A.20Cr B.20CrMnTi C.T12A D.9CrSi
A.不锈钢 B.耐热钢 C.滚动轴承钢 D.1.5% E.15% F.0.15%
A.淬火+高温回火 B.淬火+中温回火 C.淬火+低温回火
A.20Cr B.40Cr C.20CrMnTi