Abstract:Hot deformation behavior and microstructure evolution of hot isostatically pressed FGH96 P/M superalloy were studied using isothermal compression tests. The tests were performed on a Gleeble−1500 simulator in a temperature range of 1000−1150 °C and strain rate of 0.001−1.0 s⁻¹, respectively. By regression analysis of the stress—strain data, the constitutive equation for FGH96 superalloy was developed in the form of hyperbolic sine function with hot activation energy of 693.21 kJ/mol. By investigating the deformation microstructure, it is found that partial and full dynamical recrystallization occurs in specimens deformed below and above 1100 °C, respectively, and dynamical recrystallization (DRX) happens more readily with decreasing strain rate and increasing deformation temperature. Finally, equations representing the kinetics of DRX and grain size evolution were established.

Key words: FGH96 superalloy; hot compressive deformation; constitutive equation; microstructure evolution; dynamical recrystallization