钛合金薄板激光和钨极氩弧焊残余应力测试研究

采用小孔释放法对钛合金薄板激光焊和钨极氩弧焊(TIG焊)的焊接残余应力进行了测试，并分析了焊接方法、焊接线能量和焊后热处理对残余应力分布规律的影响。研究结果表明：激光焊残余应力分布规律与普通熔焊方法相似，但其分布区域较窄；在热影响区内，激光焊残余拉应力值比TIG焊的约低100MPa；在焊缝及其熔合线附近，激光焊残余应力却比TIG焊的高。对于不同线能量激光焊接，线能量越大，焊缝越宽，热影响区的残余应力也越大。焊后真空热处理能降低残余应力90％。

Residual Stress Measurements with the Hole-drilling Technique in the Joints by the Laser and TIG Welding for a Thin Plate of Titanium Alloy

A hole-drilling technique was used to determine the residual stress in laser beam welding (LBW) and TIG welding joints of titanium alloy thin plate. The effects of different welding technologies, heat input and post-weld heat treatment on residual stress distributions were analyzed. The results show that the distribution of laser welding residual stress is similar to that of traditional fusion welding processes, but the zones of distribution are much narrower. Compared to that of TIG welding in HAZ, the values of laser welding residual stress are lower about 100MPa. For the different heat input of LBW, the heat input is higher, the weld is wider and the residual stress in HAZ is bigger. Post-weld vacuum heat treatment would relieve residual stress about 90%.