Mechanical Properties and Microstructure Evolution of WASPALOY after Long Exposure

The isothermal microstructure evolution and mechanical properties of WASPALOY during long-term aging at elevated temperature were investigated.The alloy had good microstructure stability during long exposure at 704 ℃ for up to 5 000 h and the growth kinetics of the spherical γ′ phase was rather sluggish.The big particle of γ′ phase tended to aggregate in grain boundaries at 760 ℃ aging.Room temperature impact ductility decreased with the aging time increasing.Room temperature hardness decreased with prolonged aging time and this result can be attributed to the sluggish growth of γ′ phase.The aging time had almost no effect on room temperature tensile strength and ductility of the alloy.