GMAW Welding Parameters

7/30/2019 GMAW Welding Parameters

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http://www.messerwelding.com/Procedures.htm

Technical Data & Terms

Aluminum

PREMIUM FLUX-COATED ALUMINUM JOINING AND

BUILD-UP ALLOY FOR ARC OR TORCH

General CharacteristicsUniversal aluminum electrode for arc welding aluminumand aluminum alloys. Welds are strong, dense on bothproduction and maintenance applications. Arc is

exceptionally stable, operates at low amperes with aminimum of spatter and fuming. Weld deposits have goodcolor match and corrosion resistance. Ideal for weldingheat treated aluminum parts. Can also be used as a fluxcoated aluminum joining and build-up rod for use with oxy-acetylene.

ApplicationsRepairing of automotive, truck and bus parts. Also fortanks, pipes, ladders, shelves and many other aluminumstructures. Repair of machining errors and build-up ofmissing sections of castings, extrusions, plates, etc.

Technical DataTypical Tensile Strength: up to 34,000 psi (24 kg/mm2)Elongation %: 15-25Typical Hardness (HB): 40-55Color Match: good (will darken if anodized)Current: DC reverse polarity only (electrode +)

Amperage: 80-1301/8"3.25mm

Procedure

Clean weld area thoroughly prior to welding with astainless steel wire brush. Parts 1/8" or heavier should bebeveled 70-90. No preheat is necessary on thin gaugesbut faster, flatter, smoother welds are produced on heaviersections if they are preheated to approximately 400F(205C) Hold electrode vertical to workpiece, maintain ashort arc and fast travel speed. Use either stringer beadsor weaving technique. Remove slag between passes.Restart arc on existing weld deposits. Allow part to cool
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slowly. Chip off all slag before quenching. Always removeall slag residue.

Brazing

MULTI-DEOXIDIZED LOW FUMING BRONZE BAREAND FLUX COATED

General CharacteristicsBrazing alloy is available both bare and flux-coated. Thebare rods are for use with US Forge Brazing Flux. Theflux-coated rods eliminate the need for additional fluxes,therefore they usually prove to be more economical. Both

the bare and flux-coated rods are made to meet todaysindustry standards.

ApplicationsMaintenance repair of most ferrous and non-ferrousmetals. Ideal for joining parts of metal furniture, bicycles,automobiles and many more items where heat distortiondoes not allow for arc welding.

Technical DataNominal Analysis: Cu-58%, Sn-1.0%, Mn-0.40%, Fe-0.75%, Si-0.10%, Zn-remainder

Working Temperature: 1600F (870C)Typical Hardness (HB): 80-110Specifications: AWS A5.7 Class R CuZn-C

ASTM B259 Class R CuZn-CQQ-R-571a (FS-R CuZn-3)Diameter: 3/32" 1/8"2.5mm 3.25mm

ProcedureUse slightly oxidizing flame concentrated on the basemetal. When using bare rods, heat end of rod, dip into USForge flux and transfer to the working area. Put the torch

flame where the alloy is wanted; the molten alloy will followthe heat. Do not overheat; the base metal must not bemelted except when fusion welding bronze parts. Allow tocool slowly. Remove flux residue with chipping hammerand wire brush.


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Cast Iron

MAXIMUM STRENGTH ALLOY FOR DIRTY CAST IRON

General CharacteristicsUnique flux coating on alloyed core wire produces dense,strong, crack-resistant welds on virtually all types of castiron. Especially good for contaminated, old, oil-soaked,dirty base metal. Also recommended for joining cast iron tosteel. Use on gray, ductile, Meehanite and nodular castiron. Deposits are machinable.

ApplicationsUse on machine bases, transmission or gear housings,sprockets, repair of or build-up on gears and any repair ofcast iron to steel.

Technical DataTypical Tensile Strength: up to 60,000 (42 kg/mm2)Typical Hardness (HB): Brinell 210Current: AC or DC reverse polarity (electrode +)

Amperage: 70-110Diameter : 1/8"3.25mm

ProcedureOn heavy sections, remove worn, cracked metal, andbevel joint using the US Forge Cutting rod or a grinding

wheel. When repairing cracks, drill stop hole at eitherend to prevent crack travel while welding. Use shortstringer beads. Use a short to medium arc length and thelowest amperage possible to minimize base metaloverheating. When breaking arc, always back step intoweld crater. Weld joints should be allowed to slow cool formaximum strength and machinability.

Cutting

HIGH SPEED GOUGING AND CHAMFERINGELECTRODE

General CharacteristicsA highly efficient electrode that performs with all types ofwelding machines with sufficient capacity*. The forceful


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arc-blow is produced by the special coating whicheliminates the need for compressed air or oxygen. Thesize and depth of the groove can be easily controlled.Dross practically falls off; cut is smooth, uniform and canbe done in all positions.

*Contact Technical Service at 800-343-3758 forassistance.

ApplicationsGouging and chamfering of ferrous and non-ferrousmetals. Removing unwanted or defective weld metal,preparing parts prior to welding, removing risers andreducing large areas of metal prior to machining.

Technical DataCurrent: AC or DC straight polarity (electrode -)

Amperage: 100-250

Diameter: 3/32"2.5mm

ProcedureFor clean high speed cuts use DC straight polarity(electrode - ) Hold electrode at a low angle to the work-piece (10 to 15). Point the electrode in the direction ofthe desired groove, strike the arc and push the electrodeas fast as the metal is removed. Maintain contact with theelectrode to the work-piece when gouging. The maximumdepth of the groove in a single pass should not be greaterthan the diameter of the core wire. For deep grooves, use

multiple passes.

Nickel 55

NICKEL-IRON ELECTRODE FOR WELDING CASTIRON AWS-ENiFE-CI

General Characteristics

A nickel-iron type electrode for welding cast iron in allpositions. This electrode produces welds with higherstrengths than the straight nickel electrodes. Deposits aremachinable, but harder and more resistant to abrasionthan high-nickel welds.

