andamperage values compared to shortcircuit transfer
AdvantagesAdvantages
High deposition rates High electrode efficiency of 98 or more Employs a wide range of filler metal types in an
equally wide range of electrode diameters Excellent weld bead appearance High operator appeal and ease of use Requires little post weld cleanup Absence of weld spatter Excellent weld fusion Lends itself to semiautomatic robotic and hard
automation applications
LimitationsLimitations
Restricted to the flat and horizontal welding positions
Welding fume generation is higher The higher-radiated heat and the generation of a
very bright arc require extra welder and bystander protection
The use of axial spray transfer outdoors requires the use of a windscreen(s)
The shielding used to support axial spray transfer costs more than 100 CO2
Pulse Spray Transfer Pulse Spray Transfer
GMAW-P was developed for two demanding reasons control of weld spatter and the elimination of incomplete fusion defects common to globular and short-circuiting transfer
The welding current alternates between a peak current and a lower background current
This faster-freezing weld puddle is what allows the pulsed-spray transfer to be used fort thinner metals
better control on out-of-position work allows for larger wire sizes to be used on varied metal
thicknesses
In pulse spray transfer (GMAW-P) the welding power sourcersquos pulse control pulses the welding output withhigh peak currents (amperage) which are set at levels which will cause the transfer to go into a spray The background current (amperage) is set at a level that will maintain the arcbut is too low for any metal transfer to occur
Pulsed arc transferPulsed arc transfer
AdvantagesAdvantages Absent or very low levels of spatter More resistant to lack of fusion defects than other modes of
GMAW metal transfer Excellent weld bead appearance and offers an engineered
solution for the control of weld fume generation Reduced levels of heat induced distortion and tendency for arc
blow Ability to weld out-of-position and handles poor fit-up When compared to FCAW SMAW and GMAW-S pulsed
spray transfer provides a low cost high-electrode efficiency of 98
Lends itself to robotic and hard automation applications Is combined for use with Tandem GMAW or other multiple arc
scenarios Capable of arc travel speeds greater than 50 inches per minute
(12 Mmin)
LimitationsLimitationsEquipment to support the process is more
expensive than traditional systemsBlends of argon based shielding gas are
more expensive than carbon dioxideHigher arc energy requires the use of
additional safety protection for welders and bystanders
Adds complexity to weldingRequires the use of windscreens outdoors
Manual GMAW EquipmentManual GMAW Equipment
Three major elements are
1) Welding torch and accessories
2) Welding control amp Wire feed motor
3) Power Source
GMAW equipment can be used either manually or automatically
GMAW Schematic DiagramGMAW Schematic Diagram
WIRE CONTROLamp
WIRE FEED MOTOR
POWER SOURCE
Welding Torch amp AccessoriesWelding Torch amp Accessories
The welding torch guides the wire and shielding gas to the weld zone
Brings welding power to the wire alsoMajor componentsparts of the torch are the
contact tip shielding gas nozzle gas diffuser and the wire conduit
Others types of torchOthers types of torch
TRIGGER
INSTALLED
COMPONENTS
NOZZLE
CONTACT TIP
GAS DIFFUSER
Welding Control amp Wire Welding Control amp Wire Feed MotorFeed Motor
Welding control amp Wire feed motor are combined into one unit
Main function is to pull the wire from the spool and feed it to the arc
Controls wire feed speed and regulates the starting and stopping of wire feed
Wire feed speed controls Amperage
Types of Wire Feed MotorTypes of Wire Feed Motor
Types of WFM RollerTypes of WFM Roller
Types of Wire FeederTypes of Wire Feeder
WIRE FEEDER
Power SourcePower Source
Almost all GMAW is done with reverse polarity also known as DCEP
Positive (+) lead is connected to the torchNegative (-) lead is connected to the work
pieceProvides a relatively consistent voltage to the
arcArc Voltage is the voltage between the end of
the wire and the work piece
Contact Tip To Work DistanceContact Tip To Work Distance
In constant current the CTWD (contact tip to work distance) determines the arc length
As the CTWD increases the arc length increases and as the
CTWD decreases the arc length decreases This presented a
problem for semiautomatic welding because it is difficult to
maintain the same CTWD To compensate for this problem an arc voltage controlled wire
Constant voltage power source designs provide a specific arc voltage for a given pre-selected wire feed speed The volt-amp curve or slope is comparatively flat As the CTWD increases with these types of power sources there is a decrease in the welding current As the CTWD decreases there is an increase in the welding current The arc in this case becomes a series circuit and the CTWD provides resistance to current In either scenario the voltage remains the same and the arc length remains the same
POSITIVETERMINAL
NEGATIVETERMINAL
Shielding GasesShielding Gases
Purpose of shielding gas is the protect the weld area from the contaminants in the atmosphere
Gas can be Inert Reactive or Mixtures of both
Gas flow rate is between 25-35 CFHArgon Helium and Carbon Dioxide are the
main three gases used in GMAW
Properties of GasesProperties of Gases
Affect the performance of the welding process include
1) Thermal properties at elevated temperatures 2) Chemical reaction of the gas with the various
elements in the base plate and welding wire 3) Effect of each gas on the mode of metal
transfer
Types of shielding gasesTypes of shielding gases
Inert Gas
1 Argon
2 Helium
3 Ar + HeActive Gas
1 Carbon Dioxide
2 Inert gas + any type of active gas
Argon is an inert gas which is used both singularly and in combination with other gases to achieve desired arc characteristics for the welding of both ferrous and non-ferrous metals
Carbon Dioxide Pure carbon dioxide is not an inert gas because the heat of the arc breaks down the CO2 into carbon monoxide and free oxygen This oxygen will combine with elements transferring across the arc to form oxides which are released from the weld puddle in the form of slag and scale
Helium is an inert gas which is used on weld applications requiring higher heat input for improved bead wetting deeper penetration and higher travel speed In GMAW it does not produce as stable an arc as argon Compared to argon helium has a higher thermal conductivity and voltage gradient
FLOW METER
CYLCINDERPRESSUREGAUGE
CFH PRESSURE ADJUSTMENT KNOB
Filler WireFiller Wire
Wire ChemistriesWire Chemistries
GMAW Operation techniquesGMAW Operation techniques
To setting WFS (Wire Feed Speed)
Voltage-bead ChangeVoltage-bead Change
Electrode Stick-outElectrode Stick-out
ESO SettingESO Setting
EOSEOS
Gun angles and techniquesGun angles and techniques
Direction of TravelDirection of Travel
THANK YOU
DisadvantagesDisadvantages
Hard to reach locations are less easily welded because of bulky torch and cables
Wind or air drafts may compromise gas shielding Reactive metals (ie titanium) may need special
shielding provisions High heat may be uncomfortable to welders Correct parameter selection learning needs
dedicated training Equipment is more complex and expensive than
that of alternative processes
Several tips must be consider in Several tips must be consider in selecting mode of transferselecting mode of transfer
Type intensity and polarity of welding current
Electrode size Electrode composition Electrode extension Shielding gas mix composition
Types of Metal TransferTypes of Metal Transfer
The basic GMAW process includes three distinctive process techniques
1 Short Circuit (Short Arc)
2 Globular Transfer
3 Spray Arc Transfer
Modes of GMAW TransferModes of GMAW Transfer
Short Circuit (Short Arc)Short Circuit (Short Arc)
Operates at low voltages and welding current Small fast-freezing weld puddle obtained Useful in joining thin materials in any position as
well as thick materials in vertical and overhead positions
Metal transfer occurs when an electrical short circuit is established
this cycle can repeat itself between 20 and as much as 250 times per second
Short CircuitShort CircuitA - Electrode is short circuited to base metal No arc and current is flowing through electrode wire and base metalB - Resistance increases in electrode wire causing it to heat melt and ldquoneck downrdquoC - Electrode wire separates from weld puddle creating an arc Small portion of electrode wireis deposited which forms a weld puddleD - Arc length and load voltage are at maximum Heat of arc is flattening the puddle and increasingthe diameter tip of electrodeE - Wire feed speed overcomes heat of arc and wire approaches base metal againF - Arc is off and the short circuit cycle starts again
AdvantagesAdvantages
All-position capability including flat horizontal vertical-up vertical-down and overhead
Handles poor fit-up extremely well and is capable of root pass work on pipe applications
Lower heat input reduces weldment distortion Higher operator appeal and ease of use Higher electrode efficiencies 93 or more
LimitationsLimitations
Restricted to sheet metal thickness range and open roots of groove joints on heavier sections of base material
Poor welding procedure control can result in incomplete fusion Cold lap and cold shut are additional terms that serve to describe incomplete fusion defects
Poor procedure control can result in excessive spatter and will increase weldment cleanup cost
To prevent the loss of shielding gas to the wind welding outdoors may require the use of a windscreen(s)
Globular TransferGlobular Transfer
Welding current and wire speed are increased above maximum for short arc
Droplets of metal have a greater diameter than the wire being used
Spatter present Welding is most effectively done in the flat
position when using globular transfer
Globular transfer is often a high voltage high amperage high wire feed speed transfer and is the result of using CO2 shielding gas (or 75 AR-25 CO2) with parameters higher than the short-circuiting range
AdvantagesAdvantages
Uses inexpensive CO2 shielding gas but is frequently used with argonCO2 blends
Is capable of making welds at very high travel speeds
Inexpensive solid or metal-cored electrodesWelding equipment is inexpensive
LimitationsLimitations
Higher spatter levels result in costly cleanup Prone to cold lap or cold shut incomplete fusion defects
which results in costly repairs Weld bead shape is convex and welds exhibit poor
wetting at the toes High spatter level reduces electrode efficiency to a range
of 87 ndash 93 Less desirable weld appearance than spray arc transfer Welding is limited to flat positions and horizontally fillet
welds Welding is limited to metal 18 inch (3 mm) or thicker
Spray Arc TransferSpray Arc Transfer
Occurs when the current and voltage settings are increased higher than that used for Globular Transfer
Used on thick sections of base material best suited for flat position due to large weld puddle
Spatter is minimal to none Uses 5 to 10 co2 mix with argon or oxygen
gtForms very small droplets of metalgtVery good stabilitygtVery little spatter
Spray arc transfer ldquospraysrdquo a streamof tiny molten droplets across thearc from the electrode wire to thebase metalSpray arc transfer uses relativelyhigh voltage wire feed speed andamperage values compared to shortcircuit transfer
AdvantagesAdvantages
High deposition rates High electrode efficiency of 98 or more Employs a wide range of filler metal types in an
equally wide range of electrode diameters Excellent weld bead appearance High operator appeal and ease of use Requires little post weld cleanup Absence of weld spatter Excellent weld fusion Lends itself to semiautomatic robotic and hard
automation applications
LimitationsLimitations
Restricted to the flat and horizontal welding positions
Welding fume generation is higher The higher-radiated heat and the generation of a
very bright arc require extra welder and bystander protection
The use of axial spray transfer outdoors requires the use of a windscreen(s)
The shielding used to support axial spray transfer costs more than 100 CO2
Pulse Spray Transfer Pulse Spray Transfer
GMAW-P was developed for two demanding reasons control of weld spatter and the elimination of incomplete fusion defects common to globular and short-circuiting transfer
The welding current alternates between a peak current and a lower background current
This faster-freezing weld puddle is what allows the pulsed-spray transfer to be used fort thinner metals
better control on out-of-position work allows for larger wire sizes to be used on varied metal
thicknesses
In pulse spray transfer (GMAW-P) the welding power sourcersquos pulse control pulses the welding output withhigh peak currents (amperage) which are set at levels which will cause the transfer to go into a spray The background current (amperage) is set at a level that will maintain the arcbut is too low for any metal transfer to occur
Pulsed arc transferPulsed arc transfer
AdvantagesAdvantages Absent or very low levels of spatter More resistant to lack of fusion defects than other modes of
GMAW metal transfer Excellent weld bead appearance and offers an engineered
solution for the control of weld fume generation Reduced levels of heat induced distortion and tendency for arc
blow Ability to weld out-of-position and handles poor fit-up When compared to FCAW SMAW and GMAW-S pulsed
spray transfer provides a low cost high-electrode efficiency of 98
Lends itself to robotic and hard automation applications Is combined for use with Tandem GMAW or other multiple arc
scenarios Capable of arc travel speeds greater than 50 inches per minute
(12 Mmin)
LimitationsLimitationsEquipment to support the process is more
expensive than traditional systemsBlends of argon based shielding gas are
more expensive than carbon dioxideHigher arc energy requires the use of
additional safety protection for welders and bystanders
Adds complexity to weldingRequires the use of windscreens outdoors
Manual GMAW EquipmentManual GMAW Equipment
Three major elements are
1) Welding torch and accessories
2) Welding control amp Wire feed motor
3) Power Source
GMAW equipment can be used either manually or automatically
GMAW Schematic DiagramGMAW Schematic Diagram
WIRE CONTROLamp
WIRE FEED MOTOR
POWER SOURCE
Welding Torch amp AccessoriesWelding Torch amp Accessories
The welding torch guides the wire and shielding gas to the weld zone
Brings welding power to the wire alsoMajor componentsparts of the torch are the
contact tip shielding gas nozzle gas diffuser and the wire conduit
Others types of torchOthers types of torch
TRIGGER
INSTALLED
COMPONENTS
NOZZLE
CONTACT TIP
GAS DIFFUSER
Welding Control amp Wire Welding Control amp Wire Feed MotorFeed Motor
Welding control amp Wire feed motor are combined into one unit
Main function is to pull the wire from the spool and feed it to the arc
Controls wire feed speed and regulates the starting and stopping of wire feed
Wire feed speed controls Amperage
Types of Wire Feed MotorTypes of Wire Feed Motor
Types of WFM RollerTypes of WFM Roller
Types of Wire FeederTypes of Wire Feeder
WIRE FEEDER
Power SourcePower Source
Almost all GMAW is done with reverse polarity also known as DCEP
Positive (+) lead is connected to the torchNegative (-) lead is connected to the work
pieceProvides a relatively consistent voltage to the
arcArc Voltage is the voltage between the end of
the wire and the work piece
Contact Tip To Work DistanceContact Tip To Work Distance
In constant current the CTWD (contact tip to work distance) determines the arc length
As the CTWD increases the arc length increases and as the
CTWD decreases the arc length decreases This presented a
problem for semiautomatic welding because it is difficult to
maintain the same CTWD To compensate for this problem an arc voltage controlled wire
Constant voltage power source designs provide a specific arc voltage for a given pre-selected wire feed speed The volt-amp curve or slope is comparatively flat As the CTWD increases with these types of power sources there is a decrease in the welding current As the CTWD decreases there is an increase in the welding current The arc in this case becomes a series circuit and the CTWD provides resistance to current In either scenario the voltage remains the same and the arc length remains the same
POSITIVETERMINAL
NEGATIVETERMINAL
Shielding GasesShielding Gases
Purpose of shielding gas is the protect the weld area from the contaminants in the atmosphere
Gas can be Inert Reactive or Mixtures of both
Gas flow rate is between 25-35 CFHArgon Helium and Carbon Dioxide are the
main three gases used in GMAW
Properties of GasesProperties of Gases
Affect the performance of the welding process include
1) Thermal properties at elevated temperatures 2) Chemical reaction of the gas with the various
elements in the base plate and welding wire 3) Effect of each gas on the mode of metal
transfer
Types of shielding gasesTypes of shielding gases
Inert Gas
1 Argon
2 Helium
3 Ar + HeActive Gas
1 Carbon Dioxide
2 Inert gas + any type of active gas
Argon is an inert gas which is used both singularly and in combination with other gases to achieve desired arc characteristics for the welding of both ferrous and non-ferrous metals
Carbon Dioxide Pure carbon dioxide is not an inert gas because the heat of the arc breaks down the CO2 into carbon monoxide and free oxygen This oxygen will combine with elements transferring across the arc to form oxides which are released from the weld puddle in the form of slag and scale
Helium is an inert gas which is used on weld applications requiring higher heat input for improved bead wetting deeper penetration and higher travel speed In GMAW it does not produce as stable an arc as argon Compared to argon helium has a higher thermal conductivity and voltage gradient
FLOW METER
CYLCINDERPRESSUREGAUGE
CFH PRESSURE ADJUSTMENT KNOB
Filler WireFiller Wire
Wire ChemistriesWire Chemistries
GMAW Operation techniquesGMAW Operation techniques
To setting WFS (Wire Feed Speed)
Voltage-bead ChangeVoltage-bead Change
Electrode Stick-outElectrode Stick-out
ESO SettingESO Setting
EOSEOS
Gun angles and techniquesGun angles and techniques
Direction of TravelDirection of Travel
THANK YOU
Several tips must be consider in Several tips must be consider in selecting mode of transferselecting mode of transfer
Type intensity and polarity of welding current
Electrode size Electrode composition Electrode extension Shielding gas mix composition
Types of Metal TransferTypes of Metal Transfer
The basic GMAW process includes three distinctive process techniques
1 Short Circuit (Short Arc)
2 Globular Transfer
3 Spray Arc Transfer
Modes of GMAW TransferModes of GMAW Transfer
Short Circuit (Short Arc)Short Circuit (Short Arc)
Operates at low voltages and welding current Small fast-freezing weld puddle obtained Useful in joining thin materials in any position as
well as thick materials in vertical and overhead positions
Metal transfer occurs when an electrical short circuit is established
this cycle can repeat itself between 20 and as much as 250 times per second
Short CircuitShort CircuitA - Electrode is short circuited to base metal No arc and current is flowing through electrode wire and base metalB - Resistance increases in electrode wire causing it to heat melt and ldquoneck downrdquoC - Electrode wire separates from weld puddle creating an arc Small portion of electrode wireis deposited which forms a weld puddleD - Arc length and load voltage are at maximum Heat of arc is flattening the puddle and increasingthe diameter tip of electrodeE - Wire feed speed overcomes heat of arc and wire approaches base metal againF - Arc is off and the short circuit cycle starts again
AdvantagesAdvantages
All-position capability including flat horizontal vertical-up vertical-down and overhead
Handles poor fit-up extremely well and is capable of root pass work on pipe applications
Lower heat input reduces weldment distortion Higher operator appeal and ease of use Higher electrode efficiencies 93 or more
LimitationsLimitations
Restricted to sheet metal thickness range and open roots of groove joints on heavier sections of base material
Poor welding procedure control can result in incomplete fusion Cold lap and cold shut are additional terms that serve to describe incomplete fusion defects
Poor procedure control can result in excessive spatter and will increase weldment cleanup cost
To prevent the loss of shielding gas to the wind welding outdoors may require the use of a windscreen(s)
Globular TransferGlobular Transfer
Welding current and wire speed are increased above maximum for short arc
Droplets of metal have a greater diameter than the wire being used
Spatter present Welding is most effectively done in the flat
position when using globular transfer
Globular transfer is often a high voltage high amperage high wire feed speed transfer and is the result of using CO2 shielding gas (or 75 AR-25 CO2) with parameters higher than the short-circuiting range
AdvantagesAdvantages
Uses inexpensive CO2 shielding gas but is frequently used with argonCO2 blends
Is capable of making welds at very high travel speeds
Inexpensive solid or metal-cored electrodesWelding equipment is inexpensive
LimitationsLimitations
Higher spatter levels result in costly cleanup Prone to cold lap or cold shut incomplete fusion defects
which results in costly repairs Weld bead shape is convex and welds exhibit poor
wetting at the toes High spatter level reduces electrode efficiency to a range
of 87 ndash 93 Less desirable weld appearance than spray arc transfer Welding is limited to flat positions and horizontally fillet
welds Welding is limited to metal 18 inch (3 mm) or thicker
Spray Arc TransferSpray Arc Transfer
Occurs when the current and voltage settings are increased higher than that used for Globular Transfer
Used on thick sections of base material best suited for flat position due to large weld puddle
Spatter is minimal to none Uses 5 to 10 co2 mix with argon or oxygen
gtForms very small droplets of metalgtVery good stabilitygtVery little spatter
Spray arc transfer ldquospraysrdquo a streamof tiny molten droplets across thearc from the electrode wire to thebase metalSpray arc transfer uses relativelyhigh voltage wire feed speed andamperage values compared to shortcircuit transfer
AdvantagesAdvantages
High deposition rates High electrode efficiency of 98 or more Employs a wide range of filler metal types in an
equally wide range of electrode diameters Excellent weld bead appearance High operator appeal and ease of use Requires little post weld cleanup Absence of weld spatter Excellent weld fusion Lends itself to semiautomatic robotic and hard
automation applications
LimitationsLimitations
Restricted to the flat and horizontal welding positions
Welding fume generation is higher The higher-radiated heat and the generation of a
very bright arc require extra welder and bystander protection
The use of axial spray transfer outdoors requires the use of a windscreen(s)
The shielding used to support axial spray transfer costs more than 100 CO2
Pulse Spray Transfer Pulse Spray Transfer
GMAW-P was developed for two demanding reasons control of weld spatter and the elimination of incomplete fusion defects common to globular and short-circuiting transfer
The welding current alternates between a peak current and a lower background current
This faster-freezing weld puddle is what allows the pulsed-spray transfer to be used fort thinner metals
better control on out-of-position work allows for larger wire sizes to be used on varied metal
thicknesses
In pulse spray transfer (GMAW-P) the welding power sourcersquos pulse control pulses the welding output withhigh peak currents (amperage) which are set at levels which will cause the transfer to go into a spray The background current (amperage) is set at a level that will maintain the arcbut is too low for any metal transfer to occur
Pulsed arc transferPulsed arc transfer
AdvantagesAdvantages Absent or very low levels of spatter More resistant to lack of fusion defects than other modes of
GMAW metal transfer Excellent weld bead appearance and offers an engineered
solution for the control of weld fume generation Reduced levels of heat induced distortion and tendency for arc
blow Ability to weld out-of-position and handles poor fit-up When compared to FCAW SMAW and GMAW-S pulsed
spray transfer provides a low cost high-electrode efficiency of 98
Lends itself to robotic and hard automation applications Is combined for use with Tandem GMAW or other multiple arc
scenarios Capable of arc travel speeds greater than 50 inches per minute
(12 Mmin)
LimitationsLimitationsEquipment to support the process is more
expensive than traditional systemsBlends of argon based shielding gas are
more expensive than carbon dioxideHigher arc energy requires the use of
additional safety protection for welders and bystanders
Adds complexity to weldingRequires the use of windscreens outdoors
Manual GMAW EquipmentManual GMAW Equipment
Three major elements are
1) Welding torch and accessories
2) Welding control amp Wire feed motor
3) Power Source
GMAW equipment can be used either manually or automatically
GMAW Schematic DiagramGMAW Schematic Diagram
WIRE CONTROLamp
WIRE FEED MOTOR
POWER SOURCE
Welding Torch amp AccessoriesWelding Torch amp Accessories
The welding torch guides the wire and shielding gas to the weld zone
Brings welding power to the wire alsoMajor componentsparts of the torch are the
contact tip shielding gas nozzle gas diffuser and the wire conduit
Others types of torchOthers types of torch
TRIGGER
INSTALLED
COMPONENTS
NOZZLE
CONTACT TIP
GAS DIFFUSER
Welding Control amp Wire Welding Control amp Wire Feed MotorFeed Motor
Welding control amp Wire feed motor are combined into one unit
Main function is to pull the wire from the spool and feed it to the arc
Controls wire feed speed and regulates the starting and stopping of wire feed
Wire feed speed controls Amperage
Types of Wire Feed MotorTypes of Wire Feed Motor
Types of WFM RollerTypes of WFM Roller
Types of Wire FeederTypes of Wire Feeder
WIRE FEEDER
Power SourcePower Source
Almost all GMAW is done with reverse polarity also known as DCEP
Positive (+) lead is connected to the torchNegative (-) lead is connected to the work
pieceProvides a relatively consistent voltage to the
arcArc Voltage is the voltage between the end of
the wire and the work piece
Contact Tip To Work DistanceContact Tip To Work Distance
In constant current the CTWD (contact tip to work distance) determines the arc length
As the CTWD increases the arc length increases and as the
CTWD decreases the arc length decreases This presented a
problem for semiautomatic welding because it is difficult to
maintain the same CTWD To compensate for this problem an arc voltage controlled wire
Constant voltage power source designs provide a specific arc voltage for a given pre-selected wire feed speed The volt-amp curve or slope is comparatively flat As the CTWD increases with these types of power sources there is a decrease in the welding current As the CTWD decreases there is an increase in the welding current The arc in this case becomes a series circuit and the CTWD provides resistance to current In either scenario the voltage remains the same and the arc length remains the same
POSITIVETERMINAL
NEGATIVETERMINAL
Shielding GasesShielding Gases
Purpose of shielding gas is the protect the weld area from the contaminants in the atmosphere
Gas can be Inert Reactive or Mixtures of both
Gas flow rate is between 25-35 CFHArgon Helium and Carbon Dioxide are the
main three gases used in GMAW
Properties of GasesProperties of Gases
Affect the performance of the welding process include
1) Thermal properties at elevated temperatures 2) Chemical reaction of the gas with the various
elements in the base plate and welding wire 3) Effect of each gas on the mode of metal
transfer
Types of shielding gasesTypes of shielding gases
Inert Gas
1 Argon
2 Helium
3 Ar + HeActive Gas
1 Carbon Dioxide
2 Inert gas + any type of active gas
Argon is an inert gas which is used both singularly and in combination with other gases to achieve desired arc characteristics for the welding of both ferrous and non-ferrous metals
Carbon Dioxide Pure carbon dioxide is not an inert gas because the heat of the arc breaks down the CO2 into carbon monoxide and free oxygen This oxygen will combine with elements transferring across the arc to form oxides which are released from the weld puddle in the form of slag and scale
Helium is an inert gas which is used on weld applications requiring higher heat input for improved bead wetting deeper penetration and higher travel speed In GMAW it does not produce as stable an arc as argon Compared to argon helium has a higher thermal conductivity and voltage gradient
FLOW METER
CYLCINDERPRESSUREGAUGE
CFH PRESSURE ADJUSTMENT KNOB
Filler WireFiller Wire
Wire ChemistriesWire Chemistries
GMAW Operation techniquesGMAW Operation techniques
To setting WFS (Wire Feed Speed)
Voltage-bead ChangeVoltage-bead Change
Electrode Stick-outElectrode Stick-out
ESO SettingESO Setting
EOSEOS
Gun angles and techniquesGun angles and techniques
Direction of TravelDirection of Travel
THANK YOU
Types of Metal TransferTypes of Metal Transfer
The basic GMAW process includes three distinctive process techniques
1 Short Circuit (Short Arc)
2 Globular Transfer
3 Spray Arc Transfer
Modes of GMAW TransferModes of GMAW Transfer
Short Circuit (Short Arc)Short Circuit (Short Arc)
