Ece 121 (Steel)

University of Cebu-LMUniversity of Cebu-LMA.C. Cortez Avenue, Looc, Mandaue CityA.C. Cortez Avenue, Looc, Mandaue City

College of Allied EngineeringCollege of Allied Engineering(Electronics Engineering)(Electronics Engineering)

Report in Materials Engineering

(ECE 121)

Instructor Mr. Joseph Manbert Mendez

STEELSTEEL

STEELSTEEL Is an alloy of iron and carbon Is an alloy of iron and carbon

with the carbon being with the carbon being restricted within certain restricted within certain concentration limit. It is the concentration limit. It is the most prevalent metal used most prevalent metal used in engineering application due in engineering application due to the abundance of iron ore.to the abundance of iron ore.

Steel is made by reducing oxide ores of Steel is made by reducing oxide ores of iron by thermochemical reactions in a iron by thermochemical reactions in a blast furnace or direct reduction blast furnace or direct reduction vesselvessel

Thermochemical-Thermochemical-

Blast furnace-Blast furnace-

Steel RefiningSteel RefiningSteel Refining- Steel Refining- means making of steel from means making of steel from

pig iron, scrap, or ore.pig iron, scrap, or ore.

Two Primary Processes of steel makingTwo Primary Processes of steel making

1.1. Basic Oxygen FurnaceBasic Oxygen Furnace

--a refractory-lined vessel that can a refractory-lined vessel that can tip too pour. tip too pour.

2. Electric Arc Furnace2. Electric Arc Furnace

--

Steel Steel TerminologiesTerminologiesCARBON STEELCARBON STEEL

are simply alloys of iron and carbon are simply alloys of iron and carbon being the major strengthening agent.being the major strengthening agent.

CLASSIFICATION OF CARBON STEELSCLASSIFICATION OF CARBON STEELS

1. Plain Carbon Steel- are the non-sulfurized carbon steel.

a. Low Carbon steel- is the steel having less than 0.30% carbon. This type of steel is used for structural shapes, wires, screw machine parts, etc.

b. Medium-carbon steel- is the steel having 0.30 to 0.70% carbon. This type of steel is used for gears, axles, etc.

c. High-carbon steel- is the steel having 0.70 to 1.40% carbon. This type of steel is used for cutting tools, knives, drills, etc.

2. Free machining steel- resulfurized carbon steel.

Alloy SteelAlloy Steel

Are steel that have significant addition of Are steel that have significant addition of any element other than carbon. A steel any element other than carbon. A steel that exceeds one or more of the following that exceeds one or more of the following limits:limits:

Manganese, 1.65%, silicon 0.60%, copper Manganese, 1.65%, silicon 0.60%, copper 0.60% is also considered as alloy steel 0.60% is also considered as alloy steel according to the definition of the Steel according to the definition of the Steel Product Manual Product Manual

Classification of alloy Classification of alloy steelssteels

Low-alloy steelsLow-alloy steels

- are those with less than 8.0% total - are those with less than 8.0% total alloying ingredients.alloying ingredients.

High-alloy steelsHigh-alloy steels

- are those with more than 8.0% total - are those with more than 8.0% total alloying ingredientsalloying ingredients..

Tool SteelTool Steel As carbon or alloy steels capable of being As carbon or alloy steels capable of being

hardened and tempered.hardened and tempered.

Three Main Performances criteria of tool steels are:Three Main Performances criteria of tool steels are:1.1. Wear resistanceWear resistance2.2. Hot HardnessHot Hardness3.3. ToughnessToughness

Hot hardnessHot hardness- refers to the ability of steel to resist - refers to the ability of steel to resist

softening at high performance. Another term for softening at high performance. Another term for hot hardness ishot hardness is red hardness.red hardness.

Tool Tool SteelSteel::PREFIX /PREFIX /

GroupGroupDescriptionDescription

AA Air-hardened, medium alloy, cold-workAir-hardened, medium alloy, cold-work

DD High-carbon, high-chromiumHigh-carbon, high-chromium

HH Hot-workHot-work

LL Special purposeSpecial purpose

MM Molybdenum high speedMolybdenum high speed

OO Oil-hardened, cold workOil-hardened, cold work

PP MoldMold

SS Shock-resistingShock-resisting

TT Tungsten high-speedTungsten high-speed

WW Water-hardenedWater-hardened

RimmedRimmed Slightly deoxidized steels that solidify with an Slightly deoxidized steels that solidify with an

outer shell on the ingot that is low in impurities outer shell on the ingot that is low in impurities and very sound. These steels can be retain a good and very sound. These steels can be retain a good finish even after severe forming because of the finish even after severe forming because of the surface cleanliness.surface cleanliness.

