目的 利用不同激光表面离散淬火方式，改善球墨铸铁材料摩擦磨损性能。方法 采用Nd:YAG激光器对球墨铸铁圆盘试样表面分别进行激光环形淬火、条形淬火、点状淬火以及全淬处理，分析处理后球墨铸铁材料的显微组织结构、表面硬度分布状况，利用销-盘式摩擦磨损试验机研究不同激光淬火方式下球墨铸铁磨损与损伤的情况。结果 激光离散淬火球墨铸铁后，其表面生成马氏体白层，表面硬度提高约62.7%~93.8%，不同的处理方式硬化层深度相近，约55 μm。球墨铸铁试样经过激光离散淬火处理后，磨损量降低99%以上。未处理试样表面出现破坏性材料去除，损伤严重；激光离散淬火试样表面损伤轻微，以小块剥落与疲劳损伤为主。处理后的球墨铸铁材料抵抗裂纹萌生的能力增强，剖面裂纹的长度明显减小。结论 球墨铸铁材料经过不同方式的激光表面离散淬火处理后，表面硬度都得到显著增强，耐磨性能和抗损伤能力明显改善。不同的淬火方式改善效果不同，激光点状淬火效果最好，磨损量小，且剖面裂纹较小，不易向材料内部扩展。

The work aims to improve friction and wear properties of ductile iron by different laser surface dispersed quenching methods. Nd:YAG laser was applied to perform laser ring quenching, strip quenching, spot quenching and full quenching on the surface of ductile iron disc specimen. The microstructure and surface hardness distribution of the ductile iron materials were analyzed after treated. Pin-Disc friction and wear tester was used to explore the wear and damage of ductile iron by different laser quenching methods. The martensite white layer was formed on the surface of ductile iron after laser dispersed quenching. The surface hardness was increased by about 62.7% to 93.8%, and the depth of the hardening layer by different treatment methods was similar, about 55 μm. The wear loss of ductile iron samples was reduced by more than 99% after laser dispersed quenching. Material removed destructively on the surface of untreated sample resulted in severe damage. The surface damage of treated specimens was relatively slight and the dominant form of wear was small spalling and fatigue wear. The ability of ductile iron to resist crack initiation after laser treated was enhanced and the length of profile cracks was obviously reduced. The surface hardness, wear resistance and damage resistance of the ductile iron after laser quenching of different methods have been significantly im-proved. Different quenching methods have different effects. Laser spot quenching has the best effect and small wear. Cracks in the section are small and difficult to expand to the material.