| 摘要 |
PURPOSE:To prevent the sticking of inclusions to a nozzle by using an alumina graphite nozzle having a specific structure in casting a molten steel adjusted to specific contents of Al and Ti. CONSTITUTION:The molten steel adjusted to 0.01 to 0.O5% sol.Al and <=0.03% Ti is cast by using the alumina graphite nozzle having a structure provided with the gradually narrowing tapered part of the nozzle and the straight part of the nozzle while satisfying equation I. In the equation I, D; the aperture diameter of a tundish bottom, (d); the min. diameter of the nozzle, L; the length of the tapered part of the nozzle. The point (a) in the inlet part of the tapered part 10 of the nozzle and the point (b) in the inlet part of the straight part 12 of the nozzle are the start points where the inclusions stick. The nozzle having the structure satisfying the equation prevents the sticking of the inclusions at the start points where the inclusions stick. Long-term casting is thus possible. |
