The Effect of Chemical Composition on the Center-line Segregation of Continuous Casting Slabs

Abstract

The effect of chemical composition on the center-line segregation of continuous casting slabs have been studied using the simulated cast ingots. The ingots were hot-rolled and were examined mainly by means of EPMA.
Segregation of alloying elements is mostly determined by the alloy partition between molten steel and δ-ferrite phase as well as the diffusion in δ-ferrite region, and decreases with increasing temperature difference between solidus and that of -γ-phase nucleation, i.e., temperature width in δ-ferrite region. Thus the segregation of P is the largest because of the small partition co-efficient in δ-ferrite, and the increase of C content enhances the segregation due to the reduction of δ-ferrite temperature range. The segregation behaviours of Ni, Mo and Cr are also discussed.