Modeling and Simulation of Dynamic Recrystallization of Incoloy825 High-Temperature Alloy during Hot Deformation Based on Cellular Automata

Thermal compression experiments are carried out on Incoloy825 high-temperature alloy to study its thermal deformation behavior under different strain rates (0.01-10 s-1) and deformation temperatures (1000-1150 degrees C). The microstructure of Incoloy825 high-temperature alloy under different deformation conditions is characterized using electron backscatter diffraction. Modified Laasraoui-Jonas (L-J) dislocation density model and thermal processing map at peak stress for Incoloy825 alloy are established. A cellular automaton (CA) is coupled to the DEFORM-3D software to simulate the microstructure evolution during hot deformation, and numerical simulation of hot extrusion molding of tubes of Incoloy825 alloy is carried out based on the optimal thermal processing region determined by the thermal processing map. The results show that the average absolute relative error (AARE) between the simulated predicted and experimentally obtained values of dynamic recrystallization (DRX) volume fraction is 10.87%, indicating that the developed CA model can accurately predict the DRX behavior of Incoloy825 alloy. The best hot extrusion parameters of the Incoloy825 alloy tube are obtained through hot extrusion simulation: the initial temperature is 1150 degrees C, and the extrusion speed is 120-160 mm s-1.