STUDY OF FLUID FLOW, SOLIDIFICATION AND INCLUSION BEHAVIOR IN CONTINUOUS CASTING MOLD USING EMS

Abstract

Continuous casting is widely preferred by leading steelmakers worldwide due to its high productivity. With the increasing demand for clean steel and intense competition among steel producers, a significant challenge arises in pursuing high-quality steel free from impurities, particularly non-metallic inclusions. These inclusions in the final product can compromise the steel properties and overall quality, making their removal a top priority. Consequently, significant attention is given to processes and mechanisms to eliminate inclusions from the steel. The fluid flow pattern within the mold plays a crucial role as it governs various physical phenomena, including heat transfer, superheat, solidification, and the transport of inclusions. Thus, achieving an optimal flow pattern is crucial for effectively removing impurities from continuous casting steel products. Modifying and controlling the flow pattern within the mold can be achieved through various means, such as adjusting the mold geometry, utilizing a submerged entry nozzle (SEN), manipulating nozzle port geometry and depth, and other techniques. Additionally, electromagnetic forces have been reported to alter the flow pattern dynamically, improving the material's microstructure and removing inclusions from the molten steel. The effective and optimized application of electromagnetic stirring (EMS) produces cast products with superior quality. A transient numerical investigation is carried out inside the continuous casting mold with heat transfer, solidification and inclusion tracking models with and without EMS. The continuity and momentum equations were solved using realizable 𝑘−𝜀 turbulence models to simulate three-dimensional incompressible multiphase flow in a continuous casting mold. The heat transfer in the mold was solved by using the energy equation. The enthalpy porosity technique was used to solve the solidification of the molten steel in the mold. The work has been carried out in three stages. In the first stage, the time-varying electromagnetic field (EMF) is calculated by solving Maxwell's equations in Ansys EM Suite. The time-varying EMF is coupled with the multiphase turbulent flow model in the second stage. In the final stage, the data obtained from previous stages is coupled with a discrete phase model (DPM) with user-defined functions (UDFs).