Recrystallization and grain-growth behavior of a nickel-base superalloy during multi-hit deformation

The initial breakdown behavior of Waspaloy ingot material with a coarse, columnar-grain structure was established via isothermal hot compression of double-cone samples. Temperature (1177 °C), strain rate (0.1 s−1), dwell time between increments of deformation (30 or 60 s), and forging direction relative to the columnar structure were typical of industrial practice. Recrystallization kinetics were more rapid during multi-hit than during monotonic testing. The recrystallization and grain-growth behavior showed a complex dependence on imposed strain, test orientation and dwell time.