Modeling and Removal of Inclusions in Continuous Casting

Continuous casting is the central process phase with strong influence on the final quality of the steel products. Several different models for continuous casting have been developed at the Laboratory of Metallurgy at Helsinki University of Technology (TKK) concerning e.g. fluid flow, heat transfer, thermodynamic equilibria and statistical approaches. In this paper the inhouse solidification model called IDS, is presented as well as the fluid flow and inclusion calculations in the tundish and in the mould with the aim to find optimal flow conditions. IDS is a thermodynamic-kinetic-empirical tool for simulation of solidification phenomena and microstructure of steels from melt down to room temperature. Flow pattern in tundish and in mould is of great interest because it influences many important phenomena that have an effect on the steel quality, especially on inclusions removal. Numerous studies on fluid flow phenomena and inclusions behaviour in tundish and mould have been carried out at TKK for steady state and transient casting conditions. The effect of different kinds of dams in the industrial bloom tundish on the fluid flow and particle removal have been studied and presented in this paper. Similar calculations with and without electromagnetic stirring (EMS) have been carried out for the bloom caster mould. Many different submerged entry nozzle (SEN) designs were used. The results from these mould calculations are also presented. The examples show that mathematical models can be used in many ways for improved production efficiency and product quality.