SAE / AISI 4150 Steel

AISI 4150 steel is a higher carbon variation of the chromium, manganese, molybdenum 4100 series of low alloy steels.It has high strength,toughness,and high hardenability,and also has good machinability in annealed or normalized conditions.AISI 4150 steel can be welded using all conventional techniques. The mechanical properties of this steel can be affected if it is welded in the hardened condition. Post-weld heat treatment should be performed followed by an approved welding procedure.

Typical Application:

• For automotive and aircraft components with high toughness as tyres, rings, axles, bushes, shafts, steering components.
• Statically and dynamically stressed components for vehicles, engines and machines
• For parts of larger cross-sections. Components for driving gears, axles, rolls, rings.

AISI 4150 Steel Supply Form & Size

Form of Supply	Size(mm)	Length(mm)
Round bar	Φ6-Φ1,000	3,000-10,000
Square bar	100×100-600×600	3,000-6,000
Plate/Sheet	Thickness :20-400 Width:80-1,000	2,000-6,000
Flat bar/Blcoks	Thickness :120-800 Width:120-1,500	2,000-6,000

Surface Finish&Tolerance

Surface Finish	Black-Forged	Black-Rolled	Turned	Grinding	Polished	Peeled	Cold Drawn
Tolerance	(0，+5mm)	(0，+1mm)	(0，+3mm)	Best h9	Best h11	Best H11	Best H11

Chemical Composition per ASTM A29

GRADE	C	Si	Mn	P	S	Cr	Mo
4150	0.48-0.53	0.15-0.35	0.75-1.00	≤ 0.035	≤ 0.040	0.80-1.10	0.15-0.25

AISI 4150 Steel Mechanical Property

Diameter d mm	≤ 16	16-40	40-100	100-160	160-250
Thickness t mm	< 8	8-20	20-60	60-100	100-160
Yield Strength Mpa	≥900	≥780	≥700	≥650	≥550
Tensile Strength Mpa	1100-1300	1000-1200	900-1100	850-1000	800-950
Elongation, %	≥9	≥10	≥12	≥13	≥13
Reduction of area ,%	≥40	≥45	≥50	≥50	≥50
impact,J		≥30	≥30	≥30	≥30
Hardness,HB	331-380	298-359	271-331	253-298	240-286

Forging for AISI 4150 Steel

• Preheat AISI 4150 steelengineering steel uniformly and slowly;
• Increase the forging temperature up to 1150-1200°C;
• hold suitable time for the steel to be thoroughly heated before forge;
• Reheat steel  when temperature  below 950°C;
• Cooling as slowly as possible in sand after forged.

Heat Treatment

Soft Annealing

• Heat the steel  to 680-720°C uniformly and slowly
• hold suitable time for the steel to be thoroughly heated
• cool slowly in furnace
• maximum Brinell hardness of 248.

Normalizing: 840-860°C,cool in air

Hardening:820 – 860°C,oil quench

Tempering:540-680°C,cool in air

Hardness after heat treatment

• Annealed at 815°C: 197 HB
• Normalized at 870°C: 321 HB
• Oil quenched, fine grained, tempered at 205°C: 530 HB
• Oil quenched, fine grained, tempered at 315°C: 495 HB
• Oil quenched, fine grained, tempered at 425°C: 440 HB
• Oil quenched, fine grained, tempered at 540°C: 370 HB
• Oil quenched, fine grained, tempered at 650°C: 290 HB