Distribution of the residual stress on Ti600/TC18 joint welded by inertial friction welding

Abstract

In this study, the Ti600/TC18 dissimilar alloy parts were joined by inertia friction welding, which is mainly used in aerospace industry as structural components. Then the investigation of the residual stress distribution in the inertial friction welded joint of Ti600/TC18, both pre-and post-weld heat treatment, was carried out using ABAQUS software and XRD. The results show that the highest temperature during the welding is up to 1200 °C; it is subjected to tensile stress. As the welding goes on, the range of tensile stress is expanded gradually, and it is up to 8.92 MPa. During the welding, dynamic recrystallization is occurred in the weld zone, so the refined dynamic recrystallization grains are formed. After heat treatment, the martensitic transformation is occurred within the β phase, so the α_p, acicular α, α_s and residual β phase are existed in the weld zone. Moreover, the heat treatment has an obvious effect on the distribution of longitudinal residual stress, which can promote the residual stress field to be distributed more uniform and gradual. In addition, the peak tensile stress on the weld surface can be reduced effectively by stress relief annealing, which is attributed to the obvious growth of grain and the coarsening of lath-like α phase in the joint. Finally, comparing the test values with the simulation values, the later exhibits better accuracy and stability.