A.150 B.200 C.250 D.300
A.考登鋼 B.普通鋼 C.優(yōu)質(zhì)鋼 D.合金鋼
A.0.15~0.30,0.04~O.15 B.013~0.45,0.15~0.25 C.0.45~0.6,0.25~0.35 D.0.6~0.8,0.4~0.5