42CrMo化学成分: 硫 S :允许残余含量≤0.035% 磷 P :允许残余含量≤0.035% 铬 Cr:0.90~1.20% 镍 Ni:允许残余含量≤0.030% 铜 Cu:允许残余含量≤0.030% 钼 Mo:0.15~0.25%