ApplicationsWelding cast irons and nodular iron and joining these ironsto steel and other ferrous and non- ferrous materials. Also


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for heavy sections of high-strength and engineering-gradecast iron. Commonly used to weld high-phosphorus ironsand steels, ductile iron and high-nickel alloy cast iron.

Technical Data

Current: AC or DC reverse polarity (electrode +)Amperage: 40-95 70-120Diameter: 3/32" 1/8"2.5mm 3.25mmSpecifications: AWS A5.15 Class ENiFe-CI

ProcedureWhen preheat is required, preheat cast iron parts to 600F(315C). Steels and other materials usually do not requirepreheat unless they are complicated and containexcessive stresses. Use stringer beads or narrow weavebeads. Remove slag between passes when making

multiple layers. Maintain preheat temperature during entirewelding operation; when completed allow part to cool veryslowly.

Nickel 99

NICKEL ELECTRODE FOR WELDING CAST IRON AWS- ENi-CI

General CharacteristicsA high nickel content electrode with an extruded coatingfor welding cast iron. Welds are easily produced in allpositions and the deposits are readily machined.

ApplicationsUsed to join ordinary gray irons to themselves or to otherferrous and non-ferrous materials. Also for repair ofcastings when machining is to be done after welding.Welds can be satisfactorily produced on light and medium-

size castings.

Technical DataCurrent: AC or DC reverse polarity (electrode +)

Amperage: 40-75 65-115Diameter: 3/32 1/82.5mm 3.25mmSPECIFICATIONS: AWS A5.15 Class ENi-CI


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ProcedureIn most cases preheating or post-heating will not benecessary, but in cold weather or when special machiningqualities are desired the part should be preheated to400F (204C) Stringer beads and intermittent welds

should be employed to reduce stresses and cracks;peening while still hot also helps reduce these problems.

Allow part to cool slowly.

Problem Solver

THE STRONGEST, PROBLEM SOLVING, UNIVERSALELECTRODE FOR ALL STEELS

General CharacteristicsA low heat input electrode designed to produce the highesttensile welds. It can be used in all positions to producesmooth, porosity free welds without undercut or spatter.

ApplicationsWelding low, medium, and high alloy steels requiring thehighest strength and quality. Ideal for repair of springs,carbon steels, stainless steels, and as an underlayment orbuffer prior to applying hardfacing alloys. Commonly used

for joining stainless steels of unknown analysis and thesesteels to carbon steels. Ideal for broken stud removal.

Technical DataTypical Tensile Strength: as welded up to 120,000 psi (84kg/mm2)work hardens up to 180,000 psi (126 kg/mm2)Typical Yield Strength: up to 90,000 psi (63 kg/mm2)Elongation %: approx. 28Typical Hardness (HB): approx. 300Current: AC or DC reverse polarity (electrode+)

Amperage: 65-120

Diameter: 1/8"3.25mm

ProcedurePrepare joint area by removing foreign material. Bevelheavy sections to form a 90 vee. Preheat high carbonsteels to 400F (204C). Use jigs, fixtures and tack weldsto maintain alignment. Hold a short arc. Stringer beads arepreferred to prevent overheating. Allow to cool before


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removing slag. Deposits will take a high polish whensubjected to wear. All welds on stainless steel should becleaned with a stainless steel wire brush.

RustBuster

PREMIUM, HIGH STRENGTH, ALL POSITIONELECTRODE FOR QUALITY WELDS ON VERY DIRTY,RUSTY AND PAINTED STEELS

General CharacteristicsThe special premium coating on Rustbuster allows it to

weld over extremely dirty, greasy, oil soaked and/or rustysteels. It can also weld over its own slag without causinginclusions or slag interference. The low amperagecapability makes it excellent for poor fit-up applicationsand use on low, open circuit voltage buzz boxes. It is notnecessary to chip slag between passes.

ApplicationsIdeal for maintenance applications where poor fit-up isencountered. Welds are also easily made on equipment ormachines that are covered with grease and sand that cantbe cleaned before welding. Designed for machine and

automotive repair as well as general construction andfabrication.

Technical DataTypical Tensile Strength: up to 85,000 psi (58 kg/mm2)Typical Yield Strength: up to 69,000 psi (48 kg/mm2)Elongation %: . approx. 25Current: AC or DC (either polarity)

Amperage: 20-100 30-1403/32" 1/8"2.5mm 3.25mmDeposition Rate:(lbs. per hour) 1.2-2.0 1.9-2.6

ProcedureIf possible, clean the weld areas as much as is practical.Set the amperage to the specific requirements. If an edgebuild-up is required or it is thin steel, use the lower end ofthe amperage range. If heavy penetration is required orthe weld area is extremely dirty use the higher end of theamperage range. A close to medium arc gap should bemaintained. Slag chipping is recommended, but not


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necessary on multi-pass applications.

Steel

PREMIUM QUALITY, EASIEST-TO-USE, ALL POSITIONELECTRODE FOR MILD STEEL

General CharacteristicsThis electrode has been designed to operate on almostany AC or DC welding machine even when the opencircuit voltage is very low. Thespecial coating protects the weld deposit from adverse

conditions normally encountered in maintenance repairwelding. Low amperage requirement controls distortionwhen welding thin sheet metal. Virtually no spatter.Easiest to use electrode for out-of-position welding. Idealfor field work.

ApplicationsIdeal for fabrication of thin and medium gauge mild steels.Plate and angle iron can be easily welded in all positions.

Also used for filling holes or build up of worn or overmachined low carbon steel surfaces.

