A TWO-PHASE TWO-DIMENSIONAL FINITE ELEMENT THERMOMECHANICS AND MACROSEGREGATION MODEL OF MUSHY ZONE. APPLICATION TO CONTINUOUS CASTING

摘要

The main lines of a coupled thermomechanical - solute transport model are first summarized. Macroscopic conservation equations for mass, momentum, energy and solute are obtained by a spatial averaging method. The mechanical model is a "sponge-like" one: assuming a semi-solid saturated mushy zone, the solid phase is macroscopically modeled as a compressible viscoplastic continuum, while the liquid phase flow obeys Darcy's law. Regarding solute transport, the study is limited to a binary alloy for which the solidification path is not given a priori but results from a microsegregation model (here the lever rule). A validation check of the correct implementation of this coupled model is achieved by comparing with an analytical solution in the case of a free compression of a saturated semi-solid medium. Application to the study of the solidification during secondary cooling in steel continuous casting is considered.