AISI 4140 Alloy Steel

Structural steel material 4140 alloy tool steel 42CrMo grade tool steel 42CrMo steel is ultra-high-strength steel with high strength and toughness, good hardenability, no obvious temper brittleness, high fatigue limit, and multiple impact resistance after quenching and tempering, and good low-temperature impact toughness.

Product introduction

Hot Rolled Alloy Steel Plate 1.7225 42CrMo4 4140 42CrMo

1: 4140 steel introduction
AISI SAE 4140 alloy steel is a chromium molybdenum alloy steel specification widely used in general purpose high tensile steel for components, like axles, shafts, bolts, gears and other applications. Similar to alloy grade AISI 4130 chrome moly alloy steel but with a slightly higher carbon content. The higher carbon content of AISI 4140 steel gives greater strength and heat treatment capabilities in comparison to AISI / ASTM 4130 alloy steels, however it does have inferior weldability characteristics..

2: 4140 Steel equivalent

Country	Japan	Germany	Britain	USA	China	Australia
Standard	JIS G4105	DIN 17200	BS970	ASTM A29	GB/T 3077	AS 1444
Grade	SCM440	42CrMo4/1.7225	EN19/709M40	4140	42CrMo	4140

3: 4140 steel chemical composition

Grade	C	Si	Mn	P	S	Cr	Mo	Ni
4140	0.38-0.43	0.15-0.35	0.75-1.0	0.035	0.04	0.8-1.1	0.15-0.25
42CrMo4	0.38-0.45	0.4	0.6-0.9	0.035	0.035	0.9-1.2	0.15-0.3
EN19	0.35-0.45	0.1-0.35	0.5-0.8	0.05	0.05	0.9-1.5	0.2-0.4
SCM440	0.38-0.43	0.15-0.35	0.6-0.85	0.03	0.03	0.9-1.2	0.15-0.3

4: 4140 steel mechanical properties The mechanical properties mainly include tensile strength, yield strength, elongation, area or reduction, hardness, impact value, non-metalic inclusion etc. Different heat treatment, the mechanical properties will be different, such as normalized, tempered, QT. If you want to know the properties, kindly contact the salesman. 5: 4140 steel overviews

Size	Round	Dia 6-1200mm
	Plate/Flat/Block	Thickness 6mm-500mm
		Width 20mm-1000mm
Heat treatment	Normalized ; Annealed ; Quenched ; Tempered
Surface condition	Black; Peeled; Polished; Machined; Grinded; Turned; Milled
Delivery condition	Forged; Hot rolled; Cold drawn
Test	Tensile strength, Yield strength, elongation, area of reduction, impact value, hardness, grain size, ultrasonic test, US inspection, magnetic particle testing, etc.
Application	4140 alloy steels are used for Components, Adapters, Arbors,strippers, holder blocks, mold bases, ejectors, back up and support tooling, fixtures, jigs, molds, cams, drill collars, Axle Shafts, Bolts, Crankshafts,stubs, couplings, reamer bodies, axles, shafting, piston rods, rams, hydraulic machinery shafts, gears, sprockets, gear racks, chain links, spindles, tool bodies, tool holders, tie rods, Connection Rods, Chuck Bodies, Collets, Conveyor Pins & Rolls, Ejector Pins, Forks, Gears, Guide Rods, Hydraulic Shafts & Parts,Lathe Spindles, Logging Parts, Milling Spindles, Motor Shafts, Nuts, Pinch Bars, Pinions, Pump Shafts,boring bars,tracks, slides, wear strips or parts, forming dies, brake dies, trim dies, bolsters, machinery parts and components, etc..

5. 4140 Steel Application
4140steel finds many applications as forgings for the aerospace,oil and gas,automotive, agricultural and defense industries etc.
Typical applications for Scm440 steel uses include:forged gears,spindles,fixtures,jigs,collars,Axles,conveyor parts,crow bars,logging parts,shafts,sprockets,studs,pinions,pump shafts, rams, and ring gears etc

6.Quality control:
1. Melting Process: EAF/BOF+LF+VD resulting in ingots
2. Both ends cut by saw
3. Ratio of forging:minimum 3:1
4. Grain size of final product: according to ASTM E112 more than 5,preferred more than 8
5. Ultrasonic test: As per SEP1921 Class C/c or D/d

7.Heat treatment of 4140 Steel
Quenched and Tempered (+QT) of 4140 Steel
1. Heat 4140 steel slowly to 840-875°C;
2. Soak at this temperature then quench in oil;
3. Temper as soon as 4140 reach room temperature (20°C);
4. Heat uniformly to the suitable temperature of 560°C;
5. Withdraw the material from the furnace and cool in the air.
Annealing of 4140 Alloy Steel
1. Heat the 4140 slowly to 800-850°C and allow enough time.
2. Cool slowly in the furnace to 480°C followed by air cooling