Advanced CFD investigations of electromagnetic stirring of molten steel in continuous caster tundish

Abstract

Abstract. The continuous casting process is one of the initial operations in the entire metal forming chain used in the metallurgical industry. The phenomena of solidification and unification of properties that occur during slab casting are highly dependent on the steel composition and the purity of the metal. The high cleanliness of steel is the determinant of the good quality of the final products, without internal cracks or inhomogeneities in mechanical, thermal or electrical properties. Therefore, one of the production goals is to avoid the non-metallic inclusions in the molten steel by intensifying their removal processes. One of the most important metallurgy equipment responsible for cleaning the steel is the ladle furnace, where special mixing processes are executed to increase the removal process of unfavourable elements. Another critical piece of equipment is the tundish, located just before the slab casting, which can additionally improve the microstructure final composition and homogeneity. Therefore, the investigations presented in the paper are centred on the development of an advanced Computational Fluid Dynamic (CFD) model of the flow behaviour of the molten steel inside the tundish. The key element of the model is to include the effect of an additional electromagnetic stirring device which can improve the cleanliness and the composition of the steel and hence its final properties. The role of this device is often omitted during practical research, but its direct influence on the properties of the steel has a clear impact on the characteristics of the formed metallic parts under further processing operations. Therefore, optimization of the process inside the tundish is essential from an industrial point of view. The paper includes a detailed analysis of the flow and stirring energy distributions to predict and understand the active and dead zones inside the tundish to avoid the regions with stagnant velocity distribution. As an outcome of such a developed coupled electromagnetic/fluid dynamic model, optimizing the mixing processes to control the product's properties is possible.