The Role of Strain and Dynamic Recrystallization During Hot Deformation of a Fe–Ni–Cr‐Based Alloy

The hot deformation behavior of a Fe–Ni–Cr‐based superalloy is investigated by electron backscattered diffraction (EBSD) and processing map. The results show that the strain has an obvious effect on hot deformation. The flow instability domain at low temperature decreases with increasing strain. However, it expands with the increasing strain at high temperature. The optimized hot working domain at high temperature moves from low strain rate to high strain rate with the increase in strain. The hot deformation behavior of the alloy is correlated with dynamic recrystallization (DRX). The low fraction of DRX and local flow are responsible for the flow instability at low temperature. The DRX fraction rises with the increase in strain, which results in the reduction of flow instability domain at low temperature. The DRX grains grow rapidly at high temperature and low strain rate with increasing strain. The poor deformation compatibility between the large grains at high strain hinders the multiround DRX, which expands the flow instability at low strain rate and high temperature. The optimized hot working domain transforms from low strain rate to 2.0–10 s⁻¹ at 1050–1170 °C with the true strain of 1.2 due to the appropriate DRX process.