25CrMo4 / 1.7218 Steel

WALDUN is one of the top 25CrMo4 / 1.7218 Steel Manufacturers and Exporters in China. WALDUN is supplying with round,square,flat,block,and shaft etc.

25CrMo4 / 1.7218 Steel is defined as a low alloy steel which contains 1%Cr and 0.2%Mo as strengthening alloy elements.it offers good strength,toughness, corrosion resistance and machinability.Compared with AISI 4140 steel,It has lower carbon,0.28-0.33%，so it can be welded easily. 25CrMo4 / 1.7218 Steel is commonly supplied in the hardened and tempered condition with a hardness range 207-235HB.

25CrMo4 / 1.7218 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

Remark:Tolerance can be customized as per requests

Chemical Composition per EN 10083-3

GRADE	NUMBER	C	Si	Mn	P	S	Cr	Mo
25CrMo4	1.7218	0.22-0.29	≤ 0.40	0.60-0.90	≤ 0.025	≤ 0.035	0.90-1.20	0.15-0.30

25CrMo4 / 1.7218 Steel PHYSICAL PROPERTY

Density g/cm3	7.85
Melting point °C	1432
Poisson’s ratio	0.27-0.30
Machinability (AISI 1212 as 100% machinability)	70%
Specific Gravity	7.8
Thermal conductivity W/(m.K)	46
Modulus of Elasticity Tension	29

25CrMo4 / 1.7218 Steel MECHANICAL PROPERTY

	Tensile Strength Mpa	Yield Strength Mpa	Elongation %	Hardness HBW	Impact Charpy-V, -18ºC,J
60K	≥ 586	≥ 414	≥ 18	174-237	≥ 42
75K	≥ 655	≥ 517	≥ 17	197-235	≥ 42

25CrMo4 / 1.7218 Steel FORGING

Forging temperature of 25CrMo4 / 1.7218 Steel should be  carried out between 950℃-1200℃,The lower the forging-ending temperature ,the finer the grain size .Hold suitable time for the steel to be uinformly heated before forge, but don’t forge below 950℃.25CrMo4 / 1.7218 Steel should be cooled as slowly as possible after forged.

25CrMo4 / 1.7218 Steel 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 25CrMo4 / 1.7218 Steel should be carried out between 880℃-900℃. hold suitable time for the steel to be uniformly heated to  complete the ferrite to austenite transformation.Cool in still air.

25CrMo4 / 1.7218 Steel ANNEALING

25CrMo4 / 1.7218 Steel can be  annealed to  relieve stress after forging ,and obtain a good structure suitable for machining,Annealing temperature should be carried out between 800℃-850℃, hold suitable time for the steel to be heated uniformly. Cool slowly in the furnace.

25CrMo4 / 1.7218 Steel HARDENING

This heat treatment will obtain martensite structure  after quenched,it will increase the surface hardness and strength.25CrMo4 / 1.7218 Steel should be carried out between 870℃-890℃, hold suitable time for the steel to be thoroughly heated,  then quench in oil, or water.Tempering should be followed  immediately after quenched.

25CrMo4 / 1.7218 Steel TEMPERING

Tempering is usually carried out to relieve stresses from the hardening process, and will optimize hardness and mechanical properties. The actual tempering temperature will be chosen to meet the required properties.Heat the 25CrMo4 / 1.7218 Steel carefully to a suitable temperature ,usually between 400℃-570℃, soak at the temperature for 2 hours per 25mm of ruling section, then cool in air.The lower the tempering temperature the greater the strength. However, Tempering between 250-375°C is not advised as tempering within this range will seriously reduce the impact value.