Technical DataTypical Tensile Strength: up to 80,000 psi (56 kg/mm2)Typical Yield Strength: up to 68,000 psi (47 kg/mm2)Elongation%: approx. 24Current: AC or DC either polarity

Amperage: 35-80 65-1253/32" 1/8"2.5mm 3.25mm

ProcedureClean weld area of all contaminants (rust, etc.) prior towelding. DC reverse polarity (electrode +) produces deep

penetration; DC straight polarity (electrode - ) will havelimited penetration and a flatter bead. AC prevents arcblow. A medium arc length should be maintained witheither stringer or weave beads. Slag is easily removedwith a light chipping hammer.


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WearFacing

SUPERIOR HIGH ALLOY ELECTRODE FOR MEDIUMIMPACT AND SEVERE ABRASION

General CharacteristicsHigh deposition rate electrode that produces smoothbeads and in most cases the slag comes off all by itself.The arc is easily controlled and prevents excessive dilutionwith the base metal. The high chromium content of theseelectrodes makes the weld deposits maintain theirresistance even at elevated temperatures.

ApplicationsParts subjected to severe abrasion but with light impact

such as equipment for processing soil, rock, coal, cement,ceramic matter, grinding plates, dredger teeth, conveyorand press screws, coal augers, agitators, earth augers andscrapers, snowmobile wear bars and snowplow edges.

Technical DataTypical Hardness as welded: Rc 56-60Current: AC or DC reverse polarity (electrode +)

Amperage: 80-125Diameter: 1/8"3.25mm

ProceduresRemove foreign material and unsound metal from surfaceto be welded. For best results and long service life anelastic cushion layer should be applied to the part beforesurfacing with this electrode. Use Problem Solver for acushion layer on carbon steels and manganese steels, oncast iron use Nickel 99. When making the final surfacewith US Forge Wearfacing keep electrode vertical to theworkpiece and maintain a short arc. Deposits must be keptthin, never more than two layers thick. To preventexcessive local heat build-up in the part, alternate weldingarea. Allow part to cool slowly.

308L Stainless Steel

GENERAL PURPOSE, LOW CARBON STAINLESSSTEEL ELECTRODE


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General CharacteristicsHigh quality general purpose stainless steel electrode witha low carbon content that has excellent welding

characteristics. The arc is very smooth and easy to controlin all positions. It has outstanding arc-starting andrestarting features with easy slag removal.

ApplicationsWelding on 302, 304, 308 and 347 stainless steels.Designed for use on all normal and low carbon stainlesssteels except the molybdenum-bearing austenitic alloys.Ideal for welding materials that are subject to carbideprecipitation. Normally used to repair householdappliances, tanks, pipes and fittings.

Technical DataTypical Tensile Strength: up to 100,000 psi (70 kg/mm2)Typical Yield Strength: up to 62,000 psi (44 kg/mm2)Elongation %: approx. 40Corrosion Resistance: goodCurrent:AC or DC reverse polarity (electrode +)

Amperage: 25-35 35-50 40-90 75-1201/16" 5/64" 3/32" 1/8"1.6mm 2.0mm 2.5mm 3.25mm

ProcedureThoroughly clean weld area of all foreign material with a

stainless steel wire brush. A 60 bevel should be usedwhen butt welding parts 3/16" (5.0mm) and heavier. Donot preheat. Tack parts to maintain alignment. Hold amedium short arc with electrode tilted at 15 in thedirection of travel. Prevent excessive heat build-up duringwelding operations. Remove slag between passes. Allowto cool slowly.

E6011

ALL-POSITION, DEEP PENETRATING FAST FREEZEELECTRODE. WELDS ON RUSTY OR PAINTEDSURFACES.

General CharacteristicsE6011 quality electrode with a forceful arc to penetrate


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scale, rust, paint and other contaminants. It has excellentoperating characteristics in all positions. Use with AC orDC either polarity.

Applications

Use on galvanized steels and steels that may have scale,rust or paint on the surfaces to be welded.

Technical DataTypical Tensile Strength: up to 72,000 psi (50kg/mm2)Typical Yield Strength: 67,000 psi (48kg/mm2)Elongation (in 2 inches): 24%Current: AC or DC either polarity

Amperage: 40-85 70-135 110-1753/32" 1/8" 5/32"2.5mm 3.25mm 4.0mmSPECIFICATIONS: AWS A5.1, ASME SFA 5.1 Class

E6011

ProceduresWeld area should be as clean as possible. Set amperageto the low side of the range for thin material, to the highside for heavier sections and surfaces containing scale,rust, paint or grease. Hold medium arc length for flatposition. Use a slight weaving technique for vertical up.Vertical down requires higher amperage and fast travelspeed. Wire brush between passes.

E6013

GENERAL PURPOSE ELECTRODE FOR MILD STEEL.EXCELLENT FOR LIGHT GAUGE WORK ALLPOSITION

General CharacteristicsFor all types of mild steel fabrication. Ideal for light gauge

work. Best electrode available for vertical and overheadwelding.

ApplicationsUse for general production and repair work. Generallyused for thin sections and sheet metal. For farm, industrialand construction where light fabrication and repair work isperformed on a regular basis.


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Technical DataTypical Tensile Strength: up to 80,000 psi (56 kg/mm2)Typical Yield Strength: 68,000 psi (48 kg/mm2)Elongation: 24%Current: AC or DC either polarity

Amperage: 30-80 80-120 120-190Diameter: 3/32" 1/8" 5/32"2.5mm 3.25mm 4.0mm

ProcedureJoints should be as clean as possible and close fitting.Use DC straight polarity for shallow penetration. DCreverse polarity will give deeper penetration. Excellent foruse with low open circuit voltage AC welders. Tip theelectrode slightly in the direction of travel. Maintain a closearc gap and use either stringer beads or slight weave.Slag is virtually self releasing.

E7014

HIGH DEPOSITION MILD STEEL ELECTRODE. ALLPOSITION


Added iron powder in the coating gives this electrodeincreased deposition. Shallow penetration, quicksolidification, excellent restrike characteristics, easy slagremoval and excellent bead appearance makes thiselectrode excellent for all position work.

