Effect of Metal Active Gas Arc Welding Sequence on Welding Residual Stress of X80 Steel Pipe B-type Sleeve

Based on the heat source and constitutive equation of the metal active gas arc girth weld between the X80 steel large-size pipe and the B-type sleeve, the finite element model of the welded joint was established, and the residual stress distribution of the welded joint under three welding sequences of simultaneous welding of both left and right ends, the alternate welding of both left and right ends, and welding successively of both left and right ends were simulated, and the accuracy of the simulation results was verified by the blind hole method. The influence of welding sequence on the welding residual stress was discussed. The results show that the maximum residual stress in the welded joints was located within 1.8-3 mm from the outer wall to the capping bead, and the residual stress distribution at the left and right ends of the pipe and sleeve was similar under different welding sequences. The peak residual stress of the pipe and sleeve under the welding sequence of simultaneous welding of both left and right ends was the largest, which were located near the welding point of the outer wall. The relative error between finite element simulation results and test results was less than 9.15%, which verified the accuracy of the simulation results. The welding sequence of welding successively of both left and right ends had the smallest influence on the maximum welding residual stress.