| 摘要 |
PURPOSE: To cost effectively obviate the generation of the constriction and closure of an inside hole and the deterioration of structures over a long period of time without using a mechanical method, such as ejecting of inert gas. CONSTITUTION: The surface layer part of an inside hole 1 in contact with molten steel consists of 40 to 65wt.% calcium zirconate consisting essentially of CaO.ZrO2 as an ore compsn., 10 to 35wt.% graphite, calcium silicate consisting essentially of CaO.SiO2 as the ore compsn. and crystalline stabilized calcium silicate consisting essentially of 2CaO.SiO2 or 3CaO.SiO2 as the ore compsn. which are used in combination. The total thereof is 1 to 25%, and the ore compsn. consists of 5 to 25wt.% natural raw materials of an SiO2 .Al2 O3 system as the ore compsn. This nozzle 3 for continuous casting is formed by adding an org. binder to the compsn. described above, kneading and molding the mixture and firing the molding in a nonxidizing atmosphere. As a result, the constriction and closure of the inside hole by nonmetallic inclusions, such as α-alumina, are suppressed stably over a long period of time without deteriorating the structures of refractories. |
