Hot Deformation Behavior and Dynamic Recrystallization Nucleation Mechanisms of Inconel 625 during Hot Compressive Deformation

Abstract

High‐temperature compression deformation behavior of the Inconel 625 alloy is investigated using hot compression tests. The results regarding the flow behaviors and hot processing map indicate that the optimum condition for plastic deformation is determined to be at temperatures higher that 1050 °C and strain rate from 1 to 10 s−1. Herein, the hot compression microstructure evolution is characterized by electron backscattered diffraction (EBSD) and transmission electron microscopy (TEM) techniques. The results indicate that the dynamic recrystallization (DRX) mechanism is different under different compression deformation conditions. At low temperatures (<1100 °C), continuous dynamic recrystallization (CDRX) with subgrain rotation plays a dominant role in the DRX process. However, as the temperature rises beyond 1100 °C, discontinuous dynamic recrystallization (DDRX) with a bulging boundary induced by twinning becomes dominant in the dynamic recrystallization process. The findings provide a theoretical basis for the optimization of the thermoplastic processing of nickel‐based superalloys.