Hot Deformation Behavior via Isothermal Compression and Constitutive Model of GH2132 Superalloy

GH2132, an Ni-Cr-Fe-based superalloy for aero-engine components, exhibits hot workability that is highly sensitive to processing parameters. The hot deformation behavior of GH2132 alloy was investigated via isothermal compression (Gleeble-3500-GTC) over 850-1100 °C and 0.001-10 s^-1, combined with optical microscopy and EBSD characterization. A strain-compensated Arrhenius-type hyperbolic-sine model was established, achieving high predictive accuracy (R² = 0.9916; AARE = 3.86%) with an average activation energy Q = 446.2 kJ·mol^-1. Flow stress decreases with increasing temperature and increases with strain rate, while microstructural softening transitions from dynamic recovery to complete dynamic recrystallization at higher temperatures and lower strain rates. Three-dimensional power-dissipation and hot-processing maps (Dynamic Materials Model) delineate safe domains and instability regions, identifying an optimal window of 1000-1100 °C at 0.001-0.01 s^-1 and instability at 850-900 °C with 0.01-0.1 s^-1. These results provide guidance for selecting parameters for hot deformation behavior during thermomechanical processing of GH2132.