| 摘要 |
PURPOSE:To cast a cast slab without defect under good yield by floating beforehand a brake cover having heat resistance on molten steel in a ladle and pouring the molten steel into a mold through a tundish while preventing the development of free vortex in the molten steel. CONSTITUTION:The brake cover 6 having heat resistance is beforehand floated on the molten steel 2 in the ladle 1 to put a cover 3. The brake cover 6 is formed, for example, as casting alumina castable 8 by arranging projection 9 at the recessed face side of Petri dish shape steel-made dish 7 and this diameter is desirable to be about >=80% of diameter of bottom face in the ladle 1. Next, the molten steel 2 is poured into a mold (omitting figure) from a nozzle 5 through the tundish. By the above method, the development of free vortex in the molten steel 2 is prevented and impurity 4 floating on the molten surface 2a is not involved in the molten steel. In this way, the cast slab without defects caused by mixing the impurity 4 and also the molten steel 2 remaining in the ladle 1 is reduced and the yield is improved. |
