Non‐Metallic Inclusion Behaviors in a New Tundish and SEN Design Using a Swirling Flow during Continuous Casting of Steel

The behaviors of non-metallic inclusions in a new tundish and SEN design enabling a swirling flow are investigated by using a Lagrangian particle tracking scheme. The results show that 99% of both Al2O3 and Ce2O3 inclusions are removed from both the top surface and the other tundish walls with a “trap” boundary condition, while only around 60% are removed from the top surface of tundish for a “reflect” boundary condition at the other tundish walls. Large size non-metallic inclusions of different densities show a large difference under a “reflect” boundary condition at tundish walls, due to a high buoyancy of light inclusions. In the swirling flow SEN, a much smaller number of large Al2O3 inclusions touches the wall compared to Ce2O3 inclusions. This is due to that they have larger deviations from the steel flow path compared to heavy Ce2O3 inclusions, due to the centripetal force. For small size inclusions, the centripetal separation is not effective neither for the light Al2O3 inclusions nor for the heavy Ce2O3 inclusions in the current swirling flow SEN with a swirl number of 0.4. Light Al2O3 inclusions larger than 40 µm can be influenced by the current centripetal force.