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%