Prediction of the austenite-grain size of microalloyed steels based on the simulation of the evolution of carbonitride precipitates

Kinetic calculations of the evolution of carbonitride precipitates in low-alloy steels with Nb and Ti have been performed for different temperatures of austenitizing. Based on the data of the kinetic simulation of the ensembles of carbonitride precipitates, the expected size of the austenite grain has been calculated using different models. The results obtained have been compared with experimental data. It has been shown that the best agreement with the experiment is achieved for the high-temperature region (1150–1250°C) when using the Gladman model (with the parameter Z = 2) with allowance for the polydispersity of the ensemble of precipitates.