Effects of Heat Treatment on Microstructure and Mechanical Properties of GH4169 Superalloy Pulse TIG Welding Joint

Four different heat treatment processes were used for the welding joints of GH4169 superalloy, which were prepared by the pulse TIG welding. The microstructures and mechanical properties of the unheated joint and the joints after heat treatments were studied. The results show that after heat treatment processes, the joints tensile strengths at room temperature and 650 degrees C high temperature are improved, and the joints hardness are significantly increased, but the joints plasticity are significantly decreased. Among them, after 1020 degrees C solution treatment + two-stage aging, the Laves phases in the joint weld partially dissolve, and the tensile strengths of the joint at room temperature and high temperature are increased to the maximum.