Chemical composition:
|
Trademark
|
Chemical composition
|
|||||||
|
C
|
Si
|
Mn
|
P
|
S
|
Ni
|
Cr
|
Cu
|
|
|
≤
|
||||||||
|
20
|
0.17～0.23
|
0.17～0.37
|
0.35～0.65
|
0.035
|
0.035
|
0.30
|
0.25
|
0.25
|
|
25
|
0.22～0.29
|
0.17～0.37
|
0.50～0.80
|
0.035
|
0.035
|
0.30
|
0.25
|
0.25
|
Mechanical Properties:
|
Trademark
|
Blank sample
Size/mm |
Heat Treatment
|
Mechanical Properties
|
Hardness of steel delivery status/HBS
|
|||||||
|
Normalizing
|
Quench
|
Tempering
|
σb/MPa
|
σs/MPa
|
δ5(％)
|
ψ(％)
|
Ak/J
|
≤
|
|||
|
≥
|
No heat
|
Annealed steel
|
|||||||||
|
20
|
25
|
910
|
|
|
410
|
245
|
25
|
55
|
|
156
|
|
|
25
|
25
|
900
|
870
|
600
|
450
|
275
|
23
|
50
|
71
|
170
|
|