Recovery and Recrystallization Behaviors of Ni–30 Mass Pct Fe Alloy During Uniaxial Cold and Hot Compression

The recovery and recrystallization behaviors of the high-temperature γ -phase of carbon steel during deformation strongly affect the mechanical properties of steel. However, it is difficult to evaluate such behaviors at a high temperature. This study proposes the deformation behavior of the high-temperature γ -phase of low-carbon steel based on the quantitative observation of dislocation density and vacancies in the Ni–30 mass pct Fe alloy. This alloy was used because its stacking fault energy (60 to 70 mJ m -2 ) is similar to that of low-carbon steel. Uniaxial compression tests were conducted at a strain rate of 10 −3 s −1 and 1473 K (1200 °C) for dynamic recrystallization and at 293 K (20 °C) for work hardening. The compression process was interrupted at different strain values to systematically investigate microstructural changes. The changes in work hardening, recovery, and recrystallization behaviors were obtained from the true stress–true strain curves of the uniaxial compression tests. Further, the microstructure changes during cold and hot uniaxial compression were investigated from the viewpoint of lattice defects by X-ray diffraction, positron annihilation analysis, transmission electron microscopy, and electron backscatter diffraction to comprehend the work hardening, dynamic recovery (DRV), and dynamic recrystallization (DRX). This study helps understand the DRV, DRX, and work hardening behaviors in the γ -phase of the Ni–30 mass pct Fe alloy during cold and hot compression.