在相同的激光工艺参数条件下．对经调质，离子渗N、离子NC共渗和稀土催渗NC共渗的42CrMo钢进行激光相变复合处理。试验结果表明，离子NC共渗和稀土催渗NC共渗渗速快，渗层深度大，渗层和钢表面的碳浓度高，使Ms点降低，增加了复合处理的硬化层深度，提高了硬化层的硬度，硬化层组织不同于其它复合处理；在滑动磨粒磨损条件下，其耐磨性比其它复合处理的更好。 Under the same laser process parameters. 42CrMo steel quenched and tempered, ion infiltrated N, ion NC infiltrated and rare earth infiltrated NC co-infiltrated were treated by laser phase transformation. The results show that NC NCI and NC NC infiltration speed is fast, the depth of the infiltration layer is large, the carbon concentration of the infiltration layer and the steel surface is high, the Ms point is decreased, the depth of the hardened layer is increased, and the hardness of the hardened layer is increased The hardness of the hardened layer, the hardened layer structure is different from other composite treatment; in the abrasive wear conditions of sliding wear resistance better than other composite treatment.