A.HT100 B.KT30-6 C.QT40-7
A.1Cr18Ni9Ti B.1Cr13 C.20鋼 D.工業(yè)純鐵
A.鑄鐵 B.鑄造黃銅 C.鑄造合金 D.鑄鋼
A.4 B.6 C.8 D.10
A.20鋼 B.20CrMnTi滲碳 C.GCr15 D.QT700-2