20G|27SiMn|30CrMnSi|无缝钢管|合金管|上
20Cr|40Cr|42Cr..
15CrMo|42CrMo|..
20Mn|25Mn|30Mn..
34Mn2V|35Mn2V|..
31Mn2V|32Mn2V|..
20Mn2|28Mn2|40..