INCLUSION MOTION AND REMOVAL IN A STEEL SLAB CONTINUOUS CASTING STRAND UNDER EMBR

摘要

In current study, a 3-D mathematical model is built to investigate the effect of a local type ElectroMagnetic Brake (EMBr) on the motion of bubbles and inclusions in slab continuous casting strands. The results indicate that more bubbles, especially >2.0 mm bubbles, escape from the top surface between the mold Submerged Entry Nozzle (SEN) and 1/4 width for the case with a 0.39 T EMBr. This may push the top slag away and create an open "eye" on the top slag. Small bubbles (≤1mm) tend to escape from one side of wide face no matter with or without EMBr, which is induced by the swirl flow from the SEN outport. EMBr has a little effect on the overall removal fraction of inclusions; however, it affects the local distribution of inclusion in the slab. With EMBr, more inclusions accumulate the region just below the surface, thus a worse subsurface quality, while the inner quality of the slab is better than that without EMBr.