Refractory for steel casting, plate for sliding nozzle device, and method for producing refractory for steel casting

Abstract

In order to suppress destruction of a refractory which contains a metal aluminum, the refractory is a refractory for steel casting which includes a refractory material containing a free carbon in the range of 1 to 10% by mass, both inclusive, a metal aluminum in the range of 1 to 15% by mass, both inclusive, and a metal oxide in a balance. The refractory for steel casting satisfies the following Equation 1: 0.31×Al≦(P−4)/D (Equation 1), with a metal aluminum content in the refractory designated by Al % by mass, an apparent porosity thereof designated by P %, and a bulk density thereof designated by D.

1 . A refractory for steel casting, wherein the refractory for steel casting comprises a refractory material containing a free carbon in the range of 1 to 10% by mass, both inclusive, a metal aluminum in the range of 1 to 15% by mass, both inclusive, and a metal oxide in a balance; and
 the refractory for steel casting satisfies a following Equation 1,
   0.31×Al≦( P− 4)/ D    Equation 1,
 
   
       wherein a metal aluminum content in the refractory is designated by Al % by mass, an apparent porosity thereof is designated by P %, and a bulk density thereof is designated by D. 
     
     
         2 . The refractory for steel casting according to  claim 1 , wherein the metal oxide includes one or plurality of components selected from Al 2 O 3 , SiO 2 , ZrO 2 , MgO, and TiO 2 ; and a total amount of the components is 95% or more by mass when a total amount of the balance is taken as 100% by mass. 
     
     
         3 . The refractory for steel casting according to  claim 1 , wherein the refractory for steel casting contains a metal silicon in the range of 0.5 to 4% by mass, both inclusive. 
     
     
         4 . The refractory for steel casting according to  claim 1 , wherein the metal aluminum content therein is in the range of 4 to 15% by mass, both inclusive. 
     
     
         5 . The refractory for steel casting according to  claim 1 , wherein the metal aluminum content therein is in the range of 6 to 15% by mass, both inclusive. 
     
     
         6 . A plate for a sliding nozzle device, wherein part or all thereof is composed of the refractory for steel casting according to  claim 1 . 
     
     
         7 . A method for producing the refractory for steel casting of  claim 1 , the method comprising: making a body for molding by adding 1 to 7% by mass, both inclusive, of a thermosetting resin to a mixed powder which comprises a refractory material containing an aluminum-containing metal and a metal oxide including one or plurality of components selected from Al 2 O 3 , SiO 2 , ZrO 2 , MgO, and TiO 2  in a balance, which is then followed by kneading a resulting mixture; press-molding the body for molding; and carrying out a heat treatment thereof; and also,
 a metal aluminum content in the refractory after the heat treatment is made in the range of 1 to 15% by mass, both inclusive, and an apparent porosity is controlled so as to satisfy the Equation 1.   
     
     
         8 . The method for producing the refractory for steel casting according to  claim 7 , wherein the aluminum-containing metal contained in the mixed powder is derived from a raw material comprising a simple metal aluminum with one or plural forms selected from a flake-like form having a maximum length of not more than 140 μm, a granular-like form having a particle diameter of not more than 140 μm, and a fiber-like form having a maximum diameter of a cross section thereof of not more than 200 μm and a maximum length of not more than 5 mm. 
     
     
         9 . The method for producing the refractory for steel casting according to  claim 7 , wherein part or all of the aluminum-containing metal contained in the mixed powder is derived from a raw material comprising a metal aluminum-containing alloy. 
     
     
         10 . The method for producing the refractory for steel casting according to  claim 9 , wherein the metal aluminum-containing alloy is an aluminum-magnesium alloy or an aluminum-silicon alloy.