Operates at low voltages and welding current Small fast-freezing weld puddle obtained Useful in joining thin materials in any position as
well as thick materials in vertical and overhead positions
Metal transfer occurs when an electrical short circuit is established
this cycle can repeat itself between 20 and as much as 250 times per second
Short CircuitShort CircuitA - Electrode is short circuited to base metal No arc and current is flowing through electrode wire and base metalB - Resistance increases in electrode wire causing it to heat melt and ldquoneck downrdquoC - Electrode wire separates from weld puddle creating an arc Small portion of electrode wireis deposited which forms a weld puddleD - Arc length and load voltage are at maximum Heat of arc is flattening the puddle and increasingthe diameter tip of electrodeE - Wire feed speed overcomes heat of arc and wire approaches base metal againF - Arc is off and the short circuit cycle starts again
AdvantagesAdvantages
All-position capability including flat horizontal vertical-up vertical-down and overhead
Handles poor fit-up extremely well and is capable of root pass work on pipe applications
Lower heat input reduces weldment distortion Higher operator appeal and ease of use Higher electrode efficiencies 93 or more
LimitationsLimitations
Restricted to sheet metal thickness range and open roots of groove joints on heavier sections of base material
Poor welding procedure control can result in incomplete fusion Cold lap and cold shut are additional terms that serve to describe incomplete fusion defects
Poor procedure control can result in excessive spatter and will increase weldment cleanup cost
To prevent the loss of shielding gas to the wind welding outdoors may require the use of a windscreen(s)
Globular TransferGlobular Transfer
Welding current and wire speed are increased above maximum for short arc
Droplets of metal have a greater diameter than the wire being used
Spatter present Welding is most effectively done in the flat
position when using globular transfer
Globular transfer is often a high voltage high amperage high wire feed speed transfer and is the result of using CO2 shielding gas (or 75 AR-25 CO2) with parameters higher than the short-circuiting range
AdvantagesAdvantages
Uses inexpensive CO2 shielding gas but is frequently used with argonCO2 blends
Is capable of making welds at very high travel speeds
Inexpensive solid or metal-cored electrodesWelding equipment is inexpensive
LimitationsLimitations
Higher spatter levels result in costly cleanup Prone to cold lap or cold shut incomplete fusion defects
which results in costly repairs Weld bead shape is convex and welds exhibit poor
wetting at the toes High spatter level reduces electrode efficiency to a range
of 87 ndash 93 Less desirable weld appearance than spray arc transfer Welding is limited to flat positions and horizontally fillet
welds Welding is limited to metal 18 inch (3 mm) or thicker
Spray Arc TransferSpray Arc Transfer
Occurs when the current and voltage settings are increased higher than that used for Globular Transfer
Used on thick sections of base material best suited for flat position due to large weld puddle
Spatter is minimal to none Uses 5 to 10 co2 mix with argon or oxygen
gtForms very small droplets of metalgtVery good stabilitygtVery little spatter
Spray arc transfer ldquospraysrdquo a streamof tiny molten droplets across thearc from the electrode wire to thebase metalSpray arc transfer uses relativelyhigh voltage wire feed speed andamperage values compared to shortcircuit transfer
AdvantagesAdvantages
High deposition rates High electrode efficiency of 98 or more Employs a wide range of filler metal types in an
equally wide range of electrode diameters Excellent weld bead appearance High operator appeal and ease of use Requires little post weld cleanup Absence of weld spatter Excellent weld fusion Lends itself to semiautomatic robotic and hard
automation applications
LimitationsLimitations
Restricted to the flat and horizontal welding positions
Welding fume generation is higher The higher-radiated heat and the generation of a
very bright arc require extra welder and bystander protection
The use of axial spray transfer outdoors requires the use of a windscreen(s)
The shielding used to support axial spray transfer costs more than 100 CO2
Pulse Spray Transfer Pulse Spray Transfer
GMAW-P was developed for two demanding reasons control of weld spatter and the elimination of incomplete fusion defects common to globular and short-circuiting transfer
The welding current alternates between a peak current and a lower background current
This faster-freezing weld puddle is what allows the pulsed-spray transfer to be used fort thinner metals
better control on out-of-position work allows for larger wire sizes to be used on varied metal
thicknesses
In pulse spray transfer (GMAW-P) the welding power sourcersquos pulse control pulses the welding output withhigh peak currents (amperage) which are set at levels which will cause the transfer to go into a spray The background current (amperage) is set at a level that will maintain the arcbut is too low for any metal transfer to occur
Pulsed arc transferPulsed arc transfer
AdvantagesAdvantages Absent or very low levels of spatter More resistant to lack of fusion defects than other modes of
GMAW metal transfer Excellent weld bead appearance and offers an engineered
solution for the control of weld fume generation Reduced levels of heat induced distortion and tendency for arc
blow Ability to weld out-of-position and handles poor fit-up When compared to FCAW SMAW and GMAW-S pulsed
spray transfer provides a low cost high-electrode efficiency of 98
Lends itself to robotic and hard automation applications Is combined for use with Tandem GMAW or other multiple arc
scenarios Capable of arc travel speeds greater than 50 inches per minute
(12 Mmin)
LimitationsLimitationsEquipment to support the process is more
expensive than traditional systemsBlends of argon based shielding gas are
more expensive than carbon dioxideHigher arc energy requires the use of
additional safety protection for welders and bystanders
Adds complexity to weldingRequires the use of windscreens outdoors
Manual GMAW EquipmentManual GMAW Equipment
Three major elements are
1) Welding torch and accessories
2) Welding control amp Wire feed motor
3) Power Source
GMAW equipment can be used either manually or automatically
GMAW Schematic DiagramGMAW Schematic Diagram
WIRE CONTROLamp
WIRE FEED MOTOR
POWER SOURCE
Welding Torch amp AccessoriesWelding Torch amp Accessories
The welding torch guides the wire and shielding gas to the weld zone
Brings welding power to the wire alsoMajor componentsparts of the torch are the
contact tip shielding gas nozzle gas diffuser and the wire conduit
Others types of torchOthers types of torch
TRIGGER
INSTALLED
COMPONENTS
NOZZLE
CONTACT TIP
GAS DIFFUSER
Welding Control amp Wire Welding Control amp Wire Feed MotorFeed Motor
Welding control amp Wire feed motor are combined into one unit
Main function is to pull the wire from the spool and feed it to the arc
Controls wire feed speed and regulates the starting and stopping of wire feed
Wire feed speed controls Amperage
Types of Wire Feed MotorTypes of Wire Feed Motor
Types of WFM RollerTypes of WFM Roller
Types of Wire FeederTypes of Wire Feeder
WIRE FEEDER
Power SourcePower Source
Almost all GMAW is done with reverse polarity also known as DCEP
Positive (+) lead is connected to the torchNegative (-) lead is connected to the work
pieceProvides a relatively consistent voltage to the
arcArc Voltage is the voltage between the end of
the wire and the work piece
Contact Tip To Work DistanceContact Tip To Work Distance
In constant current the CTWD (contact tip to work distance) determines the arc length
As the CTWD increases the arc length increases and as the
CTWD decreases the arc length decreases This presented a
problem for semiautomatic welding because it is difficult to
maintain the same CTWD To compensate for this problem an arc voltage controlled wire
Constant voltage power source designs provide a specific arc voltage for a given pre-selected wire feed speed The volt-amp curve or slope is comparatively flat As the CTWD increases with these types of power sources there is a decrease in the welding current As the CTWD decreases there is an increase in the welding current The arc in this case becomes a series circuit and the CTWD provides resistance to current In either scenario the voltage remains the same and the arc length remains the same
POSITIVETERMINAL
NEGATIVETERMINAL
Shielding GasesShielding Gases
Purpose of shielding gas is the protect the weld area from the contaminants in the atmosphere
Gas can be Inert Reactive or Mixtures of both
Gas flow rate is between 25-35 CFHArgon Helium and Carbon Dioxide are the
main three gases used in GMAW
Properties of GasesProperties of Gases
Affect the performance of the welding process include
1) Thermal properties at elevated temperatures 2) Chemical reaction of the gas with the various
elements in the base plate and welding wire 3) Effect of each gas on the mode of metal
transfer
Types of shielding gasesTypes of shielding gases
Inert Gas
1 Argon
2 Helium
3 Ar + HeActive Gas
1 Carbon Dioxide
2 Inert gas + any type of active gas
Argon is an inert gas which is used both singularly and in combination with other gases to achieve desired arc characteristics for the welding of both ferrous and non-ferrous metals
Carbon Dioxide Pure carbon dioxide is not an inert gas because the heat of the arc breaks down the CO2 into carbon monoxide and free oxygen This oxygen will combine with elements transferring across the arc to form oxides which are released from the weld puddle in the form of slag and scale
Helium is an inert gas which is used on weld applications requiring higher heat input for improved bead wetting deeper penetration and higher travel speed In GMAW it does not produce as stable an arc as argon Compared to argon helium has a higher thermal conductivity and voltage gradient
FLOW METER
CYLCINDERPRESSUREGAUGE
CFH PRESSURE ADJUSTMENT KNOB
Filler WireFiller Wire
Wire ChemistriesWire Chemistries
GMAW Operation techniquesGMAW Operation techniques
To setting WFS (Wire Feed Speed)
Voltage-bead ChangeVoltage-bead Change
Electrode Stick-outElectrode Stick-out
ESO SettingESO Setting
EOSEOS
Gun angles and techniquesGun angles and techniques
Direction of TravelDirection of Travel
THANK YOU
Modes of GMAW TransferModes of GMAW Transfer
Short Circuit (Short Arc)Short Circuit (Short Arc)
Operates at low voltages and welding current Small fast-freezing weld puddle obtained Useful in joining thin materials in any position as
well as thick materials in vertical and overhead positions
Metal transfer occurs when an electrical short circuit is established
this cycle can repeat itself between 20 and as much as 250 times per second
Short CircuitShort CircuitA - Electrode is short circuited to base metal No arc and current is flowing through electrode wire and base metalB - Resistance increases in electrode wire causing it to heat melt and ldquoneck downrdquoC - Electrode wire separates from weld puddle creating an arc Small portion of electrode wireis deposited which forms a weld puddleD - Arc length and load voltage are at maximum Heat of arc is flattening the puddle and increasingthe diameter tip of electrodeE - Wire feed speed overcomes heat of arc and wire approaches base metal againF - Arc is off and the short circuit cycle starts again
AdvantagesAdvantages
All-position capability including flat horizontal vertical-up vertical-down and overhead
Handles poor fit-up extremely well and is capable of root pass work on pipe applications
Lower heat input reduces weldment distortion Higher operator appeal and ease of use Higher electrode efficiencies 93 or more
LimitationsLimitations
Restricted to sheet metal thickness range and open roots of groove joints on heavier sections of base material
Poor welding procedure control can result in incomplete fusion Cold lap and cold shut are additional terms that serve to describe incomplete fusion defects
Poor procedure control can result in excessive spatter and will increase weldment cleanup cost
To prevent the loss of shielding gas to the wind welding outdoors may require the use of a windscreen(s)
Globular TransferGlobular Transfer
Welding current and wire speed are increased above maximum for short arc
Droplets of metal have a greater diameter than the wire being used
Spatter present Welding is most effectively done in the flat
position when using globular transfer
Globular transfer is often a high voltage high amperage high wire feed speed transfer and is the result of using CO2 shielding gas (or 75 AR-25 CO2) with parameters higher than the short-circuiting range
AdvantagesAdvantages
Uses inexpensive CO2 shielding gas but is frequently used with argonCO2 blends
Is capable of making welds at very high travel speeds
Inexpensive solid or metal-cored electrodesWelding equipment is inexpensive
LimitationsLimitations
Higher spatter levels result in costly cleanup Prone to cold lap or cold shut incomplete fusion defects
which results in costly repairs Weld bead shape is convex and welds exhibit poor
wetting at the toes High spatter level reduces electrode efficiency to a range
of 87 ndash 93 Less desirable weld appearance than spray arc transfer Welding is limited to flat positions and horizontally fillet
welds Welding is limited to metal 18 inch (3 mm) or thicker
Spray Arc TransferSpray Arc Transfer
Occurs when the current and voltage settings are increased higher than that used for Globular Transfer
Used on thick sections of base material best suited for flat position due to large weld puddle
Spatter is minimal to none Uses 5 to 10 co2 mix with argon or oxygen
gtForms very small droplets of metalgtVery good stabilitygtVery little spatter
Spray arc transfer ldquospraysrdquo a streamof tiny molten droplets across thearc from the electrode wire to thebase metalSpray arc transfer uses relativelyhigh voltage wire feed speed andamperage values compared to shortcircuit transfer
AdvantagesAdvantages
High deposition rates High electrode efficiency of 98 or more Employs a wide range of filler metal types in an
equally wide range of electrode diameters Excellent weld bead appearance High operator appeal and ease of use Requires little post weld cleanup Absence of weld spatter Excellent weld fusion Lends itself to semiautomatic robotic and hard
automation applications
LimitationsLimitations
Restricted to the flat and horizontal welding positions
Welding fume generation is higher The higher-radiated heat and the generation of a
very bright arc require extra welder and bystander protection
The use of axial spray transfer outdoors requires the use of a windscreen(s)
The shielding used to support axial spray transfer costs more than 100 CO2
Pulse Spray Transfer Pulse Spray Transfer
GMAW-P was developed for two demanding reasons control of weld spatter and the elimination of incomplete fusion defects common to globular and short-circuiting transfer
The welding current alternates between a peak current and a lower background current
This faster-freezing weld puddle is what allows the pulsed-spray transfer to be used fort thinner metals
better control on out-of-position work allows for larger wire sizes to be used on varied metal
thicknesses
In pulse spray transfer (GMAW-P) the welding power sourcersquos pulse control pulses the welding output withhigh peak currents (amperage) which are set at levels which will cause the transfer to go into a spray The background current (amperage) is set at a level that will maintain the arcbut is too low for any metal transfer to occur
Pulsed arc transferPulsed arc transfer
AdvantagesAdvantages Absent or very low levels of spatter More resistant to lack of fusion defects than other modes of
GMAW metal transfer Excellent weld bead appearance and offers an engineered
solution for the control of weld fume generation Reduced levels of heat induced distortion and tendency for arc
blow Ability to weld out-of-position and handles poor fit-up When compared to FCAW SMAW and GMAW-S pulsed
spray transfer provides a low cost high-electrode efficiency of 98
Lends itself to robotic and hard automation applications Is combined for use with Tandem GMAW or other multiple arc
scenarios Capable of arc travel speeds greater than 50 inches per minute
(12 Mmin)
LimitationsLimitationsEquipment to support the process is more
expensive than traditional systemsBlends of argon based shielding gas are
more expensive than carbon dioxideHigher arc energy requires the use of
additional safety protection for welders and bystanders
Adds complexity to weldingRequires the use of windscreens outdoors
Manual GMAW EquipmentManual GMAW Equipment
Three major elements are
1) Welding torch and accessories
2) Welding control amp Wire feed motor
3) Power Source
GMAW equipment can be used either manually or automatically
GMAW Schematic DiagramGMAW Schematic Diagram
WIRE CONTROLamp
WIRE FEED MOTOR
POWER SOURCE
Welding Torch amp AccessoriesWelding Torch amp Accessories
The welding torch guides the wire and shielding gas to the weld zone
Brings welding power to the wire alsoMajor componentsparts of the torch are the
contact tip shielding gas nozzle gas diffuser and the wire conduit
Others types of torchOthers types of torch
TRIGGER
INSTALLED
COMPONENTS
NOZZLE
CONTACT TIP
GAS DIFFUSER
Welding Control amp Wire Welding Control amp Wire Feed MotorFeed Motor
Welding control amp Wire feed motor are combined into one unit
Main function is to pull the wire from the spool and feed it to the arc
Controls wire feed speed and regulates the starting and stopping of wire feed
Wire feed speed controls Amperage
Types of Wire Feed MotorTypes of Wire Feed Motor
Types of WFM RollerTypes of WFM Roller
Types of Wire FeederTypes of Wire Feeder
WIRE FEEDER
Power SourcePower Source
Almost all GMAW is done with reverse polarity also known as DCEP
Positive (+) lead is connected to the torchNegative (-) lead is connected to the work
pieceProvides a relatively consistent voltage to the
arcArc Voltage is the voltage between the end of
the wire and the work piece
Contact Tip To Work DistanceContact Tip To Work Distance
In constant current the CTWD (contact tip to work distance) determines the arc length
As the CTWD increases the arc length increases and as the
CTWD decreases the arc length decreases This presented a
problem for semiautomatic welding because it is difficult to
maintain the same CTWD To compensate for this problem an arc voltage controlled wire
Constant voltage power source designs provide a specific arc voltage for a given pre-selected wire feed speed The volt-amp curve or slope is comparatively flat As the CTWD increases with these types of power sources there is a decrease in the welding current As the CTWD decreases there is an increase in the welding current The arc in this case becomes a series circuit and the CTWD provides resistance to current In either scenario the voltage remains the same and the arc length remains the same
POSITIVETERMINAL
NEGATIVETERMINAL
Shielding GasesShielding Gases
Purpose of shielding gas is the protect the weld area from the contaminants in the atmosphere
Gas can be Inert Reactive or Mixtures of both
Gas flow rate is between 25-35 CFHArgon Helium and Carbon Dioxide are the
main three gases used in GMAW
Properties of GasesProperties of Gases
Affect the performance of the welding process include
1) Thermal properties at elevated temperatures 2) Chemical reaction of the gas with the various
elements in the base plate and welding wire 3) Effect of each gas on the mode of metal
transfer
Types of shielding gasesTypes of shielding gases
Inert Gas
1 Argon
2 Helium
3 Ar + HeActive Gas
1 Carbon Dioxide
2 Inert gas + any type of active gas
Argon is an inert gas which is used both singularly and in combination with other gases to achieve desired arc characteristics for the welding of both ferrous and non-ferrous metals
Carbon Dioxide Pure carbon dioxide is not an inert gas because the heat of the arc breaks down the CO2 into carbon monoxide and free oxygen This oxygen will combine with elements transferring across the arc to form oxides which are released from the weld puddle in the form of slag and scale
Helium is an inert gas which is used on weld applications requiring higher heat input for improved bead wetting deeper penetration and higher travel speed In GMAW it does not produce as stable an arc as argon Compared to argon helium has a higher thermal conductivity and voltage gradient
FLOW METER
CYLCINDERPRESSUREGAUGE
CFH PRESSURE ADJUSTMENT KNOB
Filler WireFiller Wire
Wire ChemistriesWire Chemistries
GMAW Operation techniquesGMAW Operation techniques
To setting WFS (Wire Feed Speed)
Voltage-bead ChangeVoltage-bead Change
Electrode Stick-outElectrode Stick-out
ESO SettingESO Setting
EOSEOS
Gun angles and techniquesGun angles and techniques
Direction of TravelDirection of Travel
THANK YOU
Short Circuit (Short Arc)Short Circuit (Short Arc)
Operates at low voltages and welding current Small fast-freezing weld puddle obtained Useful in joining thin materials in any position as
well as thick materials in vertical and overhead positions
Metal transfer occurs when an electrical short circuit is established
this cycle can repeat itself between 20 and as much as 250 times per second
Short CircuitShort CircuitA - Electrode is short circuited to base metal No arc and current is flowing through electrode wire and base metalB - Resistance increases in electrode wire causing it to heat melt and ldquoneck downrdquoC - Electrode wire separates from weld puddle creating an arc Small portion of electrode wireis deposited which forms a weld puddleD - Arc length and load voltage are at maximum Heat of arc is flattening the puddle and increasingthe diameter tip of electrodeE - Wire feed speed overcomes heat of arc and wire approaches base metal againF - Arc is off and the short circuit cycle starts again
AdvantagesAdvantages
All-position capability including flat horizontal vertical-up vertical-down and overhead
Handles poor fit-up extremely well and is capable of root pass work on pipe applications
Lower heat input reduces weldment distortion Higher operator appeal and ease of use Higher electrode efficiencies 93 or more
LimitationsLimitations
Restricted to sheet metal thickness range and open roots of groove joints on heavier sections of base material
Poor welding procedure control can result in incomplete fusion Cold lap and cold shut are additional terms that serve to describe incomplete fusion defects
Poor procedure control can result in excessive spatter and will increase weldment cleanup cost
To prevent the loss of shielding gas to the wind welding outdoors may require the use of a windscreen(s)
Globular TransferGlobular Transfer
Welding current and wire speed are increased above maximum for short arc
Droplets of metal have a greater diameter than the wire being used
Spatter present Welding is most effectively done in the flat
position when using globular transfer
Globular transfer is often a high voltage high amperage high wire feed speed transfer and is the result of using CO2 shielding gas (or 75 AR-25 CO2) with parameters higher than the short-circuiting range
AdvantagesAdvantages
Uses inexpensive CO2 shielding gas but is frequently used with argonCO2 blends
Is capable of making welds at very high travel speeds
Inexpensive solid or metal-cored electrodesWelding equipment is inexpensive
LimitationsLimitations
Higher spatter levels result in costly cleanup Prone to cold lap or cold shut incomplete fusion defects
which results in costly repairs Weld bead shape is convex and welds exhibit poor
wetting at the toes High spatter level reduces electrode efficiency to a range
of 87 ndash 93 Less desirable weld appearance than spray arc transfer Welding is limited to flat positions and horizontally fillet
welds Welding is limited to metal 18 inch (3 mm) or thicker
Spray Arc TransferSpray Arc Transfer
Occurs when the current and voltage settings are increased higher than that used for Globular Transfer
Used on thick sections of base material best suited for flat position due to large weld puddle
Spatter is minimal to none Uses 5 to 10 co2 mix with argon or oxygen
gtForms very small droplets of metalgtVery good stabilitygtVery little spatter
Spray arc transfer ldquospraysrdquo a streamof tiny molten droplets across thearc from the electrode wire to thebase metalSpray arc transfer uses relativelyhigh voltage wire feed speed andamperage values compared to shortcircuit transfer
AdvantagesAdvantages
High deposition rates High electrode efficiency of 98 or more Employs a wide range of filler metal types in an
equally wide range of electrode diameters Excellent weld bead appearance High operator appeal and ease of use Requires little post weld cleanup Absence of weld spatter Excellent weld fusion Lends itself to semiautomatic robotic and hard
automation applications
LimitationsLimitations
Restricted to the flat and horizontal welding positions
Welding fume generation is higher The higher-radiated heat and the generation of a
very bright arc require extra welder and bystander protection
The use of axial spray transfer outdoors requires the use of a windscreen(s)
The shielding used to support axial spray transfer costs more than 100 CO2
Pulse Spray Transfer Pulse Spray Transfer
GMAW-P was developed for two demanding reasons control of weld spatter and the elimination of incomplete fusion defects common to globular and short-circuiting transfer
The welding current alternates between a peak current and a lower background current
This faster-freezing weld puddle is what allows the pulsed-spray transfer to be used fort thinner metals
better control on out-of-position work allows for larger wire sizes to be used on varied metal
thicknesses
In pulse spray transfer (GMAW-P) the welding power sourcersquos pulse control pulses the welding output withhigh peak currents (amperage) which are set at levels which will cause the transfer to go into a spray The background current (amperage) is set at a level that will maintain the arcbut is too low for any metal transfer to occur
Pulsed arc transferPulsed arc transfer
AdvantagesAdvantages Absent or very low levels of spatter More resistant to lack of fusion defects than other modes of
GMAW metal transfer Excellent weld bead appearance and offers an engineered
solution for the control of weld fume generation Reduced levels of heat induced distortion and tendency for arc
blow Ability to weld out-of-position and handles poor fit-up When compared to FCAW SMAW and GMAW-S pulsed
spray transfer provides a low cost high-electrode efficiency of 98
Lends itself to robotic and hard automation applications Is combined for use with Tandem GMAW or other multiple arc
scenarios Capable of arc travel speeds greater than 50 inches per minute
(12 Mmin)
LimitationsLimitationsEquipment to support the process is more
expensive than traditional systemsBlends of argon based shielding gas are
more expensive than carbon dioxideHigher arc energy requires the use of
additional safety protection for welders and bystanders
Adds complexity to weldingRequires the use of windscreens outdoors
Manual GMAW EquipmentManual GMAW Equipment
Three major elements are
1) Welding torch and accessories
2) Welding control amp Wire feed motor
3) Power Source
GMAW equipment can be used either manually or automatically
GMAW Schematic DiagramGMAW Schematic Diagram
WIRE CONTROLamp
WIRE FEED MOTOR
POWER SOURCE
Welding Torch amp AccessoriesWelding Torch amp Accessories
The welding torch guides the wire and shielding gas to the weld zone
Brings welding power to the wire alsoMajor componentsparts of the torch are the
contact tip shielding gas nozzle gas diffuser and the wire conduit
Others types of torchOthers types of torch
TRIGGER
INSTALLED
COMPONENTS
NOZZLE
CONTACT TIP
GAS DIFFUSER
Welding Control amp Wire Welding Control amp Wire Feed MotorFeed Motor
Welding control amp Wire feed motor are combined into one unit
Main function is to pull the wire from the spool and feed it to the arc
Controls wire feed speed and regulates the starting and stopping of wire feed
Wire feed speed controls Amperage
Types of Wire Feed MotorTypes of Wire Feed Motor
Types of WFM RollerTypes of WFM Roller
Types of Wire FeederTypes of Wire Feeder
WIRE FEEDER
Power SourcePower Source
Almost all GMAW is done with reverse polarity also known as DCEP
Positive (+) lead is connected to the torchNegative (-) lead is connected to the work
pieceProvides a relatively consistent voltage to the
arcArc Voltage is the voltage between the end of
the wire and the work piece
Contact Tip To Work DistanceContact Tip To Work Distance
In constant current the CTWD (contact tip to work distance) determines the arc length
As the CTWD increases the arc length increases and as the
CTWD decreases the arc length decreases This presented a
problem for semiautomatic welding because it is difficult to
maintain the same CTWD To compensate for this problem an arc voltage controlled wire
Constant voltage power source designs provide a specific arc voltage for a given pre-selected wire feed speed The volt-amp curve or slope is comparatively flat As the CTWD increases with these types of power sources there is a decrease in the welding current As the CTWD decreases there is an increase in the welding current The arc in this case becomes a series circuit and the CTWD provides resistance to current In either scenario the voltage remains the same and the arc length remains the same
POSITIVETERMINAL
