Development of numerical model for the prediction of center segregation in a continuously cast high carbon steel billet

摘要

A coupled numerical model was developed topredict macrosegregation in continuously cast steel billets.Continuum formulation was adopted to investigate macroscopictransport behavior of momentum, heat and species in thecontinuous casting process. In order to model fluid flow dampingin the mushy zone solidification was considered to occur in twosuccessive stages. In the first stage with the solid fraction below acertain critical value, the relative viscosity concept was employedto treat fluid flow in the dilute mushy zone. In the second stagewith the solid fraction above critical value, the permeabilityconcept was used to treat the concentrated mushy zone as a porousmedium. Turbulent fluid flow during continuous casting wastreated by the standard k-ε model. Thermal and solutal convectionswere also considered in the simulation of solute redistribution inthe mushy zone. The effect of interdendritic flow on surfacetemperature, metallurgical length and centerline segregation wereinvestigated. It is suggested that the present model can besuccessfully applied to simulate the macrosegregation incontinuous casting of steel billets.