Study on Inclusion Removal in Tundish With Annular Argon Bubbling Process Based on the Variation of Flow Characteristics

Herein, the effect of annular argon bubbling (AAB) process on tracer diffusion and inclusion removal behaviors in a tundish was studied by water model experiments, and the influence of slag layer on the variation in results was compared as well with the aid of numerical simulation. The results show that the AAB process can significantly change the flow field structure in the pouring region, inhibit the short‐circuit flow, and increase the volume fraction of mixed flow in the tundish. The presence of slag layer can significantly slow down the diffusion rate and alter local flow behavior of the tracer underneath the slag layer; the interfacial velocity decreases from 0.031 m s −1 without oil layer to 0.007 m s −1 with oil layer when the AAB process is not adopted. When the experimental condition without argon bubbling ( q = 0 L min −1 ) and slag layer is changed to that with argon bubbling ( q = 4 L min −1 ) and slag layer, the tracer peaking time extends from 154.45 to 424.95 s, the volume fraction of piston flow increases from 18.27% to 37.26%, and the average removal rate of small sized inclusions (20–60 μm) is lifted from 64.05% to 77.10%, which was well verified in industrial tests.