Prediction of Post-deformation Recrystallization Kinetics in AISI 321 Austenitic Stainless Steel Using Double-Stage Hot Compression

In the present research, a series of double-stage hot compression tests were conducted in the temperature range of 950-1150 degrees C, strain rates in the range of 0.01-1s(-1), strain in the range of 0.1-0.3, and inter-pass time range of 3-100s to evaluate the kinetics of the post-deformation recrystallization in AISI 321 austenitic stainless steel. An Avrami-type kinetics equation has been determined based on the obtained experimental data. Results show that the extent of post-deformation recrystallization increases with increase in inter-pass time, deformation temperature, pre-strain, and strain rate. The calculated activation energy for recrystallization (174kJ/mol) is lower than the activation energy for static recrystallization of austenitic stainless steels. It is concluded that the both static and metadynamic recrystallization occurred during the inter-pass period. Also, the predicted softening fraction using the proposed kinetics equation agreed well with those obtained from experimental results.