A.0.02% B.0.77% C.2.11% D.4.3%
A.0.0008% B.0.021% C.0.77% D.2.11%
A.淬火+低溫回火 B.滲碳后淬火+低溫回火 C.調(diào)質(zhì)后表面淬火 D.正火