NEGATIVETERMINAL
Shielding GasesShielding Gases
Purpose of shielding gas is the protect the weld area from the contaminants in the atmosphere
Gas can be Inert Reactive or Mixtures of both
Gas flow rate is between 25-35 CFHArgon Helium and Carbon Dioxide are the
main three gases used in GMAW
Properties of GasesProperties of Gases
Affect the performance of the welding process include
1) Thermal properties at elevated temperatures 2) Chemical reaction of the gas with the various
elements in the base plate and welding wire 3) Effect of each gas on the mode of metal
transfer
Types of shielding gasesTypes of shielding gases
Inert Gas
1 Argon
2 Helium
3 Ar + HeActive Gas
1 Carbon Dioxide
2 Inert gas + any type of active gas
Argon is an inert gas which is used both singularly and in combination with other gases to achieve desired arc characteristics for the welding of both ferrous and non-ferrous metals
Carbon Dioxide Pure carbon dioxide is not an inert gas because the heat of the arc breaks down the CO2 into carbon monoxide and free oxygen This oxygen will combine with elements transferring across the arc to form oxides which are released from the weld puddle in the form of slag and scale
Helium is an inert gas which is used on weld applications requiring higher heat input for improved bead wetting deeper penetration and higher travel speed In GMAW it does not produce as stable an arc as argon Compared to argon helium has a higher thermal conductivity and voltage gradient
FLOW METER
CYLCINDERPRESSUREGAUGE
CFH PRESSURE ADJUSTMENT KNOB
Filler WireFiller Wire
Wire ChemistriesWire Chemistries
GMAW Operation techniquesGMAW Operation techniques
To setting WFS (Wire Feed Speed)
Voltage-bead ChangeVoltage-bead Change
Electrode Stick-outElectrode Stick-out
ESO SettingESO Setting
EOSEOS
Gun angles and techniquesGun angles and techniques
Direction of TravelDirection of Travel
THANK YOU
Short CircuitShort CircuitA - Electrode is short circuited to base metal No arc and current is flowing through electrode wire and base metalB - Resistance increases in electrode wire causing it to heat melt and ldquoneck downrdquoC - Electrode wire separates from weld puddle creating an arc Small portion of electrode wireis deposited which forms a weld puddleD - Arc length and load voltage are at maximum Heat of arc is flattening the puddle and increasingthe diameter tip of electrodeE - Wire feed speed overcomes heat of arc and wire approaches base metal againF - Arc is off and the short circuit cycle starts again
AdvantagesAdvantages
All-position capability including flat horizontal vertical-up vertical-down and overhead
Handles poor fit-up extremely well and is capable of root pass work on pipe applications
Lower heat input reduces weldment distortion Higher operator appeal and ease of use Higher electrode efficiencies 93 or more
LimitationsLimitations
Restricted to sheet metal thickness range and open roots of groove joints on heavier sections of base material
Poor welding procedure control can result in incomplete fusion Cold lap and cold shut are additional terms that serve to describe incomplete fusion defects
Poor procedure control can result in excessive spatter and will increase weldment cleanup cost
To prevent the loss of shielding gas to the wind welding outdoors may require the use of a windscreen(s)
Globular TransferGlobular Transfer
Welding current and wire speed are increased above maximum for short arc
Droplets of metal have a greater diameter than the wire being used
Spatter present Welding is most effectively done in the flat
position when using globular transfer
Globular transfer is often a high voltage high amperage high wire feed speed transfer and is the result of using CO2 shielding gas (or 75 AR-25 CO2) with parameters higher than the short-circuiting range
AdvantagesAdvantages
Uses inexpensive CO2 shielding gas but is frequently used with argonCO2 blends
Is capable of making welds at very high travel speeds
Inexpensive solid or metal-cored electrodesWelding equipment is inexpensive
LimitationsLimitations
Higher spatter levels result in costly cleanup Prone to cold lap or cold shut incomplete fusion defects
which results in costly repairs Weld bead shape is convex and welds exhibit poor
wetting at the toes High spatter level reduces electrode efficiency to a range
of 87 ndash 93 Less desirable weld appearance than spray arc transfer Welding is limited to flat positions and horizontally fillet
welds Welding is limited to metal 18 inch (3 mm) or thicker
Spray Arc TransferSpray Arc Transfer
Occurs when the current and voltage settings are increased higher than that used for Globular Transfer
Used on thick sections of base material best suited for flat position due to large weld puddle
Spatter is minimal to none Uses 5 to 10 co2 mix with argon or oxygen
gtForms very small droplets of metalgtVery good stabilitygtVery little spatter
Spray arc transfer ldquospraysrdquo a streamof tiny molten droplets across thearc from the electrode wire to thebase metalSpray arc transfer uses relativelyhigh voltage wire feed speed andamperage values compared to shortcircuit transfer
AdvantagesAdvantages
High deposition rates High electrode efficiency of 98 or more Employs a wide range of filler metal types in an
equally wide range of electrode diameters Excellent weld bead appearance High operator appeal and ease of use Requires little post weld cleanup Absence of weld spatter Excellent weld fusion Lends itself to semiautomatic robotic and hard
automation applications
LimitationsLimitations
Restricted to the flat and horizontal welding positions
Welding fume generation is higher The higher-radiated heat and the generation of a
very bright arc require extra welder and bystander protection
The use of axial spray transfer outdoors requires the use of a windscreen(s)
The shielding used to support axial spray transfer costs more than 100 CO2
Pulse Spray Transfer Pulse Spray Transfer
GMAW-P was developed for two demanding reasons control of weld spatter and the elimination of incomplete fusion defects common to globular and short-circuiting transfer
The welding current alternates between a peak current and a lower background current
This faster-freezing weld puddle is what allows the pulsed-spray transfer to be used fort thinner metals
better control on out-of-position work allows for larger wire sizes to be used on varied metal
thicknesses
In pulse spray transfer (GMAW-P) the welding power sourcersquos pulse control pulses the welding output withhigh peak currents (amperage) which are set at levels which will cause the transfer to go into a spray The background current (amperage) is set at a level that will maintain the arcbut is too low for any metal transfer to occur
Pulsed arc transferPulsed arc transfer
AdvantagesAdvantages Absent or very low levels of spatter More resistant to lack of fusion defects than other modes of
GMAW metal transfer Excellent weld bead appearance and offers an engineered
solution for the control of weld fume generation Reduced levels of heat induced distortion and tendency for arc
blow Ability to weld out-of-position and handles poor fit-up When compared to FCAW SMAW and GMAW-S pulsed
spray transfer provides a low cost high-electrode efficiency of 98
Lends itself to robotic and hard automation applications Is combined for use with Tandem GMAW or other multiple arc
scenarios Capable of arc travel speeds greater than 50 inches per minute
(12 Mmin)
LimitationsLimitationsEquipment to support the process is more
expensive than traditional systemsBlends of argon based shielding gas are
more expensive than carbon dioxideHigher arc energy requires the use of
additional safety protection for welders and bystanders
Adds complexity to weldingRequires the use of windscreens outdoors
Manual GMAW EquipmentManual GMAW Equipment
Three major elements are
1) Welding torch and accessories
2) Welding control amp Wire feed motor
3) Power Source
GMAW equipment can be used either manually or automatically
GMAW Schematic DiagramGMAW Schematic Diagram
WIRE CONTROLamp
WIRE FEED MOTOR
POWER SOURCE
Welding Torch amp AccessoriesWelding Torch amp Accessories
The welding torch guides the wire and shielding gas to the weld zone
Brings welding power to the wire alsoMajor componentsparts of the torch are the
contact tip shielding gas nozzle gas diffuser and the wire conduit
Others types of torchOthers types of torch
TRIGGER
INSTALLED
COMPONENTS
NOZZLE
CONTACT TIP
GAS DIFFUSER
Welding Control amp Wire Welding Control amp Wire Feed MotorFeed Motor
Welding control amp Wire feed motor are combined into one unit
Main function is to pull the wire from the spool and feed it to the arc
Controls wire feed speed and regulates the starting and stopping of wire feed
Wire feed speed controls Amperage
Types of Wire Feed MotorTypes of Wire Feed Motor
Types of WFM RollerTypes of WFM Roller
Types of Wire FeederTypes of Wire Feeder
WIRE FEEDER
Power SourcePower Source
Almost all GMAW is done with reverse polarity also known as DCEP
Positive (+) lead is connected to the torchNegative (-) lead is connected to the work
pieceProvides a relatively consistent voltage to the
arcArc Voltage is the voltage between the end of
the wire and the work piece
Contact Tip To Work DistanceContact Tip To Work Distance
In constant current the CTWD (contact tip to work distance) determines the arc length
As the CTWD increases the arc length increases and as the
CTWD decreases the arc length decreases This presented a
problem for semiautomatic welding because it is difficult to
maintain the same CTWD To compensate for this problem an arc voltage controlled wire
Constant voltage power source designs provide a specific arc voltage for a given pre-selected wire feed speed The volt-amp curve or slope is comparatively flat As the CTWD increases with these types of power sources there is a decrease in the welding current As the CTWD decreases there is an increase in the welding current The arc in this case becomes a series circuit and the CTWD provides resistance to current In either scenario the voltage remains the same and the arc length remains the same
POSITIVETERMINAL
NEGATIVETERMINAL
Shielding GasesShielding Gases
Purpose of shielding gas is the protect the weld area from the contaminants in the atmosphere
Gas can be Inert Reactive or Mixtures of both
Gas flow rate is between 25-35 CFHArgon Helium and Carbon Dioxide are the
main three gases used in GMAW
Properties of GasesProperties of Gases
Affect the performance of the welding process include
1) Thermal properties at elevated temperatures 2) Chemical reaction of the gas with the various
elements in the base plate and welding wire 3) Effect of each gas on the mode of metal
transfer
Types of shielding gasesTypes of shielding gases
Inert Gas
1 Argon
2 Helium
3 Ar + HeActive Gas
1 Carbon Dioxide
2 Inert gas + any type of active gas
Argon is an inert gas which is used both singularly and in combination with other gases to achieve desired arc characteristics for the welding of both ferrous and non-ferrous metals
Carbon Dioxide Pure carbon dioxide is not an inert gas because the heat of the arc breaks down the CO2 into carbon monoxide and free oxygen This oxygen will combine with elements transferring across the arc to form oxides which are released from the weld puddle in the form of slag and scale
Helium is an inert gas which is used on weld applications requiring higher heat input for improved bead wetting deeper penetration and higher travel speed In GMAW it does not produce as stable an arc as argon Compared to argon helium has a higher thermal conductivity and voltage gradient
FLOW METER
CYLCINDERPRESSUREGAUGE
CFH PRESSURE ADJUSTMENT KNOB
Filler WireFiller Wire
Wire ChemistriesWire Chemistries
GMAW Operation techniquesGMAW Operation techniques
To setting WFS (Wire Feed Speed)
Voltage-bead ChangeVoltage-bead Change
Electrode Stick-outElectrode Stick-out
ESO SettingESO Setting
EOSEOS
Gun angles and techniquesGun angles and techniques
Direction of TravelDirection of Travel
THANK YOU
AdvantagesAdvantages
All-position capability including flat horizontal vertical-up vertical-down and overhead
Handles poor fit-up extremely well and is capable of root pass work on pipe applications
Lower heat input reduces weldment distortion Higher operator appeal and ease of use Higher electrode efficiencies 93 or more
LimitationsLimitations
Restricted to sheet metal thickness range and open roots of groove joints on heavier sections of base material
Poor welding procedure control can result in incomplete fusion Cold lap and cold shut are additional terms that serve to describe incomplete fusion defects
Poor procedure control can result in excessive spatter and will increase weldment cleanup cost
To prevent the loss of shielding gas to the wind welding outdoors may require the use of a windscreen(s)
Globular TransferGlobular Transfer
Welding current and wire speed are increased above maximum for short arc
Droplets of metal have a greater diameter than the wire being used
Spatter present Welding is most effectively done in the flat
position when using globular transfer
Globular transfer is often a high voltage high amperage high wire feed speed transfer and is the result of using CO2 shielding gas (or 75 AR-25 CO2) with parameters higher than the short-circuiting range
AdvantagesAdvantages
Uses inexpensive CO2 shielding gas but is frequently used with argonCO2 blends
Is capable of making welds at very high travel speeds
Inexpensive solid or metal-cored electrodesWelding equipment is inexpensive
LimitationsLimitations
Higher spatter levels result in costly cleanup Prone to cold lap or cold shut incomplete fusion defects
which results in costly repairs Weld bead shape is convex and welds exhibit poor
wetting at the toes High spatter level reduces electrode efficiency to a range
of 87 ndash 93 Less desirable weld appearance than spray arc transfer Welding is limited to flat positions and horizontally fillet
welds Welding is limited to metal 18 inch (3 mm) or thicker
Spray Arc TransferSpray Arc Transfer
Occurs when the current and voltage settings are increased higher than that used for Globular Transfer
Used on thick sections of base material best suited for flat position due to large weld puddle
Spatter is minimal to none Uses 5 to 10 co2 mix with argon or oxygen
gtForms very small droplets of metalgtVery good stabilitygtVery little spatter
Spray arc transfer ldquospraysrdquo a streamof tiny molten droplets across thearc from the electrode wire to thebase metalSpray arc transfer uses relativelyhigh voltage wire feed speed andamperage values compared to shortcircuit transfer
AdvantagesAdvantages
High deposition rates High electrode efficiency of 98 or more Employs a wide range of filler metal types in an
equally wide range of electrode diameters Excellent weld bead appearance High operator appeal and ease of use Requires little post weld cleanup Absence of weld spatter Excellent weld fusion Lends itself to semiautomatic robotic and hard
automation applications
LimitationsLimitations
Restricted to the flat and horizontal welding positions
Welding fume generation is higher The higher-radiated heat and the generation of a
very bright arc require extra welder and bystander protection
The use of axial spray transfer outdoors requires the use of a windscreen(s)
The shielding used to support axial spray transfer costs more than 100 CO2
Pulse Spray Transfer Pulse Spray Transfer
GMAW-P was developed for two demanding reasons control of weld spatter and the elimination of incomplete fusion defects common to globular and short-circuiting transfer
The welding current alternates between a peak current and a lower background current
This faster-freezing weld puddle is what allows the pulsed-spray transfer to be used fort thinner metals
better control on out-of-position work allows for larger wire sizes to be used on varied metal
thicknesses
In pulse spray transfer (GMAW-P) the welding power sourcersquos pulse control pulses the welding output withhigh peak currents (amperage) which are set at levels which will cause the transfer to go into a spray The background current (amperage) is set at a level that will maintain the arcbut is too low for any metal transfer to occur
Pulsed arc transferPulsed arc transfer
AdvantagesAdvantages Absent or very low levels of spatter More resistant to lack of fusion defects than other modes of
GMAW metal transfer Excellent weld bead appearance and offers an engineered
solution for the control of weld fume generation Reduced levels of heat induced distortion and tendency for arc
blow Ability to weld out-of-position and handles poor fit-up When compared to FCAW SMAW and GMAW-S pulsed
spray transfer provides a low cost high-electrode efficiency of 98
Lends itself to robotic and hard automation applications Is combined for use with Tandem GMAW or other multiple arc
scenarios Capable of arc travel speeds greater than 50 inches per minute
(12 Mmin)
LimitationsLimitationsEquipment to support the process is more
expensive than traditional systemsBlends of argon based shielding gas are
more expensive than carbon dioxideHigher arc energy requires the use of
additional safety protection for welders and bystanders
Adds complexity to weldingRequires the use of windscreens outdoors
Manual GMAW EquipmentManual GMAW Equipment
Three major elements are
1) Welding torch and accessories
2) Welding control amp Wire feed motor
3) Power Source
GMAW equipment can be used either manually or automatically
GMAW Schematic DiagramGMAW Schematic Diagram
WIRE CONTROLamp
WIRE FEED MOTOR
POWER SOURCE
Welding Torch amp AccessoriesWelding Torch amp Accessories
The welding torch guides the wire and shielding gas to the weld zone
Brings welding power to the wire alsoMajor componentsparts of the torch are the
contact tip shielding gas nozzle gas diffuser and the wire conduit
Others types of torchOthers types of torch
TRIGGER
INSTALLED
COMPONENTS
NOZZLE
CONTACT TIP
GAS DIFFUSER
Welding Control amp Wire Welding Control amp Wire Feed MotorFeed Motor
Welding control amp Wire feed motor are combined into one unit
Main function is to pull the wire from the spool and feed it to the arc
Controls wire feed speed and regulates the starting and stopping of wire feed
Wire feed speed controls Amperage
Types of Wire Feed MotorTypes of Wire Feed Motor
Types of WFM RollerTypes of WFM Roller
Types of Wire FeederTypes of Wire Feeder
WIRE FEEDER
Power SourcePower Source
Almost all GMAW is done with reverse polarity also known as DCEP
Positive (+) lead is connected to the torchNegative (-) lead is connected to the work
pieceProvides a relatively consistent voltage to the
arcArc Voltage is the voltage between the end of
the wire and the work piece
Contact Tip To Work DistanceContact Tip To Work Distance
In constant current the CTWD (contact tip to work distance) determines the arc length
As the CTWD increases the arc length increases and as the
CTWD decreases the arc length decreases This presented a
problem for semiautomatic welding because it is difficult to
maintain the same CTWD To compensate for this problem an arc voltage controlled wire
Constant voltage power source designs provide a specific arc voltage for a given pre-selected wire feed speed The volt-amp curve or slope is comparatively flat As the CTWD increases with these types of power sources there is a decrease in the welding current As the CTWD decreases there is an increase in the welding current The arc in this case becomes a series circuit and the CTWD provides resistance to current In either scenario the voltage remains the same and the arc length remains the same
POSITIVETERMINAL
NEGATIVETERMINAL
Shielding GasesShielding Gases
Purpose of shielding gas is the protect the weld area from the contaminants in the atmosphere
Gas can be Inert Reactive or Mixtures of both
Gas flow rate is between 25-35 CFHArgon Helium and Carbon Dioxide are the
main three gases used in GMAW
Properties of GasesProperties of Gases
Affect the performance of the welding process include
1) Thermal properties at elevated temperatures 2) Chemical reaction of the gas with the various
elements in the base plate and welding wire 3) Effect of each gas on the mode of metal
transfer
Types of shielding gasesTypes of shielding gases
Inert Gas
1 Argon
2 Helium
3 Ar + HeActive Gas
1 Carbon Dioxide
2 Inert gas + any type of active gas
Argon is an inert gas which is used both singularly and in combination with other gases to achieve desired arc characteristics for the welding of both ferrous and non-ferrous metals
Carbon Dioxide Pure carbon dioxide is not an inert gas because the heat of the arc breaks down the CO2 into carbon monoxide and free oxygen This oxygen will combine with elements transferring across the arc to form oxides which are released from the weld puddle in the form of slag and scale
Helium is an inert gas which is used on weld applications requiring higher heat input for improved bead wetting deeper penetration and higher travel speed In GMAW it does not produce as stable an arc as argon Compared to argon helium has a higher thermal conductivity and voltage gradient
FLOW METER
CYLCINDERPRESSUREGAUGE
CFH PRESSURE ADJUSTMENT KNOB
Filler WireFiller Wire
Wire ChemistriesWire Chemistries
GMAW Operation techniquesGMAW Operation techniques
To setting WFS (Wire Feed Speed)
Voltage-bead ChangeVoltage-bead Change
Electrode Stick-outElectrode Stick-out
ESO SettingESO Setting
EOSEOS
Gun angles and techniquesGun angles and techniques
Direction of TravelDirection of Travel
THANK YOU
LimitationsLimitations
Restricted to sheet metal thickness range and open roots of groove joints on heavier sections of base material
Poor welding procedure control can result in incomplete fusion Cold lap and cold shut are additional terms that serve to describe incomplete fusion defects
Poor procedure control can result in excessive spatter and will increase weldment cleanup cost
To prevent the loss of shielding gas to the wind welding outdoors may require the use of a windscreen(s)
Globular TransferGlobular Transfer
Welding current and wire speed are increased above maximum for short arc
Droplets of metal have a greater diameter than the wire being used
Spatter present Welding is most effectively done in the flat
position when using globular transfer
Globular transfer is often a high voltage high amperage high wire feed speed transfer and is the result of using CO2 shielding gas (or 75 AR-25 CO2) with parameters higher than the short-circuiting range
AdvantagesAdvantages
Uses inexpensive CO2 shielding gas but is frequently used with argonCO2 blends
Is capable of making welds at very high travel speeds
Inexpensive solid or metal-cored electrodesWelding equipment is inexpensive
LimitationsLimitations
Higher spatter levels result in costly cleanup Prone to cold lap or cold shut incomplete fusion defects
which results in costly repairs Weld bead shape is convex and welds exhibit poor
wetting at the toes High spatter level reduces electrode efficiency to a range
of 87 ndash 93 Less desirable weld appearance than spray arc transfer Welding is limited to flat positions and horizontally fillet
welds Welding is limited to metal 18 inch (3 mm) or thicker
Spray Arc TransferSpray Arc Transfer
Occurs when the current and voltage settings are increased higher than that used for Globular Transfer
Used on thick sections of base material best suited for flat position due to large weld puddle
Spatter is minimal to none Uses 5 to 10 co2 mix with argon or oxygen
gtForms very small droplets of metalgtVery good stabilitygtVery little spatter
Spray arc transfer ldquospraysrdquo a streamof tiny molten droplets across thearc from the electrode wire to thebase metalSpray arc transfer uses relativelyhigh voltage wire feed speed andamperage values compared to shortcircuit transfer
AdvantagesAdvantages
High deposition rates High electrode efficiency of 98 or more Employs a wide range of filler metal types in an
equally wide range of electrode diameters Excellent weld bead appearance High operator appeal and ease of use Requires little post weld cleanup Absence of weld spatter Excellent weld fusion Lends itself to semiautomatic robotic and hard
automation applications
LimitationsLimitations
Restricted to the flat and horizontal welding positions
Welding fume generation is higher The higher-radiated heat and the generation of a
very bright arc require extra welder and bystander protection
The use of axial spray transfer outdoors requires the use of a windscreen(s)
The shielding used to support axial spray transfer costs more than 100 CO2
Pulse Spray Transfer Pulse Spray Transfer
GMAW-P was developed for two demanding reasons control of weld spatter and the elimination of incomplete fusion defects common to globular and short-circuiting transfer
The welding current alternates between a peak current and a lower background current
This faster-freezing weld puddle is what allows the pulsed-spray transfer to be used fort thinner metals
better control on out-of-position work allows for larger wire sizes to be used on varied metal
thicknesses
In pulse spray transfer (GMAW-P) the welding power sourcersquos pulse control pulses the welding output withhigh peak currents (amperage) which are set at levels which will cause the transfer to go into a spray The background current (amperage) is set at a level that will maintain the arcbut is too low for any metal transfer to occur
Pulsed arc transferPulsed arc transfer
AdvantagesAdvantages Absent or very low levels of spatter More resistant to lack of fusion defects than other modes of
GMAW metal transfer Excellent weld bead appearance and offers an engineered
solution for the control of weld fume generation Reduced levels of heat induced distortion and tendency for arc
blow Ability to weld out-of-position and handles poor fit-up When compared to FCAW SMAW and GMAW-S pulsed
spray transfer provides a low cost high-electrode efficiency of 98
Lends itself to robotic and hard automation applications Is combined for use with Tandem GMAW or other multiple arc
scenarios Capable of arc travel speeds greater than 50 inches per minute
(12 Mmin)
LimitationsLimitationsEquipment to support the process is more
expensive than traditional systemsBlends of argon based shielding gas are
more expensive than carbon dioxideHigher arc energy requires the use of
additional safety protection for welders and bystanders
Adds complexity to weldingRequires the use of windscreens outdoors
Manual GMAW EquipmentManual GMAW Equipment
Three major elements are
1) Welding torch and accessories
2) Welding control amp Wire feed motor
3) Power Source
GMAW equipment can be used either manually or automatically
GMAW Schematic DiagramGMAW Schematic Diagram
WIRE CONTROLamp
WIRE FEED MOTOR
POWER SOURCE
Welding Torch amp AccessoriesWelding Torch amp Accessories
The welding torch guides the wire and shielding gas to the weld zone
Brings welding power to the wire alsoMajor componentsparts of the torch are the
contact tip shielding gas nozzle gas diffuser and the wire conduit
Others types of torchOthers types of torch
TRIGGER
INSTALLED
COMPONENTS
NOZZLE
CONTACT TIP
GAS DIFFUSER
Welding Control amp Wire Welding Control amp Wire Feed MotorFeed Motor
Welding control amp Wire feed motor are combined into one unit
Main function is to pull the wire from the spool and feed it to the arc
Controls wire feed speed and regulates the starting and stopping of wire feed
Wire feed speed controls Amperage
Types of Wire Feed MotorTypes of Wire Feed Motor
Types of WFM RollerTypes of WFM Roller
Types of Wire FeederTypes of Wire Feeder
WIRE FEEDER
Power SourcePower Source
Almost all GMAW is done with reverse polarity also known as DCEP
Positive (+) lead is connected to the torchNegative (-) lead is connected to the work
pieceProvides a relatively consistent voltage to the
arcArc Voltage is the voltage between the end of
the wire and the work piece
Contact Tip To Work DistanceContact Tip To Work Distance
In constant current the CTWD (contact tip to work distance) determines the arc length
As the CTWD increases the arc length increases and as the
CTWD decreases the arc length decreases This presented a
problem for semiautomatic welding because it is difficult to
maintain the same CTWD To compensate for this problem an arc voltage controlled wire
Constant voltage power source designs provide a specific arc voltage for a given pre-selected wire feed speed The volt-amp curve or slope is comparatively flat As the CTWD increases with these types of power sources there is a decrease in the welding current As the CTWD decreases there is an increase in the welding current The arc in this case becomes a series circuit and the CTWD provides resistance to current In either scenario the voltage remains the same and the arc length remains the same
POSITIVETERMINAL
NEGATIVETERMINAL
Shielding GasesShielding Gases
Purpose of shielding gas is the protect the weld area from the contaminants in the atmosphere
Gas can be Inert Reactive or Mixtures of both
Gas flow rate is between 25-35 CFHArgon Helium and Carbon Dioxide are the
main three gases used in GMAW
Properties of GasesProperties of Gases
Affect the performance of the welding process include
1) Thermal properties at elevated temperatures 2) Chemical reaction of the gas with the various
elements in the base plate and welding wire 3) Effect of each gas on the mode of metal
transfer
Types of shielding gasesTypes of shielding gases
Inert Gas
1 Argon
2 Helium
3 Ar + HeActive Gas
1 Carbon Dioxide
2 Inert gas + any type of active gas
Argon is an inert gas which is used both singularly and in combination with other gases to achieve desired arc characteristics for the welding of both ferrous and non-ferrous metals