KilledKilled Strongly deoxidized, usually by chemical additions Strongly deoxidized, usually by chemical additions

to melt.to melt.

Galvanized Galvanized Zinc coated steel products. The zinc is applied by Zinc coated steel products. The zinc is applied by

hot dipping.hot dipping.

CoilCoil Rolled steel in the thickness range of sheet or Rolled steel in the thickness range of sheet or

strip.strip.

SheetSheet Rolled steel primarily in the thickness range of Rolled steel primarily in the thickness range of

0.010 to 0.250 in. ( 0.25 to 6.4 mm) and with a 0.010 to 0.250 in. ( 0.25 to 6.4 mm) and with a width o 24 in. ( 610 mm) or more.width o 24 in. ( 610 mm) or more.

Free MachiningFree Machining Steels with additions of sulfur, lead, selenium, or Steels with additions of sulfur, lead, selenium, or

other elements in sufficient quantity that they other elements in sufficient quantity that they machine more easily than untreated grades.machine more easily than untreated grades.

Commercial QualityCommercial Quality Steels produced from standard rimmed, capped, Steels produced from standard rimmed, capped,

concast, or semikilled steel. These steels may concast, or semikilled steel. These steels may have significant segregation and variation in have significant segregation and variation in composition, and they are not made to composition, and they are not made to guaranteed mechanical property requirements.guaranteed mechanical property requirements.

GalvannealedGalvannealed Zinc-coated and heat-treated steel. There Zinc-coated and heat-treated steel. There

are usually paint-adhesion problems with are usually paint-adhesion problems with galvanized steels. The heat treatment galvanized steels. The heat treatment given to galvannealed steels creates an given to galvannealed steels creates an oxide layer that allows better paint oxide layer that allows better paint adhesion.adhesion.

Stainless steelStainless steel

Are alloy of iron, chromium and other Are alloy of iron, chromium and other elements that resist corrosion from elements that resist corrosion from many environment. For steel to many environment. For steel to qualify the stainless prefix, it must qualify the stainless prefix, it must have at least 10% chromium.have at least 10% chromium.

Classes of stainless steelClasses of stainless steel

a.a. Ferritic stainless steelsFerritic stainless steels- contain chromium in the range of - contain chromium in the range of

16% to 20%. It has low carbon content which is 16% to 20%. It has low carbon content which is less than 0.2%.less than 0.2%.

b. Martensitic stainlessb. Martensitic stainless- contain chromium in the range of - contain chromium in the range of

12% to 18%. It has a carbon as high as 1.2%.12% to 18%. It has a carbon as high as 1.2%.

c. Austenitic stainlessc. Austenitic stainless- steels have at least four major - steels have at least four major

alloying elements, namely iron, chromium, alloying elements, namely iron, chromium, carbon and nickel. The chromium content carbon and nickel. The chromium content ranges 16% to 26%.ranges 16% to 26%.

Properties of Properties of STEELSTEELHardening CharacteristicsHardening CharacteristicsSafety in HardeningSafety in Hardening

- This property rates tool steels on the - This property rates tool steels on the probability or relative risk of cracking during probability or relative risk of cracking during hardening operation.hardening operation.

Depth HardeningDepth Hardening

- - This property is a rank of hardenability.This property is a rank of hardenability.

Size Change in HardeningSize Change in Hardening- This property refers to the net size of - This property refers to the net size of

change that will occur in a part after hardening change that will occur in a part after hardening and tempering.and tempering.

Resistance to DecarburizationResistance to Decarburization- - This property rates steel on their ability to This property rates steel on their ability to

resist loss of carbon at the surface during resist loss of carbon at the surface during hardening.hardening.

Physical Properties of Stainless SteelPhysical Properties of Stainless SteelDensityDensity

--Since these alloys are iron based, the Since these alloys are iron based, the density is about the same as carbon or low-alloy density is about the same as carbon or low-alloy steels.steels.

ConductivityConductivity- - Stainless steel are fairly poor conductors of Stainless steel are fairly poor conductors of

both heat and electricity compared with carbon.both heat and electricity compared with carbon.

