Microstructural Models of Dynamic Recrystallization in Hot-Deformed Inconel 625 Superalloy

Hot compression tests of In conel 625 super alloy were conducted between 1,000 degrees C and 1,200 degrees C with strain rates ranging from 0.01 to 10 s(-1). A series of flow stress curves were obtained and the microstructure evolution during dynamic recrystallization (DRX) was investigated. The results show that the dependence of the peak stress on deformation temperature and strain rate can be expressed by a hyperbolic-sine type model, and the initiation of DRX occurs earlier by the increasing deformation temperature or decreasing strain rate. Microstructure analysis shows that the nucleation mechanism of DRX for the alloy deformed at 1,150 degrees C is composed of discontinuous dynamic recrystallization (DDRX) and continuous dynamic recrystallization (CDRX), and the deformation parameters have a great influence on the microstructures. The optimizing hot processing parameters can be determined to be of deformed to a true stain large than 0.7 at temperature range of 1,100-1,200 degrees C with strain rates of 0.01 10 s(-1).