A.優(yōu)質(zhì)鋼不標(biāo)字 B.優(yōu)質(zhì)鋼標(biāo)Y C.高級優(yōu)質(zhì)鋼標(biāo)A D.特級優(yōu)質(zhì)鋼標(biāo)E。
A.0.25%~0.50% B.0.35%~0.65% C.0.50%~0.80% D.0.9%~1.20%
A.A B.B C.C D.D