Agglomeration behavior of rare earth inclusions and alumina inclusions at the interface between argon and molten steel

Nozzle clogging frequently occurs in steel containing rare earth (RE) due to the aggregation of RE inclusions, which seriously interferes with the application of RE in steel. To provide insights into nozzle clogging, the agglomeration behavior of inclusions in RE-containing steel was investigated by laboratory experiments and theoretical calculations. High-temperature confocal laser scanning microscopy (HT-CLSM) was applied to observe the behavior of inclusions at molten steel surfaces and their interactive forces. Kralchevsky–Paunov (K–P) model was used to predict the capillary force acting on different inclusions. The results show that the interactive forces that acted on inclusions were investigated as a function of inclusion size, inter-distance, and inclusion composition. It was found that the capillary force acting on the inclusions decreased in the order of Ce 2 O 3 > CeAlO 3 > Al 2 O 3 . This study verified the applicability of the K–P model in RE-containing steel, which can provide theoretical support to help solve the nozzle clogging problem during rare earth steel production. Rare earth inclusion will attract each other under interactive force in molten steel, and the interactive force will increase with the size.