| 摘要 |
PURPOSE:To provide the nozzle for continuous casting of a molten steel which is economical and does not generate the narrowing and further closing of an inside hole and the deterioration of the structure over a long period of time without using a mechanical method, such as ejecting an inert gas. CONSTITUTION:At least the surface layer part of the inside hole 1 is formed by making combination use of 40 to 89wt.% calcium zirconate essentially consisting of CaO ZrO2 as an ore compsn., 10 to 35wt.% graphite, calcium silicate essentially consisting of CaO SiO2 as the ore compsn. and crystal stabilized calcium silicate essentially consisting of 2CaO SiO2 and 3CaO SiO2 as the ore component. The total content of the above-mentioned calcium silicate is 1 to 35wt.% and the mixture is kneaded and molded under addition of an org. binder thereto. The molding is calcined in a nonoxidative atmosphere. As a result, the generation of the deterioration in the structure of the refractories is obviated. The narrowing of the inside hole by the nonmetallic inclusion, such as alpha-alumina and further the closing of the hole are stably suppressed over a long period of time. |
