40CrNiMo - GB /T 17107-1997

Grade	40CrNiMo
Corresponding Standard	GB /T 17107-1997 Structural Steel Grades And Mechanical Property For Forgings
Classification	Alloy Steel

40CrNiMo Chemical Element Composition Content (%)

Component	C	Si	Mn	P	S	Cr	Ni	Cu	Mo
Minimum Value	0.37	0.17	0.5	-	-	0.6	1.25	-	0.15
Maximum Value	0.44	0.37	0.8	0.035	0.035	0.9	1.65	0.3	0.25

• High-quality steel——P≤0.035；S≤0.035；Cu≤0.3；Cr≤0.3；Ni≤0.3
• Extra-quality steel （Suffix A）——P≤0.025；S≤0.025；Cu≤0.25；Cr≤0.3；Ni≤0.3
• Special High-Quality Steel (Suffix E)——P≤0.025；S≤0.015；Cu≤0.25；Cr≤0.3；Ni≤0.3

40CrNiMo Mechanical Properties

diameter or thickness d mm	Mark	Heat Treatment or Condition	Tensile Strength σ_b Mpa	Yield Point σ_s Mpa	Elongation or Extension Rate δ %	Reduction of Area ψ %	Hardness HBW	Impact Energy Absorption KV2 J
d≤80	Sample Direction: Longitudinal	Quenching + tempering	≥980	≥835	≥12	≥55	-	≥78
80＜d≤100	Sample Direction: Longitudinal	Quenching + tempering	≥980	≥835	≥11	≥50	-	≥74
100＜d≤150	Sample Direction: Longitudinal	Quenching + tempering	≥980	≥835	≥10	≥45	-	≥70
150＜d≤250	Sample Direction: Longitudinal	Quenching + tempering	≥980	≥835	≥9	≥40	-	≥66
100≤d≤300	Sample Direction: Longitudinal	Tempering	≥785	≥640	≥12	≥38	241~293	≥39
300≤d≤500	Sample Direction: Longitudinal	Tempering	≥685	≥540	≥12	≥33	207~262	≥35

• The forgings must be inspected for mechanical properties after performance heat treatment and before any surface treatment.
• After the samples are removed, no heat treatments that affect the mechanical properties or any processing that influences the test results shall be conducted.
• Mechanical property testing primarily evaluates the material\'s tensile strength, impact resistance, and hardness. When conducting tensile, impact, and hardness tests simultaneously, the hardness value is for reference only. Alternatively, one may choose to perform only one of the tensile, impact, or hardness tests.

1 Approximate Comparison Table

China	International Organization for Standardization
GB	ISO
40CrNiMo	36CrNiMo4

2 Approximate Comparison Table structural alloy steel

China	European Standard
GB	EN	Numerical Grade
40CrNiMo	39NiCrMo3	1.6510

3 Approximate Comparison Table structural alloy steel

China	United Kingdom
GB	BS EN/BS
40CrNiMo	817M40

4 Approximate Comparison Table structural alloy steel

China	United States
GB	ASTM/AISI
40CrNiMo	AISI9840

40CrNiMo Corresponding Standards(Same grade name, different standards)

1	YB /T 158-1999
	40CrNiMo
2	GB /T 17107-1997
	40CrNiMo
3	GB /T 3077-2015
	40CrNiMo A50402
4	GB /T 3078-2019
	40CrNiMo
5	JB /T 6396-2006
	40CrNiMo
6	JB /T 6908-2020
	40CrNiMo A50402

Note: The data is for reference only! If you have any questions, please fill out "I want to correct it"!