Microstructure Characteristics of GH80A Superalloy and Thermodynamic Calculation on Precipitated Phases

Abstract:

The as-heat-treated microstructure characteristics of GH80A superalloy were analyzed qualitatively and quantitatively by HRTEM, XRD and physical-chemical phase analysis. Results show that M7C3 and M23C6 carbides distribute at the grain boundaries to strengthen the grain boundaries and γ' phase distribute dispersively in the grains to increase the high-temperature strength. Besides, the equilibrium precipitates and non-equilibrium solidification process were simulated and calculated by Thermo-Calc software and Ni-base database. The effect of Al and Ti on the precipitated temperature and mass fraction of γ' phase and the effect of carbon on the carbide precipitation rules of MC, M7C3 and M23C6 were also studied

Key words:GH80A; microstructure; Thermo-Calc; equilibrium precipitates