DIN 1.7225 Steel |AISI 4140 | 42CrMo4 | SCM440

DIN 1.7225 Steel : High strength, hardenability, good toughness, and small deformation during quenching. High creep strength and lasting strength at high temperature.

DIN 1.7225 Steel 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

DIN 1.7225 Steel Standard

Grade :	42CrMo4
Number:	1.7225
Classification:	Alloy special steel
Standard:	EN 10083-3: 2006 Steels for quenching and tempering. Technical delivery conditions for alloy steels EN 10132-3: 2000 Cold rolled narrow steel strip for heat treatment. Technical delivery conditions. Steels for quenching and tempering EN 10305-1: 2010 Steel tubes for precision applications. Seamless cold drawn tubes. Technical delivery conditions EN 10269: 1999 Steels and nickel alloys for fasteners with specified elevated and/or low temperature properties EN 10263-4: 2001 Steel rod, bars and wire for cold heading and cold extrusion. Technical delivery conditions for steels for quenching and tempering EN 10250-3: 2000 Open steel die forgings for general engineering purposes. Alloy special steels EN 10297-1: 2003 Seamless circular steel tubes for mechanical and general engineering purposes. Non-alloy and alloy steel tubes. Technical delivery conditions

DIN 1.7225 Steel Equivalent grades:

EU EN

USA

Germany

Japan

France

England

Italy

Spain

China

Sweden

Finland

Russia

Inter

–

DIN,WNr

JIS

AFNOR

BS

UNI

UNE

GB

SS

SFS

GOST

ISO

42CrMo4 (1.7225)

4140 4142

42CrMo4

SCM440H

42CD4

708M40 CFS11

42CrMo4

40CrMo4 F1252

42CrMo

2244

42CrMo4

35KHM 38KHM

42CrMo4

DIN 1.7225 Steel 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

DIN 1.7225 Steel 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 ℃	200 ℃	300 ℃	400 ℃	500 ℃
	205	195	185	175	165
Thermal expansion 10^6 m/(m.K)	100 ℃	200 ℃	300 ℃	400 ℃	500 ℃
	11.1	12.1	12.9	13.5	13.9

DIN 1.7225 Steel 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

DIN 1.7225 Steel High Temperature Strength

For quenched and tempered heavy forgings
Diameter mm	Yield strength MPa
	20 ℃	100 ℃	200 ℃	250 ℃	300 ℃	350℃	400℃
≤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

 

Forging

Forging temperature should be carried out between 900℃-1200℃,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 850℃.1.7225 steel should be cooled as slowly as possible in still air or in sand after forged.

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 1.7225 steel should be carried out between 870℃-900℃. hold suitable time for the steel to be thoroughly heated to  complete the ferrite to austenite transformation.Cool in still air.

Annealing

After Forged,1.7225 steel may be annealed .Annealing temperature should be carried out between 800℃-850℃, 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.

Hardening

This heat treatment will obtain martensite structure  after quenched.It should be carried out between 840℃-875℃, 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.

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 1.7225 carefully to a suitable temperature ,usually between 550℃-700℃, soak at the temperature for 2 hours per 25mm of ruling section, then cool in air.Tempering between 250℃-375℃ is not avoided as tempering within this range will seriously reduce the impact value,result in temper brittleness .

Application

1.7225 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

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