| 摘要 |
PROBLEM TO BE SOLVED: To provide a coating agent, by which chemically stable oxide is formed on the inner and the outer tube surfaces of an immersion nozzle for continuous casting and the formed oxide film has a smooth surface having little ruggedness. SOLUTION: (1) In the coating agent 8 constituted of refractory oxide, binder, organic base paste agent and dispersion medium, the ultra fine granular refractory oxide having 10-200 nm grain diameter is contained by 50-80 wt.% as a blending ratio excluding the organic base paste agent and the dispersion medium, and MgO in the ultra fine grain is contained by 40-80 wt.%. (2) The refractory oxide except MgO as the main components in the ultra fine grain mentioned in the above (1), is one or more kinds among MnO, SiO2, Na2O, K2O, Fe2O3, Al2O3, TiO2, CaO, Y2O3 and ZrO3. (3) In the refractory oxide in the ultra fine grain mentioned in the above (2), the total blending ratio of one or more kinds of Fe2O3, Al2O3 and TiO2 is <10 wt.% as the blending ratio excluding the organic base paste agent and the dispersion medium. |
