建立304不锈钢T形接头三维有限元模型，研究激光电弧复合焊接顺序对304不锈钢T形接头热变形及残余应力的影响. 采用高斯面热源加高斯锥形体热源组合的热源模型，模拟激光电弧复合热源，并通过304不锈钢激光电弧复合堆焊工艺试验验证数值模拟激光电弧复合焊接过程的可靠性. 结果表明，焊缝截面熔池形貌的数值仿真结果与焊接工艺试验结果吻合较好，该热源模型能有效模拟激光电弧两种热源的复合作用. 确定多种焊接顺序方案，分析不同焊接顺序下T形接头温度场、残余应力和热变形情况，激光电弧复合焊接顺序对T形接头残余应力及热变形均有影响，通过对比不同顺序下残余应力值及热变形量发现，顺序焊接能有效减小焊接残余应力，同时反向焊接产生的热变形量最小. 综合分析，不锈钢T形接头顺序反向焊接的效果最佳.
The three-dimensional finite element model of 304 stainless steel T-joint was established to study the influence of welding sequence on thermal deformation and residual stress of T-joint during laser-arc hybrid welding. A composite heat source model combining Gaussian surface heat source and 3D Gaussian body heat source was used to simulate the laser and arc hybrid heat sources. The reliability of numerical simulation was verified by laser-arc hybrid build up welding test of 304 stainless steel. Numerical simulation results of weld section pool morphology are in good agreement with the actual welding experimental results, which indicates that the established heat source model can effectively simulate the coupling effect of laser-arc hybrid heat sources. The temperature field, residual stress and thermal deformation of 304 stainless steel T-joint under different welding sequence were analyzed. Experimental results show that the welding sequence has influence on the residual stress and thermal deformation of T-joint in laser-arc hybrid welding. In comparison of the residual stress and thermal deformation under different welding sequences, it is found that the sequential welding can effectively reduce the welding residual stress, and the thermal deformation of simultaneous reverse welding is minimum. Comprehensive analysis shows that the effect of sequence reverse welding for 304 stainless steel T-joint is the best.
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