目的 研究光斑搭接率对激光冲击处理后残余应力分布的影响。 方法 采用不同的光斑搭接率对 AISI202 不锈钢焊接接头进行激光冲击处理,利用 X 射线衍射法测定激光冲击强化后的残余应力。结果 随着光斑搭接率的增加, 残余应力场得到增强, 并且应力分布更加均匀。 搭接率由 50% 增加到80% ,平均横向残余压应力增加了 20% ,波动减少了 30% ;平均纵向残余压应力增加了 30% ,波动减少了13% 。 结论 提高光斑搭接率可以优化激光冲击处理后焊接接头的应力分布。

Objective The effects of the overlapping rate of laser spots on the residual stress distribution after laser shock processing ( LSP ) were investigated. Methods The surface of AISI202 stainless steel welding joint was processed by LSP with different overlapping rates of laser spots. The residual stress of welding joint treated by LSP was determined by the X-ray diffraction method. Results The residual stress was enhanced and its distribution became more uniform when the overlapping rate increased. As the overlapping rate increased from 50 % to 80 % ,the average of landscape orientation residual compressive stress σ_y was improved by 20 % and its fluctuation was decreased by 30 % , while the average of longitudinal direction residual compressive stress σ_x was improved by 30 % and its fluctuation was decreased by 13 % . Conclusion The distribution of the residual stress of welding joint treated by LSP can be optimized by increasing the overlapping rate.