| 摘要 |
PURPOSE:To stably restrain narrowing and further clogging of an inner hole caused by non-metallic inclusion of alpha-alumina, etc., without developing deterioration of structure in a refractory for long time by specifying composition of the surface layer part of the inner hole in a nozzle. CONSTITUTION:The inner hole 1 in the nozzle for pouring the molten steel consists of the compsn. contg. 50-89wt.% calcium zirconate containing CaO ZrO2 as the essential component as mineral composition, 10-35% graphite and 0.5-10% fluorite containing calcium fluoride (CaF2) as the essential component as mineral composition. For the nozzle for pouring molten metal composed of this refractory, the phenomenon that CaO component is vigorously reacted with water or moisture in the air is suppressed and the deterioration of structure in the nozzle is prevented. |