ApplicationsProduction and repair of mild steel. Use on farm, industrial,and construction equipment. Excellent restrikecharacteristic and drag technique makes this electrode afavorite of all welders.

Technical DataTypical Tensile Strength: up to 81,000 psi (56 kg/mm2)Typical Yield Strength: 73,000 psi (51 kg/mm2)Elongation: 26%Current: AC or DC either polarity

Amperage: 80-125 110-150 140-1903/32" 1/8" 5/32"2.5mm 3.25mm 4.0mm


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ProceduresWhile special preparation of the base metal is notnecessary in many cases, best results are obtained by firstcleaning the weld area of grease, oxides or rust. Maintaina short arc. Use stringer beads or weave beads. When

making stringer beads, a drag type technique may beused.

E7018

QUALITY, LOW HYDROGEN ELECTRODE WITHMOISTURE GUARD COATING. FOR X-RAY QUALITYWELDS ON CONSTRUCTION STEELS.

General CharacteristicsE7018 quality, iron powder low hydrogen electrodedesigned for joining construction grade and problemsteels. Product features a moisture guard coating tominimize hydrogen embrittlement and under-beadcracking. Weldability is excellent on both AC and DCreverse polarity. The first choice for x-ray quality weldsfeaturing high impact resistance.

Applications

Used primarily on carbon and medium tensile steels,especially under conditions of restraint. Excellent for highsulphur and tramp steels, boiler plate and cast steel.

Technical DataTypical Tensile Strength: up to 76,000 psi (54kg/mm2)Typical Yield Strength: 69,000 psi (49kg/mm2)Elongation (in 2 inches): 30%Current: AC or DC (reverse polarity)

Amperage: 60-100 110-150 140-2003/32" 1/8" 5/32"2.5mm 3.25mm 4.0mm

SPECIFICATIONS: AWS A5.1, ASME SFA 5.1 ClassE7018

ProcedureArea to be welded should be clean and free of surfacecontamination such as rust, scale, grease, etc. On DC,use reverse polarity (electrode +) Preheat of 400 to 450should be employed with heavy sections and hardenablegrades of base metal. For highest x-ray quality, maintain a


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short arc gap. On vertical welds, start at bottom andweave slightly while pausing at the edges. For rootpasses, set a minimum gap (3/32" for 1/8" electrodes) andrun stringer beads. For fill and cover passes, a weavingtechnique is best employed. When AC welding, it is

recommended to set the machine at the higher end of therange.

E71T-GS Flux-Cored MIG Wire

PREMIUM GASLESS, FLUX-CORED MILD STEEL, ALLPOSITION FOR MAINTENANCE AND REPAIRWELDING OF MILD STEEL AND GALVANIZED

STEELS.

General CharacteristicsThis self-shielded, flux-cored, mild steel wire is designedfor single pass, semi-automatic welding applicationsencountered by the maintenance and repair welder. It isexcellent for carbon steels, galvanized steels and zinc-coated steels. The specially formulated flux containedinside the wire eliminates the need for an externalshielding gas and provides the necessary slag to producethe same high quality weld as US Forge Steel. US Forge

Flux-Cored MIG Wire is excellent for use with smallconstant current wire feeders which are lightweight.

ApplicationsFabrication and repair of lightweight structural steel,trailers, tanks, hoppers and machinery parts. Excellent foruse on fillet and lap welds on thin gauge steel where burnthrough is a problem with other wires and electrodes. Anideal electrode to use in drafty or windy conditions wheregas-shielded wire cannot be used.

Technical Data

Typical Tensile Strength: up to 83,000 psiCurrent: DCEN (electrode-)Diameters Available: .030", .035", .045"Spool Sizes Available: 2 lb., 10lb.SPECIFICATIONS: AWS A5.20 SFA 5.20 E71T-GS

RECOMMENDED WELDING PARAMETERS:Diameter Volts Amps Wire Stickout Approx..030" 14-17 25-100 3/8" - 1/2"


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.035" 13-19 50-150 3/8" - 1/2"

.045" 15-18 75-200 1/2" - 3/4"

ER70S-6

SOLID MILD STEEL MIG WIRE

General CharacteristicsThe US Forge ER70S-6 is an excellent wire designed forsingle and multiple pass welding. It can also be used forsheet metal applications when smooth welds are needed.

A shielding gas is required when welding with this wire.

ApplicationsFabrication and repair of lightweight structural steel.Excellent choice for welding Low Carbon Steel (MildSteel). Ideal for body panel repair, fences, yard tools, etc.

Technical DataCurrent: DC ReverseShielding: Gas Co2Typical Tensile Strength: 70,000 psiTypical Yield Strength: 58,000 psiElongation: 22%

RECOMMENDED WELDING PARAMETERS:Diameter Volts Amps.023" 40 125.030" 50 150.035" 75 175

ProcedureClean area to be welded with wire brush, grinder, etc.Weld area to be free of paint, rust, grease, oil, etc. Basematerial 1/4" or thicker should be beveled prior to joining.

ER5356

ALUMINUM MIG WIRE


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The US Forge ER5356 has a high magnesium content.

This will help increase weld strength and decrease crack

sensitivity when welding on base metals; 5086, 5083 or

5456. The US Forge ER5356 also provides excellent

ductility when welding base metals; 5456, 6061, 6063,7005 and 7039.

Applications

Excellent for repair of automotive, truck and bus parts.

Also for tanks, pipes, ladders, shelves, regrigeration

equipment, foundry patterns and many other aluminum

structures. Repair of machining errors and buildup of

missing sections of casting, extrusions, plates, etc.

Technical Data

US Forge ER5356 meets AWS A5.10 ER5356

Current: DC Reverse

Shielding Gas: 100% Argon

RECOMMENDED WELDING PARAMETERS:

Diameter Volts Amps

.030" 15-22 70-110

.035" 17-24 75-115

Procedure

Use a stainless steel brush to clean the weld area. Thestainless steel brush should be used only for aluminum.

