Investigation of Dynamic Recrystallization in a Martensitic Stainless Steel Containing of 13%Cr

Hot deformation behavior of a martensitic stainless steel was investigated by conducting hot compression tests at temperature range of 900-1150ºC and strain rate of 0.001-1s-1. The relation between flow stress and Zener-Hollomon parameter was successfully modeled via the hyperbolic sine function under the whole range of deformation condition. The value of apparent activation energy, Q, and the empirical material constants of A and n were determined. The values of peak and steady-state stress were related to the dimensionless parameter of Z/A using power-law equations. It was also found that flow stress deviated from linear dependence on Z/A parameter at <0.8 and >1.2. The deviations proposed power and exponential equations respectively for low and high stress levels. The variation of peak and steady state strains with Z parameter were studied and the best models were developed. A model based on the Avrami equation was developed to estimate the kinetics of DRX at different deformation conditions. It was found that the Avrami exponent decreases as Z rises. Otherwise, the Avrami constant of k was shown to have no distinct relation with Z.