63.5mm 65mm ASTM 4140 42CrMo 40CrNiMoA Steel Rod Alloy Bar Carbon Steel Round Flat Bar

• Customization: Available
• Type: Round
• Standard: AISI, ASTM, DIN, JIS, GB, BS
• Composition: Stainless Steel Scrap
• Technique: Forged
• Shape: Plate
• Surface Treatment: Polished
• Special Use: High-strength Steel Plate, Wear Resistant Steel, Silicon Steel, Cold Heading Steel, Free Cutting Steel, Mold Steel
• Application: Tool Steel Bar
• Surface: Milled/Bright/Black
• Length: 1-10m
• Transport Package: Wooden
• Specification: 6-400mm
• Trademark: Smooth
• Origin: China
• HS Code: 7214100000
• Production Capacity: 5000 Ton/Year

Product Description

Introduction:  

AISI 4140 steel Manufacturer and Exporter,supplied with round,square,flat,block,and shaft etc.AISI 4140 is defined as a low alloy steel which has 1% Cr-Mo as strengthening alloy elements.Compared with AISI 4130, it has a higher carbon content with good balance of strength, toughness ,abrasion and impact resistance and heat treatment capabilities,but poor in weldability characteristics.AISI 4140 is generally supplied in quenched and tempered condition with hardness 28-32HRC.

1.Supply Form & Size & Tolerance

Supply Form	Size(mm)	Process	Tolerance
Round	Φ6-Φ100	Cold Drawn	Bright/Black	Best H11
	Φ16-Φ350	Hot Rolled	Black	-0/+1mm
			Peeled/ground	Best H11
	Φ90-Φ1000	Hot Forged	Black	-0/+5mm
			Rough Turned	-0/+3mm
Flat/Square/Block	Thickness :120-800	Hot Forged	Black	-0/+8mm
	Width:120-1500		Rough Machined	-0/+3mm

Remark:Tolerance can be customized as per requests
2.Chemical Composition

Standard	Grade	C	Si	Mn	P	S	Cr	Ni	Mo
ASTM A29	4140	0.38-0.43	0.15-0.35	0.75-1.00	≤ 0.035	≤ 0.04	0.8-1.1	-	0.15-0.25
EN10083	42CrMo4	0.38-0.45	≤ 0.4	0.6-0.90	≤ 0.025	≤ 0.035	0.9-1.2	-	0.15-0.30
	1.7225
JIS G4105	SCM440	0.38-0.43	0.15-0.35	0.6-0.85	≤ 0.035	≤ 0.04	0.9-1.2	-	0.15-0.30
GB 3077	42CrMo	0.38-0.45	0.17-0.37	0.5-0.80	≤ 0.035	≤ 0.035	0.9-1.2	-	0.15-0.25
BS 970	EN19	0.35-0.45	0.15-0.35	0.5-0.80	≤ 0.035	≤ 0.035	0.9-1.5	-	0.2-0.40

3.Physical Property

Density g/cm3	7.85
Melting point °C	1416
Poisson's ratio	0.27-0.30
Machinability (AISI 1212 as 100% machinability)	65%
Thermal expansion co-efficient µm/m°C	12.2
Thermal conductivity W/(m.K)	46
Modulus of elasticity 10^3 N/mm2	210
Electric resistivity Ohm.mm2 /m	0.19
Specific heat capacity J/(kg.K)	460
Modulus of elasticity 10^3 N/mm2	100 ºC	200 ºC	300 ºC	400 ºC	500 ºC
	205	195	185	175	165
Thermal expansion 10^6 m/(m.K)	100 ºC	200 ºC	300 ºC	400 ºC	500 ºC
	11.1	12.1	12.9	13.5	13.9

4. Mechanical Property

Mechanical Condition	R	S	S	T	U	V	W
Ruling Section mm	250	250	150	100	63	30	20
Tensile Strength Mpa	700-850	770-930	770-930	850-1000	930-1080	1000-1150	1080-1230
Yield Strength Mpa Min	480	540	570	655	740	835	925
Elongation %	15	13	15	13	12	12	12
Izod Impact J Min	34	27	54	54	47	47	40
Charpy Impact J Min	28	22	50	50	42	42	35
Hardness Brinell HB	201-255	233-277	233-277	248-302	269-331	293-352	311-375

5.High Temperature Strength

For quenched and tempered heavy forgings
Diameter mm	Yield strength MPa
	20 ºC	100 ºC	200 ºC	250 ºC	300 ºC	350ºC	400ºC
≤250	510	486	461	441	422	392	363
250-500	460	431	412	402	382	353	324
500-750	390	333	333	324	304	275	245

6.Forging
Forging temperature should be carried out between 900ºC-1200ºC,The lower the forging-ending temperature ,the finer the grain size .Hold the temperature till uniform before forge,minimum forging temperature 850°C,so don't forge below 850ºC.AISI 4140 steel  should be cooled as slowly as possible in still air or in sand after forged.
7.Normalizing
Normalizing is used to refine the structure of forgings that might have cooled non-uniformly after forged,and considered as a conditioning treatment before final heat treatment.Normalizing temperature for AISI 4140 steel should be carried out between 870ºC-900ºC. hold suitable time for the steel to be thoroughly heated to  complete the ferrite to austenite transformation.Cool in still air.
8.Annealing
After Forged,AISI 4140 steel  may be annealed .Annealing temperature should be carried out between 800ºC-850ºC, hold suitable time for the steel to be thoroughly heated. Cool slowly in the furnace.This treatment will form a structure suitable for machining.The maximum Hardness is 241 HB.
9.Hardening
This heat treatment will obtain martensite structure  after quenched.It should be carried out between 840ºC-875ºC, hold suitable time for the steel to be thoroughly heated, soak for 10-15 minutes per 25 mm section, and quench in oil, water, or polymer as required.Tempering should be followed  immediately after quenched.
10.Tempering
Tempering is usually carried out to relieve stresses from the hardening process, but primarily to obtain the required  hardness and mechanical properties. The actual tempering temperature will be chosen to meet the required properties.Heat the AISI 4140 carefully to a suitable temperature ,usually between 550ºC-700ºC, soak at the temperature for 2 hours per 25mm of ruling section, then cool in air.Tempering between 250ºC-375ºC is not avoided as tempering within this range will seriously reduce the impact value,result in temper brittleness .
11.Application
AISI 4140 steel finds many applications as forgings for the aerospace,oil and gas,automotive, agricultural and defense industries etc.
Typical applications for 4140 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