Base material 1/4" and thicker should be beveled prior to

welding.

ER308L

STAINLESS STEEL MIG WIRE

General CharacteristicsUS Forge ER308L is an excellent choice for weldingstainless steel and provides a smooth, clean and brightsurface.

ApplicationsThis wire is designed for dairy, pulp, paper, refinery and


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chemical equipment. Low carbon content reduces carbideprecipitation.

Technical DataCurrent: DC Reverse

Shielding Gas: 75% Argon, 25% Co2Amps: 40-130Volts: 14-20SPECIFICATIONS: AWS A5.9 ER308L SFA 5.9

ProcedureClean materials of foreign substances, set parameters toranges recommended (appropriate for base metalthickness and position) by machine manufacturer. Usestringer passes to minimize overheating which can causedistortion.

Definitions of Welding Terms

AC or Alternating Current:Electricity which reverses its direction based on currentcycle (sine wave). For 60 cycle current, the current goes inone direction and then in the other direction 60 times in thesame second, so that the current changes its direction 120times in one second.

Arc Blow:Magnetic disturbance of the arc which causes it to waverfrom its intended path.

Arc Length:The distance from the end of the electrode to the pointwhere the arc makes contact with the work surface.

As Welded:The condition of weld metal, welded joints and weldmentsafter welding prior to any subsequent thermal or

mechanical treatment.

Base Metal:The metal to be welded.

Butt Joint:A joint between two members aligned approximately in thesame place.


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Carbon:The addition of carbon to steel increases its ability toharden and adds strength and wear resistance.

Carbon Steel:

Steel that owes its properties chiefly to the presence ofcarbon, without substantial amounts of other alloyingelements; also termed ordinary steel, straight carbonsteel, plain carbon steel.

Chromium:Chromium raised the ultimate strength, hardness andtoughness, and adds wear resistance to steel.

Coated Electrode:A filler-metal electrode, used in arc welding, consisting of ametal core wire with a relatively thick covering which

provides protection for the molten metal and stabilizes thearc.

DC or Direct Current:Electric current which flows only in one direction. Inwelding an arc welding process wherein the power supplyat the arc is direct current.

Flat Position:The welding position used to weld from the upper side ofthe joint, the face of the weld is approximately horizontal.

Flux:Material used to prevent, dissolve, or facilitate removal ofoxides and other undesirable surface substances.

Low Carbon Steel:Steel containing 20% or less carbon. Refferred to as mildsteel.

Manganese:Manganese helps to make the steel sound, increases thedepth of hardening and makes it easier to work.

Molybdenum:Molybdenum increases red hardness, wear resistance,hardness depth, and inclines the steel to oil or airhardening.

Nickel:Nickel adds toughness and wear resistance to steel whenused in conjunction to other alloys such as chromium.


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Open-Circuit Voltage:The voltage between the output terminals of the weldingmachine when no current is flowing in the welding circuit.

Pass (also: Weld Pass):

A single progression of a welding or surfacing operationalong a joint, weld deposit or substrate. The result of apass is a weld bead, layer or spray deposit.

Peening:Mechanical working of metal by means of hammer blows.

Penetration:The distance the fusion zone extends below the surface ofthe part or parts being welded.

Porosity:

Gas pockets or voids in metal.

Postheating:A process used immediately after welding, whereby heat isapplied to the weld zone either for tempering or forproviding a controlled rate of cooling, in order to avoid ahard or brittle structure.

Reverse Polarity:The arrangement of arc welding leads wherein the work isthe negative pole and the electrode is the positive pole inthe arc circuit.

Slag Inclusion:Non-metallic solid material entrapped in weld metal orbetween weld metal and base metal.

Spatter:In arc and gas welding, the metal particles expelled duringwelding and which do not form a part of the weld.

Straight Polarity:The arrangement of arc welding leads wherein the work isthe positive pole and the electrode is the negative pole of

the arc circuit.

Stringer Bead:A type of weld bead made without appreciable transverseoscillation.

Tack Weld:A weld (generally short) made to hold parts of a weldmentin proper alignment until the final welds are made.


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Tensile Strength:The value obtained by dividing the maximum loadobserved during tensile straining by the specimen crosssectional area before straining. Also called ultimate

strength.

Underbead Crack:A crack in the heat affected zone not extending to thesurface of the base metal.

Vanadium:Retards grain growth, increases toughness, may add redhardness and permits higher hardening or quenchingtemperatures.

Weaving:

A technique of depositing weld metal in which theelectrode is oscillated.

Weld Metal:That portion of a weld which had been melted duringwelding.

Whipping:A term applied to an inward and upward movement of theelectrode which is employed in vertical welding to avoidundercut.

Yield Strength:The stress at which a material exhibits a specified limitingdeviation from proportionality of stress to strain. An offsetof 0.2% is used for many metals such as aluminum- baseand magnesium-base alloys, while a 0.5% total elongationunder load is frequently used for copper alloys.

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TROUBLESHOOTING PROCEDURES

OXYACETYLENE WELDING1. DISTORTION (fig. C-1)

Step 1. Check to see whether shrinkage of deposited metal has pulled welded parts together.

a. Properly clamp or tack weld parts to resist shrinkage.

b. Separate or preform parts sufficiently to allow for shrinkage of welds.

c. Peen the deposited metal while still hot.

Step 2. Check for uniform heating of parts during welding.

a. Support parts of structure to be welded to prevent buckling in heated sections due to weightof parts themselves.

b. Preheating is desirable in some heavy structures.

c. Removal of rolling or forming strains before welding is sometimes helpful.

Step 3. Check for proper welding sequence.

a. Study the structure and develop a definite sequence of welding.

b. Distribute welding to prevent excessive local heating.

2. WELDING STRESSESStep 1. Check the joint design for excessive rigidity.

a. Slight movement of parts during welding will reduce welding stresses.

b. Develop a welding procedure that permits all parts to be free to move as long as possible.

