A Mathematical Model of Solidification Based on the Fe-C System Equilibrium Phase Diagram

Abstract

A mathematical model for the estimation of the solidification processes of steels of various carbon concentrations has been made.
In this model, it is assumed that the latent heat release is proportional to the solid precipitation volume, and the solid precipitations of each δ and γ phases and also the latter at the peritectic point based on the Fe-C equilibrium phase diagram are considered.
The calculated time-temperature curve shows the constant-temperature time at the liquidus, and the higher the initial liquid carbon concentration, the shorter is the constant-temperature time.
From the distributions of the solid fraction for various initial liquid carbon concentrations, it is induced that the initial high carbon concentration is one of the factors to promote the equiaxed grain growth, on the contrary the low carbon concentration to promote the columnar grain growth.