Abstract
Recently, the high grade quality has been demanded for strips and surface-treatment steel plates. Especially, the cleanliness of molten steel in tundishs plays a crucial part in order to improve the quality of steel plate as well as to prevent immersion nozzle clogging. The tundish has functions of floatation and removal of inclusions, though, some contaminations to the molten steel also occur in tundishs. Therefore, it is necessary to make clear the cause of each contamination and their level for producing super clean steels.
In this study, the contamination factors to molten steel in the tundish and their influences were analyzed by continual metal sampling during operation and of investigation of size, number and composition of inclusions. The results are as follows.
(1) Air-oxidation to molten steel is the biggest factor of contamination in the tundish.
(2)As the influence of air-oxidation decreases, slag contamination increases during continuous operations.
