用连续 CO2 激光束对 5 0钢模切辊进行了激光表面相变硬化试验 ,研究了淬火层的显微组织、硬度分布及工艺参数对强化效果的影响。结果表明 :5 0钢模切辊经激光表面淬火后 ,硬化层组织由细小的位错马氏体及少量的残余奥氏体组成。模切辊变形很小 ,且表面硬度高 ,整体硬度分布较为均匀 ,能够达到技术要求。采用激光淬火技术对 5 0钢模切辊进行表面强化是可行的 The laser surface transformation hardening test was carried out on the 50 steel die with continuous CO2 laser beam. The effects of microstructure, hardness distribution and process parameters on the strengthening effect of the quenched layer were studied. The results show that the microstructure of the hardened layer consists of fine dislocation martensite and a small amount of retained austenite after the laser surface quenching of the 50 steel die roll. Mold roller deformation is small, and the surface hardness, the overall hardness distribution is more uniform, to meet the technical requirements. It is feasible to use laser quenching technique to strengthen the surface of 50 steel die roll