| 摘要 |
PURPOSE:To prevent defect in a cast slab caused by inclusion in molten steel by arranging molten steel discharging hole at lower part of a nozzle body, arranging gas flow passage in the nozzle body and flowing out gas into the molten steel from lower part of the molten steel discharging hole. CONSTITUTION:The molten steel discharging hole 15 is arranged at lower end part of outer part in the nozzle body 11 and also separately the gas flow pas sage 12 is formed at longitudinal direction in the nozzle 11, to connect with a gas supplying device. The molten steel is poured into a mold 14 from the nozzle body 11 and also argon gas is supplied from the gas flow passage 12 and blown into the molten steel 20 from gas flow-out hole 13. The lowering of the apparent specific gravity of molten steel flow is eliminated and staying of the molten steel flow near the nozzle 11 is prevented. Therefore, the accumula tion of inclusions and lowering of the molten steel temp. are prevented and removability of inclusions by powder 18 is not reduced. By this method, the development of defect in the cast slab is prevented. |
