【摘要】 研究了Ｗ１８Ｃｒ４Ｖ高速钢激光相变强化层的组织及奥氏体晶粒超细化的机理．强化层的组织由马氏体、残余奥氏体及未溶碳化物组成，其中片状马氏体量较多，板条马氏体量较少，其亚结构分别为孪晶和密度较高的位错．残余奥氏体量约为１０％～１５％，较常规热处理有明显减少，激光相变强化后晶粒度由原来的８级提高到１２级．更多还原

【Abstract】 Deals with the structure and the mechanism of grain super-refining ofthe laser phase transformation strengthening layer in a high-speed steel of W18Cr4V. Thestructure of the strengthened layer is consisted of martensite,retained austenite and undisolved carbide, in which there are a large amount of plate martensite with twinned substructure and a small amount of lath martensite with high density dislocations substructure. The amount of the retained austenite is about 10% -15 % after laser treatment,beingclearly less than that of treated by conventional treatment. The grade of grain size is increased from 8 to 12 after laser phase transformation strengthening.更多还原