Effect of Groove Shape on Microstructures and Mechanical Properties of Welded Joint in GH536 Superalloy

In order to study the effect of different groove angles on the microstructure and mechanical properties of the welded joint in GH536 Ni-based superalloy, the microstructure, hardness and fatigue crack growth rate of the weld center and heat affected zone were studied. The results show that with the decrease of the groove angle, the weld size becomes larger, the range of the heat affected zone is enlarged, the microstructure of the weld center changes, and the hardness increases. Under the conditions of the same stress intensity factors, the fatigue crack propagation rate of the welded joint of GH536 superalloy with large groove angle is larger, while the fatigue crack growth rate of welded joint with a small groove angle increases faster. In the design of GH536 Ni-based superalloy welding groove, it is necessary to take into account the inclination of weld cracking and fatigue crack growth rate.