| 摘要 |
PURPOSE:To improve the surface characteristics of a continuously cast ingot which is obtained by maintaining the surface position of molten metal in a mold constant by supplying an inert gas of specific pressure to a hermetic chamber formed in the upper part of the mold of a continuous casting machine. CONSTITUTION:A charging nozzle 2 of a tundish 1 is inserted into the mold 7 of a continuous casting machine and the leading end part thereof is held immersed in molten metal M below the meniscus 8 of the molten metal in the mold 7, whereby the molten metal is cast continuously. A sealing fitting 5 and a bellows 6 are provided between the outside circumferential surface of the nozzle 2 and the mold 7 to seal the inside of the mold above the meniscus 7 airtightly. In this case, an inert gas is forced through a supply pipe 4 into the hermetic chamber 3 and the atmosphere pressure in the chamber 3 is maintained above the static pressure of the molten metal at the leading end of the nozzle 2. Even when the static pressure of the molten metal M in the mold 8 fluctuates, the gas flows in the nozzle 2 until the gaseous pressure and the static pressure of the molten metal balance. The position of the meniscus of the molten metal in the mold 7 is maintained always constant and the continuously cast ingot of the superior surface characteristics is obtained. |