Carbon Dioxide Pure carbon dioxide is not an inert gas because the heat of the arc breaks down the CO2 into carbon monoxide and free oxygen This oxygen will combine with elements transferring across the arc to form oxides which are released from the weld puddle in the form of slag and scale
Helium is an inert gas which is used on weld applications requiring higher heat input for improved bead wetting deeper penetration and higher travel speed In GMAW it does not produce as stable an arc as argon Compared to argon helium has a higher thermal conductivity and voltage gradient
FLOW METER
CYLCINDERPRESSUREGAUGE
CFH PRESSURE ADJUSTMENT KNOB
Filler WireFiller Wire
Wire ChemistriesWire Chemistries
GMAW Operation techniquesGMAW Operation techniques
To setting WFS (Wire Feed Speed)
Voltage-bead ChangeVoltage-bead Change
Electrode Stick-outElectrode Stick-out
ESO SettingESO Setting
EOSEOS
Gun angles and techniquesGun angles and techniques
Direction of TravelDirection of Travel
THANK YOU
Globular TransferGlobular Transfer
Welding current and wire speed are increased above maximum for short arc
Droplets of metal have a greater diameter than the wire being used
Spatter present Welding is most effectively done in the flat
position when using globular transfer
Globular transfer is often a high voltage high amperage high wire feed speed transfer and is the result of using CO2 shielding gas (or 75 AR-25 CO2) with parameters higher than the short-circuiting range
AdvantagesAdvantages
Uses inexpensive CO2 shielding gas but is frequently used with argonCO2 blends
Is capable of making welds at very high travel speeds
Inexpensive solid or metal-cored electrodesWelding equipment is inexpensive
LimitationsLimitations
Higher spatter levels result in costly cleanup Prone to cold lap or cold shut incomplete fusion defects
which results in costly repairs Weld bead shape is convex and welds exhibit poor
wetting at the toes High spatter level reduces electrode efficiency to a range
of 87 ndash 93 Less desirable weld appearance than spray arc transfer Welding is limited to flat positions and horizontally fillet
welds Welding is limited to metal 18 inch (3 mm) or thicker
Spray Arc TransferSpray Arc Transfer
Occurs when the current and voltage settings are increased higher than that used for Globular Transfer
Used on thick sections of base material best suited for flat position due to large weld puddle
Spatter is minimal to none Uses 5 to 10 co2 mix with argon or oxygen
gtForms very small droplets of metalgtVery good stabilitygtVery little spatter
Spray arc transfer ldquospraysrdquo a streamof tiny molten droplets across thearc from the electrode wire to thebase metalSpray arc transfer uses relativelyhigh voltage wire feed speed andamperage values compared to shortcircuit transfer
AdvantagesAdvantages
High deposition rates High electrode efficiency of 98 or more Employs a wide range of filler metal types in an
equally wide range of electrode diameters Excellent weld bead appearance High operator appeal and ease of use Requires little post weld cleanup Absence of weld spatter Excellent weld fusion Lends itself to semiautomatic robotic and hard
automation applications
LimitationsLimitations
Restricted to the flat and horizontal welding positions
Welding fume generation is higher The higher-radiated heat and the generation of a
very bright arc require extra welder and bystander protection
The use of axial spray transfer outdoors requires the use of a windscreen(s)
The shielding used to support axial spray transfer costs more than 100 CO2
Pulse Spray Transfer Pulse Spray Transfer
GMAW-P was developed for two demanding reasons control of weld spatter and the elimination of incomplete fusion defects common to globular and short-circuiting transfer
The welding current alternates between a peak current and a lower background current
This faster-freezing weld puddle is what allows the pulsed-spray transfer to be used fort thinner metals
better control on out-of-position work allows for larger wire sizes to be used on varied metal
thicknesses
In pulse spray transfer (GMAW-P) the welding power sourcersquos pulse control pulses the welding output withhigh peak currents (amperage) which are set at levels which will cause the transfer to go into a spray The background current (amperage) is set at a level that will maintain the arcbut is too low for any metal transfer to occur
Pulsed arc transferPulsed arc transfer
AdvantagesAdvantages Absent or very low levels of spatter More resistant to lack of fusion defects than other modes of
GMAW metal transfer Excellent weld bead appearance and offers an engineered
solution for the control of weld fume generation Reduced levels of heat induced distortion and tendency for arc
blow Ability to weld out-of-position and handles poor fit-up When compared to FCAW SMAW and GMAW-S pulsed
spray transfer provides a low cost high-electrode efficiency of 98
Lends itself to robotic and hard automation applications Is combined for use with Tandem GMAW or other multiple arc
scenarios Capable of arc travel speeds greater than 50 inches per minute
(12 Mmin)
LimitationsLimitationsEquipment to support the process is more
expensive than traditional systemsBlends of argon based shielding gas are
more expensive than carbon dioxideHigher arc energy requires the use of
additional safety protection for welders and bystanders
Adds complexity to weldingRequires the use of windscreens outdoors
Manual GMAW EquipmentManual GMAW Equipment
Three major elements are
1) Welding torch and accessories
2) Welding control amp Wire feed motor
3) Power Source
GMAW equipment can be used either manually or automatically
GMAW Schematic DiagramGMAW Schematic Diagram
WIRE CONTROLamp
WIRE FEED MOTOR
POWER SOURCE
Welding Torch amp AccessoriesWelding Torch amp Accessories
The welding torch guides the wire and shielding gas to the weld zone
Brings welding power to the wire alsoMajor componentsparts of the torch are the
contact tip shielding gas nozzle gas diffuser and the wire conduit
Others types of torchOthers types of torch
TRIGGER
INSTALLED
COMPONENTS
NOZZLE
CONTACT TIP
GAS DIFFUSER
Welding Control amp Wire Welding Control amp Wire Feed MotorFeed Motor
Welding control amp Wire feed motor are combined into one unit
Main function is to pull the wire from the spool and feed it to the arc
Controls wire feed speed and regulates the starting and stopping of wire feed
Wire feed speed controls Amperage
Types of Wire Feed MotorTypes of Wire Feed Motor
Types of WFM RollerTypes of WFM Roller
Types of Wire FeederTypes of Wire Feeder
WIRE FEEDER
Power SourcePower Source
Almost all GMAW is done with reverse polarity also known as DCEP
Positive (+) lead is connected to the torchNegative (-) lead is connected to the work
pieceProvides a relatively consistent voltage to the
arcArc Voltage is the voltage between the end of
the wire and the work piece
Contact Tip To Work DistanceContact Tip To Work Distance
In constant current the CTWD (contact tip to work distance) determines the arc length
As the CTWD increases the arc length increases and as the
CTWD decreases the arc length decreases This presented a
problem for semiautomatic welding because it is difficult to
maintain the same CTWD To compensate for this problem an arc voltage controlled wire
Constant voltage power source designs provide a specific arc voltage for a given pre-selected wire feed speed The volt-amp curve or slope is comparatively flat As the CTWD increases with these types of power sources there is a decrease in the welding current As the CTWD decreases there is an increase in the welding current The arc in this case becomes a series circuit and the CTWD provides resistance to current In either scenario the voltage remains the same and the arc length remains the same
POSITIVETERMINAL
NEGATIVETERMINAL
Shielding GasesShielding Gases
Purpose of shielding gas is the protect the weld area from the contaminants in the atmosphere
Gas can be Inert Reactive or Mixtures of both
Gas flow rate is between 25-35 CFHArgon Helium and Carbon Dioxide are the
main three gases used in GMAW
Properties of GasesProperties of Gases
Affect the performance of the welding process include
1) Thermal properties at elevated temperatures 2) Chemical reaction of the gas with the various
elements in the base plate and welding wire 3) Effect of each gas on the mode of metal
transfer
Types of shielding gasesTypes of shielding gases
Inert Gas
1 Argon
2 Helium
3 Ar + HeActive Gas
1 Carbon Dioxide
2 Inert gas + any type of active gas
Argon is an inert gas which is used both singularly and in combination with other gases to achieve desired arc characteristics for the welding of both ferrous and non-ferrous metals
Carbon Dioxide Pure carbon dioxide is not an inert gas because the heat of the arc breaks down the CO2 into carbon monoxide and free oxygen This oxygen will combine with elements transferring across the arc to form oxides which are released from the weld puddle in the form of slag and scale
Helium is an inert gas which is used on weld applications requiring higher heat input for improved bead wetting deeper penetration and higher travel speed In GMAW it does not produce as stable an arc as argon Compared to argon helium has a higher thermal conductivity and voltage gradient
FLOW METER
CYLCINDERPRESSUREGAUGE
CFH PRESSURE ADJUSTMENT KNOB
Filler WireFiller Wire
Wire ChemistriesWire Chemistries
GMAW Operation techniquesGMAW Operation techniques
To setting WFS (Wire Feed Speed)
Voltage-bead ChangeVoltage-bead Change
Electrode Stick-outElectrode Stick-out
ESO SettingESO Setting
EOSEOS
Gun angles and techniquesGun angles and techniques
Direction of TravelDirection of Travel
THANK YOU
Globular transfer is often a high voltage high amperage high wire feed speed transfer and is the result of using CO2 shielding gas (or 75 AR-25 CO2) with parameters higher than the short-circuiting range
AdvantagesAdvantages
Uses inexpensive CO2 shielding gas but is frequently used with argonCO2 blends
Is capable of making welds at very high travel speeds
Inexpensive solid or metal-cored electrodesWelding equipment is inexpensive
LimitationsLimitations
Higher spatter levels result in costly cleanup Prone to cold lap or cold shut incomplete fusion defects
which results in costly repairs Weld bead shape is convex and welds exhibit poor
wetting at the toes High spatter level reduces electrode efficiency to a range
of 87 ndash 93 Less desirable weld appearance than spray arc transfer Welding is limited to flat positions and horizontally fillet
welds Welding is limited to metal 18 inch (3 mm) or thicker
Spray Arc TransferSpray Arc Transfer
Occurs when the current and voltage settings are increased higher than that used for Globular Transfer
Used on thick sections of base material best suited for flat position due to large weld puddle
Spatter is minimal to none Uses 5 to 10 co2 mix with argon or oxygen
gtForms very small droplets of metalgtVery good stabilitygtVery little spatter
Spray arc transfer ldquospraysrdquo a streamof tiny molten droplets across thearc from the electrode wire to thebase metalSpray arc transfer uses relativelyhigh voltage wire feed speed andamperage values compared to shortcircuit transfer
AdvantagesAdvantages
High deposition rates High electrode efficiency of 98 or more Employs a wide range of filler metal types in an
equally wide range of electrode diameters Excellent weld bead appearance High operator appeal and ease of use Requires little post weld cleanup Absence of weld spatter Excellent weld fusion Lends itself to semiautomatic robotic and hard
automation applications
LimitationsLimitations
Restricted to the flat and horizontal welding positions
Welding fume generation is higher The higher-radiated heat and the generation of a
very bright arc require extra welder and bystander protection
The use of axial spray transfer outdoors requires the use of a windscreen(s)
The shielding used to support axial spray transfer costs more than 100 CO2
Pulse Spray Transfer Pulse Spray Transfer
GMAW-P was developed for two demanding reasons control of weld spatter and the elimination of incomplete fusion defects common to globular and short-circuiting transfer
The welding current alternates between a peak current and a lower background current
This faster-freezing weld puddle is what allows the pulsed-spray transfer to be used fort thinner metals
better control on out-of-position work allows for larger wire sizes to be used on varied metal
thicknesses
In pulse spray transfer (GMAW-P) the welding power sourcersquos pulse control pulses the welding output withhigh peak currents (amperage) which are set at levels which will cause the transfer to go into a spray The background current (amperage) is set at a level that will maintain the arcbut is too low for any metal transfer to occur
Pulsed arc transferPulsed arc transfer
AdvantagesAdvantages Absent or very low levels of spatter More resistant to lack of fusion defects than other modes of
GMAW metal transfer Excellent weld bead appearance and offers an engineered
solution for the control of weld fume generation Reduced levels of heat induced distortion and tendency for arc
blow Ability to weld out-of-position and handles poor fit-up When compared to FCAW SMAW and GMAW-S pulsed
spray transfer provides a low cost high-electrode efficiency of 98
Lends itself to robotic and hard automation applications Is combined for use with Tandem GMAW or other multiple arc
scenarios Capable of arc travel speeds greater than 50 inches per minute
(12 Mmin)
LimitationsLimitationsEquipment to support the process is more
expensive than traditional systemsBlends of argon based shielding gas are
more expensive than carbon dioxideHigher arc energy requires the use of
additional safety protection for welders and bystanders
Adds complexity to weldingRequires the use of windscreens outdoors
Manual GMAW EquipmentManual GMAW Equipment
Three major elements are
1) Welding torch and accessories
2) Welding control amp Wire feed motor
3) Power Source
GMAW equipment can be used either manually or automatically
GMAW Schematic DiagramGMAW Schematic Diagram
WIRE CONTROLamp
WIRE FEED MOTOR
POWER SOURCE
Welding Torch amp AccessoriesWelding Torch amp Accessories
The welding torch guides the wire and shielding gas to the weld zone
Brings welding power to the wire alsoMajor componentsparts of the torch are the
contact tip shielding gas nozzle gas diffuser and the wire conduit
Others types of torchOthers types of torch
TRIGGER
INSTALLED
COMPONENTS
NOZZLE
CONTACT TIP
GAS DIFFUSER
Welding Control amp Wire Welding Control amp Wire Feed MotorFeed Motor
Welding control amp Wire feed motor are combined into one unit
Main function is to pull the wire from the spool and feed it to the arc
Controls wire feed speed and regulates the starting and stopping of wire feed
Wire feed speed controls Amperage
Types of Wire Feed MotorTypes of Wire Feed Motor
Types of WFM RollerTypes of WFM Roller
Types of Wire FeederTypes of Wire Feeder
WIRE FEEDER
Power SourcePower Source
Almost all GMAW is done with reverse polarity also known as DCEP
Positive (+) lead is connected to the torchNegative (-) lead is connected to the work
pieceProvides a relatively consistent voltage to the
arcArc Voltage is the voltage between the end of
the wire and the work piece
Contact Tip To Work DistanceContact Tip To Work Distance
In constant current the CTWD (contact tip to work distance) determines the arc length
As the CTWD increases the arc length increases and as the
CTWD decreases the arc length decreases This presented a
problem for semiautomatic welding because it is difficult to
maintain the same CTWD To compensate for this problem an arc voltage controlled wire
Constant voltage power source designs provide a specific arc voltage for a given pre-selected wire feed speed The volt-amp curve or slope is comparatively flat As the CTWD increases with these types of power sources there is a decrease in the welding current As the CTWD decreases there is an increase in the welding current The arc in this case becomes a series circuit and the CTWD provides resistance to current In either scenario the voltage remains the same and the arc length remains the same
POSITIVETERMINAL
NEGATIVETERMINAL
Shielding GasesShielding Gases
Purpose of shielding gas is the protect the weld area from the contaminants in the atmosphere
Gas can be Inert Reactive or Mixtures of both
Gas flow rate is between 25-35 CFHArgon Helium and Carbon Dioxide are the
main three gases used in GMAW
Properties of GasesProperties of Gases
Affect the performance of the welding process include
1) Thermal properties at elevated temperatures 2) Chemical reaction of the gas with the various
elements in the base plate and welding wire 3) Effect of each gas on the mode of metal
transfer
Types of shielding gasesTypes of shielding gases
Inert Gas
1 Argon
2 Helium
3 Ar + HeActive Gas
1 Carbon Dioxide
2 Inert gas + any type of active gas
Argon is an inert gas which is used both singularly and in combination with other gases to achieve desired arc characteristics for the welding of both ferrous and non-ferrous metals
Carbon Dioxide Pure carbon dioxide is not an inert gas because the heat of the arc breaks down the CO2 into carbon monoxide and free oxygen This oxygen will combine with elements transferring across the arc to form oxides which are released from the weld puddle in the form of slag and scale
Helium is an inert gas which is used on weld applications requiring higher heat input for improved bead wetting deeper penetration and higher travel speed In GMAW it does not produce as stable an arc as argon Compared to argon helium has a higher thermal conductivity and voltage gradient
FLOW METER
CYLCINDERPRESSUREGAUGE
CFH PRESSURE ADJUSTMENT KNOB
Filler WireFiller Wire
Wire ChemistriesWire Chemistries
GMAW Operation techniquesGMAW Operation techniques
To setting WFS (Wire Feed Speed)
Voltage-bead ChangeVoltage-bead Change
Electrode Stick-outElectrode Stick-out
ESO SettingESO Setting
EOSEOS
Gun angles and techniquesGun angles and techniques
Direction of TravelDirection of Travel
THANK YOU
AdvantagesAdvantages
Uses inexpensive CO2 shielding gas but is frequently used with argonCO2 blends
Is capable of making welds at very high travel speeds
Inexpensive solid or metal-cored electrodesWelding equipment is inexpensive
LimitationsLimitations
Higher spatter levels result in costly cleanup Prone to cold lap or cold shut incomplete fusion defects
which results in costly repairs Weld bead shape is convex and welds exhibit poor
wetting at the toes High spatter level reduces electrode efficiency to a range
of 87 ndash 93 Less desirable weld appearance than spray arc transfer Welding is limited to flat positions and horizontally fillet
welds Welding is limited to metal 18 inch (3 mm) or thicker
Spray Arc TransferSpray Arc Transfer
Occurs when the current and voltage settings are increased higher than that used for Globular Transfer
Used on thick sections of base material best suited for flat position due to large weld puddle
Spatter is minimal to none Uses 5 to 10 co2 mix with argon or oxygen
gtForms very small droplets of metalgtVery good stabilitygtVery little spatter
Spray arc transfer ldquospraysrdquo a streamof tiny molten droplets across thearc from the electrode wire to thebase metalSpray arc transfer uses relativelyhigh voltage wire feed speed andamperage values compared to shortcircuit transfer
AdvantagesAdvantages
High deposition rates High electrode efficiency of 98 or more Employs a wide range of filler metal types in an
equally wide range of electrode diameters Excellent weld bead appearance High operator appeal and ease of use Requires little post weld cleanup Absence of weld spatter Excellent weld fusion Lends itself to semiautomatic robotic and hard
automation applications
LimitationsLimitations
Restricted to the flat and horizontal welding positions
Welding fume generation is higher The higher-radiated heat and the generation of a
very bright arc require extra welder and bystander protection
The use of axial spray transfer outdoors requires the use of a windscreen(s)
The shielding used to support axial spray transfer costs more than 100 CO2
Pulse Spray Transfer Pulse Spray Transfer
GMAW-P was developed for two demanding reasons control of weld spatter and the elimination of incomplete fusion defects common to globular and short-circuiting transfer
The welding current alternates between a peak current and a lower background current
This faster-freezing weld puddle is what allows the pulsed-spray transfer to be used fort thinner metals
better control on out-of-position work allows for larger wire sizes to be used on varied metal
thicknesses
In pulse spray transfer (GMAW-P) the welding power sourcersquos pulse control pulses the welding output withhigh peak currents (amperage) which are set at levels which will cause the transfer to go into a spray The background current (amperage) is set at a level that will maintain the arcbut is too low for any metal transfer to occur
Pulsed arc transferPulsed arc transfer
AdvantagesAdvantages Absent or very low levels of spatter More resistant to lack of fusion defects than other modes of
GMAW metal transfer Excellent weld bead appearance and offers an engineered
solution for the control of weld fume generation Reduced levels of heat induced distortion and tendency for arc
blow Ability to weld out-of-position and handles poor fit-up When compared to FCAW SMAW and GMAW-S pulsed
spray transfer provides a low cost high-electrode efficiency of 98
Lends itself to robotic and hard automation applications Is combined for use with Tandem GMAW or other multiple arc
scenarios Capable of arc travel speeds greater than 50 inches per minute
(12 Mmin)
LimitationsLimitationsEquipment to support the process is more
expensive than traditional systemsBlends of argon based shielding gas are
more expensive than carbon dioxideHigher arc energy requires the use of
additional safety protection for welders and bystanders
Adds complexity to weldingRequires the use of windscreens outdoors
Manual GMAW EquipmentManual GMAW Equipment
Three major elements are
1) Welding torch and accessories
2) Welding control amp Wire feed motor
3) Power Source
GMAW equipment can be used either manually or automatically
GMAW Schematic DiagramGMAW Schematic Diagram
WIRE CONTROLamp
WIRE FEED MOTOR
POWER SOURCE
Welding Torch amp AccessoriesWelding Torch amp Accessories
The welding torch guides the wire and shielding gas to the weld zone
Brings welding power to the wire alsoMajor componentsparts of the torch are the
contact tip shielding gas nozzle gas diffuser and the wire conduit
Others types of torchOthers types of torch
TRIGGER
INSTALLED
COMPONENTS
NOZZLE
CONTACT TIP
GAS DIFFUSER
Welding Control amp Wire Welding Control amp Wire Feed MotorFeed Motor
Welding control amp Wire feed motor are combined into one unit
Main function is to pull the wire from the spool and feed it to the arc
Controls wire feed speed and regulates the starting and stopping of wire feed
Wire feed speed controls Amperage
Types of Wire Feed MotorTypes of Wire Feed Motor
Types of WFM RollerTypes of WFM Roller
Types of Wire FeederTypes of Wire Feeder
WIRE FEEDER
Power SourcePower Source
Almost all GMAW is done with reverse polarity also known as DCEP
Positive (+) lead is connected to the torchNegative (-) lead is connected to the work
pieceProvides a relatively consistent voltage to the
arcArc Voltage is the voltage between the end of
the wire and the work piece
Contact Tip To Work DistanceContact Tip To Work Distance
In constant current the CTWD (contact tip to work distance) determines the arc length
As the CTWD increases the arc length increases and as the
CTWD decreases the arc length decreases This presented a
problem for semiautomatic welding because it is difficult to
maintain the same CTWD To compensate for this problem an arc voltage controlled wire
Constant voltage power source designs provide a specific arc voltage for a given pre-selected wire feed speed The volt-amp curve or slope is comparatively flat As the CTWD increases with these types of power sources there is a decrease in the welding current As the CTWD decreases there is an increase in the welding current The arc in this case becomes a series circuit and the CTWD provides resistance to current In either scenario the voltage remains the same and the arc length remains the same
POSITIVETERMINAL
NEGATIVETERMINAL
Shielding GasesShielding Gases
Purpose of shielding gas is the protect the weld area from the contaminants in the atmosphere
Gas can be Inert Reactive or Mixtures of both
Gas flow rate is between 25-35 CFHArgon Helium and Carbon Dioxide are the
main three gases used in GMAW
Properties of GasesProperties of Gases
Affect the performance of the welding process include
1) Thermal properties at elevated temperatures 2) Chemical reaction of the gas with the various
elements in the base plate and welding wire 3) Effect of each gas on the mode of metal
transfer
Types of shielding gasesTypes of shielding gases
Inert Gas
1 Argon
2 Helium
3 Ar + HeActive Gas
1 Carbon Dioxide
2 Inert gas + any type of active gas
Argon is an inert gas which is used both singularly and in combination with other gases to achieve desired arc characteristics for the welding of both ferrous and non-ferrous metals
Carbon Dioxide Pure carbon dioxide is not an inert gas because the heat of the arc breaks down the CO2 into carbon monoxide and free oxygen This oxygen will combine with elements transferring across the arc to form oxides which are released from the weld puddle in the form of slag and scale
Helium is an inert gas which is used on weld applications requiring higher heat input for improved bead wetting deeper penetration and higher travel speed In GMAW it does not produce as stable an arc as argon Compared to argon helium has a higher thermal conductivity and voltage gradient
FLOW METER
CYLCINDERPRESSUREGAUGE
CFH PRESSURE ADJUSTMENT KNOB
Filler WireFiller Wire
Wire ChemistriesWire Chemistries
GMAW Operation techniquesGMAW Operation techniques
To setting WFS (Wire Feed Speed)
Voltage-bead ChangeVoltage-bead Change
Electrode Stick-outElectrode Stick-out
ESO SettingESO Setting
EOSEOS
Gun angles and techniquesGun angles and techniques
Direction of TravelDirection of Travel
THANK YOU
LimitationsLimitations
Higher spatter levels result in costly cleanup Prone to cold lap or cold shut incomplete fusion defects
which results in costly repairs Weld bead shape is convex and welds exhibit poor
wetting at the toes High spatter level reduces electrode efficiency to a range
of 87 ndash 93 Less desirable weld appearance than spray arc transfer Welding is limited to flat positions and horizontally fillet
welds Welding is limited to metal 18 inch (3 mm) or thicker
Spray Arc TransferSpray Arc Transfer
Occurs when the current and voltage settings are increased higher than that used for Globular Transfer
Used on thick sections of base material best suited for flat position due to large weld puddle
Spatter is minimal to none Uses 5 to 10 co2 mix with argon or oxygen
gtForms very small droplets of metalgtVery good stabilitygtVery little spatter
Spray arc transfer ldquospraysrdquo a streamof tiny molten droplets across thearc from the electrode wire to thebase metalSpray arc transfer uses relativelyhigh voltage wire feed speed andamperage values compared to shortcircuit transfer
AdvantagesAdvantages
High deposition rates High electrode efficiency of 98 or more Employs a wide range of filler metal types in an
equally wide range of electrode diameters Excellent weld bead appearance High operator appeal and ease of use Requires little post weld cleanup Absence of weld spatter Excellent weld fusion Lends itself to semiautomatic robotic and hard
automation applications
LimitationsLimitations
Restricted to the flat and horizontal welding positions
Welding fume generation is higher The higher-radiated heat and the generation of a
very bright arc require extra welder and bystander protection
The use of axial spray transfer outdoors requires the use of a windscreen(s)
The shielding used to support axial spray transfer costs more than 100 CO2
Pulse Spray Transfer Pulse Spray Transfer
GMAW-P was developed for two demanding reasons control of weld spatter and the elimination of incomplete fusion defects common to globular and short-circuiting transfer
The welding current alternates between a peak current and a lower background current
This faster-freezing weld puddle is what allows the pulsed-spray transfer to be used fort thinner metals
better control on out-of-position work allows for larger wire sizes to be used on varied metal
thicknesses
In pulse spray transfer (GMAW-P) the welding power sourcersquos pulse control pulses the welding output withhigh peak currents (amperage) which are set at levels which will cause the transfer to go into a spray The background current (amperage) is set at a level that will maintain the arcbut is too low for any metal transfer to occur
Pulsed arc transferPulsed arc transfer
AdvantagesAdvantages Absent or very low levels of spatter More resistant to lack of fusion defects than other modes of
GMAW metal transfer Excellent weld bead appearance and offers an engineered
solution for the control of weld fume generation Reduced levels of heat induced distortion and tendency for arc
blow Ability to weld out-of-position and handles poor fit-up When compared to FCAW SMAW and GMAW-S pulsed
spray transfer provides a low cost high-electrode efficiency of 98
