| 摘要 |
PURPOSE:To obtain a nozzle refractory having excellent spalling resistance, oxidizing resistance and wear resistance by continuously or stepwisely increasing graphite content from outer wall surface side toward inner wall surface side of the nozzle and improving crack developing resistance at the time of using. CONSTITUTION:Components except graphitic quality in a composite material content oxide material series components of alumina, silica, zirconia, etc., as main component, and SiC, B4C, etc., in the above components may be contained to the max. prescribed concns. In the case of continuously varying the graphite content, a cylindrical mold for forming is set at center of rotation of a rotating table and while rotating the mold at high speed, refractory raw material is charged little by little to manufacture the refractory raw material filling body, in which the graphite content is continuously increased from the outside toward the inside. As the components except the graphite are heavy, they are filled much toward the outside with centrifugal force. This filling body is pressurizing-formed by an isotropic pressurized forming method and further, produced through purning. The graphite is less than the oxide in these thermal expansion ratio and on the other hand, the oxide is more than the graphite in these breakage stress resistance. By this method, the nozzle refractory having excellent spalling resistance and oxidizing resistance can be obtd. |
