Numerical Modeling of Diffusion-Based Peritectic Solidification in Iron Carbon System and Experimental Validation

Abstract

Continuous casting of high-strength steels is challenging owing to peritectic phase transformation during solidification. This transformation is reported to be either diffusion controlled or “massive” like. The experimental evidence suggests that constant thermal gradients lead to diffusion-controlled phenomena, whereas the concentric solidification technique induces massive transformation. Diffusion-controlled peritectic solidification is more desirable during continuous casting to ensure a suitable cast quality compared with massive transformation. Accordingly, the authors demonstrate a general one-dimensional numerical modeling of the solidification process in steel by incorporating a diffusion-controlled peritectic phase transformation. The model is dynamically linked with the FactSage thermodynamic database through ChemAppV 7.1.4 library for input of accurate thermodynamic data. The modeling details are presented for a binary Fe-C system, and the results are compared with the experimental data available in the literature. The growth and dissolution of phases are accurately predicted as a function of composition and cooling rate.