ExpansionExpansion- -

Modulus of ElasticityModulus of Elasticity- Stainless steel have tensile moduli slightly - Stainless steel have tensile moduli slightly

lower than those of carbon and alloy steels, 28 to lower than those of carbon and alloy steels, 28 to 29 compared with 30(x 10 psi ) .29 compared with 30(x 10 psi ) .

SteelSteel Alloying Ingredients and its Alloying Ingredients and its effecteffect

1.1.Aluminum- aids nitriding, deoxidation, restrict grain Aluminum- aids nitriding, deoxidation, restrict grain growth, removes oxygen in steel melting. (range < growth, removes oxygen in steel melting. (range < 2%)2%)

2. Boron- increase hardness (range 0.0005-0.003%)2. Boron- increase hardness (range 0.0005-0.003%)

3. Carbon- increase hardness and strength (range 0.1 3. Carbon- increase hardness and strength (range 0.1 to 4.0%)to 4.0%)

4. Chromium- increase hardness and strength (range 4. Chromium- increase hardness and strength (range 4-18%)4-18%)

5. Copper- increase atmospheric corrosion resistance, 5. Copper- increase atmospheric corrosion resistance, promotes tenacious oxide film (range 0.2 to 0.5%) promotes tenacious oxide film (range 0.2 to 0.5%)

6. Iron Sulfide- increase brittleness.6. Iron Sulfide- increase brittleness.

7. Lead- added only to aid machinability (range < 7. Lead- added only to aid machinability (range < 0.3%)0.3%)

8. Manganese- reduce brittleness, combined with sulfur 8. Manganese- reduce brittleness, combined with sulfur (range 0.23 to 0.4%)(range 0.23 to 0.4%)

9. Manganese sulfide- increase machinability (range 9. Manganese sulfide- increase machinability (range 0.08 to 0.155)0.08 to 0.155)

10. Molybdenum- increase dynamic and high- 10. Molybdenum- increase dynamic and high- temperature strength and hardness, promotes grain temperature strength and hardness, promotes grain refinement (range 0.1 to 0.55)refinement (range 0.1 to 0.55)

11. Nickel- increase toughness and hardness (range 11. Nickel- increase toughness and hardness (range 2 to 5%)2 to 5%)

12. Nitrogen- acts like carbon strengthening (range 12. Nitrogen- acts like carbon strengthening (range <0.1%)<0.1%)

13. Phosphorous- increase hardness and corrosion 13. Phosphorous- increase hardness and corrosion resistance (range 0.04-0.15%)resistance (range 0.04-0.15%)

14. Silicon- increase strength (range 0.2 to 0.7%)14. Silicon- increase strength (range 0.2 to 0.7%)

improves magnetic properties (range 1 to 5%)improves magnetic properties (range 1 to 5%)

15. Sulfur- adds machinability (range < 0.5%)15. Sulfur- adds machinability (range < 0.5%)

16. Titanium- fix carbon in inert particles, reduce 16. Titanium- fix carbon in inert particles, reduce martensitic hardness.martensitic hardness.

17. Tungsten- increase high temperature hardness.17. Tungsten- increase high temperature hardness.

18. Vanadium- increase strength, promotes grain 18. Vanadium- increase strength, promotes grain refinement (range 0.1 to 0.3%)refinement (range 0.1 to 0.3%)

Steel IdentificationSteel Identification

Letters prefixes and suffixes in steel Letters prefixes and suffixes in steel identificationidentificationPrefixPrefix MeaningMeaning

EE Made in an electric furnaceMade in an electric furnace

XX Composition varies from normal limitsComposition varies from normal limits

SuffixSuffix MeaningMeaning

HHSteel will meet certain hardenability Steel will meet certain hardenability requirementsrequirements

OTHER LETTERSOTHER LETTERS MeaningMeaning

xxBxxxxBxx Steel with boron as an alloying Steel with boron as an alloying elementelement

xxLxxxxLxx Steel with lead additions to aid Steel with lead additions to aid machinabilitymachinability

AISI- SAEAISI- SAE Steel Designation Steel Designation

AISI-SAE AISI-SAE stands forstands for ( ( American Iron and Steel Institute – American Iron and Steel Institute – Society of Automotive Engineers)Society of Automotive Engineers)

1.1. CarbonCarbon SteelSteel

SeriesSeries Major ConstituentsMajor Constituents

10xx10xx Nonsulfurized Nonsulfurized carbon steelcarbon steel

11xx11xx Resulfurized carbon Resulfurized carbon steelsteel

12xx12xx Resulfurized and Resulfurized and rephosphorized rephosphorized carbon steelcarbon steel

