Cellular automata model for austenite formation and grain growth during heating and holding above austenization temperature

Abstract

Understanding the steel microstructure formation during thermal treatments is crucial for controlling the mechanical properties of a steel product. One of the important factors affecting the subsequent microstructure development is the austenite grain size. To gain understanding of the effect of temperature dependent nucleation and growth rates, as well as providing the tools for quantitatively control the austenite grain size distribution, we have implemented a cellular automata (CA) model for describing austenite nucleation and growth during heating, as well as austenite grain growth during holding in temperatures above the austenitization temperature. The model implementation is based on previous study of Sieradzki and Madej for grain growth during recrystallization now augmetned with the relevant equations for describing the austenite nucleation and growth. The model parameters and their effect on austenite grain size distributions are tested with numerical experiments. The developed computational tool will serve as a basis that can be parameterized with experimental data in the future, which will then enable quantitative predictions for austenite phase transformation and grain size development.