Numerical Simulation of Temperature Field and Residual Stresses in Stainless Steel T-Joint

T-joint, an important type of welding joint, is widely used in automobiles, ships, aerospace, and other industries. The variation in the temperature field and the stress field for T-joint is more complicated than that in other joint methods, and it is difficult to control the welding quality. The temperature field and stress field in 316L stainless steel T-joint were analyzed in this research by using simulation software, considering the thermal–metallurgical–mechanical coupling behavior, the isotropic hardening model and moving heat source condition. In the end, the simulation results were verified by the test results, and it was shown that the numerical simulation results agreed with the test results, which proved the reliability of the simulation results in 316L T-joint. The simulation results showed that the temperature distribution of T-joint cross section changed from a fan shape to an elliptical shape and the temperature distribution range increased with time. The temperature field was distributed symmetrically along the center of the weld. There was a large temperature difference between the weld zone and the base metal. The peak temperature was obtained in the second pass, and the peak temperature in the web plate was significantly higher than that in the flange plate; with farther away from the weld, a little variation happened in the thermal cycle curve. Whether it was longitudinal residual stress or transverse residual stress presented a hat-like distribution trend along the weld direction. The maximum tensile longitudinal residual stress appeared in the middle, while the maximum transverse residual stress appeared near the middle. In the vertical weld, the larger tensile stress in longitudinal and transverse direction appeared near the weld zone.