Lends itself to robotic and hard automation applications Is combined for use with Tandem GMAW or other multiple arc
scenarios Capable of arc travel speeds greater than 50 inches per minute
(12 Mmin)
LimitationsLimitationsEquipment to support the process is more
expensive than traditional systemsBlends of argon based shielding gas are
more expensive than carbon dioxideHigher arc energy requires the use of
additional safety protection for welders and bystanders
Adds complexity to weldingRequires the use of windscreens outdoors
Manual GMAW EquipmentManual GMAW Equipment
Three major elements are
1) Welding torch and accessories
2) Welding control amp Wire feed motor
3) Power Source
GMAW equipment can be used either manually or automatically
GMAW Schematic DiagramGMAW Schematic Diagram
WIRE CONTROLamp
WIRE FEED MOTOR
POWER SOURCE
Welding Torch amp AccessoriesWelding Torch amp Accessories
The welding torch guides the wire and shielding gas to the weld zone
Brings welding power to the wire alsoMajor componentsparts of the torch are the
contact tip shielding gas nozzle gas diffuser and the wire conduit
Others types of torchOthers types of torch
TRIGGER
INSTALLED
COMPONENTS
NOZZLE
CONTACT TIP
GAS DIFFUSER
Welding Control amp Wire Welding Control amp Wire Feed MotorFeed Motor
Welding control amp Wire feed motor are combined into one unit
Main function is to pull the wire from the spool and feed it to the arc
Controls wire feed speed and regulates the starting and stopping of wire feed
Wire feed speed controls Amperage
Types of Wire Feed MotorTypes of Wire Feed Motor
Types of WFM RollerTypes of WFM Roller
Types of Wire FeederTypes of Wire Feeder
WIRE FEEDER
Power SourcePower Source
Almost all GMAW is done with reverse polarity also known as DCEP
Positive (+) lead is connected to the torchNegative (-) lead is connected to the work
pieceProvides a relatively consistent voltage to the
arcArc Voltage is the voltage between the end of
the wire and the work piece
Contact Tip To Work DistanceContact Tip To Work Distance
In constant current the CTWD (contact tip to work distance) determines the arc length
As the CTWD increases the arc length increases and as the
CTWD decreases the arc length decreases This presented a
problem for semiautomatic welding because it is difficult to
maintain the same CTWD To compensate for this problem an arc voltage controlled wire
Constant voltage power source designs provide a specific arc voltage for a given pre-selected wire feed speed The volt-amp curve or slope is comparatively flat As the CTWD increases with these types of power sources there is a decrease in the welding current As the CTWD decreases there is an increase in the welding current The arc in this case becomes a series circuit and the CTWD provides resistance to current In either scenario the voltage remains the same and the arc length remains the same
POSITIVETERMINAL
NEGATIVETERMINAL
Shielding GasesShielding Gases
Purpose of shielding gas is the protect the weld area from the contaminants in the atmosphere
Gas can be Inert Reactive or Mixtures of both
Gas flow rate is between 25-35 CFHArgon Helium and Carbon Dioxide are the
main three gases used in GMAW
Properties of GasesProperties of Gases
Affect the performance of the welding process include
1) Thermal properties at elevated temperatures 2) Chemical reaction of the gas with the various
elements in the base plate and welding wire 3) Effect of each gas on the mode of metal
transfer
Types of shielding gasesTypes of shielding gases
Inert Gas
1 Argon
2 Helium
3 Ar + HeActive Gas
1 Carbon Dioxide
2 Inert gas + any type of active gas
Argon is an inert gas which is used both singularly and in combination with other gases to achieve desired arc characteristics for the welding of both ferrous and non-ferrous metals
Carbon Dioxide Pure carbon dioxide is not an inert gas because the heat of the arc breaks down the CO2 into carbon monoxide and free oxygen This oxygen will combine with elements transferring across the arc to form oxides which are released from the weld puddle in the form of slag and scale
Helium is an inert gas which is used on weld applications requiring higher heat input for improved bead wetting deeper penetration and higher travel speed In GMAW it does not produce as stable an arc as argon Compared to argon helium has a higher thermal conductivity and voltage gradient
FLOW METER
CYLCINDERPRESSUREGAUGE
CFH PRESSURE ADJUSTMENT KNOB
Filler WireFiller Wire
Wire ChemistriesWire Chemistries
GMAW Operation techniquesGMAW Operation techniques
To setting WFS (Wire Feed Speed)
Voltage-bead ChangeVoltage-bead Change
Electrode Stick-outElectrode Stick-out
ESO SettingESO Setting
EOSEOS
Gun angles and techniquesGun angles and techniques
Direction of TravelDirection of Travel
THANK YOU
Spray Arc TransferSpray Arc Transfer
Occurs when the current and voltage settings are increased higher than that used for Globular Transfer
Used on thick sections of base material best suited for flat position due to large weld puddle
Spatter is minimal to none Uses 5 to 10 co2 mix with argon or oxygen
gtForms very small droplets of metalgtVery good stabilitygtVery little spatter
Spray arc transfer ldquospraysrdquo a streamof tiny molten droplets across thearc from the electrode wire to thebase metalSpray arc transfer uses relativelyhigh voltage wire feed speed andamperage values compared to shortcircuit transfer
AdvantagesAdvantages
High deposition rates High electrode efficiency of 98 or more Employs a wide range of filler metal types in an
equally wide range of electrode diameters Excellent weld bead appearance High operator appeal and ease of use Requires little post weld cleanup Absence of weld spatter Excellent weld fusion Lends itself to semiautomatic robotic and hard
automation applications
LimitationsLimitations
Restricted to the flat and horizontal welding positions
Welding fume generation is higher The higher-radiated heat and the generation of a
very bright arc require extra welder and bystander protection
The use of axial spray transfer outdoors requires the use of a windscreen(s)
The shielding used to support axial spray transfer costs more than 100 CO2
Pulse Spray Transfer Pulse Spray Transfer
GMAW-P was developed for two demanding reasons control of weld spatter and the elimination of incomplete fusion defects common to globular and short-circuiting transfer
The welding current alternates between a peak current and a lower background current
This faster-freezing weld puddle is what allows the pulsed-spray transfer to be used fort thinner metals
better control on out-of-position work allows for larger wire sizes to be used on varied metal
thicknesses
In pulse spray transfer (GMAW-P) the welding power sourcersquos pulse control pulses the welding output withhigh peak currents (amperage) which are set at levels which will cause the transfer to go into a spray The background current (amperage) is set at a level that will maintain the arcbut is too low for any metal transfer to occur
Pulsed arc transferPulsed arc transfer
AdvantagesAdvantages Absent or very low levels of spatter More resistant to lack of fusion defects than other modes of
GMAW metal transfer Excellent weld bead appearance and offers an engineered
solution for the control of weld fume generation Reduced levels of heat induced distortion and tendency for arc
blow Ability to weld out-of-position and handles poor fit-up When compared to FCAW SMAW and GMAW-S pulsed
spray transfer provides a low cost high-electrode efficiency of 98
Lends itself to robotic and hard automation applications Is combined for use with Tandem GMAW or other multiple arc
scenarios Capable of arc travel speeds greater than 50 inches per minute
(12 Mmin)
LimitationsLimitationsEquipment to support the process is more
expensive than traditional systemsBlends of argon based shielding gas are
more expensive than carbon dioxideHigher arc energy requires the use of
additional safety protection for welders and bystanders
Adds complexity to weldingRequires the use of windscreens outdoors
Manual GMAW EquipmentManual GMAW Equipment
Three major elements are
1) Welding torch and accessories
2) Welding control amp Wire feed motor
3) Power Source
GMAW equipment can be used either manually or automatically
GMAW Schematic DiagramGMAW Schematic Diagram
WIRE CONTROLamp
WIRE FEED MOTOR
POWER SOURCE
Welding Torch amp AccessoriesWelding Torch amp Accessories
The welding torch guides the wire and shielding gas to the weld zone
Brings welding power to the wire alsoMajor componentsparts of the torch are the
contact tip shielding gas nozzle gas diffuser and the wire conduit
Others types of torchOthers types of torch
TRIGGER
INSTALLED
COMPONENTS
NOZZLE
CONTACT TIP
GAS DIFFUSER
Welding Control amp Wire Welding Control amp Wire Feed MotorFeed Motor
Welding control amp Wire feed motor are combined into one unit
Main function is to pull the wire from the spool and feed it to the arc
Controls wire feed speed and regulates the starting and stopping of wire feed
Wire feed speed controls Amperage
Types of Wire Feed MotorTypes of Wire Feed Motor
Types of WFM RollerTypes of WFM Roller
Types of Wire FeederTypes of Wire Feeder
WIRE FEEDER
Power SourcePower Source
Almost all GMAW is done with reverse polarity also known as DCEP
Positive (+) lead is connected to the torchNegative (-) lead is connected to the work
pieceProvides a relatively consistent voltage to the
arcArc Voltage is the voltage between the end of
the wire and the work piece
Contact Tip To Work DistanceContact Tip To Work Distance
In constant current the CTWD (contact tip to work distance) determines the arc length
As the CTWD increases the arc length increases and as the
CTWD decreases the arc length decreases This presented a
problem for semiautomatic welding because it is difficult to
maintain the same CTWD To compensate for this problem an arc voltage controlled wire
Constant voltage power source designs provide a specific arc voltage for a given pre-selected wire feed speed The volt-amp curve or slope is comparatively flat As the CTWD increases with these types of power sources there is a decrease in the welding current As the CTWD decreases there is an increase in the welding current The arc in this case becomes a series circuit and the CTWD provides resistance to current In either scenario the voltage remains the same and the arc length remains the same
POSITIVETERMINAL
NEGATIVETERMINAL
Shielding GasesShielding Gases
Purpose of shielding gas is the protect the weld area from the contaminants in the atmosphere
Gas can be Inert Reactive or Mixtures of both
Gas flow rate is between 25-35 CFHArgon Helium and Carbon Dioxide are the
main three gases used in GMAW
Properties of GasesProperties of Gases
Affect the performance of the welding process include
1) Thermal properties at elevated temperatures 2) Chemical reaction of the gas with the various
elements in the base plate and welding wire 3) Effect of each gas on the mode of metal
transfer
Types of shielding gasesTypes of shielding gases
Inert Gas
1 Argon
2 Helium
3 Ar + HeActive Gas
1 Carbon Dioxide
2 Inert gas + any type of active gas
Argon is an inert gas which is used both singularly and in combination with other gases to achieve desired arc characteristics for the welding of both ferrous and non-ferrous metals
Carbon Dioxide Pure carbon dioxide is not an inert gas because the heat of the arc breaks down the CO2 into carbon monoxide and free oxygen This oxygen will combine with elements transferring across the arc to form oxides which are released from the weld puddle in the form of slag and scale
Helium is an inert gas which is used on weld applications requiring higher heat input for improved bead wetting deeper penetration and higher travel speed In GMAW it does not produce as stable an arc as argon Compared to argon helium has a higher thermal conductivity and voltage gradient
FLOW METER
CYLCINDERPRESSUREGAUGE
CFH PRESSURE ADJUSTMENT KNOB
Filler WireFiller Wire
Wire ChemistriesWire Chemistries
GMAW Operation techniquesGMAW Operation techniques
To setting WFS (Wire Feed Speed)
Voltage-bead ChangeVoltage-bead Change
Electrode Stick-outElectrode Stick-out
ESO SettingESO Setting
EOSEOS
Gun angles and techniquesGun angles and techniques
Direction of TravelDirection of Travel
THANK YOU
Spray arc transfer ldquospraysrdquo a streamof tiny molten droplets across thearc from the electrode wire to thebase metalSpray arc transfer uses relativelyhigh voltage wire feed speed andamperage values compared to shortcircuit transfer
AdvantagesAdvantages
High deposition rates High electrode efficiency of 98 or more Employs a wide range of filler metal types in an
equally wide range of electrode diameters Excellent weld bead appearance High operator appeal and ease of use Requires little post weld cleanup Absence of weld spatter Excellent weld fusion Lends itself to semiautomatic robotic and hard
automation applications
LimitationsLimitations
Restricted to the flat and horizontal welding positions
Welding fume generation is higher The higher-radiated heat and the generation of a
very bright arc require extra welder and bystander protection
The use of axial spray transfer outdoors requires the use of a windscreen(s)
The shielding used to support axial spray transfer costs more than 100 CO2
Pulse Spray Transfer Pulse Spray Transfer
GMAW-P was developed for two demanding reasons control of weld spatter and the elimination of incomplete fusion defects common to globular and short-circuiting transfer
The welding current alternates between a peak current and a lower background current
This faster-freezing weld puddle is what allows the pulsed-spray transfer to be used fort thinner metals
better control on out-of-position work allows for larger wire sizes to be used on varied metal
thicknesses
In pulse spray transfer (GMAW-P) the welding power sourcersquos pulse control pulses the welding output withhigh peak currents (amperage) which are set at levels which will cause the transfer to go into a spray The background current (amperage) is set at a level that will maintain the arcbut is too low for any metal transfer to occur
Pulsed arc transferPulsed arc transfer
AdvantagesAdvantages Absent or very low levels of spatter More resistant to lack of fusion defects than other modes of
GMAW metal transfer Excellent weld bead appearance and offers an engineered
solution for the control of weld fume generation Reduced levels of heat induced distortion and tendency for arc
blow Ability to weld out-of-position and handles poor fit-up When compared to FCAW SMAW and GMAW-S pulsed
spray transfer provides a low cost high-electrode efficiency of 98
Lends itself to robotic and hard automation applications Is combined for use with Tandem GMAW or other multiple arc
scenarios Capable of arc travel speeds greater than 50 inches per minute
(12 Mmin)
LimitationsLimitationsEquipment to support the process is more
expensive than traditional systemsBlends of argon based shielding gas are
more expensive than carbon dioxideHigher arc energy requires the use of
additional safety protection for welders and bystanders
Adds complexity to weldingRequires the use of windscreens outdoors
Manual GMAW EquipmentManual GMAW Equipment
Three major elements are
1) Welding torch and accessories
2) Welding control amp Wire feed motor
3) Power Source
GMAW equipment can be used either manually or automatically
GMAW Schematic DiagramGMAW Schematic Diagram
WIRE CONTROLamp
WIRE FEED MOTOR
POWER SOURCE
Welding Torch amp AccessoriesWelding Torch amp Accessories
The welding torch guides the wire and shielding gas to the weld zone
Brings welding power to the wire alsoMajor componentsparts of the torch are the
contact tip shielding gas nozzle gas diffuser and the wire conduit
Others types of torchOthers types of torch
TRIGGER
INSTALLED
COMPONENTS
NOZZLE
CONTACT TIP
GAS DIFFUSER
Welding Control amp Wire Welding Control amp Wire Feed MotorFeed Motor
Welding control amp Wire feed motor are combined into one unit
Main function is to pull the wire from the spool and feed it to the arc
Controls wire feed speed and regulates the starting and stopping of wire feed
Wire feed speed controls Amperage
Types of Wire Feed MotorTypes of Wire Feed Motor
Types of WFM RollerTypes of WFM Roller
Types of Wire FeederTypes of Wire Feeder
WIRE FEEDER
Power SourcePower Source
Almost all GMAW is done with reverse polarity also known as DCEP
Positive (+) lead is connected to the torchNegative (-) lead is connected to the work
pieceProvides a relatively consistent voltage to the
arcArc Voltage is the voltage between the end of
the wire and the work piece
Contact Tip To Work DistanceContact Tip To Work Distance
In constant current the CTWD (contact tip to work distance) determines the arc length
As the CTWD increases the arc length increases and as the
CTWD decreases the arc length decreases This presented a
problem for semiautomatic welding because it is difficult to
maintain the same CTWD To compensate for this problem an arc voltage controlled wire
Constant voltage power source designs provide a specific arc voltage for a given pre-selected wire feed speed The volt-amp curve or slope is comparatively flat As the CTWD increases with these types of power sources there is a decrease in the welding current As the CTWD decreases there is an increase in the welding current The arc in this case becomes a series circuit and the CTWD provides resistance to current In either scenario the voltage remains the same and the arc length remains the same
POSITIVETERMINAL
NEGATIVETERMINAL
Shielding GasesShielding Gases
Purpose of shielding gas is the protect the weld area from the contaminants in the atmosphere
Gas can be Inert Reactive or Mixtures of both
Gas flow rate is between 25-35 CFHArgon Helium and Carbon Dioxide are the
main three gases used in GMAW
Properties of GasesProperties of Gases
Affect the performance of the welding process include
1) Thermal properties at elevated temperatures 2) Chemical reaction of the gas with the various
elements in the base plate and welding wire 3) Effect of each gas on the mode of metal
transfer
Types of shielding gasesTypes of shielding gases
Inert Gas
1 Argon
2 Helium
3 Ar + HeActive Gas
1 Carbon Dioxide
2 Inert gas + any type of active gas
Argon is an inert gas which is used both singularly and in combination with other gases to achieve desired arc characteristics for the welding of both ferrous and non-ferrous metals
Carbon Dioxide Pure carbon dioxide is not an inert gas because the heat of the arc breaks down the CO2 into carbon monoxide and free oxygen This oxygen will combine with elements transferring across the arc to form oxides which are released from the weld puddle in the form of slag and scale
Helium is an inert gas which is used on weld applications requiring higher heat input for improved bead wetting deeper penetration and higher travel speed In GMAW it does not produce as stable an arc as argon Compared to argon helium has a higher thermal conductivity and voltage gradient
FLOW METER
CYLCINDERPRESSUREGAUGE
CFH PRESSURE ADJUSTMENT KNOB
Filler WireFiller Wire
Wire ChemistriesWire Chemistries
GMAW Operation techniquesGMAW Operation techniques
To setting WFS (Wire Feed Speed)
Voltage-bead ChangeVoltage-bead Change
Electrode Stick-outElectrode Stick-out
ESO SettingESO Setting
EOSEOS
Gun angles and techniquesGun angles and techniques
Direction of TravelDirection of Travel
THANK YOU
AdvantagesAdvantages
High deposition rates High electrode efficiency of 98 or more Employs a wide range of filler metal types in an
equally wide range of electrode diameters Excellent weld bead appearance High operator appeal and ease of use Requires little post weld cleanup Absence of weld spatter Excellent weld fusion Lends itself to semiautomatic robotic and hard
automation applications
LimitationsLimitations
Restricted to the flat and horizontal welding positions
Welding fume generation is higher The higher-radiated heat and the generation of a
very bright arc require extra welder and bystander protection
The use of axial spray transfer outdoors requires the use of a windscreen(s)
The shielding used to support axial spray transfer costs more than 100 CO2
Pulse Spray Transfer Pulse Spray Transfer
GMAW-P was developed for two demanding reasons control of weld spatter and the elimination of incomplete fusion defects common to globular and short-circuiting transfer
The welding current alternates between a peak current and a lower background current
This faster-freezing weld puddle is what allows the pulsed-spray transfer to be used fort thinner metals
better control on out-of-position work allows for larger wire sizes to be used on varied metal
thicknesses
In pulse spray transfer (GMAW-P) the welding power sourcersquos pulse control pulses the welding output withhigh peak currents (amperage) which are set at levels which will cause the transfer to go into a spray The background current (amperage) is set at a level that will maintain the arcbut is too low for any metal transfer to occur
Pulsed arc transferPulsed arc transfer
AdvantagesAdvantages Absent or very low levels of spatter More resistant to lack of fusion defects than other modes of
GMAW metal transfer Excellent weld bead appearance and offers an engineered
solution for the control of weld fume generation Reduced levels of heat induced distortion and tendency for arc
blow Ability to weld out-of-position and handles poor fit-up When compared to FCAW SMAW and GMAW-S pulsed
spray transfer provides a low cost high-electrode efficiency of 98
Lends itself to robotic and hard automation applications Is combined for use with Tandem GMAW or other multiple arc
scenarios Capable of arc travel speeds greater than 50 inches per minute
(12 Mmin)
LimitationsLimitationsEquipment to support the process is more
expensive than traditional systemsBlends of argon based shielding gas are
more expensive than carbon dioxideHigher arc energy requires the use of
additional safety protection for welders and bystanders
Adds complexity to weldingRequires the use of windscreens outdoors
Manual GMAW EquipmentManual GMAW Equipment
Three major elements are
1) Welding torch and accessories
2) Welding control amp Wire feed motor
3) Power Source
GMAW equipment can be used either manually or automatically
GMAW Schematic DiagramGMAW Schematic Diagram
WIRE CONTROLamp
WIRE FEED MOTOR
POWER SOURCE
Welding Torch amp AccessoriesWelding Torch amp Accessories
The welding torch guides the wire and shielding gas to the weld zone
Brings welding power to the wire alsoMajor componentsparts of the torch are the
contact tip shielding gas nozzle gas diffuser and the wire conduit
Others types of torchOthers types of torch
TRIGGER
INSTALLED
COMPONENTS
NOZZLE
CONTACT TIP
GAS DIFFUSER
Welding Control amp Wire Welding Control amp Wire Feed MotorFeed Motor
Welding control amp Wire feed motor are combined into one unit
Main function is to pull the wire from the spool and feed it to the arc
Controls wire feed speed and regulates the starting and stopping of wire feed
Wire feed speed controls Amperage
Types of Wire Feed MotorTypes of Wire Feed Motor
Types of WFM RollerTypes of WFM Roller
Types of Wire FeederTypes of Wire Feeder
WIRE FEEDER
Power SourcePower Source
Almost all GMAW is done with reverse polarity also known as DCEP
Positive (+) lead is connected to the torchNegative (-) lead is connected to the work
pieceProvides a relatively consistent voltage to the
arcArc Voltage is the voltage between the end of
the wire and the work piece
Contact Tip To Work DistanceContact Tip To Work Distance
In constant current the CTWD (contact tip to work distance) determines the arc length
As the CTWD increases the arc length increases and as the
CTWD decreases the arc length decreases This presented a
problem for semiautomatic welding because it is difficult to
maintain the same CTWD To compensate for this problem an arc voltage controlled wire
Constant voltage power source designs provide a specific arc voltage for a given pre-selected wire feed speed The volt-amp curve or slope is comparatively flat As the CTWD increases with these types of power sources there is a decrease in the welding current As the CTWD decreases there is an increase in the welding current The arc in this case becomes a series circuit and the CTWD provides resistance to current In either scenario the voltage remains the same and the arc length remains the same
POSITIVETERMINAL
NEGATIVETERMINAL
Shielding GasesShielding Gases
Purpose of shielding gas is the protect the weld area from the contaminants in the atmosphere
Gas can be Inert Reactive or Mixtures of both
Gas flow rate is between 25-35 CFHArgon Helium and Carbon Dioxide are the
main three gases used in GMAW
Properties of GasesProperties of Gases
Affect the performance of the welding process include
1) Thermal properties at elevated temperatures 2) Chemical reaction of the gas with the various
elements in the base plate and welding wire 3) Effect of each gas on the mode of metal
transfer
Types of shielding gasesTypes of shielding gases
Inert Gas
1 Argon
2 Helium
3 Ar + HeActive Gas
1 Carbon Dioxide
2 Inert gas + any type of active gas
Argon is an inert gas which is used both singularly and in combination with other gases to achieve desired arc characteristics for the welding of both ferrous and non-ferrous metals
Carbon Dioxide Pure carbon dioxide is not an inert gas because the heat of the arc breaks down the CO2 into carbon monoxide and free oxygen This oxygen will combine with elements transferring across the arc to form oxides which are released from the weld puddle in the form of slag and scale
Helium is an inert gas which is used on weld applications requiring higher heat input for improved bead wetting deeper penetration and higher travel speed In GMAW it does not produce as stable an arc as argon Compared to argon helium has a higher thermal conductivity and voltage gradient
FLOW METER
CYLCINDERPRESSUREGAUGE
CFH PRESSURE ADJUSTMENT KNOB
Filler WireFiller Wire
Wire ChemistriesWire Chemistries
GMAW Operation techniquesGMAW Operation techniques
To setting WFS (Wire Feed Speed)
Voltage-bead ChangeVoltage-bead Change
Electrode Stick-outElectrode Stick-out
ESO SettingESO Setting
EOSEOS
Gun angles and techniquesGun angles and techniques
Direction of TravelDirection of Travel
THANK YOU
LimitationsLimitations
Restricted to the flat and horizontal welding positions
Welding fume generation is higher The higher-radiated heat and the generation of a
very bright arc require extra welder and bystander protection
The use of axial spray transfer outdoors requires the use of a windscreen(s)
The shielding used to support axial spray transfer costs more than 100 CO2
Pulse Spray Transfer Pulse Spray Transfer
GMAW-P was developed for two demanding reasons control of weld spatter and the elimination of incomplete fusion defects common to globular and short-circuiting transfer
The welding current alternates between a peak current and a lower background current
This faster-freezing weld puddle is what allows the pulsed-spray transfer to be used fort thinner metals
better control on out-of-position work allows for larger wire sizes to be used on varied metal
thicknesses
In pulse spray transfer (GMAW-P) the welding power sourcersquos pulse control pulses the welding output withhigh peak currents (amperage) which are set at levels which will cause the transfer to go into a spray The background current (amperage) is set at a level that will maintain the arcbut is too low for any metal transfer to occur
Pulsed arc transferPulsed arc transfer
AdvantagesAdvantages Absent or very low levels of spatter More resistant to lack of fusion defects than other modes of
GMAW metal transfer Excellent weld bead appearance and offers an engineered
solution for the control of weld fume generation Reduced levels of heat induced distortion and tendency for arc
blow Ability to weld out-of-position and handles poor fit-up When compared to FCAW SMAW and GMAW-S pulsed
spray transfer provides a low cost high-electrode efficiency of 98
Lends itself to robotic and hard automation applications Is combined for use with Tandem GMAW or other multiple arc
scenarios Capable of arc travel speeds greater than 50 inches per minute
(12 Mmin)
LimitationsLimitationsEquipment to support the process is more
expensive than traditional systemsBlends of argon based shielding gas are
more expensive than carbon dioxideHigher arc energy requires the use of
additional safety protection for welders and bystanders
Adds complexity to weldingRequires the use of windscreens outdoors
Manual GMAW EquipmentManual GMAW Equipment
Three major elements are
1) Welding torch and accessories
2) Welding control amp Wire feed motor
3) Power Source
GMAW equipment can be used either manually or automatically
GMAW Schematic DiagramGMAW Schematic Diagram
WIRE CONTROLamp
WIRE FEED MOTOR
POWER SOURCE
Welding Torch amp AccessoriesWelding Torch amp Accessories
The welding torch guides the wire and shielding gas to the weld zone
Brings welding power to the wire alsoMajor componentsparts of the torch are the
contact tip shielding gas nozzle gas diffuser and the wire conduit
Others types of torchOthers types of torch
TRIGGER
INSTALLED
COMPONENTS
NOZZLE
CONTACT TIP
GAS DIFFUSER
Welding Control amp Wire Welding Control amp Wire Feed MotorFeed Motor
Welding control amp Wire feed motor are combined into one unit
Main function is to pull the wire from the spool and feed it to the arc
Controls wire feed speed and regulates the starting and stopping of wire feed
Wire feed speed controls Amperage
Types of Wire Feed MotorTypes of Wire Feed Motor
Types of WFM RollerTypes of WFM Roller
