Modeling of Solidification in a Meniscus Free Continuous Casting.

Abstract

IRSID (Central research laboratory of Usinor-Sacilor) and EMN (Ecole des Mines de Nancy) are working to develop a physical and numerical model of the shell solidification in a new concept of vertical continuous casters. This new concept involves a shifting of the free surface position upstream so that hydrodynamical pertubations of the liquid steel meniscus do not affect the solidification. This model describes the thermal behavior of a solidifying shell in the upper part of the mold, taking into account the shell movement against the copper mold. Two different parts of the steel shell are considered: one part of the shell has a static solidification (solidifying shell without motion against the mold); the other part experiences a dynamical solidification (the solidified shell is withdrawn at the casting speed). From casting experiments performed on a continuous caster, heat flux between the solidified shell and the upper part of the mold was determined. The heat flux used as the boundary condition in the solidification model takes into account the nature of the contact between the mold and the solid steel and the solidified steel thickness. Such a model is useful to calculate heat fluxes and to evaluate the effect of the casting speed on the solidified shell shape and thickness.