Critical condition parameters and kinetics of dynamic recrystallization for hot deformed 1 wt%Cr-1 wt%Mo rotor steel

Abstract

Isothermal hot compression tests of low alloy 1 wt%Cr-1 wt%Mo medium carbon rotor steel were carried out over the temperature range from 850°C-1050°C under three strain rates e ( )  varying from 0.001 s −1 -0.1 .1 s −1 . The hot deformation behavior, activation energy and material constants were determined by constitutive analysis. Onset of critical condition parameters for dynamic recrystallization (DRX) of the present steel were determined with the help of mathematical models developed by Poliak and Jonas. DRX kinetics were studied to determine the fraction of dynamic recrystallization with the help of Avrami type model. Also, the values of Avrami power exponent n ( ) and material constant K ( )were calculated for Avrami equation in each deformation condition. Optical and scanning electron (SEM) micrographs of the as-received and the deformed specimens were analyzed to understand the flow stress behavior of this steel.