目的 提高316L不锈钢的重位点阵晶界比例，减少随机晶界的比例，改善材料的抗晶间腐蚀性能。方法 选择合适的辐照温度，利用Nd:YAG激光器对SUS316L奥氏体不锈钢表面进行飞秒和纳秒激光辐照。通过电子背散射衍射技术分析辐照样品的晶界特征分布，研究不同激光辐照条件对试样晶界的影响。此外，在透射电镜下，观察脉冲激光辐照样品中的晶体缺陷和Σ3晶界。结果 相比于未辐照试样，723 K下飞秒激光辐照使试样的Σ3晶界比例增加2.88%，R晶界比例减少4.24%；723 K下纳秒激光辐照使试样的Σ3晶界比例增加10.78%，R晶界比例减少9.97%；773 K下纳秒激光辐照使试样的Σ3晶界比例增加12.52%，R晶界比例减少10.68%。在透射电镜下观察到，773 K下脉冲激光辐照试样中存在大量的堆垛层错四面体，但在孪晶形核的“台阶”内部没有发现该类缺陷。结论 重位点阵晶界比例的变化主要与晶界迁移和孪晶形成有关，其中脉冲激光辐照产生的能量为试样趋肤层的晶界迁移提供有利的条件，而辐照引起的晶体缺陷会促进晶界迁移过程中孪晶的形核和生长。

The work aims to improve the intergranular corrosion resistance by increasing the proportion of coincidence site lattice (CSL) grain boundaries and reducing the proportion of random grain boundaries in 316L stainless steel. The surface of SUS316L austenitic stainless steel was irradiated by femtosecond and nanosecond laser with Nd:YAG laser at suitable tempera-ture. The grain boundary character distributions of irradiated samples were analyzed by electron backscatter diffraction (EBSD) to study the effect of different laser irradiation conditions on the grain boundary. In addition, the crystal defects and Σ3 grain boundaries in the pulsed laser irradiation sample were observed under a transmission electron microscope (TEM). Compared with non-irradiated specimens, the proportion of the Σ3 grain boundary of specimens under femtosecond laser irradiation at 723 K increased by 2.88% and random grain boundary decreased by 4.24%; Compared with non-irradiated specimens, the proportion of the Σ3 grain boundary of specimens under nanosecond laser irradiation at 723 K increased by 10.78% and random grain boundary decreased by 9.97%; The proportion of the Σ3 grain boundary of specimens under nanosecond laser irradiation at 773 K increased by 12.52% and random grain boundary decreased by 10.68%. TEM images showed that there were a large number of stacking fault tetrahedrons in the pulsed laser irradiated sample at 773 K, but few such defects were found in the "step" of twin nucleation. The change of CSL grain boundary ratio is mainly related to grain boundary migration and twin formation, in which the energy generated by the pulse laser irradiation provides favorable conditions for the grain boundary migration in the skin layer of specimens, and the crystal defects caused by pulsed laser irradiation might promote the nucleation and growth of twins during grain boundary migration.