Types of Wire FeederTypes of Wire Feeder
WIRE FEEDER
Power SourcePower Source
Almost all GMAW is done with reverse polarity also known as DCEP
Positive (+) lead is connected to the torchNegative (-) lead is connected to the work
pieceProvides a relatively consistent voltage to the
arcArc Voltage is the voltage between the end of
the wire and the work piece
Contact Tip To Work DistanceContact Tip To Work Distance
In constant current the CTWD (contact tip to work distance) determines the arc length
As the CTWD increases the arc length increases and as the
CTWD decreases the arc length decreases This presented a
problem for semiautomatic welding because it is difficult to
maintain the same CTWD To compensate for this problem an arc voltage controlled wire
Constant voltage power source designs provide a specific arc voltage for a given pre-selected wire feed speed The volt-amp curve or slope is comparatively flat As the CTWD increases with these types of power sources there is a decrease in the welding current As the CTWD decreases there is an increase in the welding current The arc in this case becomes a series circuit and the CTWD provides resistance to current In either scenario the voltage remains the same and the arc length remains the same
POSITIVETERMINAL
NEGATIVETERMINAL
Shielding GasesShielding Gases
Purpose of shielding gas is the protect the weld area from the contaminants in the atmosphere
Gas can be Inert Reactive or Mixtures of both
Gas flow rate is between 25-35 CFHArgon Helium and Carbon Dioxide are the
main three gases used in GMAW
Properties of GasesProperties of Gases
Affect the performance of the welding process include
1) Thermal properties at elevated temperatures 2) Chemical reaction of the gas with the various
elements in the base plate and welding wire 3) Effect of each gas on the mode of metal
transfer
Types of shielding gasesTypes of shielding gases
Inert Gas
1 Argon
2 Helium
3 Ar + HeActive Gas
1 Carbon Dioxide
2 Inert gas + any type of active gas
Argon is an inert gas which is used both singularly and in combination with other gases to achieve desired arc characteristics for the welding of both ferrous and non-ferrous metals
Carbon Dioxide Pure carbon dioxide is not an inert gas because the heat of the arc breaks down the CO2 into carbon monoxide and free oxygen This oxygen will combine with elements transferring across the arc to form oxides which are released from the weld puddle in the form of slag and scale
Helium is an inert gas which is used on weld applications requiring higher heat input for improved bead wetting deeper penetration and higher travel speed In GMAW it does not produce as stable an arc as argon Compared to argon helium has a higher thermal conductivity and voltage gradient
FLOW METER
CYLCINDERPRESSUREGAUGE
CFH PRESSURE ADJUSTMENT KNOB
Filler WireFiller Wire
Wire ChemistriesWire Chemistries
GMAW Operation techniquesGMAW Operation techniques
To setting WFS (Wire Feed Speed)
Voltage-bead ChangeVoltage-bead Change
Electrode Stick-outElectrode Stick-out
ESO SettingESO Setting
EOSEOS
Gun angles and techniquesGun angles and techniques
Direction of TravelDirection of Travel
THANK YOU
Pulse Spray Transfer Pulse Spray Transfer
GMAW-P was developed for two demanding reasons control of weld spatter and the elimination of incomplete fusion defects common to globular and short-circuiting transfer
The welding current alternates between a peak current and a lower background current
This faster-freezing weld puddle is what allows the pulsed-spray transfer to be used fort thinner metals
better control on out-of-position work allows for larger wire sizes to be used on varied metal
thicknesses
In pulse spray transfer (GMAW-P) the welding power sourcersquos pulse control pulses the welding output withhigh peak currents (amperage) which are set at levels which will cause the transfer to go into a spray The background current (amperage) is set at a level that will maintain the arcbut is too low for any metal transfer to occur
Pulsed arc transferPulsed arc transfer
AdvantagesAdvantages Absent or very low levels of spatter More resistant to lack of fusion defects than other modes of
GMAW metal transfer Excellent weld bead appearance and offers an engineered
solution for the control of weld fume generation Reduced levels of heat induced distortion and tendency for arc
blow Ability to weld out-of-position and handles poor fit-up When compared to FCAW SMAW and GMAW-S pulsed
spray transfer provides a low cost high-electrode efficiency of 98
Lends itself to robotic and hard automation applications Is combined for use with Tandem GMAW or other multiple arc
scenarios Capable of arc travel speeds greater than 50 inches per minute
(12 Mmin)
LimitationsLimitationsEquipment to support the process is more
expensive than traditional systemsBlends of argon based shielding gas are
more expensive than carbon dioxideHigher arc energy requires the use of
additional safety protection for welders and bystanders
Adds complexity to weldingRequires the use of windscreens outdoors
Manual GMAW EquipmentManual GMAW Equipment
Three major elements are
1) Welding torch and accessories
2) Welding control amp Wire feed motor
3) Power Source
GMAW equipment can be used either manually or automatically
GMAW Schematic DiagramGMAW Schematic Diagram
WIRE CONTROLamp
WIRE FEED MOTOR
POWER SOURCE
Welding Torch amp AccessoriesWelding Torch amp Accessories
The welding torch guides the wire and shielding gas to the weld zone
Brings welding power to the wire alsoMajor componentsparts of the torch are the
contact tip shielding gas nozzle gas diffuser and the wire conduit
Others types of torchOthers types of torch
TRIGGER
INSTALLED
COMPONENTS
NOZZLE
CONTACT TIP
GAS DIFFUSER
Welding Control amp Wire Welding Control amp Wire Feed MotorFeed Motor
Welding control amp Wire feed motor are combined into one unit
Main function is to pull the wire from the spool and feed it to the arc
Controls wire feed speed and regulates the starting and stopping of wire feed
Wire feed speed controls Amperage
Types of Wire Feed MotorTypes of Wire Feed Motor
Types of WFM RollerTypes of WFM Roller
Types of Wire FeederTypes of Wire Feeder
WIRE FEEDER
Power SourcePower Source
Almost all GMAW is done with reverse polarity also known as DCEP
Positive (+) lead is connected to the torchNegative (-) lead is connected to the work
pieceProvides a relatively consistent voltage to the
arcArc Voltage is the voltage between the end of
the wire and the work piece
Contact Tip To Work DistanceContact Tip To Work Distance
In constant current the CTWD (contact tip to work distance) determines the arc length
As the CTWD increases the arc length increases and as the
CTWD decreases the arc length decreases This presented a
problem for semiautomatic welding because it is difficult to
maintain the same CTWD To compensate for this problem an arc voltage controlled wire
Constant voltage power source designs provide a specific arc voltage for a given pre-selected wire feed speed The volt-amp curve or slope is comparatively flat As the CTWD increases with these types of power sources there is a decrease in the welding current As the CTWD decreases there is an increase in the welding current The arc in this case becomes a series circuit and the CTWD provides resistance to current In either scenario the voltage remains the same and the arc length remains the same
POSITIVETERMINAL
NEGATIVETERMINAL
Shielding GasesShielding Gases
Purpose of shielding gas is the protect the weld area from the contaminants in the atmosphere
Gas can be Inert Reactive or Mixtures of both
Gas flow rate is between 25-35 CFHArgon Helium and Carbon Dioxide are the
main three gases used in GMAW
Properties of GasesProperties of Gases
Affect the performance of the welding process include
1) Thermal properties at elevated temperatures 2) Chemical reaction of the gas with the various
elements in the base plate and welding wire 3) Effect of each gas on the mode of metal
transfer
Types of shielding gasesTypes of shielding gases
Inert Gas
1 Argon
2 Helium
3 Ar + HeActive Gas
1 Carbon Dioxide
2 Inert gas + any type of active gas
Argon is an inert gas which is used both singularly and in combination with other gases to achieve desired arc characteristics for the welding of both ferrous and non-ferrous metals
Carbon Dioxide Pure carbon dioxide is not an inert gas because the heat of the arc breaks down the CO2 into carbon monoxide and free oxygen This oxygen will combine with elements transferring across the arc to form oxides which are released from the weld puddle in the form of slag and scale
Helium is an inert gas which is used on weld applications requiring higher heat input for improved bead wetting deeper penetration and higher travel speed In GMAW it does not produce as stable an arc as argon Compared to argon helium has a higher thermal conductivity and voltage gradient
FLOW METER
CYLCINDERPRESSUREGAUGE
CFH PRESSURE ADJUSTMENT KNOB
Filler WireFiller Wire
Wire ChemistriesWire Chemistries
GMAW Operation techniquesGMAW Operation techniques
To setting WFS (Wire Feed Speed)
Voltage-bead ChangeVoltage-bead Change
Electrode Stick-outElectrode Stick-out
ESO SettingESO Setting
EOSEOS
Gun angles and techniquesGun angles and techniques
Direction of TravelDirection of Travel
THANK YOU
In pulse spray transfer (GMAW-P) the welding power sourcersquos pulse control pulses the welding output withhigh peak currents (amperage) which are set at levels which will cause the transfer to go into a spray The background current (amperage) is set at a level that will maintain the arcbut is too low for any metal transfer to occur
Pulsed arc transferPulsed arc transfer
AdvantagesAdvantages Absent or very low levels of spatter More resistant to lack of fusion defects than other modes of
GMAW metal transfer Excellent weld bead appearance and offers an engineered
solution for the control of weld fume generation Reduced levels of heat induced distortion and tendency for arc
blow Ability to weld out-of-position and handles poor fit-up When compared to FCAW SMAW and GMAW-S pulsed
spray transfer provides a low cost high-electrode efficiency of 98
Lends itself to robotic and hard automation applications Is combined for use with Tandem GMAW or other multiple arc
scenarios Capable of arc travel speeds greater than 50 inches per minute
(12 Mmin)
LimitationsLimitationsEquipment to support the process is more
expensive than traditional systemsBlends of argon based shielding gas are
more expensive than carbon dioxideHigher arc energy requires the use of
additional safety protection for welders and bystanders
Adds complexity to weldingRequires the use of windscreens outdoors
Manual GMAW EquipmentManual GMAW Equipment
Three major elements are
1) Welding torch and accessories
2) Welding control amp Wire feed motor
3) Power Source
GMAW equipment can be used either manually or automatically
GMAW Schematic DiagramGMAW Schematic Diagram
WIRE CONTROLamp
WIRE FEED MOTOR
POWER SOURCE
Welding Torch amp AccessoriesWelding Torch amp Accessories
The welding torch guides the wire and shielding gas to the weld zone
Brings welding power to the wire alsoMajor componentsparts of the torch are the
contact tip shielding gas nozzle gas diffuser and the wire conduit
Others types of torchOthers types of torch
TRIGGER
INSTALLED
COMPONENTS
NOZZLE
CONTACT TIP
GAS DIFFUSER
Welding Control amp Wire Welding Control amp Wire Feed MotorFeed Motor
Welding control amp Wire feed motor are combined into one unit
Main function is to pull the wire from the spool and feed it to the arc
Controls wire feed speed and regulates the starting and stopping of wire feed
Wire feed speed controls Amperage
Types of Wire Feed MotorTypes of Wire Feed Motor
Types of WFM RollerTypes of WFM Roller
Types of Wire FeederTypes of Wire Feeder
WIRE FEEDER
Power SourcePower Source
Almost all GMAW is done with reverse polarity also known as DCEP
Positive (+) lead is connected to the torchNegative (-) lead is connected to the work
pieceProvides a relatively consistent voltage to the
arcArc Voltage is the voltage between the end of
the wire and the work piece
Contact Tip To Work DistanceContact Tip To Work Distance
In constant current the CTWD (contact tip to work distance) determines the arc length
As the CTWD increases the arc length increases and as the
CTWD decreases the arc length decreases This presented a
problem for semiautomatic welding because it is difficult to
maintain the same CTWD To compensate for this problem an arc voltage controlled wire
Constant voltage power source designs provide a specific arc voltage for a given pre-selected wire feed speed The volt-amp curve or slope is comparatively flat As the CTWD increases with these types of power sources there is a decrease in the welding current As the CTWD decreases there is an increase in the welding current The arc in this case becomes a series circuit and the CTWD provides resistance to current In either scenario the voltage remains the same and the arc length remains the same
POSITIVETERMINAL
NEGATIVETERMINAL
Shielding GasesShielding Gases
Purpose of shielding gas is the protect the weld area from the contaminants in the atmosphere
Gas can be Inert Reactive or Mixtures of both
Gas flow rate is between 25-35 CFHArgon Helium and Carbon Dioxide are the
main three gases used in GMAW
Properties of GasesProperties of Gases
Affect the performance of the welding process include
1) Thermal properties at elevated temperatures 2) Chemical reaction of the gas with the various
elements in the base plate and welding wire 3) Effect of each gas on the mode of metal
transfer
Types of shielding gasesTypes of shielding gases
Inert Gas
1 Argon
2 Helium
3 Ar + HeActive Gas
1 Carbon Dioxide
2 Inert gas + any type of active gas
Argon is an inert gas which is used both singularly and in combination with other gases to achieve desired arc characteristics for the welding of both ferrous and non-ferrous metals
Carbon Dioxide Pure carbon dioxide is not an inert gas because the heat of the arc breaks down the CO2 into carbon monoxide and free oxygen This oxygen will combine with elements transferring across the arc to form oxides which are released from the weld puddle in the form of slag and scale
Helium is an inert gas which is used on weld applications requiring higher heat input for improved bead wetting deeper penetration and higher travel speed In GMAW it does not produce as stable an arc as argon Compared to argon helium has a higher thermal conductivity and voltage gradient
FLOW METER
CYLCINDERPRESSUREGAUGE
CFH PRESSURE ADJUSTMENT KNOB
Filler WireFiller Wire
Wire ChemistriesWire Chemistries
GMAW Operation techniquesGMAW Operation techniques
To setting WFS (Wire Feed Speed)
Voltage-bead ChangeVoltage-bead Change
Electrode Stick-outElectrode Stick-out
ESO SettingESO Setting
EOSEOS
Gun angles and techniquesGun angles and techniques
Direction of TravelDirection of Travel
THANK YOU
Pulsed arc transferPulsed arc transfer
AdvantagesAdvantages Absent or very low levels of spatter More resistant to lack of fusion defects than other modes of
GMAW metal transfer Excellent weld bead appearance and offers an engineered
solution for the control of weld fume generation Reduced levels of heat induced distortion and tendency for arc
blow Ability to weld out-of-position and handles poor fit-up When compared to FCAW SMAW and GMAW-S pulsed
spray transfer provides a low cost high-electrode efficiency of 98
Lends itself to robotic and hard automation applications Is combined for use with Tandem GMAW or other multiple arc
scenarios Capable of arc travel speeds greater than 50 inches per minute
(12 Mmin)
LimitationsLimitationsEquipment to support the process is more
expensive than traditional systemsBlends of argon based shielding gas are
more expensive than carbon dioxideHigher arc energy requires the use of
additional safety protection for welders and bystanders
Adds complexity to weldingRequires the use of windscreens outdoors
Manual GMAW EquipmentManual GMAW Equipment
Three major elements are
1) Welding torch and accessories
2) Welding control amp Wire feed motor
3) Power Source
GMAW equipment can be used either manually or automatically
GMAW Schematic DiagramGMAW Schematic Diagram
WIRE CONTROLamp
WIRE FEED MOTOR
POWER SOURCE
Welding Torch amp AccessoriesWelding Torch amp Accessories
The welding torch guides the wire and shielding gas to the weld zone
Brings welding power to the wire alsoMajor componentsparts of the torch are the
contact tip shielding gas nozzle gas diffuser and the wire conduit
Others types of torchOthers types of torch
TRIGGER
INSTALLED
COMPONENTS
NOZZLE
CONTACT TIP
GAS DIFFUSER
Welding Control amp Wire Welding Control amp Wire Feed MotorFeed Motor
Welding control amp Wire feed motor are combined into one unit
Main function is to pull the wire from the spool and feed it to the arc
Controls wire feed speed and regulates the starting and stopping of wire feed
Wire feed speed controls Amperage
Types of Wire Feed MotorTypes of Wire Feed Motor
Types of WFM RollerTypes of WFM Roller
Types of Wire FeederTypes of Wire Feeder
WIRE FEEDER
Power SourcePower Source
Almost all GMAW is done with reverse polarity also known as DCEP
Positive (+) lead is connected to the torchNegative (-) lead is connected to the work
pieceProvides a relatively consistent voltage to the
arcArc Voltage is the voltage between the end of
the wire and the work piece
Contact Tip To Work DistanceContact Tip To Work Distance
In constant current the CTWD (contact tip to work distance) determines the arc length
As the CTWD increases the arc length increases and as the
CTWD decreases the arc length decreases This presented a
problem for semiautomatic welding because it is difficult to
maintain the same CTWD To compensate for this problem an arc voltage controlled wire
Constant voltage power source designs provide a specific arc voltage for a given pre-selected wire feed speed The volt-amp curve or slope is comparatively flat As the CTWD increases with these types of power sources there is a decrease in the welding current As the CTWD decreases there is an increase in the welding current The arc in this case becomes a series circuit and the CTWD provides resistance to current In either scenario the voltage remains the same and the arc length remains the same
POSITIVETERMINAL
NEGATIVETERMINAL
Shielding GasesShielding Gases
Purpose of shielding gas is the protect the weld area from the contaminants in the atmosphere
Gas can be Inert Reactive or Mixtures of both
Gas flow rate is between 25-35 CFHArgon Helium and Carbon Dioxide are the
main three gases used in GMAW
Properties of GasesProperties of Gases
Affect the performance of the welding process include
1) Thermal properties at elevated temperatures 2) Chemical reaction of the gas with the various
elements in the base plate and welding wire 3) Effect of each gas on the mode of metal
transfer
Types of shielding gasesTypes of shielding gases
Inert Gas
1 Argon
2 Helium
3 Ar + HeActive Gas
1 Carbon Dioxide
2 Inert gas + any type of active gas
Argon is an inert gas which is used both singularly and in combination with other gases to achieve desired arc characteristics for the welding of both ferrous and non-ferrous metals
Carbon Dioxide Pure carbon dioxide is not an inert gas because the heat of the arc breaks down the CO2 into carbon monoxide and free oxygen This oxygen will combine with elements transferring across the arc to form oxides which are released from the weld puddle in the form of slag and scale
Helium is an inert gas which is used on weld applications requiring higher heat input for improved bead wetting deeper penetration and higher travel speed In GMAW it does not produce as stable an arc as argon Compared to argon helium has a higher thermal conductivity and voltage gradient
FLOW METER
CYLCINDERPRESSUREGAUGE
CFH PRESSURE ADJUSTMENT KNOB
Filler WireFiller Wire
Wire ChemistriesWire Chemistries
GMAW Operation techniquesGMAW Operation techniques
To setting WFS (Wire Feed Speed)
Voltage-bead ChangeVoltage-bead Change
Electrode Stick-outElectrode Stick-out
ESO SettingESO Setting
EOSEOS
Gun angles and techniquesGun angles and techniques
Direction of TravelDirection of Travel
THANK YOU
AdvantagesAdvantages Absent or very low levels of spatter More resistant to lack of fusion defects than other modes of
GMAW metal transfer Excellent weld bead appearance and offers an engineered
solution for the control of weld fume generation Reduced levels of heat induced distortion and tendency for arc
blow Ability to weld out-of-position and handles poor fit-up When compared to FCAW SMAW and GMAW-S pulsed
spray transfer provides a low cost high-electrode efficiency of 98
Lends itself to robotic and hard automation applications Is combined for use with Tandem GMAW or other multiple arc
scenarios Capable of arc travel speeds greater than 50 inches per minute
(12 Mmin)
LimitationsLimitationsEquipment to support the process is more
expensive than traditional systemsBlends of argon based shielding gas are
more expensive than carbon dioxideHigher arc energy requires the use of
additional safety protection for welders and bystanders
Adds complexity to weldingRequires the use of windscreens outdoors
Manual GMAW EquipmentManual GMAW Equipment
Three major elements are
1) Welding torch and accessories
2) Welding control amp Wire feed motor
3) Power Source
GMAW equipment can be used either manually or automatically
GMAW Schematic DiagramGMAW Schematic Diagram
WIRE CONTROLamp
WIRE FEED MOTOR
POWER SOURCE
Welding Torch amp AccessoriesWelding Torch amp Accessories
The welding torch guides the wire and shielding gas to the weld zone
Brings welding power to the wire alsoMajor componentsparts of the torch are the
contact tip shielding gas nozzle gas diffuser and the wire conduit
Others types of torchOthers types of torch
TRIGGER
INSTALLED
COMPONENTS
NOZZLE
CONTACT TIP
GAS DIFFUSER
Welding Control amp Wire Welding Control amp Wire Feed MotorFeed Motor
Welding control amp Wire feed motor are combined into one unit
Main function is to pull the wire from the spool and feed it to the arc
Controls wire feed speed and regulates the starting and stopping of wire feed
Wire feed speed controls Amperage
Types of Wire Feed MotorTypes of Wire Feed Motor
Types of WFM RollerTypes of WFM Roller
Types of Wire FeederTypes of Wire Feeder
WIRE FEEDER
Power SourcePower Source
Almost all GMAW is done with reverse polarity also known as DCEP
Positive (+) lead is connected to the torchNegative (-) lead is connected to the work
pieceProvides a relatively consistent voltage to the
arcArc Voltage is the voltage between the end of
the wire and the work piece
Contact Tip To Work DistanceContact Tip To Work Distance
In constant current the CTWD (contact tip to work distance) determines the arc length
As the CTWD increases the arc length increases and as the
CTWD decreases the arc length decreases This presented a
problem for semiautomatic welding because it is difficult to
maintain the same CTWD To compensate for this problem an arc voltage controlled wire
Constant voltage power source designs provide a specific arc voltage for a given pre-selected wire feed speed The volt-amp curve or slope is comparatively flat As the CTWD increases with these types of power sources there is a decrease in the welding current As the CTWD decreases there is an increase in the welding current The arc in this case becomes a series circuit and the CTWD provides resistance to current In either scenario the voltage remains the same and the arc length remains the same
POSITIVETERMINAL
NEGATIVETERMINAL
Shielding GasesShielding Gases
Purpose of shielding gas is the protect the weld area from the contaminants in the atmosphere
Gas can be Inert Reactive or Mixtures of both
Gas flow rate is between 25-35 CFHArgon Helium and Carbon Dioxide are the
main three gases used in GMAW
Properties of GasesProperties of Gases
Affect the performance of the welding process include
1) Thermal properties at elevated temperatures 2) Chemical reaction of the gas with the various
elements in the base plate and welding wire 3) Effect of each gas on the mode of metal
transfer
Types of shielding gasesTypes of shielding gases
Inert Gas
1 Argon
2 Helium
3 Ar + HeActive Gas
1 Carbon Dioxide
2 Inert gas + any type of active gas
Argon is an inert gas which is used both singularly and in combination with other gases to achieve desired arc characteristics for the welding of both ferrous and non-ferrous metals
Carbon Dioxide Pure carbon dioxide is not an inert gas because the heat of the arc breaks down the CO2 into carbon monoxide and free oxygen This oxygen will combine with elements transferring across the arc to form oxides which are released from the weld puddle in the form of slag and scale
Helium is an inert gas which is used on weld applications requiring higher heat input for improved bead wetting deeper penetration and higher travel speed In GMAW it does not produce as stable an arc as argon Compared to argon helium has a higher thermal conductivity and voltage gradient
FLOW METER
CYLCINDERPRESSUREGAUGE
CFH PRESSURE ADJUSTMENT KNOB
Filler WireFiller Wire
Wire ChemistriesWire Chemistries
GMAW Operation techniquesGMAW Operation techniques
To setting WFS (Wire Feed Speed)
Voltage-bead ChangeVoltage-bead Change
Electrode Stick-outElectrode Stick-out
ESO SettingESO Setting
EOSEOS
Gun angles and techniquesGun angles and techniques
Direction of TravelDirection of Travel
THANK YOU
LimitationsLimitationsEquipment to support the process is more
expensive than traditional systemsBlends of argon based shielding gas are
more expensive than carbon dioxideHigher arc energy requires the use of
additional safety protection for welders and bystanders
Adds complexity to weldingRequires the use of windscreens outdoors
Manual GMAW EquipmentManual GMAW Equipment
Three major elements are
1) Welding torch and accessories
2) Welding control amp Wire feed motor
3) Power Source
GMAW equipment can be used either manually or automatically
GMAW Schematic DiagramGMAW Schematic Diagram
WIRE CONTROLamp
WIRE FEED MOTOR
POWER SOURCE
Welding Torch amp AccessoriesWelding Torch amp Accessories
The welding torch guides the wire and shielding gas to the weld zone
Brings welding power to the wire alsoMajor componentsparts of the torch are the
contact tip shielding gas nozzle gas diffuser and the wire conduit
Others types of torchOthers types of torch
TRIGGER
INSTALLED
COMPONENTS
NOZZLE
CONTACT TIP
GAS DIFFUSER
Welding Control amp Wire Welding Control amp Wire Feed MotorFeed Motor
Welding control amp Wire feed motor are combined into one unit
Main function is to pull the wire from the spool and feed it to the arc
Controls wire feed speed and regulates the starting and stopping of wire feed
Wire feed speed controls Amperage
Types of Wire Feed MotorTypes of Wire Feed Motor
Types of WFM RollerTypes of WFM Roller
Types of Wire FeederTypes of Wire Feeder
WIRE FEEDER
Power SourcePower Source
Almost all GMAW is done with reverse polarity also known as DCEP
Positive (+) lead is connected to the torchNegative (-) lead is connected to the work
pieceProvides a relatively consistent voltage to the
arcArc Voltage is the voltage between the end of
the wire and the work piece
Contact Tip To Work DistanceContact Tip To Work Distance
In constant current the CTWD (contact tip to work distance) determines the arc length
As the CTWD increases the arc length increases and as the
CTWD decreases the arc length decreases This presented a
problem for semiautomatic welding because it is difficult to
maintain the same CTWD To compensate for this problem an arc voltage controlled wire
Constant voltage power source designs provide a specific arc voltage for a given pre-selected wire feed speed The volt-amp curve or slope is comparatively flat As the CTWD increases with these types of power sources there is a decrease in the welding current As the CTWD decreases there is an increase in the welding current The arc in this case becomes a series circuit and the CTWD provides resistance to current In either scenario the voltage remains the same and the arc length remains the same
POSITIVETERMINAL
NEGATIVETERMINAL
Shielding GasesShielding Gases
Purpose of shielding gas is the protect the weld area from the contaminants in the atmosphere
Gas can be Inert Reactive or Mixtures of both
Gas flow rate is between 25-35 CFHArgon Helium and Carbon Dioxide are the
main three gases used in GMAW
Properties of GasesProperties of Gases
Affect the performance of the welding process include
1) Thermal properties at elevated temperatures 2) Chemical reaction of the gas with the various
elements in the base plate and welding wire 3) Effect of each gas on the mode of metal
transfer
Types of shielding gasesTypes of shielding gases
Inert Gas
1 Argon
2 Helium
3 Ar + HeActive Gas
1 Carbon Dioxide
2 Inert gas + any type of active gas
Argon is an inert gas which is used both singularly and in combination with other gases to achieve desired arc characteristics for the welding of both ferrous and non-ferrous metals
Carbon Dioxide Pure carbon dioxide is not an inert gas because the heat of the arc breaks down the CO2 into carbon monoxide and free oxygen This oxygen will combine with elements transferring across the arc to form oxides which are released from the weld puddle in the form of slag and scale
Helium is an inert gas which is used on weld applications requiring higher heat input for improved bead wetting deeper penetration and higher travel speed In GMAW it does not produce as stable an arc as argon Compared to argon helium has a higher thermal conductivity and voltage gradient
