Study on the slag-metal interfacial behavior under the impact of bubbles in different sizes

A novel ladle shroud was employed to produce small bubbles to remove inclusions smaller than 50 μm meanwhile inhibiting the formation of slag eye. Both water modeling and industrial tests were carried out to confirm the generation of small bubbles with the ladle shroud. The numerical model was developed to investigate slag-metal interfacial behaviors, considering the effects of bubble sizes and distributions. The gas flux through the surface was employed to evaluate the impact of bubble swarm on slag layer. The results show that reducing bubble sizes can effectively disperse bubbles passing through the slag layer, so as to inhibit the formation of slag eye, under the same gas flow rate. The diameter of slag eye matches well 1.7 times diameter of the region with gas flux higher than 0.0025 m/s. The heat loss of the entire tundish was estimated, considering the convection and radiation heat transfer of slag eye. Characteristic diameters of the slag eye, regions with bubble escape and gas flux, under different bubble conditions. [Display omitted] •The impact of bubbles on slag layer was characterized by surface gas flux.•Micro-bubbles were observed by online sampling the liquid steel in bubbly region.•The heat loss of liquid steel was predicted, considering the impact of slag eye.