Effect of Semi-Aging Heat Treatment on Microstructure and Mechanical Properties of an Inertia Friction Welded Joint of FGH96 Powder Metallurgy Superalloy

Inertia friction welded joints often present different microstructures than the base metal, and subsequent heat treatment processes are always needed to maintain superior performance. This study investigates effect of semi-aging after welding on microstructure, residual stress, micro-hardness, tensile properties inertia FGH96 powder metallurgy superalloy using optical microscopy, scanning electron X-ray diffraction, hardness tests. The results show that does not affect grain size or morphology metal. However, recrystallization process can be further promoted in weld nugget zone transition zone. Meanwhile, is refined stress significantly reduced joint same treatment. Under synergetic strengthening γ′ phase, increased micro-hardness from 470 HV 530 improved average strength at room temperature by 118 MPa. These findings provide a reference for selection nickel-based superalloys.