FLOW METER
CYLCINDERPRESSUREGAUGE
CFH PRESSURE ADJUSTMENT KNOB
Filler WireFiller Wire
Wire ChemistriesWire Chemistries
GMAW Operation techniquesGMAW Operation techniques
To setting WFS (Wire Feed Speed)
Voltage-bead ChangeVoltage-bead Change
Electrode Stick-outElectrode Stick-out
ESO SettingESO Setting
EOSEOS
Gun angles and techniquesGun angles and techniques
Direction of TravelDirection of Travel
THANK YOU
Manual GMAW EquipmentManual GMAW Equipment
Three major elements are
1) Welding torch and accessories
2) Welding control amp Wire feed motor
3) Power Source
GMAW equipment can be used either manually or automatically
GMAW Schematic DiagramGMAW Schematic Diagram
WIRE CONTROLamp
WIRE FEED MOTOR
POWER SOURCE
Welding Torch amp AccessoriesWelding Torch amp Accessories
The welding torch guides the wire and shielding gas to the weld zone
Brings welding power to the wire alsoMajor componentsparts of the torch are the
contact tip shielding gas nozzle gas diffuser and the wire conduit
Others types of torchOthers types of torch
TRIGGER
INSTALLED
COMPONENTS
NOZZLE
CONTACT TIP
GAS DIFFUSER
Welding Control amp Wire Welding Control amp Wire Feed MotorFeed Motor
Welding control amp Wire feed motor are combined into one unit
Main function is to pull the wire from the spool and feed it to the arc
Controls wire feed speed and regulates the starting and stopping of wire feed
Wire feed speed controls Amperage
Types of Wire Feed MotorTypes of Wire Feed Motor
Types of WFM RollerTypes of WFM Roller
Types of Wire FeederTypes of Wire Feeder
WIRE FEEDER
Power SourcePower Source
Almost all GMAW is done with reverse polarity also known as DCEP
Positive (+) lead is connected to the torchNegative (-) lead is connected to the work
pieceProvides a relatively consistent voltage to the
arcArc Voltage is the voltage between the end of
the wire and the work piece
Contact Tip To Work DistanceContact Tip To Work Distance
In constant current the CTWD (contact tip to work distance) determines the arc length
As the CTWD increases the arc length increases and as the
CTWD decreases the arc length decreases This presented a
problem for semiautomatic welding because it is difficult to
maintain the same CTWD To compensate for this problem an arc voltage controlled wire
Constant voltage power source designs provide a specific arc voltage for a given pre-selected wire feed speed The volt-amp curve or slope is comparatively flat As the CTWD increases with these types of power sources there is a decrease in the welding current As the CTWD decreases there is an increase in the welding current The arc in this case becomes a series circuit and the CTWD provides resistance to current In either scenario the voltage remains the same and the arc length remains the same
POSITIVETERMINAL
NEGATIVETERMINAL
Shielding GasesShielding Gases
Purpose of shielding gas is the protect the weld area from the contaminants in the atmosphere
Gas can be Inert Reactive or Mixtures of both
Gas flow rate is between 25-35 CFHArgon Helium and Carbon Dioxide are the
main three gases used in GMAW
Properties of GasesProperties of Gases
Affect the performance of the welding process include
1) Thermal properties at elevated temperatures 2) Chemical reaction of the gas with the various
elements in the base plate and welding wire 3) Effect of each gas on the mode of metal
transfer
Types of shielding gasesTypes of shielding gases
Inert Gas
1 Argon
2 Helium
3 Ar + HeActive Gas
1 Carbon Dioxide
2 Inert gas + any type of active gas
Argon is an inert gas which is used both singularly and in combination with other gases to achieve desired arc characteristics for the welding of both ferrous and non-ferrous metals
Carbon Dioxide Pure carbon dioxide is not an inert gas because the heat of the arc breaks down the CO2 into carbon monoxide and free oxygen This oxygen will combine with elements transferring across the arc to form oxides which are released from the weld puddle in the form of slag and scale
Helium is an inert gas which is used on weld applications requiring higher heat input for improved bead wetting deeper penetration and higher travel speed In GMAW it does not produce as stable an arc as argon Compared to argon helium has a higher thermal conductivity and voltage gradient
FLOW METER
CYLCINDERPRESSUREGAUGE
CFH PRESSURE ADJUSTMENT KNOB
Filler WireFiller Wire
Wire ChemistriesWire Chemistries
GMAW Operation techniquesGMAW Operation techniques
To setting WFS (Wire Feed Speed)
Voltage-bead ChangeVoltage-bead Change
Electrode Stick-outElectrode Stick-out
ESO SettingESO Setting
EOSEOS
Gun angles and techniquesGun angles and techniques
Direction of TravelDirection of Travel
THANK YOU
GMAW Schematic DiagramGMAW Schematic Diagram
WIRE CONTROLamp
WIRE FEED MOTOR
POWER SOURCE
Welding Torch amp AccessoriesWelding Torch amp Accessories
The welding torch guides the wire and shielding gas to the weld zone
Brings welding power to the wire alsoMajor componentsparts of the torch are the
contact tip shielding gas nozzle gas diffuser and the wire conduit
Others types of torchOthers types of torch
TRIGGER
INSTALLED
COMPONENTS
NOZZLE
CONTACT TIP
GAS DIFFUSER
Welding Control amp Wire Welding Control amp Wire Feed MotorFeed Motor
Welding control amp Wire feed motor are combined into one unit
Main function is to pull the wire from the spool and feed it to the arc
Controls wire feed speed and regulates the starting and stopping of wire feed
Wire feed speed controls Amperage
Types of Wire Feed MotorTypes of Wire Feed Motor
Types of WFM RollerTypes of WFM Roller
Types of Wire FeederTypes of Wire Feeder
WIRE FEEDER
Power SourcePower Source
Almost all GMAW is done with reverse polarity also known as DCEP
Positive (+) lead is connected to the torchNegative (-) lead is connected to the work
pieceProvides a relatively consistent voltage to the
arcArc Voltage is the voltage between the end of
the wire and the work piece
Contact Tip To Work DistanceContact Tip To Work Distance
In constant current the CTWD (contact tip to work distance) determines the arc length
As the CTWD increases the arc length increases and as the
CTWD decreases the arc length decreases This presented a
problem for semiautomatic welding because it is difficult to
maintain the same CTWD To compensate for this problem an arc voltage controlled wire
Constant voltage power source designs provide a specific arc voltage for a given pre-selected wire feed speed The volt-amp curve or slope is comparatively flat As the CTWD increases with these types of power sources there is a decrease in the welding current As the CTWD decreases there is an increase in the welding current The arc in this case becomes a series circuit and the CTWD provides resistance to current In either scenario the voltage remains the same and the arc length remains the same
POSITIVETERMINAL
NEGATIVETERMINAL
Shielding GasesShielding Gases
Purpose of shielding gas is the protect the weld area from the contaminants in the atmosphere
Gas can be Inert Reactive or Mixtures of both
Gas flow rate is between 25-35 CFHArgon Helium and Carbon Dioxide are the
main three gases used in GMAW
Properties of GasesProperties of Gases
Affect the performance of the welding process include
1) Thermal properties at elevated temperatures 2) Chemical reaction of the gas with the various
elements in the base plate and welding wire 3) Effect of each gas on the mode of metal
transfer
Types of shielding gasesTypes of shielding gases
Inert Gas
1 Argon
2 Helium
3 Ar + HeActive Gas
1 Carbon Dioxide
2 Inert gas + any type of active gas
Argon is an inert gas which is used both singularly and in combination with other gases to achieve desired arc characteristics for the welding of both ferrous and non-ferrous metals
Carbon Dioxide Pure carbon dioxide is not an inert gas because the heat of the arc breaks down the CO2 into carbon monoxide and free oxygen This oxygen will combine with elements transferring across the arc to form oxides which are released from the weld puddle in the form of slag and scale
Helium is an inert gas which is used on weld applications requiring higher heat input for improved bead wetting deeper penetration and higher travel speed In GMAW it does not produce as stable an arc as argon Compared to argon helium has a higher thermal conductivity and voltage gradient
FLOW METER
CYLCINDERPRESSUREGAUGE
CFH PRESSURE ADJUSTMENT KNOB
Filler WireFiller Wire
Wire ChemistriesWire Chemistries
GMAW Operation techniquesGMAW Operation techniques
To setting WFS (Wire Feed Speed)
Voltage-bead ChangeVoltage-bead Change
Electrode Stick-outElectrode Stick-out
ESO SettingESO Setting
EOSEOS
Gun angles and techniquesGun angles and techniques
Direction of TravelDirection of Travel
THANK YOU
WIRE CONTROLamp
WIRE FEED MOTOR
POWER SOURCE
Welding Torch amp AccessoriesWelding Torch amp Accessories
The welding torch guides the wire and shielding gas to the weld zone
Brings welding power to the wire alsoMajor componentsparts of the torch are the
contact tip shielding gas nozzle gas diffuser and the wire conduit
Others types of torchOthers types of torch
TRIGGER
INSTALLED
COMPONENTS
NOZZLE
CONTACT TIP
GAS DIFFUSER
Welding Control amp Wire Welding Control amp Wire Feed MotorFeed Motor
Welding control amp Wire feed motor are combined into one unit
Main function is to pull the wire from the spool and feed it to the arc
Controls wire feed speed and regulates the starting and stopping of wire feed
Wire feed speed controls Amperage
Types of Wire Feed MotorTypes of Wire Feed Motor
Types of WFM RollerTypes of WFM Roller
Types of Wire FeederTypes of Wire Feeder
WIRE FEEDER
Power SourcePower Source
Almost all GMAW is done with reverse polarity also known as DCEP
Positive (+) lead is connected to the torchNegative (-) lead is connected to the work
pieceProvides a relatively consistent voltage to the
arcArc Voltage is the voltage between the end of
the wire and the work piece
Contact Tip To Work DistanceContact Tip To Work Distance
In constant current the CTWD (contact tip to work distance) determines the arc length
As the CTWD increases the arc length increases and as the
CTWD decreases the arc length decreases This presented a
problem for semiautomatic welding because it is difficult to
maintain the same CTWD To compensate for this problem an arc voltage controlled wire
Constant voltage power source designs provide a specific arc voltage for a given pre-selected wire feed speed The volt-amp curve or slope is comparatively flat As the CTWD increases with these types of power sources there is a decrease in the welding current As the CTWD decreases there is an increase in the welding current The arc in this case becomes a series circuit and the CTWD provides resistance to current In either scenario the voltage remains the same and the arc length remains the same
POSITIVETERMINAL
NEGATIVETERMINAL
Shielding GasesShielding Gases
Purpose of shielding gas is the protect the weld area from the contaminants in the atmosphere
Gas can be Inert Reactive or Mixtures of both
Gas flow rate is between 25-35 CFHArgon Helium and Carbon Dioxide are the
main three gases used in GMAW
Properties of GasesProperties of Gases
Affect the performance of the welding process include
1) Thermal properties at elevated temperatures 2) Chemical reaction of the gas with the various
elements in the base plate and welding wire 3) Effect of each gas on the mode of metal
transfer
Types of shielding gasesTypes of shielding gases
Inert Gas
1 Argon
2 Helium
3 Ar + HeActive Gas
1 Carbon Dioxide
2 Inert gas + any type of active gas
Argon is an inert gas which is used both singularly and in combination with other gases to achieve desired arc characteristics for the welding of both ferrous and non-ferrous metals
Carbon Dioxide Pure carbon dioxide is not an inert gas because the heat of the arc breaks down the CO2 into carbon monoxide and free oxygen This oxygen will combine with elements transferring across the arc to form oxides which are released from the weld puddle in the form of slag and scale
Helium is an inert gas which is used on weld applications requiring higher heat input for improved bead wetting deeper penetration and higher travel speed In GMAW it does not produce as stable an arc as argon Compared to argon helium has a higher thermal conductivity and voltage gradient
FLOW METER
CYLCINDERPRESSUREGAUGE
CFH PRESSURE ADJUSTMENT KNOB
Filler WireFiller Wire
Wire ChemistriesWire Chemistries
GMAW Operation techniquesGMAW Operation techniques
To setting WFS (Wire Feed Speed)
Voltage-bead ChangeVoltage-bead Change
Electrode Stick-outElectrode Stick-out
ESO SettingESO Setting
EOSEOS
Gun angles and techniquesGun angles and techniques
Direction of TravelDirection of Travel
THANK YOU
Welding Torch amp AccessoriesWelding Torch amp Accessories
The welding torch guides the wire and shielding gas to the weld zone
Brings welding power to the wire alsoMajor componentsparts of the torch are the
contact tip shielding gas nozzle gas diffuser and the wire conduit
Others types of torchOthers types of torch
TRIGGER
INSTALLED
COMPONENTS
NOZZLE
CONTACT TIP
GAS DIFFUSER
Welding Control amp Wire Welding Control amp Wire Feed MotorFeed Motor
Welding control amp Wire feed motor are combined into one unit
Main function is to pull the wire from the spool and feed it to the arc
Controls wire feed speed and regulates the starting and stopping of wire feed
Wire feed speed controls Amperage
Types of Wire Feed MotorTypes of Wire Feed Motor
Types of WFM RollerTypes of WFM Roller
Types of Wire FeederTypes of Wire Feeder
WIRE FEEDER
Power SourcePower Source
Almost all GMAW is done with reverse polarity also known as DCEP
Positive (+) lead is connected to the torchNegative (-) lead is connected to the work
pieceProvides a relatively consistent voltage to the
arcArc Voltage is the voltage between the end of
the wire and the work piece
Contact Tip To Work DistanceContact Tip To Work Distance
In constant current the CTWD (contact tip to work distance) determines the arc length
As the CTWD increases the arc length increases and as the
CTWD decreases the arc length decreases This presented a
problem for semiautomatic welding because it is difficult to
maintain the same CTWD To compensate for this problem an arc voltage controlled wire
Constant voltage power source designs provide a specific arc voltage for a given pre-selected wire feed speed The volt-amp curve or slope is comparatively flat As the CTWD increases with these types of power sources there is a decrease in the welding current As the CTWD decreases there is an increase in the welding current The arc in this case becomes a series circuit and the CTWD provides resistance to current In either scenario the voltage remains the same and the arc length remains the same
POSITIVETERMINAL
NEGATIVETERMINAL
Shielding GasesShielding Gases
Purpose of shielding gas is the protect the weld area from the contaminants in the atmosphere
Gas can be Inert Reactive or Mixtures of both
Gas flow rate is between 25-35 CFHArgon Helium and Carbon Dioxide are the
main three gases used in GMAW
Properties of GasesProperties of Gases
Affect the performance of the welding process include
1) Thermal properties at elevated temperatures 2) Chemical reaction of the gas with the various
elements in the base plate and welding wire 3) Effect of each gas on the mode of metal
transfer
Types of shielding gasesTypes of shielding gases
Inert Gas
1 Argon
2 Helium
3 Ar + HeActive Gas
1 Carbon Dioxide
2 Inert gas + any type of active gas
Argon is an inert gas which is used both singularly and in combination with other gases to achieve desired arc characteristics for the welding of both ferrous and non-ferrous metals
Carbon Dioxide Pure carbon dioxide is not an inert gas because the heat of the arc breaks down the CO2 into carbon monoxide and free oxygen This oxygen will combine with elements transferring across the arc to form oxides which are released from the weld puddle in the form of slag and scale
Helium is an inert gas which is used on weld applications requiring higher heat input for improved bead wetting deeper penetration and higher travel speed In GMAW it does not produce as stable an arc as argon Compared to argon helium has a higher thermal conductivity and voltage gradient
FLOW METER
CYLCINDERPRESSUREGAUGE
CFH PRESSURE ADJUSTMENT KNOB
Filler WireFiller Wire
Wire ChemistriesWire Chemistries
GMAW Operation techniquesGMAW Operation techniques
To setting WFS (Wire Feed Speed)
Voltage-bead ChangeVoltage-bead Change
Electrode Stick-outElectrode Stick-out
ESO SettingESO Setting
EOSEOS
Gun angles and techniquesGun angles and techniques
Direction of TravelDirection of Travel
THANK YOU
Others types of torchOthers types of torch
TRIGGER
INSTALLED
COMPONENTS
NOZZLE
CONTACT TIP
GAS DIFFUSER
Welding Control amp Wire Welding Control amp Wire Feed MotorFeed Motor
Welding control amp Wire feed motor are combined into one unit
Main function is to pull the wire from the spool and feed it to the arc
Controls wire feed speed and regulates the starting and stopping of wire feed
Wire feed speed controls Amperage
Types of Wire Feed MotorTypes of Wire Feed Motor
Types of WFM RollerTypes of WFM Roller
Types of Wire FeederTypes of Wire Feeder
WIRE FEEDER
Power SourcePower Source
Almost all GMAW is done with reverse polarity also known as DCEP
Positive (+) lead is connected to the torchNegative (-) lead is connected to the work
pieceProvides a relatively consistent voltage to the
arcArc Voltage is the voltage between the end of
the wire and the work piece
Contact Tip To Work DistanceContact Tip To Work Distance
In constant current the CTWD (contact tip to work distance) determines the arc length
As the CTWD increases the arc length increases and as the
CTWD decreases the arc length decreases This presented a
problem for semiautomatic welding because it is difficult to
maintain the same CTWD To compensate for this problem an arc voltage controlled wire
Constant voltage power source designs provide a specific arc voltage for a given pre-selected wire feed speed The volt-amp curve or slope is comparatively flat As the CTWD increases with these types of power sources there is a decrease in the welding current As the CTWD decreases there is an increase in the welding current The arc in this case becomes a series circuit and the CTWD provides resistance to current In either scenario the voltage remains the same and the arc length remains the same
POSITIVETERMINAL
NEGATIVETERMINAL
Shielding GasesShielding Gases
Purpose of shielding gas is the protect the weld area from the contaminants in the atmosphere
Gas can be Inert Reactive or Mixtures of both
Gas flow rate is between 25-35 CFHArgon Helium and Carbon Dioxide are the
main three gases used in GMAW
Properties of GasesProperties of Gases
Affect the performance of the welding process include
1) Thermal properties at elevated temperatures 2) Chemical reaction of the gas with the various
elements in the base plate and welding wire 3) Effect of each gas on the mode of metal
transfer
Types of shielding gasesTypes of shielding gases
Inert Gas
1 Argon
2 Helium
3 Ar + HeActive Gas
1 Carbon Dioxide
2 Inert gas + any type of active gas
Argon is an inert gas which is used both singularly and in combination with other gases to achieve desired arc characteristics for the welding of both ferrous and non-ferrous metals
Carbon Dioxide Pure carbon dioxide is not an inert gas because the heat of the arc breaks down the CO2 into carbon monoxide and free oxygen This oxygen will combine with elements transferring across the arc to form oxides which are released from the weld puddle in the form of slag and scale
Helium is an inert gas which is used on weld applications requiring higher heat input for improved bead wetting deeper penetration and higher travel speed In GMAW it does not produce as stable an arc as argon Compared to argon helium has a higher thermal conductivity and voltage gradient
FLOW METER
CYLCINDERPRESSUREGAUGE
CFH PRESSURE ADJUSTMENT KNOB
Filler WireFiller Wire
Wire ChemistriesWire Chemistries
GMAW Operation techniquesGMAW Operation techniques
To setting WFS (Wire Feed Speed)
Voltage-bead ChangeVoltage-bead Change
Electrode Stick-outElectrode Stick-out
ESO SettingESO Setting
EOSEOS
Gun angles and techniquesGun angles and techniques
Direction of TravelDirection of Travel
THANK YOU
TRIGGER
INSTALLED
COMPONENTS
NOZZLE
CONTACT TIP
GAS DIFFUSER
Welding Control amp Wire Welding Control amp Wire Feed MotorFeed Motor
Welding control amp Wire feed motor are combined into one unit
Main function is to pull the wire from the spool and feed it to the arc
Controls wire feed speed and regulates the starting and stopping of wire feed
Wire feed speed controls Amperage
Types of Wire Feed MotorTypes of Wire Feed Motor
Types of WFM RollerTypes of WFM Roller
Types of Wire FeederTypes of Wire Feeder
WIRE FEEDER
Power SourcePower Source
Almost all GMAW is done with reverse polarity also known as DCEP
Positive (+) lead is connected to the torchNegative (-) lead is connected to the work
pieceProvides a relatively consistent voltage to the
arcArc Voltage is the voltage between the end of
the wire and the work piece
Contact Tip To Work DistanceContact Tip To Work Distance
In constant current the CTWD (contact tip to work distance) determines the arc length
As the CTWD increases the arc length increases and as the
CTWD decreases the arc length decreases This presented a
problem for semiautomatic welding because it is difficult to
maintain the same CTWD To compensate for this problem an arc voltage controlled wire
Constant voltage power source designs provide a specific arc voltage for a given pre-selected wire feed speed The volt-amp curve or slope is comparatively flat As the CTWD increases with these types of power sources there is a decrease in the welding current As the CTWD decreases there is an increase in the welding current The arc in this case becomes a series circuit and the CTWD provides resistance to current In either scenario the voltage remains the same and the arc length remains the same
POSITIVETERMINAL
NEGATIVETERMINAL
Shielding GasesShielding Gases
Purpose of shielding gas is the protect the weld area from the contaminants in the atmosphere
Gas can be Inert Reactive or Mixtures of both
Gas flow rate is between 25-35 CFHArgon Helium and Carbon Dioxide are the
main three gases used in GMAW
Properties of GasesProperties of Gases
Affect the performance of the welding process include
1) Thermal properties at elevated temperatures 2) Chemical reaction of the gas with the various
elements in the base plate and welding wire 3) Effect of each gas on the mode of metal
transfer
Types of shielding gasesTypes of shielding gases
Inert Gas
1 Argon
2 Helium
3 Ar + HeActive Gas
1 Carbon Dioxide
2 Inert gas + any type of active gas
Argon is an inert gas which is used both singularly and in combination with other gases to achieve desired arc characteristics for the welding of both ferrous and non-ferrous metals
Carbon Dioxide Pure carbon dioxide is not an inert gas because the heat of the arc breaks down the CO2 into carbon monoxide and free oxygen This oxygen will combine with elements transferring across the arc to form oxides which are released from the weld puddle in the form of slag and scale
Helium is an inert gas which is used on weld applications requiring higher heat input for improved bead wetting deeper penetration and higher travel speed In GMAW it does not produce as stable an arc as argon Compared to argon helium has a higher thermal conductivity and voltage gradient
FLOW METER
CYLCINDERPRESSUREGAUGE
CFH PRESSURE ADJUSTMENT KNOB
Filler WireFiller Wire
Wire ChemistriesWire Chemistries
GMAW Operation techniquesGMAW Operation techniques
To setting WFS (Wire Feed Speed)
Voltage-bead ChangeVoltage-bead Change
Electrode Stick-outElectrode Stick-out
ESO SettingESO Setting
EOSEOS
Gun angles and techniquesGun angles and techniques
Direction of TravelDirection of Travel
THANK YOU
Welding Control amp Wire Welding Control amp Wire Feed MotorFeed Motor
Welding control amp Wire feed motor are combined into one unit
Main function is to pull the wire from the spool and feed it to the arc
Controls wire feed speed and regulates the starting and stopping of wire feed
Wire feed speed controls Amperage
Types of Wire Feed MotorTypes of Wire Feed Motor
Types of WFM RollerTypes of WFM Roller
Types of Wire FeederTypes of Wire Feeder
WIRE FEEDER
Power SourcePower Source
Almost all GMAW is done with reverse polarity also known as DCEP
Positive (+) lead is connected to the torchNegative (-) lead is connected to the work
pieceProvides a relatively consistent voltage to the
arcArc Voltage is the voltage between the end of
the wire and the work piece
Contact Tip To Work DistanceContact Tip To Work Distance
In constant current the CTWD (contact tip to work distance) determines the arc length
As the CTWD increases the arc length increases and as the
CTWD decreases the arc length decreases This presented a
problem for semiautomatic welding because it is difficult to
maintain the same CTWD To compensate for this problem an arc voltage controlled wire
Constant voltage power source designs provide a specific arc voltage for a given pre-selected wire feed speed The volt-amp curve or slope is comparatively flat As the CTWD increases with these types of power sources there is a decrease in the welding current As the CTWD decreases there is an increase in the welding current The arc in this case becomes a series circuit and the CTWD provides resistance to current In either scenario the voltage remains the same and the arc length remains the same
POSITIVETERMINAL
NEGATIVETERMINAL
Shielding GasesShielding Gases
Purpose of shielding gas is the protect the weld area from the contaminants in the atmosphere
Gas can be Inert Reactive or Mixtures of both
Gas flow rate is between 25-35 CFHArgon Helium and Carbon Dioxide are the
main three gases used in GMAW
Properties of GasesProperties of Gases
Affect the performance of the welding process include
1) Thermal properties at elevated temperatures 2) Chemical reaction of the gas with the various
elements in the base plate and welding wire 3) Effect of each gas on the mode of metal
transfer
Types of shielding gasesTypes of shielding gases
Inert Gas
1 Argon
2 Helium
3 Ar + HeActive Gas
1 Carbon Dioxide
2 Inert gas + any type of active gas
Argon is an inert gas which is used both singularly and in combination with other gases to achieve desired arc characteristics for the welding of both ferrous and non-ferrous metals
Carbon Dioxide Pure carbon dioxide is not an inert gas because the heat of the arc breaks down the CO2 into carbon monoxide and free oxygen This oxygen will combine with elements transferring across the arc to form oxides which are released from the weld puddle in the form of slag and scale
Helium is an inert gas which is used on weld applications requiring higher heat input for improved bead wetting deeper penetration and higher travel speed In GMAW it does not produce as stable an arc as argon Compared to argon helium has a higher thermal conductivity and voltage gradient
FLOW METER
CYLCINDERPRESSUREGAUGE
CFH PRESSURE ADJUSTMENT KNOB
Filler WireFiller Wire
Wire ChemistriesWire Chemistries
GMAW Operation techniquesGMAW Operation techniques
To setting WFS (Wire Feed Speed)
Voltage-bead ChangeVoltage-bead Change
Electrode Stick-outElectrode Stick-out
ESO SettingESO Setting
EOSEOS
Gun angles and techniquesGun angles and techniques
Direction of TravelDirection of Travel
THANK YOU
Types of Wire Feed MotorTypes of Wire Feed Motor
Types of WFM RollerTypes of WFM Roller
Types of Wire FeederTypes of Wire Feeder
WIRE FEEDER
Power SourcePower Source
Almost all GMAW is done with reverse polarity also known as DCEP
Positive (+) lead is connected to the torchNegative (-) lead is connected to the work
pieceProvides a relatively consistent voltage to the
arcArc Voltage is the voltage between the end of
the wire and the work piece
Contact Tip To Work DistanceContact Tip To Work Distance
In constant current the CTWD (contact tip to work distance) determines the arc length
As the CTWD increases the arc length increases and as the
CTWD decreases the arc length decreases This presented a
problem for semiautomatic welding because it is difficult to
maintain the same CTWD To compensate for this problem an arc voltage controlled wire
Constant voltage power source designs provide a specific arc voltage for a given pre-selected wire feed speed The volt-amp curve or slope is comparatively flat As the CTWD increases with these types of power sources there is a decrease in the welding current As the CTWD decreases there is an increase in the welding current The arc in this case becomes a series circuit and the CTWD provides resistance to current In either scenario the voltage remains the same and the arc length remains the same
POSITIVETERMINAL
NEGATIVETERMINAL
Shielding GasesShielding Gases
Purpose of shielding gas is the protect the weld area from the contaminants in the atmosphere
Gas can be Inert Reactive or Mixtures of both
Gas flow rate is between 25-35 CFHArgon Helium and Carbon Dioxide are the
main three gases used in GMAW
Properties of GasesProperties of Gases
Affect the performance of the welding process include
1) Thermal properties at elevated temperatures 2) Chemical reaction of the gas with the various
elements in the base plate and welding wire 3) Effect of each gas on the mode of metal
transfer
Types of shielding gasesTypes of shielding gases
Inert Gas
1 Argon
2 Helium
3 Ar + HeActive Gas
1 Carbon Dioxide
2 Inert gas + any type of active gas
