Modeling the initiation of dynamic recrystallization using a dynamic recovery model

Dynamic recrystallization flow curve was studied in AISI 410 martensitic stainless steel by performing hot compression tests in a temperature range of 900–1150 °C and at strain rates of 0.001–1 s−1. The Estrin and Mecking's equation for dynamic recovery was used to model the work hardening region of the flow curves. The critical strain and stress for the initiation of dynamic recrystallization were determined using the method developed by Poliak and Jonas. The critical dislocation density for starting dynamic recrystallization was estimated using the Estrin and Mecking's dynamic recovery model. A modified Arrhenius-type equation was used to relate the critical dislocation density to strain rate and temperature. The proposed model was also verified by the model proposed by Roberts and Ahlblom and developed to describe the variation of dislocation density and fractional softening due to dynamic recrystallization up to the peak of flow curve.

► The hyperbolic sine function models the dependence of flow stress on deformation regime.
► The critical dislocation density for DRX is determined using a DRV model.
► An Arrhenious-type equation relates critical dislocation density to deformation regime.
► The fractional softening due to DRX at the peak is constantly about 10%.