Hot deformation characteristics and dynamic recrystallization mechanism of GH4730 Ni-based superalloy

Abstract The hot deformation behavior of GH4730 Ni-based superalloy above γ′ solvus temperature was studied in this work. The constitutive equation of this alloy was established and the dynamic recrystallization mechanism was studied. The results indicate that the recrystallization mechanism of the GH4730 superalloy is dominated by discontinuous dynamic recrystallization nucleation, involving grain boundary bulging. The dislocation substructures transform from dislocation cells and walls into sub-grain boundaries during further deformation. The grain boundaries produce step-shaped structures in order to maintain the low-energy surface state during the dynamic recrystallization.