Plastic thermal deformation behavior and microstructure evolution of solid solution strengthened Ni-based superalloy

The plastic thermal deformation behaviors of solid solution strengthened Ni-based superalloy Inconel 617B during different temperatures were systematically investigated using a Gleeble-3500 thermal compression simulation machine. The strain rate power-law accurately describes the steady-state stress at temperatures ranging from 1023 to 1123 K. The threshold stress to be overcome by alloy deformation, caused by the obstruction of M23C6 precipitated phase particles, decreases with the increase in temperature. M23C6 particles are predominant precipitated phase in this alloy. The average size and interparticle spacing of M23C6 particles are related to temperature. Under the high temperature range (1098-1123 K), the apparent interaction energy is only 44.37 kJ/mol when dislocation movements bypass the M23C6 particles. The calculated threshold stress is comparable to the Orowan stress. The apparent interaction energy necessary for the slip dislocations to overcome the particle obstruction is 104.23 kJ/mol at temperatures below 1073 K, which is likely associated with the formation of the stacking faults (SFs) in M23C6 particles.