化学成分碳 C :0.35~0.45硅 Si:0.80~1.20锰 Mn:0.25~0.70硫 S :≤0.030磷 P :≤0.030铬 Cr:3.00~3.75镍 Ni:允许残余含量≤0.25铜 Cu:允许残余含量≤0.30钒 V :0.25~0.75钼 Mo:2.00~3.00