Dynamic recrystallization behavior and numerical simulation of S280 ultra-high strength stainless steel

Abstract

The S280 ultra-high strength stainless steel was subjected to isothermal constant strain rate compression experiments under the conditions of deformation temperature 1000–1150 °C and strain rate 0.001–10 s−1 by Thermecmaster-Z thermal simulation testing machine. The flow behavior of S280 ultra-high strength stainless steel was analyzed; the dynamic recrystallization critical strain model, dynamic recrystallization volume fraction model, dynamic recrystallization grain size and average grain size model of the steel were established, and its dynamic recrystallization behavior was numerically simulated. The results show that the flow stress of S280 ultra-high strength stainless steel increases with the increase of strain rate and the decrease of deformation temperature. The distribution of dynamic recrystallization volume fraction and average grain size in each deformation region after thermal compression is not uniform, and the dynamic recrystallization volume fraction increases with the increase of deformation temperature and decrease of strain rate; the average grain size increases with the increase of deformation temperature and strain rate. The numerical simulation results are in good agreement with the experimental results, which can provide a theoretical basis for the microstructure control of the steel during thermal deformation.