¨美國AISI8140(SAE8140)合金結構鋼的化學成分:
C碳:0.37-0.45
Si硅:0.20-0.35
Mn錳: 0.7-1.0
P磷: ≤0.040
S硫: ≤0.040
Cr鉻: 0.30-0.50
Ni鎳:0.20-0.40 Mo:0.08-0.15
B:-¨