Modelling Kinetics Of Dynamic Recrystallisation: Introducing New Characteristic Parameters

A new characteristic parameter (T-M50) is introduced which is defined as threshold temperature below which it is not possible to obtain 50% dynamically recrystallised grains for a given strain rate. This parameter is emerged during analysis of kinetics of dynamic recrystallisation (DRX) by introducing another new parameter. The latter is defined as the maximum possible fraction of dynamically recrystallised grains for a given set of temperature and strain rate. The parameters X-s and T-M50 are related through a sigmoidal relationship. Typically, the kinetics of DRX is studied using different forms of Avrami-type equation. In the present investigation, kinetics of DRX is simulated using Logistic model. Unlike Avrami-type models, the mathematical expression for Logistic model does not include exponent. The fitting parameters associated with Logistic model are shown to be connected with the nature of DRX curves and distinct physical interpretation can be given to each parameter. The fitting parameters also exhibit definite mathematical relationship with temperature and strain rate. The strain required for 50% of DRX is shown to have non-linear relationship with inverse of temperature.