Step 2. Check for proper welding procedure.

a. Make weld in as few passes as practical.

b. Use special intermittent or alternating welding sequence and backstep or skip weldingprocedure.

c. Properly clamp parts adjacent to the joint. Use backup fixtures to cool parts rapidly.

Step 3. If no improper conditions exist, stresses could merely be those inherent in any weld,especially in heavy parts.

Peen each deposit of weld metal. Stress relieve finished product at 1100 to 1250F (593 to677C) 1 hour per 1.0 in. (25.4 cm) of thickness.

3. WARPING OF THIN PLATES (fig. C-2)


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Step 1. Check for shrinkage of deposited weld metal.

Distribute heat input more evenly over full length of seam.

Step 2. Check for excessive local heating at the joint.

Weld rapidly with a minimum heat input to prevent excessive local heating of the plates adjacentto the weld.

Step 3. Check for proper preparation of the joint.

a. Do not have excessive space between the parts to be welded. Prepare thin plate edges withflanged joints, making offset approximately equal to the thickness of the plates. No filler rod isnecessary for this type of joint.

b. Fabricate a U-shaped corrugation in the plates parallel to and approximately 1/2 in. (12.7mm) away from the seam. This will serve as an expansion joint to take up movement during andafter the welding operation.


a. Use special welding sequence and backstep or skip procedure.

b. Preheat material to relieve stress.

Step 5. Check for proper clamping of parts.

Properly clamp parts adjacent to the joint. Use backup fixtures to cool parts rapidly.

4. POOR WELD APPEARANCE (fig. C-3)

Step 1. Check the welding technique, flame adjustment, and welding rod manipulation.

a. Ensure the use of the proper welding technique for the welding rod used.

b. Do not use excessive heat.

c. Use a uniform weave and welding speed at all times.

Step 2. Check the welding rod used, as the poor appearance may be due to the inherentcharacteristics of the particular rod.

Use a welding rod designed for the type of weld being made.

Step 3. Check for proper joint preparation.

Prepare all joints properly.

5. CRACKED WELDS (fig. C-4)

Step 1. Check the joint design for excessive rigidity.


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Redesign the structure or modify the welding procedure in order to eliminate rigid joints.

Step 2. Check to see if the welds are too small for the size of the parts joined.

Do not use too small a weld between heavy plates. Increase the size of welds by adding morefiller metal.


a. Do not make welds in string beads. Deposit weld metal full size in short sections 8.0 to 10.0in. (203.2 to 254.0 mm) long. (This is called block sequence.)

b. Welding sequence should be such as to leave ends free to move as long as possible.

c. Preheating parts to be welded sometimes helps to reduce high contraction stresses causedby localized high temperatures.

Step 4. Check for poor welds.

Make sure welds are sound and the fusion is good.

Step 5. Check for proper preparation of joints.

Prepare joints with a uniform and proper free space. In some cases a free space is essential. Inother cases a shrink or press fit may be required.

6. UNDERCUTStep 1. Check for excessive weaving of the bead, improper tip size, and insufficient welding rodadded to molten puddle.

a. Modify welding procedure to balance weave of bead and rate of welding rod deposition, usingproper tip size.

b. Do not use too small a welding rod.

Step 2. Check for proper manipulation of the welding.

a. Avoid excessive and nonuniform weaving.

b. A uniform weave with unvarying heat input will aid greatly in preventing undercut in buttwelds.

Step 3. Check for proper welding technique -- improper welding rod deposition with nonuniform

heating.

Do not hold welding rod too near the lower edge of the vertical plate when making a horizontalfillet weld, as undercut on the vertical plate will result.

7. INCOMPLETE PENETRATION (fig. C-5)

Step 1. Check for proper preparation of joint.


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a. Be sure to allow the proper free space at the bottom of the weld.

b. Deposit a layer of weld metal on the back side of the joint, where accessible, to ensurecomplete fusion at the root of the joint.

Step 2. Check the size of the welding rod used.

a. Select proper sized welding rod to obtain a balance in the heat requirements for meltingwelding rod, breaking down side walls, and maintaining the puddle of molten metal at thedesired size.

b. Use small diameter welding rods in a narrow welding groove.

Step 3. Check to see if welding tip is too small, resulting in insufficient heat input.

Use sufficient heat input to obtain proper penetration for the plate thickness being welded.

Step 4. Check for an excessive welding speed.

Welding speed should be slow enough to allow welding heat to penetrate to the bottom of thejoint.

8. POROUS WELDS (fig. C-6)

Step 1. Check the inherent properties of the particular type of welding rod.

Use welding rod of proper chemical analysis.

Step 2. Check the welding procedure and flame adjustment.

a. Avoid overheating molten puddle of weld metal.

b. Use the proper flame adjustment and flux, if necessary, to ensure sound welds.

Step 3. Check to see if puddling time is sufficient to allow entrapped gas, oxides, and slaginclusions to escape to the surface.

a. Use the multilayer welding technique to avoid carrying too large a molten puddle of weldmetal.

b. Puddling keeps the weld metal longer and often ensures sounder welds.

Step 4. Check for poor base metal.

Modify the normal welding procedure to weld poor base metals of a given type.

9. BRITTLE WELDSStep 1. Check for unsatisfactory welding rod, producing air-hardening weld metal.

Avoid welding rods producing air-hardening weld metal where ductility is desired. High tensilestrength, low alloy steel rods are air-hardened and require proper base metal preheating,postheating, or both to avoid cracking due to brittleness.


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Step 2. Check for excessive heat input from oversized welding tip, causing coarse-grained andburnt metal.

Do not use excessive heat input, as this may cause coarse grain structure and oxide inclusionsin weld metal deposits.

Step 3. Check for high carbon or alloy base metal which has not been taken into consideration.

Welds may absorb alloy elements from the patent metal and become hard. Do not weld a steelunless the composition and characteristics are known.

