A Simplified Model for Semi-continuous Casting of Steel

We developed a simplified heat-transfer model to simulate the semi-continuous casting of steel. The complicated fluid flow enhanced by natural convection and electromagnetic stirring (EMS) was abbreviated to the effective thermal conductivity in the liquid. The solidification of the cast slab was simulated using heat conduction. The system domain was designed to move according to the scenario of the casting process, with boundary conditions in fixed positions. The cast microstructure was predicted using the Hunt and Niyama criteria for columnar-to-equiaxed transition (CET) and microporosity, respectively. The simulation well predicted the experimental cast structure of the slab. The CET analysis was also compared with the simulated results using cellular automata. It was found that microporosity formed along the centerline of the slab, regardless of EMS application, and EMS did not increase or decrease microporosity in the cast slab. The simulation model developed in this study did not provide detailed results on heat transfer, fluid flow, or electromagnetic fields. However, it was successfully applied to the new semi-continuous casting process, and it proved to be a quick and effective method for analyzing the process.