The formation of centre segregations during the continuous casting of high carbon steels detrimentally affects the product quality. An increasing fraction of equiaxed solidification has proven most advantageous for a minimisation of these segregations. This can be attained by either decreasing the steel superheat or by the application of mould electromagnetic stirring. In this thesis different approaches for a modelling of the equiaxed solidification are assessed. Hereby the mechanism of dendrite fragmentation is considered on the one hand, and heterogenous nucleation on the other. On the basis of these approaches, a model for a prognosis of the fraction of equiaxed solidification is implemented into an existing solidification model. With the use of parallelly conducted plant trials at a continuous casting plant, first estimates of the significance of such a model are made.