Abstract:The flow stress curve of Nickel base Alloy Hastelloy C-276 during hot deformation was investigated by compression test under varying temperature and strain rates up to a true strain of 0.7 on Gleeble 3500 simulator. Dynamic recrystallization(DRX) occurred during hot deformation. The recrystallization critical conditions were determined by relationships between work hardening rate and stress curve. Adopt Johnson-Mehl-Avrami(JMA) equation to calculate recrystallization volume fraction experimental value, established the dynamic recrystallization volume fraction model and grain growth forecast model of Hastelloy C-276 alloy. The results show that the increasement of recrystallization volume fraction presents the typical "S" type curve with the increase of strain. The equation of critical strain conditions was established ．The equation of recrystallization volume fraction is ，and the average error of the predicted values and experimental values was 2.16%. The grain growth equation is , the average error was 6.63%.