METHOD FOR MELTING MULTI-CONTINUOUS CAST CLEANLINESS STEEL

摘要

PROBLEM TO BE SOLVED: To provide a means which prevents the contamination of molten steel caused by slag in multi-continuous casting, improves the cleanliness of the molten steel supplied into a tundish and further, prevents the contamination in the tundish. SOLUTION: (a) The molten steel is tapped into a ladle after refining in an electric furnace. (b) Slag in the left molten steel in the ladle is discharged. (c) The slag is removed. (d) A ladle-refining is performed. (e) A circulating flow vacuum degassing treatment is performed to make the clean molten steel. (f) The clean molten steel is supplied from the ladle to the tundish and continuously cast. (g) The four tons of the molten steel and the slag are left and the supplying of the molten steel into the tundish is stopped and the left molten steel is returned back into the ladle in the (b) process. In this case, the molten steel left in the ladle is supplied onto the molten steel in the other ladle tapped in the following heat and each process from the (b) process is circulately performed.