CONTINUOUS CASTING METHOD OF CLEAN STEEL

摘要

PURPOSE:To prevent the defective cleaning of a bottom side billet and to improve the yield of continuous casting by bisecting a continuous casting mold to an upper part having poor heat conductivity and a lower part having good heat conductivity, disposing a dummy bar head to the bottom end in the upper part of the mold, melting preliminarily a flux in the upper part and pouring a molten steel into the mold. CONSTITUTION:The composite casting mold made by bisecting the continuous casting mold to the upper half and lower half and forming a heat insulating mold surface only to the upper part 1 of such mold is used. A dummy bar 8 is introduced into the composite casting mold and the continuous casting flux is melted in the upper part 1 of the casting mold so that the level of the molten flux 9 arrives at the section covering the discharge port of an immersion nozzle 6. The nozzle 6 is then opened and the pouring of the molten steel 5 into the composite casting mold is started. The upper half of the casting mold is heat- insulated in order to prevent the solidification of the powder. The bar 8 is lowered and the ordinary continuous casting operation is continued after the pouring basin is formed. The reason for lowering the molten metal surface lies in that the powder is admitted between the solidified shell and the mold.