采用两种极端的多道顺序激光扫描工艺,证实了马氏体不锈钢激光表面熔化处理后表层残余应力并非都是压应力。残余应力性质与熔池尺寸和重叠区相对大小有关。表面重叠区宽度大于熔池表面宽度一半,才会有明显的表层压应力；重叠区过小,往往为拉应力。

It is demonstrated that the residual stress in the fur face layer of martensite stainless steel treated by laser surface melting(LSM)is not always compressive under the condition of extreme multi-pass laser scanning. The sign of the residual stresses depends on the relative size of melting Pool to overlapping zone. When the surface width of the overlapping zone is larger than half of surface width of the melting Pool, there exists obvious compressive stress in the surface layer, otherwise, too small overlapping zone will result in surface tensile stress.