Step 4. Check for proper flame adjustment and welding procedure.

a. Adjust the flare so that the molten metal does not boil, foam, or spark.

b. A single pass weld maybe more brittle than multilayer weld, because it has not been refinedby successive layers of weld metal.

10. POOR FUSION (fig. C-7)

Step 1. Check the welding rod size.

When welding in narrow grooves, use a welding rod small enough to reach the bottom.

Step 2. Check the tip size and heat input.

Use sufficient heat to melt welding rod and to break down sidewalls of plate edges.

Step 3. Check the welding technique.

Be sure the weave is wide enough to melt the sides of the joint thoroughly.

Step 4. Check for proper preparation of the joint.

The deposited metal should completely fuse with the side walls of the plate metal to form aconsolidated joint of base and weld metal.

11. CORROSIONStep 1. Check the type of welding rod used.

Select welding rods with the proper corrosion resistance properties which are not changed bythe welding process.

Step 2. Check whether the weld deposit is proper for the corrosive fluid or atmosphere.

a. Use the proper flux on both parent metal and welding rod to produce welds with the desiredcorrosion resistance.

b. Do not expect more from the weld than from the parent metal. On stainless steels, usewelding rods that are equal to or better than the base metal in corrosion resistance.


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c. For best corrosion resistance, use a filler rod whose composition is the same as the basemetal.

Step 3. Check the metallurgical effect of welding.

When welding 18-8 austenitic stainless steel, be sure the analysis of the steel and the welding

procedure are correct, so that the welding process does not cause carbide precipitation. Thiscondition can be corrected by annealing at 1900 to 2100F (1038 to 1149C).

Step 4. Check for proper cleaning of weld.

Certain materials such as aluminum require special procedures for thorough cleaning of all slagto prevent corrosion.

12. BRITTLE JOINTSStep 1. Check base metal for air hardening characteristics.

In welding on medium carbon steel or certain alloy steels, the fusion zone may be hard as the

result of rapid cooling. Preheating at 300 to 500F (149 to 260C) should be resorted to beforewelding.

Step 2. Check welding procedure.

Multilayer welds will tend to anneal hard zones. Stress relieving at 1000 to 1250F (538 to677C) after welding generally reduce hard areas formed during welding.

Step 3. Check type of welding rod used.

The use of austenitic welding rods will often work on special steels, but the fusion zone willgenerally contain an alloy which is hard.

ARC WELDING13. DISTORTION (fig. C-1)Step 1. Check for shrinkage of deposited metal.

a. Properly tack weld or clamp parts to resist shrinkage.

b. Separate or preform parts so as to allow for shrinkage of welds.

c. Peen the deposited metal while still hot.

Step 2. Check for uniform heating of parts.

a. Preheating is desirable in some heavy structures.

b. Removal of rolling or forming strains by stress relieving before welding is sometimes helpful.

Step 3. Check the welding sequence.

a. Study structure and develop a definite sequence of welding.

b. Distribute welding to prevent excessive local heating.


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14. WELDING STRESSESStep 1. Check for excessive rigidity of joints.

a. Slight movement of parts during welding will reduce welding stresses.

b. Develop a welding procedure that permits all parts to be free to move as long as possible.

Step 2. Check the welding procedure.

a. Make weld in as few passes as practical.

b. Use special intermittent or alternating welding sequence and backstep or skip procedures.

c. Properly clamp parts adjacent to the joint. Use backup fixtures to cool parts rapidly.

Step 3. If no improper conditions exist, stresses could merely be those inherent in any weld,especially in heavy parts.

a. Peen each deposit of weld metal.

b. Stress relieve finished product at 1100 to 1250F (593 to 677C) 1 hour per 1.0 in. (25.4 cm)of thickness.

15. WARPING OF THIN PLATES (fig. C-2)Step 1. Check for shrinkage of deposited weld metal.

Select electrode with high welding speed and moderate penetrating properties.

Step 2. Check for excessive local heating at the joint.

Weld rapidly to prevent excessive local heating of the plates adjacent to the weld.

Step 3. Check for proper preparation of joint.

a. Do not have excessive root opening in the joint between the parts to be welded.

b. Hammer joint edges thinner than the rest of the plates before welding. This elongates theedges and the weld shrinkage causes them to pull back to the original shape.


a. Use special intermittent or alternating welding sequence and backstep or skip procedure.

b. Preheat material to achieve stress.

Step 5. Check the clamping of parts.

Properly clamp parts adjacent to the joint. Use backup fixtures to cool parts rapidly.

16. POOR WELD APPEARANCE (fig. C-3)Step 1. Check welding technique for proper current and electrode manipulation.


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a. Ensure the use of the proper welding technique for the electrode used.

b. Do not use excessive welding current.

c. Use a uniform weave or rate of travel at all times.

Step 2. Check characteristics of type of electrode used.

Use an electrode designed for the type of weld and base metal and the position in which theweld is to be made.

Step 3. Check welding position for which electrode is designed.

Do not make fillet welds with downhand (flat position) electrodes unless the parts are positionedproperly.

Step 4. Check for proper joint preparation.

Prepare all joints properly.

17. CRACKED WELDS (fig. C-4)Step 1. Check for excessive rigidity of joint.

Redesign the structure and modify the welding procedure in order to eliminate rigid joints.

Step 2. Check to see if the welds are too small for the size of the parts joined.

Do not use too small a weld between heavy plates. Increase the size of welds by adding morefiller metal.


a. Do not make welds in string beads. Deposit weld metal full size in short sections 8.0 to 10.0in. (203.2 to 254.0 mm) long. (This is called block sequence.)

b. Welding sequence should be such as to leave ends free to move as long as possible.

c. Preheating parts to be welded sometimes helps to reduce high contraction stresses causedby localized high temperature.

d. Fill all craters at the end of the weld pass by moving the electrode back over the finished weldfor a short distance equal to the length of the crater.

Step 4. Check for poor welds.

