Influence of Welding Sequence on Residual Stress of Q370qE Steel

The influence of welding sequence on the residual stress of Q370qE bridge steel cross joint was studied by means of numerical simulation and experiment, using the double ellipsoid volume heat source coupled with thermal-mechanical finite element model considering material properties. Compared with the welding residual stress by numerical simulation and hole drilling method, the accuracy of finite element model was verified. According to the welding bead direction during actual welding, the residual stress of cross welding under different welding sequence was simulated. The results show that the welding sequence significantly affects the magnitude and distribution of residual stress of cross joint,while the welding direction of weld bead has little influence on the magnitude and distribution of residual stress of cross joint.The last pass plays a key role in the location of the peak stress, which appears at the root of the last pass and root of the adjacent pass. Compared with other simulated welding sequences, diagonal welding can reduce the peak tensile stress by about 15%, and the peak tensile residual stress is only 342 MPa.