| 摘要 |
PURPOSE:To form a compound having low melting point with precipitated alumina in molten steel and to prevent clogging of submerged nozzle with alumina by arranging a bottom part made of a CaO refractory in the submerged nozzle for a tundish in continuous casting apparatus. CONSTITUTION:At the time of pouring the molten steel in the tundish into a mold for continuous casting through the submerged nozzle 1 in the continuous casting apparatus for the molten steel, Al2O3 existing as dispersing in the molten steel in the case of aluminum killed steel, etc., is precipitated from the molten steel, and molten steel flowing hole 2 in the submerged nozzle 1 is clogged and the molten steel from the tundish comes to be impossible to pour into the mold for continuous casting and the continuous casting operation is interrupted. In this case, a well 4 is arranged below molten steel discharging holes 3 at lower part of the submerged nozzle 1 and the bottom member 5 composing of the refractory containing CaO as the main component and SiO2, etc., is set in the well 4. As the Al2O3 precipitated from the molten steel forms the compound having low melting point together with CaO and SiO2 and flows out from the nozzle 1, the interruption of the continuous casting operation caused by deposit and clogging of Al2O3 in the flowing hole 2 of the nozzle 1 is prevented. |
