In this research, the hot deformation behavior of AD730 Ni-based superalloy was studied by hot compression tests in the temperature range of 950-1200 °C, strain rates of 0.001-1 s−1 up to the strain of 0.5. The stress-strain curves showed that the peak stress rises with decreasing temperature and increasing strain rate while the stress level at 950-1050 °C was significantly higher than that at 1100-1200 °C for all strain rates. A sinh function was used to model the flow behavior of AD730 alloy with different activation energies of 1287 and 486.25 kJ/mol for temperature ranges of 950-1050 °C and 1100-1200 °C, respectively, which was depended to solution temperature of phase at 1079 °C. Processing maps and microstructure evaluation were used to indicate the optimum conditions for the hot deformation of AD730 alloy. Processing maps showed that the instability region with low workability was located in the temperature range of 950-1050 °C and almost for all strain rates due to the presence of precipitates and their role as an effective obstacle against DRX development. The power dissipation efficiency presented the values between 30 to 45% with increasing temperature from 1100 to 1200 °C indicating occurring DRX and good workability in this region which was in agreement with microstructure results. Microstructure results at 1100-1200 °C showed that DRX in AD730 alloy occurred via two mechanisms including grain boundary migration induced by strain (SIBM mechanism) and particle stimulated nucleation (PSN mechanism) around the carbide particles.

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