Numerical study of effect of sulphur element on mesosegregation by thermosolutal convection in Iron-Carbon-Sulphur system

Abstract

The effects of a sulphur element on the mesosegregation formation by the multicomponent thermosolutal convection in a Fe-0.21wt pct C-X wt pct S system studied numerically. A two-dimensional solidification model that describes conservations of mass, momentum, energy and solute is presented. Simulations are performed on the Hebditch-Hunt casting. The validation of codes is carried out by the comparison with a consensus of previous numerical simulation for the Sn-5 wt pct Pb alloy. Three cases, encompassing variations of the initial concentration of the sulphur (0, 0.05, 0.1 wt pct), are studied. Simulated results show that no mesosegregates form for S=0.0 wt pct. The mesosegregates are triggered by the weak instabilities of the solidification front growth for S0.05 wt pct. The increased fluid flow induces the local remelting, and results in the mesosegregation for S=0.1 wt pct. © Published under licence by IOP Publishing Ltd.