Abstract: Disclosed is anti-alumina-buildup refractories for casting nozzles, which comprises a refractory aggregate including 20 mass % or more of CaO component, and 10 mass % or more of clinker particles each containing CaO as a mineral phase, on the basis of 100 mass % of the entire composition. At least a part of the surfaces of the CaO exposed from the surfaces of the corresponding clinker particles is formed with a CaCO3 film. The CaCO3 film releases CO2 gas through thermal decomposition to smooth an operative surface of the nozzle so as to prevent the accretion of metal thereon, so that CaO is continuously supplied to alumina attached on the operative surface to prevent alumina buildup. In addition, the CaCO3 film effectively prevents the hydration of CaO due to a hydration reaction.

Abstract: Disclosed is anti-alumina-buildup refractories for casting nozzles, which comprises a refractory aggregate including 20 mass % or more of CaO component, and 10 mass % or more of clinker particles each containing CaO as a mineral phase, on the basis of 100 mass % of the entire composition. At least a part of the surfaces of the CaO exposed from the surfaces of the corresponding clinker particles is formed with a CaCO3 film. The CaCO3 film releases CO2 gas through thermal decomposition to smooth an operative surface of the nozzle so as to prevent the accretion of metal thereon, so that CaO is continuously supplied to alumina attached on the operative surface to prevent alumina buildup. In addition, the CaCO3 film effectively prevents the hydration of CaO due to a hydration reaction.

Abstract: A method of producing an immersion nozzle for continuous casting, which includes integrally molding a first zirconia-graphite compound applied to a powder-line portion of the nozzle, and a second compound applied to at least an inner hole portion of the nozzle. The second compound includes 10 mass % or more of clinker particles each containing CaO as a mineral phase, and the surface of at least a part of the clinker particles is subjected to an anti-hydration treatment, such as a heat treatment to be performed under a CO2 atmosphere to convert CaO to CaCO3. The method can suppress volume expansion caused by the reaction between CaO and water released from resin added as binder, so as to prevent the occurrence of cracks during a burning process of the molded piece.

Abstract: A method of producing an immersion nozzle for continuous casting, which includes integrally molding a first zirconia-graphite compound applied to a powder-line portion of the nozzle, and a second compound applied to at least an inner hole portion of the nozzle. The second compound includes 10 mass % or more of clinker particles each containing CaO as a mineral phase, and the surface of at least a part of the clinker particles is subjected to an anti-hydration treatment, such as a heat treatment to be performed under a CO2 atmosphere to convert CaO to CaCO3. The method can suppress volume expansion caused by the reaction between CaO and water released from resin added as binder, so as to prevent the occurrence of cracks during a burning process of the molded piece.

Abstract: A bonding structure between a nozzle body of a continuous casting nozzle and a refractory sleeve inserted into the nozzle body, wherein the refractory sleeve contains 20 mass % or more of CaO. An adhesive including a mixture of a refractory aggregate and a binder is applied to a joint zone defined in either one of at least a portion of the outer peripheral surface of the refractory sleeve and at least a portion of the inner surface of the hollowed nozzle to which the refractory sleeve is attached, or between the inner surface of the nozzle body and the outer peripheral surface of the refractory sleeve inserted into the nozzle body. The adhesive is adjusted to have a porosity in the range of 15 to 90% after dried in the joint zone.