Simulation of electromagnetic stirring in continuous casting of stainless steel

Electromagnetic stirring in the bending zone of a continuous casting machine is known to increase the amount of equiaxed crystals. A simulation model for the liquid steel flow and temperature under the influence of an electromagnetic stirrer has been developed in order to optimise the design of such a stirrer. The turbulent flow of the liquid steel inside the strand as well as the magnetic field and its forces acting on the liquid steel are calculated in transient simulations. The stirring intensity and the stirrer position are varied in the simulations. The influence of the stirring on the flow, especially on the mould surface flow, and on the superheat are compared for the different parameters. The results show that above a certain stirring intensity, the mould flow is significantly influenced by the stirring and thus the stirring intensity should be chosen below this critical intensity. The superheat temperature is lowered by the stirrer in a region that is distinctly larger than the region where the magnetic forces of the stirrer are relevant. The results show how these regions vary with the stirrer position. Nevertheless, the difference between stirring and no stirring is significantly higher than varying the position of the stirrer.