| 摘要 |
PURPOSE:To produce a refractory for casting excellent in oxidation resistance and prevent the strength from deteriorating due to the structure embrittlement even in the case of a caused oxidation phenomenon after use for a long period while maintaining the corrosion and spalling resistance. CONSTITUTION:A binary to ternary component system containing at least two among alumina, silica and zirconia in an amount of 5-25wt.% is added to an alumina raw material. The resultant mixture, together with the alumina raw material, is used as a main aggregate. Mesophase pitch and/or graphite in an amount of 2-10wt.%, metallic Si in an amount of 2-5wt.% and metallic Fe in an amount of 1-5wt.% respectively having <=100 mesh particle diameter are further added to the obtained aggregate to provide 100wt.%. The obtained mixture, together with an adequate amount of a phenolic resin liquid, is kneaded, formed and subsequently burned in a reducing atmosphere and the metallic Fe forms cementite in the coexistence of carbon. On the other hand, the cementite slowly dissociates into Fe and C with operation. Thereby, oxidation proceeds and the dissociated Fe is simultaneously made to react with the aggregate alumina to produce hercynite. |
