PREVENTING METHOD FOR MOISTURE ABSORPTION OF ALUMINA-GRAPHITE-BASE NOZZLE FOR CONTINUOUS CASTING

摘要

PURPOSE:To enhance corrosion resistance by blending fire resistant aggregate, graphite powder and metallic Al powder and adding thermo-setting resin, kneading and molding the mixture and thereafter heattreating the molded body to produce a nozzle for continuous casting and preliminarily drying this nozzle before utilization and thereafter coating the nozzle with oil paint. CONSTITUTION:A nozzle for continuous casting is produced by blending 40-90wt.% (hereinafter shown in %) fire resistant aggregate, 10-50% graphite powder and 0.5-20% metallic Al powder and furthermore adding thermosetting resin and kneading the mixture and thereafter molding this kneaded material and then heat-treating the molded body at 500-800 deg.C in the nonoxidative atmosphere. Then before utilization, the nozzle is introduced into a drying furnace at the atmospheric temp. of 150-400 deg.C and preparatorily dried for at least 5 hours and thereafter slowly cooled to room temp. The nozzle is coated with oil paint to form a moisture preventive film. Thereby the Al2O3-graphite-based nozzle for continuous casting is obtained which is subjected to moisture preventive treatment.