A physical modelling study of inclusion removal in tundish using inert gas curtain.

Abstract

The control and minimization of non-metallic inclusions content in the tundish and in the mold of a continuous casting unit is crucial for ensuring the final quality of the steel cast product. Nonmetallic inclusions of sizes smaller than 15 m are hard to remove, as they are difficult to float. They are easily carried by the flow of steel melt into the mold and adversely affect the steel cleanliness. It is suggested that a gas curtain made of small bubbles of argon can be used to capture and remove these inclusions in the tundish, thus avoiding their transport into the mold. A 1:3 scale physical model of tundish of the continuous casting unit of ArcelorMittal plant, in Vitória, Brazil, was built to investigate the effects of gas flow, shape and positioning of the gas curtain inside the tundish, on the efficiency of removal of inclusions. The results suggest that the gas bubbling inside the tundish can be effective in inclusion removal. The efficiency is dependent upon the location of argon bubbling.