Modeling and Simulation of Dynamic Recrystallization Behavior in Alloyed Steel 15V38 during Hot Rolling

Abstract

Dynamic recrystallization (DRX) occurring during hot rolling significantly affects the microstructural evolution and final mechanical properties of steel. In this study, single hot compression tests are performed at temperatures between 1000 and 1300 °C with strain rates between 0.01 and 15 s−1 to investigate dynamic recrystallization behavior of a 15V38 steel. Critical strains for initiation of dynamic recrystallization and peak strains are identified through the analysis of work hardening rate from the measured stress–strain results. Dynamic recrystallization is identified by the softening in the flow stress during plastic deformation and quantified as the difference between a calculated dynamic recovery curve and the measured stress–strain curve. Dynamic recrystallization is modeled using calculated critical strain, peak strain, Zener‐Hollomon (Z) parameter, and volume fraction of dynamic recrystallization. Subroutines accounting for dynamic recrystallization are developed and implemented into a three‐dimensional finite element model for hot rolling of a round bar. Simulation results show that dynamic recrystallization is distributed throughout the bar and exhibits a positive relationship with equivalent plastic strain. Temperature effects on dynamic recrystallization are also investigated using different rolling temperatures, and results show that the fraction of dynamic recrystallization is significantly increased as rolling temperature increases.