Make sure welds are sound and the fusion is good. Be sure arc length and polarity are correct.

Step 5. Check for proper preparation of joints.

Prepare joints with a uniform and proper root opening. In some cases, a root opening isessential. In other cases, a shrink or press fit may be required.


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18. UNDERCUTStep 1. Check the welding current setting.

Use a moderate welding sent and do not try to weld at too high a speed.

Step 2. Check for proper manipulation of the electrode.

a. Do not use too large an electrode. If the puddle of molten metal becomes too large, undercutmay result.

b. Excessive width of weave will cause undercut and should not be used. A uniform weave, notover three times the electrode diameter, will aid greatly in preventing undercut in butt welds.

c. If an electrode is held to near the vertical plate in making a horizontal fillet weld, undercut onthe vertical plate will result.

19. POOR PENETRATION (fig. C-5)Step 1. Check to see if the electrode is designed for the welding position being used.

a. Electrodes should be used for welding in the position for which they were designed.

b. Be sure to allow the proper root openings at the bottom of a weld.

c. Use a backup bar if possible.

d. Chip or cut out the back of the joint and deposit a bead of weld metal at this point.

Step 2. Check size of electrode used.

a. Do not expect excessive penetration from an electrode.

b. Use small diameter electrodes in a narrow welding groove.

Step 3. Check the welding current setting.

Use sufficient welding current to obtain proper penetration. Do not weld too rapidly.

Step 4. Check the welding speed.

Control the welding speed to penetrate to the bottom of the welded joint.

20. POROUS WELDS (fig. C-6)Step 1. Check the properties of the electrode used.

Some electrodes inherently produce sounder welds than others. Be sure that proper electrodesare used.

Step 2. Check welding procedure and current setting.

A weld made of a series of string beads may contain small pinholes. Weaving will ofteneliminate this trouble.


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Step 3. Check puddling time to see whether it is sufficient to allow entrapped gas to escape.

Puddling keeps the weld metal molten longer and often insures sounder welds.

Step 4. Check for dirty base metal.

In some cases, the base metal may be at fault. Check this for segregations and impurities.

21. BRITTLE WELDSStep 1. Check the type of electrode used.

Bare electrodes produce brittle welds. Shielded arc electrodes must be used if ductile welds arerequired.


Do not use excessive welding current, as this may cause coarse-grained structure and oxidizeddeposits.

Step 3. Check for high carbon or alloy base metal which has not been taken into consideration.

a. A single pass weld may be more brittle than a multilayer weld because its microstructure hasnot been refined by successive layers of weld metal.

b. Welds may absorb alloy elements from the parent metal and become hard.

c. Do not weld a metal unless the composition and characteristics are known.

22. POOR FUSION (fig. C-7)Step 1. Check diameter of electrode.

When welding in narrow groove joints use an electrode small enough to properly reach thebottom of the joint.


a. Use sufficient welding current to deposit the metal and penetrate into the plates.

b. Heavier plates require higher current for a given electrode than light plates.

Step 3. Check the welding technique.

Be sure the weave is wide enough to melt the sidewalls of the joint thoroughly.

Step 4. Check the preparation of the joint.

The deposited metal should fuse with the base metal and not curl away from it or merely adhereto it.

23. CORROSIONStep 1. Check the type of electrode used.


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a. Bare electrodes produce welds that are less resistant to corrosion than the parent metal.

b. Shield arc electrodes produce welds that are more resistant to corrosion than the parentmetal.

c. For the best corrosion resistance, use a filler rod whose composition is similar to that of the

base metal.

Step 2. Check to see if the weld metal deposited is proper for the corrosive fluid or atmosphereto be encountered.

Do not expect more from the weld than you do from the parent metal. On stainless steels, useelectrodes that are equal to or better than the parent metal in corrosion resistance.

Step 3. Check on the metallurgical effect of the welding.

When welding 18-8 austenitic stainless steel, be sure the analysis of the steel and weldingprocedure is correct, so that the welding does not cause carbide precipitations. Carbide

precipitation is the rising of carbon to the surface of the weld zone. This condition can becorrected by annealing at 1900 to 2100F (1038 to 1149C) after welding. By doing thiscorrosion in the form of iron oxide, or rust, can be eliminated.

Step 4. Check for proper cleaning of the weld.

Certain materials, such as aluminum, require careful cleaning of all slag after welding to preventcorrosion in service.

24. BRITTLE JOINTSStep 1. Check for air hardening of the base metal.

In medium carbon steel or certain alloy steals, the heat affected zone may be hard as a result ofrapid cooling. Preheating at 300 to 500F (149 to 260C) should be resorted to before welding.


a. Multilayer welds will tend to anneal hard heat affected zones.

b. Stress relieving at 1100 to 1250F (593 to 677C) after welding will generally reduce hardareas formed during welding.

Step 3. Check the type of electrode used.

The use of austenitic electrodes will often be successful on special steels, but the heat-affected

zone will generally contain an alloy which is hard.

25. MAGNETIC BLOWStep 1. Check for deflection of the arc from its normal path, particularly at the ends of joints andin corners.

a. Make sure the ground is properly located on the work. Placing the ground in the direction ofthe arc deflection is often helpful.


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b. Separating the ground into two or more parts is helpful.

c. Weld toward the direction in which the arc blows.

d. Hold a short arc.

e. Changing the angle of the electrode relative to the work may help to stabilize the arc.

f. Magnetic blow is held to a minimum in alternating current welding.

26. SPATTERStep 1. Check the properties of the electrode used.

Select the proper type of electrode.

Step 2. Check to see if the welding current is excessive for the type and diameter of electrodeused.

Use a short arc but do not use excessive welding current

Step 3. Check for spalls.

a. Paint parts adjacent to welds with whitewash or other protective coating. This prevents spallsfrom welding to parts, and they can be easily removed.

b. Coated electrodes produce larger spalls than bare electrodes.

GMAW Welding Parameters

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