Modeling and simulation of dynamic recrystallization for Inconel 718 in the presence of δ phase particles using a developed cellular automaton model

The dynamic recrystallization (DRX) behavior of Inconel 718 superalloy containing second phase particles (δ phase) was investigated through isothermal compression deformation tests under the deformation temperatures of 960 °C-1000 °C and strain rates of 0.01, 0.1, 1 s^-1. A developed cellular automaton (CA) model was established to describe the DRX process, considering the ellipsoid particle effects of particle stimulated nucleation and pinning grain boundary mobility. The comparisons of average grain size evolution and DRX kinetics were carried out between the studied superalloy with and without a δ phase. The results show that the δ phase could reduce the critical strain triggering DRX, average grain size at steady state and peak stress while increase the value of the Avrami exponent. And the effects of δ phase on average grain size is more and more obvious with the increase of strain rate. A great agreement between the simulated and experimental results was obtained, which indicates that the developed CA model considering the δ phase effects could well describe the DRX process of the studied superalloy.