# Hot Deformation Behavior and Microstructure Evolution of a Fe-Ni-Cr Based Superalloy

## TL;DR

This study examines how a Fe-Ni-Cr superalloy deforms at high temperatures and how its microstructure changes, providing insights for optimizing its processing.

## Contribution

The study introduces a new constitutive model and identifies the dominant recrystallization mechanisms in GH2787 superalloy during hot deformation.

## Key findings

- An Arrhenius-type equation accurately predicts the flow behavior with an activation energy of 364,401.19 J/mol.
- Discontinuous dynamic recrystallization is the main mechanism, while continuous dynamic recrystallization acts as a synergistic mechanism.
- Microstructural evolution increases with higher temperature and strain rate, with no flow instability observed.

## Abstract

The present study systematically investigated the hot deformation behavior of GH2787 superalloy within the temperature range of 1060–1120 °C and strain rates of 0.1–10 s−1. An Arrhenius-type constitutive equation was developed that accurately predicts the flow behavior, and the calculated thermal deformation activation energy Q is 364,401.19 J/mol. The hot working map was constructed based on the dynamic material model, which identified two preferred processing regions with power dissipation efficiency exceeding 0.3, and no flow instability was observed across the entire parameter range. Microstructural analysis reveals that the extent of dynamic recrystallization significantly increases with rising temperature and strain rate. Discontinuous dynamic recrystallization (via grain boundary bulging nucleation) serves as the dominant recrystallization mechanism in GH2787 superalloy during hot deformation, while continuous dynamic recrystallization (via subgrain rotation and coalescence) acts as a synergistic auxiliary mechanism, jointly driving microstructural evolution. This study provides important theoretical foundations for optimizing the hot working processes of GH2787 superalloy.