A.聚乙烯和聚氯乙烯 B.聚氯乙烯和酚醛樹(shù)脂 C.聚乙烯和環(huán)氧樹(shù)脂 D.酚醛樹(shù)脂和環(huán)氧樹(shù)脂
A.35CrMnSiA B.5CrNiMo C.20CrMo D.38CrMoAlA
A.淬火 B.等溫淬火 C.淬火+中溫回火 D.淬火+低溫回火