MODIFIED REFRACTORY JIG MADE OF CARBON MATERIAL AND PRODUCTION THEREOF

摘要

PURPOSE:To inhibit spalling phenomena and to improve wear resistance and impact resistance to enhance durability and also to prevent carburizing by forming a hardened layer reinforced by insoluble chromium compd. to a refractory jig made of carbon material. CONSTITUTION:Such treatment is performed at one or more times that a refractory jig made of carbon material which has been molded into a final shape and calcined is impregnated with the concd. aq. soln. of water soluble chromium compd. and thereafter dried and heated at 350-600 deg.C. Furthermore such treatment is performed at one or more times that this refractory jig is impregnated with the concn. aq. soln. of chromic acid and thereafter dried and then heated at 350-600 deg.C. The above-mentioned impregnation is performed by immersion or brush coating, etc. By this treatment, the water soluble chromium compd. is converted into chromium oxide and this is settled and packed in the opened bores of the refractory jig. The bonding strength of carbon is increased by this chromium oxide and oxidation of carbon at high temp. is prevented. Wear resistance and carburizing preventability are enhanced by the hardened layer on the surface.