Method for manufacturing immersion nozzle less susceptible to deposition of alumina for use in continuous casting

Abstract

Disclosed is a method of producing an immersion nozzle for continuous casting, which comprises 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 CO 2 atmosphere to convert CaO to CaCO 3 . The method of the present invention 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.

1 . A method of producing an immersion nozzle for continuous casting, which has zirconia-graphite refractories applied to a powder-line portion hereof, said method comprising: 
 integrally molding said zirconia-graphite refractories, and a compound applied to at least an inner hole portion of said immersion nozzle, said compound including 10 mass % or more of clinker particles each containing CaO as a mineral phase, wherein the surface of at least a part of said clinker particles is subjected to an anti-hydration treatment.    
     
     
         2 . The method as defined in  claim 1 , wherein said anti-hydration treatment comprises converting the CaO exposed outside from the surface of said clinker particle, to CaCO 3 .