A Comparative Study of Observed and Predicted Austenite Micro-structures during Hot Rolling of a Medium Carbon Steel

摘要

Two-step deformation sequences, applied by laboratory rolling to a medium carbon steel, were used to assess the applicability of the most important models of microstructural evolution to describe the actual behavior of the austenite in this material. The model developed by the IRSID group gave the best overall agreement with the metallographic observations, mainly due to a better prediction of the rates of grain growth in the temperature range of 1 173 to 1 473 K, as compared to the models proposed by the researchers at Sheffield University and Nippon Steel Corp., which predictions resulted grossly inaccurate at the higher temperatures. Nevertheless, all three models contain the essential features to lead to reasonable values of the austenite grain size, especially as the number of deformation steps increases concurrently with a progressive decrease in the temperatures of deformation.