| 摘要 |
PROBLEM TO BE SOLVED: To obtain a magnesia-carbon based brick having improved resistance to oxidation by adding an organic binder to a raw material compound having a specific composition containing magnesia, carbon powder and Cr2 N, molding and heat processing at the prescribed temperature. SOLUTION: This raw material compound is obtained by mixing 70-90wt.pts. of magnesia, 30-10wt.pts of carbon powder mainly composed of graphite and 0.5-7.5wt.pts of Cr2 N based on the total of the magnesia and graphite. The raw compound is molded after adding organic binder (e.g.; phenol resin) and mixing throughly. The molded article is then heat processed at 150-300 deg.C to give the magnesia based brick. The added Cr2 N has affinity to graphite having typical covalency, effectively acting on bonds of the graphite, manifesting reactivity with oxygen at high temperature and effective on suppressing the oxidation of carbon powder mainly composed of graphite. The resistance to oxidation of the brick is improved by the addition of the Cr2 N without reducing the properties such as heat shock resistance, corrosion resistance. |
