Plane Strain Deformation Behavior and Evolution of Grain Boundary Characteristics of Inconel 625 Alloy

Studying the thermal deformation behavior and microstructure evolution under different conditions is a crucial step in improving the formability of a material. In this study, the deformation behavior and microstructural evolution of Inconel 625 alloy sheet under plane strain compression were studied using scanning electron microscopy, electron backscatter diffraction and transmission electron microscopy. The results indicate that the serrated flow phenomenon in the effective stress-strain curve is caused by dislocation pinning and depinning near carbides. Additionally, the recrystallization behavior and grain boundary evolution of the alloy were thoroughly investigated. At high temperatures and low strain rates, the primary recrystallization mechanism in Inconel 625 alloy is discontinuous dynamic recrystallization. As the deformation temperature increases, dynamic recrystallization behavior become more dominant, leading to a higher proportion of special grain boundaries in the alloy. Moreover, due to the adiabatic temperature rise effect, fully recrystallized microstructures and a high fraction of special grain boundaries were obtained at both high and low strain rates. These findings providing valuable insights for enhancing the formability and optimizing the performance of the alloy in practical applications.