A.滲碳鋼 B.調(diào)質(zhì)鋼 C.彈簧鋼 D.普碳鋼
A.850-900 B.1000-1100 C.1200-1350 D.1400以上
A.700-800 B.850-900 C.1000-1100 D.1200-1350