结构钢:C18 C20 C20E4 C20M2 C25 C25E4 C25M2 C30 C30E4 C30M2 C35 C35E4 C35M2 ***0 ***0E4 ***0M2 ***5 ***5E4 ***5M2 C50 C50E4 C50M2 C60 C60E4 C60M2 28Mn6 36Mn6 42Mn6 34Cr4 34CrS4 37Cr4 37CrS4 41Cr4 41CrS4 25CrMo4 35CrMoS4 34CrMo4 34CrMoS4 42CrMoS4 42CrMo4 50CrMo4 36CrNiMo4 36CrNiMo6 31CrNiMo8 30CrNiMo8 51CrV6…………