In this study, the flow behavior, microstructural evaluation and dynamic recrystallization (DRX) mechanisms of a new AD730 Ni-based superalloy with initial coarse grain size were investigated by hot compression tests in a wide temperature range of 950-1200 °C and strain rates of 0.001 s-1, 0.01 s-1, 0.1 s-1 and 1 s-1. According to the dissolution temperature of the precipitates in the studied alloy at 1079 °C, a significant difference was observed in the flow stress, activation energy and microstructure in the two temperature ranges of 950-1050 °C and 1100-1200 °C for all strain rates. In the temperature range of 950-1050 °C, higher stress level in flow curves and activation energy value (1284.9 kJ/mol) were obtained. Microstructural observations showed that the high-volume fraction of fine precipitates formed during heating up to deformation temperature and holding at 950-1050 °C prevented DRX development which resulted in the formation of cracks and a non-uniform deformation. In the temperature range of 1100-1200 °C, the dissolution of fine precipitates decreased the flow stress level and the activation energy to 468.94 kJ/mol as a result of development of DRX. DRX in coarse grain AD730 was occurred by strain induced boundary migration (SIBM) and particle stimulated nucleation (PSN) mechanisms which was enhanced by the twins.

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