| 摘要 |
PURPOSE:To prolong the service life of the nozzle by integrally forming the refractory layer of the specific composition containing carbon, zirconia, etc. at the specific percent and the nozzle body. CONSTITUTION:Material of the nozzle body 13 can be alumina-graphite base refractories. A refractory layer 20 is provided to the portion of the nozzle body 13 in contact with the molten mold powder layer on the molten steel surfaces when dipped into the molten steel in the mold. This refractory layer 20 is composed of 2-35% carbon, 50-85% zirconia, 5-30% silicon carbide, 5-30% molten silica, and 3% or less unavoidable impurities (hereabove in wt%). Tar and pitch are mixed as binders. These refractories are molded by an ordinary rubber press method, thence the molding is fired, whereby the immersion nozzle is made. |
