A.5CrMnMo B.9M2V C.WL8Cr4V D.CrL2
A.Q195 B.T12 C.20 D.GCr9
A.碳的質(zhì)量分?jǐn)?shù)低的鋼 B.碳的質(zhì)量分?jǐn)?shù)高的鋼 C.碳的質(zhì)量分?jǐn)?shù)中等的鋼