9th ECCC European Continuous Casting Conference – ECCC 2017

In continuous casting of ferritic stainless steel electromagnetic stirring (EMS) is a common approach to generate an equiaxed crystal zone as large as possible. The layout of the electromagnetic device directly affects the intended solidification structure in the strand. In order to predict this influence, SMS group has developed a numerical model to simulate the interaction between flow field, solidified shell and electromagnetic field in the caster. The transient melt flow (SEN, mold, strand) is solved with a numerical tool based on the open source library OpenFOAM. In order to consider turbulence phenomena, a hybrid large-eddy turbulence model has been used in addition to the Magnetohydrodynamic (MHD) equations which are solved time-dependent in a fully coupled manner in the strand. The magnetic fields induced by the stirring coils are calculated by ANSYS EMAG. In the present case the influence of different stirring concepts on the flow and temperature distribution in the strand has been investigated. It is shown that the stirrer geometry - with same amperage in the stirring coils - has a significant impact on the induced magnetic flux density and thus on the stirring behavior. Based on the calculated temperature distribution and solidification rate the solidification structure in the strand has been calculated by a corresponding microstructural model.