2. Alloy steel2. Alloy steel

a. Manganesea. Manganese

b. Nickelb. Nickel

SeriesSeries Major ConstituentsMajor Constituents

13xx13xx Manganese 1.75%Manganese 1.75%

15xx15xx Manganese 1.00%Manganese 1.00%

SeriesSeries Major ConstituentsMajor Constituents

23xx23xx Nickel 3.50%Nickel 3.50%

25xx25xx Nickel 5.00%Nickel 5.00%

c. Nickel-chromiumc. Nickel-chromium

SeriesSeries Major ConstituentsMajor Constituents

31xx31xx Nickel 1.25%, Chromium Nickel 1.25%, Chromium 0.65% or 0.8%0.65% or 0.8%

33xx33xx Nickel 3.50%, Chromium Nickel 3.50%, Chromium 1.55%1.55%

d. Molybdenumd. MolybdenumSeriesSeries Major ConstituentsMajor Constituents

40xx40xx Molybdenum 0.25%Molybdenum 0.25%

41xx41xx Chromium 0.5 to 0.95%, Chromium 0.5 to 0.95%, molybdenum 0.12 to 0.20%molybdenum 0.12 to 0.20%

43xx43xx Nickel 1.80%,Nickel 1.80%,

Chromium 0.5 to 0.8%, Chromium 0.5 to 0.8%, molybdenum 0.25%molybdenum 0.25%

46xx46xx Nickel 1.80%, molybdenum 0.25%Nickel 1.80%, molybdenum 0.25%

48xx48xx Nickel 3.50%, molybdenum 0.25%Nickel 3.50%, molybdenum 0.25%

e. Chromiume. Chromium f. Chromium - Vanadiumf. Chromium - Vanadium

SeriesSeries Major Major ConstituentsConstituents

50xx50xx Chromium Chromium 0.38 or 0.38 or 0.40%0.40%

51xx51xx Chromium Chromium 0.80, 0.88, 0.80, 0.88, 0.93, 0.95 or 0.93, 0.95 or 1.00%1.00%

52xxx52xxx Chromium Chromium 1.45%1.45%

SeriesSeries Major Major ConstituentsConstituents

61xx61xx Chromium 0.80 Chromium 0.80 or 0.95 %, or 0.95 %, vanadium 0.10 vanadium 0.10 or 0.15 min.or 0.15 min.

g. Multiple Alloyg. Multiple Alloy

SeriesSeries Major ConstituentsMajor Constituents

86xx86xx Nickel 0.55%, chromium 0.50%, Nickel 0.55%, chromium 0.50%, molybdenum 0.20%molybdenum 0.20%

87xx87xx Nickel 0.55%, chromium 0.50%, Nickel 0.55%, chromium 0.50%, molybdenum 0.25%molybdenum 0.25%

92xx92xx Silicon 2.00% or 1.40% and Silicon 2.00% or 1.40% and chromium 0.7%chromium 0.7%

93xx93xx Manganese 1.00%, nickel 0.45%, Manganese 1.00%, nickel 0.45%, chromium .40%, molybdenum 0.12%chromium .40%, molybdenum 0.12%

94Bxx94Bxx Nickel 0.45%, chromium 0.40%, Nickel 0.45%, chromium 0.40%, molybdenum 0.12%molybdenum 0.12%

3. Heat and Corrosion- Resistant Steels3. Heat and Corrosion- Resistant Steels

SeriesSeries Major ConstituentsMajor Constituents

2xx2xx Chromium-nickel-manganese Chromium-nickel-manganese (nonhardenable, austenitic, (nonhardenable, austenitic, nonmagnetic)nonmagnetic)

3xx3xx Chromium-nickel Chromium-nickel (nonhardenable, austenitic, (nonhardenable, austenitic, nonmagnetic)nonmagnetic)

4xx4xx Chromium (hardenable, Chromium (hardenable, martenistic, magnetic)martenistic, magnetic)

4xx4xx Chromium (generally not Chromium (generally not hardenable, ferritic, magnetichardenable, ferritic, magnetic

5xx5xx Chromium (low chromium, heat-Chromium (low chromium, heat-resistance) resistance)

REPORTERS:REPORTERS:

Angie RubioAngie Rubio

Charles More GomezCharles More Gomez

JerwinJerwin

Neil BautistaNeil Bautista