Determination of critical strain for initiation of dynamic recrystallization

Using the work hardening rate–strain curves, an effective mathematical model has been developed to predict the stress–strain curves of alloy steel during hot deformation up to the peak stress regardless of the level of the strain, weather smaller or larger than the critical strain. This model is expressed in terms of peak stress, peak strain and one temperature-sensitive parameter, S. In addition, one new model, which is a function of peak strain, was proposed to predict the critical strain for the initiation of dynamic recrystallization using the second derivative of work hardening rate with respect to stress. Besides the theoretical study, the analysis is used to determine the stress–strain curves and critical strain of 304 austenitic stainless steel. The predicted results were found to be in accord with the experimental data.