Recrystallization behavior of pure tungsten hot-rolled with high accumulated strain during annealing at 1250 °C-1350 °C

摘要

The recrystallization behavior of pure tungsten after 90% thickness reduction by hot rolling was investigated by isothermal annealing at the temperature range from 1250 to 1350 °C. Electron Backscatter Diffraction and hardness measurement were applied for the microstructural and textural characterization and mechanical properties evolution regarding the kinetics of recrystallization, respectively. The microstructure of the as-received hot-rolled tungsten plate is very heterogeneous and consists of numerous elongated fibrous deformed grains and some approximately equiaxed recrystallized grains. After complete recrystallization, the recrystallized texture is completely different from the deformed texture and the 8 fiber texture increases significantly. The hot-rolled tungsten plate mainly undergo meta-dynamic recrystallization during annealing, which can be described approximately by the modified Johnson-Mehl-Avrami-Kolmogorov relationship. The activation energy for half the recrystallization process was calculated by a modified Arrhenius relationship.