Effect of Post-Deformation Heat Treatment on the Microstructure and Properties of Inconel 617 Alloy

Post-deformation heat treatment has the potential to improve the microstructure and mechanical properties of nickel-based superalloys. In this work, cold rolling and annealing treatment processes were used to control the microstructure and properties of the Inconel 617 alloy. The microstructure was characterized by electron backscatter diffraction (EBSD) and transmission electron microscopy (TEM). The strengthening mechanism of the Inconel 617 alloy was analyzed based on several strengthening models. The results show that the grain size of Inconel 617 alloy is refined by recrystallization after cold rolling and annealing. Special Σ3 boundaries appear simultaneously within the recrystallization grain and the fraction increases with increasing temperature. The strength and ductility of Inconel 617 alloy increase synergistically after rolling-annealing. The synergistic effect comes from dislocation strengthening, fine grain strengthening, and twin strengthening. Our present work can provide a reference for realizing the strength-ductility synergy of solid-solution strengthened nickel-based superalloys.