| abstract |
PURPOSE:To prevent the occurrence of splash caused by spattering of molten steel and the development of crack at the initial stage of pouring the molten steel by coating outer surface of a submerged nozzle for continuous casting by internal layer made of graphite sheet and outer layer for oxidizing prevention body arranged on the internal layer. CONSTITUTION:At the time of pouring the molten steel in a mold for continuous casting from the submerged nozzle for a tundish in the continuous casting apparatus, by sticking and piling the molten steel near a discharging hole 13 of the nozzle 10 caused by the splash of molten steel at the initial stage of pouring, the flowing of molten steel is disturded or sometimes the crack of nozzle caused by spalling phenomenon is developed. In order to prevent this, to the part brought into contact with mold powder layer 40 on the molten steel and to the suitable part of the range to reach to the nozzle bottom part 15 at the outer face of submerged nozzle 10, a graphite sheet 11 having composition composing of 40-90 wt.% expanded graphite, 5-55 wt.% high alumina refractory powder and 0.5-10 wt.% oxidizing prevention agent, such as BN, etc., is coated and further on this, oxidizing prevention body 12 made of ceramic fiber, such as silica, alumina, etc., is laminated. |