A.合金結(jié)構(gòu)鋼,碳的質(zhì)量分?jǐn)?shù)0.4%,含鉻的質(zhì)量分?jǐn)?shù)小于1.5%
B.合金結(jié)構(gòu)鋼,鉻的質(zhì)量分?jǐn)?shù)0.4%,碳的質(zhì)量分?jǐn)?shù)小于1.5%
C.合金工具鋼,碳的質(zhì)量分?jǐn)?shù)0.4%,含鉻的質(zhì)量分?jǐn)?shù)小于1.5%
D.合金工具鋼,鉻的質(zhì)量分?jǐn)?shù)0.4%,碳的質(zhì)量分?jǐn)?shù)小于1.5%