激光冲击对不锈钢焊接结构影响的数值分析

Numerical Analysis for the Structure Effect on Stainless Steel Welding Treated by Laser Shock Processing

为了探究激光冲击对不锈钢焊接接头残余应力分布的影响,对不锈钢焊接过程和激光冲击焊缝过程进行了数值分析。结果显示,焊后焊接结构的残余应力分布很不均匀,焊缝表面表现出较大的残余拉应力,横向和纵向残余应力相差较大。经激光冲击处理后,焊接区域的残余应力都有明显的改善,表面残余应力由拉应力转变成压应力,且应力值随着激光功率密度和冲击次数的增加而增大,横向应力和纵向应力分布也趋于均匀;选用合适的搭接率可以产生均匀的残余压应力。分析结果为激光冲击改善焊接结构性能提供参考依据。

In order to investigate the influence of laser shock processing on the residual stress distribution of stainless steel welding joint, the numerical analysis of the stainless steel welding process and laser shock processing weld is implemented. The results show that the residual stress distribution of welded structure is not uniform after welding, and the large residual tensile stress is produced on welding surface, meanwhile, the differences of welding residual stress between horizontal and vertical orientation are large. The residual stress of welding area is notably improved after laser shock processing, the residual stress on surface is changed from tensile residual stress into compressive residual stress, and the residual stress increases with laser power density and shocking times increasing. The residual stresses on horizontal and vertical orientation become uniform. The uniform residual stress can be induced with suitable overlapping rate. It provides a reference for the application of the laser shock processing in improving welding structure performance.