Effect of Welding Sequence on Residual Stress and Distortion of TC4 Titanium Alloy TIG Welding T-Joint

The finite element model of TC4 titanium alloy tungsten inert gas shielded welding (TIG welding) T-joint was established and the heat source was verified. The effect of both-side simultaneous codirection (case 1), one-side sequential codirection (case 2) and one-side sequential reverse direction (case 3) welding sequences on the residual stress and distortion of T-joint were studied. The results show that the simulated thermal cycle curve and test curve were basically consistent, and the relative error of the peak temperature was less than 5%, which proved that the model was accurate. The longitudinal residual stress of T-joints obtained by three welding sequences was tensile stress near the weld and compressive stress away from the weld. The residual stress gradient of joint position by case 1 was the smallest. The distortion of the joint obtained by case 1 was the smallest, and the verticality of the wing plate after welding was the best. Therefore, the both-side simultaneous codirectional welding was more suitable for the occasions where the overall deformation of the welding component needed to be strictly controlled.