Argon is an inert gas which is used both singularly and in combination with other gases to achieve desired arc characteristics for the welding of both ferrous and non-ferrous metals
Carbon Dioxide Pure carbon dioxide is not an inert gas because the heat of the arc breaks down the CO2 into carbon monoxide and free oxygen This oxygen will combine with elements transferring across the arc to form oxides which are released from the weld puddle in the form of slag and scale
Helium is an inert gas which is used on weld applications requiring higher heat input for improved bead wetting deeper penetration and higher travel speed In GMAW it does not produce as stable an arc as argon Compared to argon helium has a higher thermal conductivity and voltage gradient
FLOW METER
CYLCINDERPRESSUREGAUGE
CFH PRESSURE ADJUSTMENT KNOB
Filler WireFiller Wire
Wire ChemistriesWire Chemistries
GMAW Operation techniquesGMAW Operation techniques
To setting WFS (Wire Feed Speed)
Voltage-bead ChangeVoltage-bead Change
Electrode Stick-outElectrode Stick-out
ESO SettingESO Setting
EOSEOS
Gun angles and techniquesGun angles and techniques
Direction of TravelDirection of Travel
THANK YOU
Types of WFM RollerTypes of WFM Roller
Types of Wire FeederTypes of Wire Feeder
WIRE FEEDER
Power SourcePower Source
Almost all GMAW is done with reverse polarity also known as DCEP
Positive (+) lead is connected to the torchNegative (-) lead is connected to the work
pieceProvides a relatively consistent voltage to the
arcArc Voltage is the voltage between the end of
the wire and the work piece
Contact Tip To Work DistanceContact Tip To Work Distance
In constant current the CTWD (contact tip to work distance) determines the arc length
As the CTWD increases the arc length increases and as the
CTWD decreases the arc length decreases This presented a
problem for semiautomatic welding because it is difficult to
maintain the same CTWD To compensate for this problem an arc voltage controlled wire
Constant voltage power source designs provide a specific arc voltage for a given pre-selected wire feed speed The volt-amp curve or slope is comparatively flat As the CTWD increases with these types of power sources there is a decrease in the welding current As the CTWD decreases there is an increase in the welding current The arc in this case becomes a series circuit and the CTWD provides resistance to current In either scenario the voltage remains the same and the arc length remains the same
POSITIVETERMINAL
NEGATIVETERMINAL
Shielding GasesShielding Gases
Purpose of shielding gas is the protect the weld area from the contaminants in the atmosphere
Gas can be Inert Reactive or Mixtures of both
Gas flow rate is between 25-35 CFHArgon Helium and Carbon Dioxide are the
main three gases used in GMAW
Properties of GasesProperties of Gases
Affect the performance of the welding process include
1) Thermal properties at elevated temperatures 2) Chemical reaction of the gas with the various
elements in the base plate and welding wire 3) Effect of each gas on the mode of metal
transfer
Types of shielding gasesTypes of shielding gases
Inert Gas
1 Argon
2 Helium
3 Ar + HeActive Gas
1 Carbon Dioxide
2 Inert gas + any type of active gas
Argon is an inert gas which is used both singularly and in combination with other gases to achieve desired arc characteristics for the welding of both ferrous and non-ferrous metals
Carbon Dioxide Pure carbon dioxide is not an inert gas because the heat of the arc breaks down the CO2 into carbon monoxide and free oxygen This oxygen will combine with elements transferring across the arc to form oxides which are released from the weld puddle in the form of slag and scale
Helium is an inert gas which is used on weld applications requiring higher heat input for improved bead wetting deeper penetration and higher travel speed In GMAW it does not produce as stable an arc as argon Compared to argon helium has a higher thermal conductivity and voltage gradient
FLOW METER
CYLCINDERPRESSUREGAUGE
CFH PRESSURE ADJUSTMENT KNOB
Filler WireFiller Wire
Wire ChemistriesWire Chemistries
GMAW Operation techniquesGMAW Operation techniques
To setting WFS (Wire Feed Speed)
Voltage-bead ChangeVoltage-bead Change
Electrode Stick-outElectrode Stick-out
ESO SettingESO Setting
EOSEOS
Gun angles and techniquesGun angles and techniques
Direction of TravelDirection of Travel
THANK YOU
Types of Wire FeederTypes of Wire Feeder
WIRE FEEDER
Power SourcePower Source
Almost all GMAW is done with reverse polarity also known as DCEP
Positive (+) lead is connected to the torchNegative (-) lead is connected to the work
pieceProvides a relatively consistent voltage to the
arcArc Voltage is the voltage between the end of
the wire and the work piece
Contact Tip To Work DistanceContact Tip To Work Distance
In constant current the CTWD (contact tip to work distance) determines the arc length
As the CTWD increases the arc length increases and as the
CTWD decreases the arc length decreases This presented a
problem for semiautomatic welding because it is difficult to
maintain the same CTWD To compensate for this problem an arc voltage controlled wire
Constant voltage power source designs provide a specific arc voltage for a given pre-selected wire feed speed The volt-amp curve or slope is comparatively flat As the CTWD increases with these types of power sources there is a decrease in the welding current As the CTWD decreases there is an increase in the welding current The arc in this case becomes a series circuit and the CTWD provides resistance to current In either scenario the voltage remains the same and the arc length remains the same
POSITIVETERMINAL
NEGATIVETERMINAL
Shielding GasesShielding Gases
Purpose of shielding gas is the protect the weld area from the contaminants in the atmosphere
Gas can be Inert Reactive or Mixtures of both
Gas flow rate is between 25-35 CFHArgon Helium and Carbon Dioxide are the
main three gases used in GMAW
Properties of GasesProperties of Gases
Affect the performance of the welding process include
1) Thermal properties at elevated temperatures 2) Chemical reaction of the gas with the various
elements in the base plate and welding wire 3) Effect of each gas on the mode of metal
transfer
Types of shielding gasesTypes of shielding gases
Inert Gas
1 Argon
2 Helium
3 Ar + HeActive Gas
1 Carbon Dioxide
2 Inert gas + any type of active gas
Argon is an inert gas which is used both singularly and in combination with other gases to achieve desired arc characteristics for the welding of both ferrous and non-ferrous metals
Carbon Dioxide Pure carbon dioxide is not an inert gas because the heat of the arc breaks down the CO2 into carbon monoxide and free oxygen This oxygen will combine with elements transferring across the arc to form oxides which are released from the weld puddle in the form of slag and scale
Helium is an inert gas which is used on weld applications requiring higher heat input for improved bead wetting deeper penetration and higher travel speed In GMAW it does not produce as stable an arc as argon Compared to argon helium has a higher thermal conductivity and voltage gradient
FLOW METER
CYLCINDERPRESSUREGAUGE
CFH PRESSURE ADJUSTMENT KNOB
Filler WireFiller Wire
Wire ChemistriesWire Chemistries
GMAW Operation techniquesGMAW Operation techniques
To setting WFS (Wire Feed Speed)
Voltage-bead ChangeVoltage-bead Change
Electrode Stick-outElectrode Stick-out
ESO SettingESO Setting
EOSEOS
Gun angles and techniquesGun angles and techniques
Direction of TravelDirection of Travel
THANK YOU
WIRE FEEDER
Power SourcePower Source
Almost all GMAW is done with reverse polarity also known as DCEP
Positive (+) lead is connected to the torchNegative (-) lead is connected to the work
pieceProvides a relatively consistent voltage to the
arcArc Voltage is the voltage between the end of
the wire and the work piece
Contact Tip To Work DistanceContact Tip To Work Distance
In constant current the CTWD (contact tip to work distance) determines the arc length
As the CTWD increases the arc length increases and as the
CTWD decreases the arc length decreases This presented a
problem for semiautomatic welding because it is difficult to
maintain the same CTWD To compensate for this problem an arc voltage controlled wire
Constant voltage power source designs provide a specific arc voltage for a given pre-selected wire feed speed The volt-amp curve or slope is comparatively flat As the CTWD increases with these types of power sources there is a decrease in the welding current As the CTWD decreases there is an increase in the welding current The arc in this case becomes a series circuit and the CTWD provides resistance to current In either scenario the voltage remains the same and the arc length remains the same
POSITIVETERMINAL
NEGATIVETERMINAL
Shielding GasesShielding Gases
Purpose of shielding gas is the protect the weld area from the contaminants in the atmosphere
Gas can be Inert Reactive or Mixtures of both
Gas flow rate is between 25-35 CFHArgon Helium and Carbon Dioxide are the
main three gases used in GMAW
Properties of GasesProperties of Gases
Affect the performance of the welding process include
1) Thermal properties at elevated temperatures 2) Chemical reaction of the gas with the various
elements in the base plate and welding wire 3) Effect of each gas on the mode of metal
transfer
Types of shielding gasesTypes of shielding gases
Inert Gas
1 Argon
2 Helium
3 Ar + HeActive Gas
1 Carbon Dioxide
2 Inert gas + any type of active gas
Argon is an inert gas which is used both singularly and in combination with other gases to achieve desired arc characteristics for the welding of both ferrous and non-ferrous metals
Carbon Dioxide Pure carbon dioxide is not an inert gas because the heat of the arc breaks down the CO2 into carbon monoxide and free oxygen This oxygen will combine with elements transferring across the arc to form oxides which are released from the weld puddle in the form of slag and scale
Helium is an inert gas which is used on weld applications requiring higher heat input for improved bead wetting deeper penetration and higher travel speed In GMAW it does not produce as stable an arc as argon Compared to argon helium has a higher thermal conductivity and voltage gradient
FLOW METER
CYLCINDERPRESSUREGAUGE
CFH PRESSURE ADJUSTMENT KNOB
Filler WireFiller Wire
Wire ChemistriesWire Chemistries
GMAW Operation techniquesGMAW Operation techniques
To setting WFS (Wire Feed Speed)
Voltage-bead ChangeVoltage-bead Change
Electrode Stick-outElectrode Stick-out
ESO SettingESO Setting
EOSEOS
Gun angles and techniquesGun angles and techniques
Direction of TravelDirection of Travel
THANK YOU
Power SourcePower Source
Almost all GMAW is done with reverse polarity also known as DCEP
Positive (+) lead is connected to the torchNegative (-) lead is connected to the work
pieceProvides a relatively consistent voltage to the
arcArc Voltage is the voltage between the end of
the wire and the work piece
Contact Tip To Work DistanceContact Tip To Work Distance
In constant current the CTWD (contact tip to work distance) determines the arc length
As the CTWD increases the arc length increases and as the
CTWD decreases the arc length decreases This presented a
problem for semiautomatic welding because it is difficult to
maintain the same CTWD To compensate for this problem an arc voltage controlled wire
Constant voltage power source designs provide a specific arc voltage for a given pre-selected wire feed speed The volt-amp curve or slope is comparatively flat As the CTWD increases with these types of power sources there is a decrease in the welding current As the CTWD decreases there is an increase in the welding current The arc in this case becomes a series circuit and the CTWD provides resistance to current In either scenario the voltage remains the same and the arc length remains the same
POSITIVETERMINAL
NEGATIVETERMINAL
Shielding GasesShielding Gases
Purpose of shielding gas is the protect the weld area from the contaminants in the atmosphere
Gas can be Inert Reactive or Mixtures of both
Gas flow rate is between 25-35 CFHArgon Helium and Carbon Dioxide are the
main three gases used in GMAW
Properties of GasesProperties of Gases
Affect the performance of the welding process include
1) Thermal properties at elevated temperatures 2) Chemical reaction of the gas with the various
elements in the base plate and welding wire 3) Effect of each gas on the mode of metal
transfer
Types of shielding gasesTypes of shielding gases
Inert Gas
1 Argon
2 Helium
3 Ar + HeActive Gas
1 Carbon Dioxide
2 Inert gas + any type of active gas
Argon is an inert gas which is used both singularly and in combination with other gases to achieve desired arc characteristics for the welding of both ferrous and non-ferrous metals
Carbon Dioxide Pure carbon dioxide is not an inert gas because the heat of the arc breaks down the CO2 into carbon monoxide and free oxygen This oxygen will combine with elements transferring across the arc to form oxides which are released from the weld puddle in the form of slag and scale
Helium is an inert gas which is used on weld applications requiring higher heat input for improved bead wetting deeper penetration and higher travel speed In GMAW it does not produce as stable an arc as argon Compared to argon helium has a higher thermal conductivity and voltage gradient
FLOW METER
CYLCINDERPRESSUREGAUGE
CFH PRESSURE ADJUSTMENT KNOB
Filler WireFiller Wire
Wire ChemistriesWire Chemistries
GMAW Operation techniquesGMAW Operation techniques
To setting WFS (Wire Feed Speed)
Voltage-bead ChangeVoltage-bead Change
Electrode Stick-outElectrode Stick-out
ESO SettingESO Setting
EOSEOS
Gun angles and techniquesGun angles and techniques
Direction of TravelDirection of Travel
THANK YOU
Contact Tip To Work DistanceContact Tip To Work Distance
In constant current the CTWD (contact tip to work distance) determines the arc length
As the CTWD increases the arc length increases and as the
CTWD decreases the arc length decreases This presented a
problem for semiautomatic welding because it is difficult to
maintain the same CTWD To compensate for this problem an arc voltage controlled wire
Constant voltage power source designs provide a specific arc voltage for a given pre-selected wire feed speed The volt-amp curve or slope is comparatively flat As the CTWD increases with these types of power sources there is a decrease in the welding current As the CTWD decreases there is an increase in the welding current The arc in this case becomes a series circuit and the CTWD provides resistance to current In either scenario the voltage remains the same and the arc length remains the same
POSITIVETERMINAL
NEGATIVETERMINAL
Shielding GasesShielding Gases
Purpose of shielding gas is the protect the weld area from the contaminants in the atmosphere
Gas can be Inert Reactive or Mixtures of both
Gas flow rate is between 25-35 CFHArgon Helium and Carbon Dioxide are the
main three gases used in GMAW
Properties of GasesProperties of Gases
Affect the performance of the welding process include
1) Thermal properties at elevated temperatures 2) Chemical reaction of the gas with the various
elements in the base plate and welding wire 3) Effect of each gas on the mode of metal
transfer
Types of shielding gasesTypes of shielding gases
Inert Gas
1 Argon
2 Helium
3 Ar + HeActive Gas
1 Carbon Dioxide
2 Inert gas + any type of active gas
Argon is an inert gas which is used both singularly and in combination with other gases to achieve desired arc characteristics for the welding of both ferrous and non-ferrous metals
Carbon Dioxide Pure carbon dioxide is not an inert gas because the heat of the arc breaks down the CO2 into carbon monoxide and free oxygen This oxygen will combine with elements transferring across the arc to form oxides which are released from the weld puddle in the form of slag and scale
Helium is an inert gas which is used on weld applications requiring higher heat input for improved bead wetting deeper penetration and higher travel speed In GMAW it does not produce as stable an arc as argon Compared to argon helium has a higher thermal conductivity and voltage gradient
FLOW METER
CYLCINDERPRESSUREGAUGE
CFH PRESSURE ADJUSTMENT KNOB
Filler WireFiller Wire
Wire ChemistriesWire Chemistries
GMAW Operation techniquesGMAW Operation techniques
To setting WFS (Wire Feed Speed)
Voltage-bead ChangeVoltage-bead Change
Electrode Stick-outElectrode Stick-out
ESO SettingESO Setting
EOSEOS
Gun angles and techniquesGun angles and techniques
Direction of TravelDirection of Travel
THANK YOU
Constant voltage power source designs provide a specific arc voltage for a given pre-selected wire feed speed The volt-amp curve or slope is comparatively flat As the CTWD increases with these types of power sources there is a decrease in the welding current As the CTWD decreases there is an increase in the welding current The arc in this case becomes a series circuit and the CTWD provides resistance to current In either scenario the voltage remains the same and the arc length remains the same
POSITIVETERMINAL
NEGATIVETERMINAL
Shielding GasesShielding Gases
Purpose of shielding gas is the protect the weld area from the contaminants in the atmosphere
Gas can be Inert Reactive or Mixtures of both
Gas flow rate is between 25-35 CFHArgon Helium and Carbon Dioxide are the
main three gases used in GMAW
Properties of GasesProperties of Gases
Affect the performance of the welding process include
1) Thermal properties at elevated temperatures 2) Chemical reaction of the gas with the various
elements in the base plate and welding wire 3) Effect of each gas on the mode of metal
transfer
Types of shielding gasesTypes of shielding gases
Inert Gas
1 Argon
2 Helium
3 Ar + HeActive Gas
1 Carbon Dioxide
2 Inert gas + any type of active gas
Argon is an inert gas which is used both singularly and in combination with other gases to achieve desired arc characteristics for the welding of both ferrous and non-ferrous metals
Carbon Dioxide Pure carbon dioxide is not an inert gas because the heat of the arc breaks down the CO2 into carbon monoxide and free oxygen This oxygen will combine with elements transferring across the arc to form oxides which are released from the weld puddle in the form of slag and scale
Helium is an inert gas which is used on weld applications requiring higher heat input for improved bead wetting deeper penetration and higher travel speed In GMAW it does not produce as stable an arc as argon Compared to argon helium has a higher thermal conductivity and voltage gradient
FLOW METER
CYLCINDERPRESSUREGAUGE
CFH PRESSURE ADJUSTMENT KNOB
Filler WireFiller Wire
Wire ChemistriesWire Chemistries
GMAW Operation techniquesGMAW Operation techniques
To setting WFS (Wire Feed Speed)
Voltage-bead ChangeVoltage-bead Change
Electrode Stick-outElectrode Stick-out
ESO SettingESO Setting
EOSEOS
Gun angles and techniquesGun angles and techniques
Direction of TravelDirection of Travel
THANK YOU
POSITIVETERMINAL
NEGATIVETERMINAL
Shielding GasesShielding Gases
Purpose of shielding gas is the protect the weld area from the contaminants in the atmosphere
Gas can be Inert Reactive or Mixtures of both
Gas flow rate is between 25-35 CFHArgon Helium and Carbon Dioxide are the
main three gases used in GMAW
Properties of GasesProperties of Gases
Affect the performance of the welding process include
1) Thermal properties at elevated temperatures 2) Chemical reaction of the gas with the various
elements in the base plate and welding wire 3) Effect of each gas on the mode of metal
transfer
Types of shielding gasesTypes of shielding gases
Inert Gas
1 Argon
2 Helium
3 Ar + HeActive Gas
1 Carbon Dioxide
2 Inert gas + any type of active gas
Argon is an inert gas which is used both singularly and in combination with other gases to achieve desired arc characteristics for the welding of both ferrous and non-ferrous metals
Carbon Dioxide Pure carbon dioxide is not an inert gas because the heat of the arc breaks down the CO2 into carbon monoxide and free oxygen This oxygen will combine with elements transferring across the arc to form oxides which are released from the weld puddle in the form of slag and scale
Helium is an inert gas which is used on weld applications requiring higher heat input for improved bead wetting deeper penetration and higher travel speed In GMAW it does not produce as stable an arc as argon Compared to argon helium has a higher thermal conductivity and voltage gradient
FLOW METER
CYLCINDERPRESSUREGAUGE
CFH PRESSURE ADJUSTMENT KNOB
Filler WireFiller Wire
Wire ChemistriesWire Chemistries
GMAW Operation techniquesGMAW Operation techniques
To setting WFS (Wire Feed Speed)
Voltage-bead ChangeVoltage-bead Change
Electrode Stick-outElectrode Stick-out
ESO SettingESO Setting
EOSEOS
Gun angles and techniquesGun angles and techniques
Direction of TravelDirection of Travel
THANK YOU
Shielding GasesShielding Gases
Purpose of shielding gas is the protect the weld area from the contaminants in the atmosphere
Gas can be Inert Reactive or Mixtures of both
Gas flow rate is between 25-35 CFHArgon Helium and Carbon Dioxide are the
main three gases used in GMAW
Properties of GasesProperties of Gases
Affect the performance of the welding process include
1) Thermal properties at elevated temperatures 2) Chemical reaction of the gas with the various
elements in the base plate and welding wire 3) Effect of each gas on the mode of metal
transfer
Types of shielding gasesTypes of shielding gases
Inert Gas
1 Argon
2 Helium
3 Ar + HeActive Gas
1 Carbon Dioxide
2 Inert gas + any type of active gas
Argon is an inert gas which is used both singularly and in combination with other gases to achieve desired arc characteristics for the welding of both ferrous and non-ferrous metals
Carbon Dioxide Pure carbon dioxide is not an inert gas because the heat of the arc breaks down the CO2 into carbon monoxide and free oxygen This oxygen will combine with elements transferring across the arc to form oxides which are released from the weld puddle in the form of slag and scale
Helium is an inert gas which is used on weld applications requiring higher heat input for improved bead wetting deeper penetration and higher travel speed In GMAW it does not produce as stable an arc as argon Compared to argon helium has a higher thermal conductivity and voltage gradient
FLOW METER
CYLCINDERPRESSUREGAUGE
CFH PRESSURE ADJUSTMENT KNOB
Filler WireFiller Wire
Wire ChemistriesWire Chemistries
GMAW Operation techniquesGMAW Operation techniques
To setting WFS (Wire Feed Speed)
Voltage-bead ChangeVoltage-bead Change
Electrode Stick-outElectrode Stick-out
ESO SettingESO Setting
EOSEOS
Gun angles and techniquesGun angles and techniques
Direction of TravelDirection of Travel
THANK YOU
Properties of GasesProperties of Gases
Affect the performance of the welding process include
1) Thermal properties at elevated temperatures 2) Chemical reaction of the gas with the various
elements in the base plate and welding wire 3) Effect of each gas on the mode of metal
transfer
Types of shielding gasesTypes of shielding gases
Inert Gas
1 Argon
2 Helium
3 Ar + HeActive Gas
1 Carbon Dioxide
2 Inert gas + any type of active gas
Argon is an inert gas which is used both singularly and in combination with other gases to achieve desired arc characteristics for the welding of both ferrous and non-ferrous metals
Carbon Dioxide Pure carbon dioxide is not an inert gas because the heat of the arc breaks down the CO2 into carbon monoxide and free oxygen This oxygen will combine with elements transferring across the arc to form oxides which are released from the weld puddle in the form of slag and scale
Helium is an inert gas which is used on weld applications requiring higher heat input for improved bead wetting deeper penetration and higher travel speed In GMAW it does not produce as stable an arc as argon Compared to argon helium has a higher thermal conductivity and voltage gradient
FLOW METER
CYLCINDERPRESSUREGAUGE
CFH PRESSURE ADJUSTMENT KNOB
Filler WireFiller Wire
Wire ChemistriesWire Chemistries
GMAW Operation techniquesGMAW Operation techniques
To setting WFS (Wire Feed Speed)
Voltage-bead ChangeVoltage-bead Change
Electrode Stick-outElectrode Stick-out
ESO SettingESO Setting
EOSEOS
Gun angles and techniquesGun angles and techniques
Direction of TravelDirection of Travel
THANK YOU
Types of shielding gasesTypes of shielding gases
Inert Gas
1 Argon
2 Helium
3 Ar + HeActive Gas
1 Carbon Dioxide
2 Inert gas + any type of active gas
Argon is an inert gas which is used both singularly and in combination with other gases to achieve desired arc characteristics for the welding of both ferrous and non-ferrous metals
Carbon Dioxide Pure carbon dioxide is not an inert gas because the heat of the arc breaks down the CO2 into carbon monoxide and free oxygen This oxygen will combine with elements transferring across the arc to form oxides which are released from the weld puddle in the form of slag and scale
Helium is an inert gas which is used on weld applications requiring higher heat input for improved bead wetting deeper penetration and higher travel speed In GMAW it does not produce as stable an arc as argon Compared to argon helium has a higher thermal conductivity and voltage gradient
FLOW METER
CYLCINDERPRESSUREGAUGE
CFH PRESSURE ADJUSTMENT KNOB
Filler WireFiller Wire
Wire ChemistriesWire Chemistries
GMAW Operation techniquesGMAW Operation techniques
To setting WFS (Wire Feed Speed)
Voltage-bead ChangeVoltage-bead Change
Electrode Stick-outElectrode Stick-out
ESO SettingESO Setting
EOSEOS
Gun angles and techniquesGun angles and techniques
Direction of TravelDirection of Travel
THANK YOU
Argon is an inert gas which is used both singularly and in combination with other gases to achieve desired arc characteristics for the welding of both ferrous and non-ferrous metals
Carbon Dioxide Pure carbon dioxide is not an inert gas because the heat of the arc breaks down the CO2 into carbon monoxide and free oxygen This oxygen will combine with elements transferring across the arc to form oxides which are released from the weld puddle in the form of slag and scale
Helium is an inert gas which is used on weld applications requiring higher heat input for improved bead wetting deeper penetration and higher travel speed In GMAW it does not produce as stable an arc as argon Compared to argon helium has a higher thermal conductivity and voltage gradient
FLOW METER
CYLCINDERPRESSUREGAUGE
CFH PRESSURE ADJUSTMENT KNOB
Filler WireFiller Wire
Wire ChemistriesWire Chemistries
GMAW Operation techniquesGMAW Operation techniques
To setting WFS (Wire Feed Speed)
Voltage-bead ChangeVoltage-bead Change
Electrode Stick-outElectrode Stick-out
ESO SettingESO Setting
EOSEOS
Gun angles and techniquesGun angles and techniques
Direction of TravelDirection of Travel
THANK YOU
Helium is an inert gas which is used on weld applications requiring higher heat input for improved bead wetting deeper penetration and higher travel speed In GMAW it does not produce as stable an arc as argon Compared to argon helium has a higher thermal conductivity and voltage gradient
FLOW METER
CYLCINDERPRESSUREGAUGE
CFH PRESSURE ADJUSTMENT KNOB
Filler WireFiller Wire
Wire ChemistriesWire Chemistries
GMAW Operation techniquesGMAW Operation techniques
To setting WFS (Wire Feed Speed)
Voltage-bead ChangeVoltage-bead Change
Electrode Stick-outElectrode Stick-out
ESO SettingESO Setting
EOSEOS
Gun angles and techniquesGun angles and techniques
Direction of TravelDirection of Travel
THANK YOU
FLOW METER
CYLCINDERPRESSUREGAUGE
CFH PRESSURE ADJUSTMENT KNOB
Filler WireFiller Wire
Wire ChemistriesWire Chemistries
GMAW Operation techniquesGMAW Operation techniques
To setting WFS (Wire Feed Speed)
Voltage-bead ChangeVoltage-bead Change
Electrode Stick-outElectrode Stick-out
ESO SettingESO Setting
EOSEOS
Gun angles and techniquesGun angles and techniques
Direction of TravelDirection of Travel
THANK YOU
Filler WireFiller Wire
Wire ChemistriesWire Chemistries
GMAW Operation techniquesGMAW Operation techniques
To setting WFS (Wire Feed Speed)
Voltage-bead ChangeVoltage-bead Change
Electrode Stick-outElectrode Stick-out
ESO SettingESO Setting
EOSEOS
Gun angles and techniquesGun angles and techniques
Direction of TravelDirection of Travel
THANK YOU
Wire ChemistriesWire Chemistries
GMAW Operation techniquesGMAW Operation techniques
To setting WFS (Wire Feed Speed)
Voltage-bead ChangeVoltage-bead Change
Electrode Stick-outElectrode Stick-out
ESO SettingESO Setting
EOSEOS
Gun angles and techniquesGun angles and techniques
Direction of TravelDirection of Travel
THANK YOU
GMAW Operation techniquesGMAW Operation techniques
To setting WFS (Wire Feed Speed)
Voltage-bead ChangeVoltage-bead Change
Electrode Stick-outElectrode Stick-out
ESO SettingESO Setting
EOSEOS
Gun angles and techniquesGun angles and techniques
Direction of TravelDirection of Travel
THANK YOU
Voltage-bead ChangeVoltage-bead Change
Electrode Stick-outElectrode Stick-out
ESO SettingESO Setting
EOSEOS
Gun angles and techniquesGun angles and techniques
Direction of TravelDirection of Travel
THANK YOU
Electrode Stick-outElectrode Stick-out
ESO SettingESO Setting
EOSEOS
Gun angles and techniquesGun angles and techniques
Direction of TravelDirection of Travel
THANK YOU
ESO SettingESO Setting
EOSEOS
Gun angles and techniquesGun angles and techniques
Direction of TravelDirection of Travel
THANK YOU
EOSEOS
Gun angles and techniquesGun angles and techniques
Direction of TravelDirection of Travel
THANK YOU
Gun angles and techniquesGun angles and techniques
Direction of TravelDirection of Travel
THANK YOU
Direction of TravelDirection of Travel
THANK YOU
THANK YOU