Continuous casting mold and method

Abstract

An improved mold assembly for a continuous casting machine includes a mold liner assembly having an inner surface defining a casting space in which molten metal is shaped and cooled, an immersion nozzle, terminating within the casting space, for introducing molten metal into the casting space, and selective cooling structure for selectively cooling the mold liner assembly in such a manner that cooling is directed in varying intensities to different portions of the inner surface of the mold liner assembly according to predetermined circulation patterns in the molten metal, whereby heat transfer inequality as a result of convection is accommodated over the entire inner surface of the mold liner assembly.

What is claimed is:  
     
         1 . An improved mold assembly for a continuous casting machine, comprising: 
 a mold liner assembly having an inner surface defining a casting space in which molten metal is shaped and cooled;    an immersion nozzle, terminating within the casting space, for introducing molten metal into the casting space; and    selective cooling means for selectively cooling said mold liner assembly in such a manner that cooling is directed in varying intensities to different portions of the inner surface of the mold liner assembly according to predetermined circulation patterns in the molten metal, whereby heat transfer inequality as a result of convection is accommodated over the inner surface of the mold liner assembly.    
     
     
         2 . An assembly according to  claim 1 , wherein said mold liner assembly comprises a funnel-type mold for making a thin slab casting, said funnel type mold comprising a relatively wide central region, relatively narrow end regions, and transition regions between said central region and said end regions.  
     
     
         3 . An assembly according to  claim 2 , wherein said selective cooling means is constructed and arranged to direct enhanced cooling to said transition regions.  
     
     
         4 . An assembly according to  claim 2 , wherein said selective cooling means is constructed and arranged to direct diminished cooling to said central region.  
     
     
         5 . An assembly according to  claim 1 , wherein said selective cooling means is further constructed and arranged to provide enhanced cooling to a portion of said inner surface of said mold liner assembly that corresponds to where the meniscus of the molten metal will be positioned during casting.  
     
     
         6 . An assembly according to  claim 1 , wherein said selective cooling means is constructed and arranged to direct cooling at varying intensities by accordingly varying distances between the inner surface of the mold liner assembly and the bottoms of cooling slots that are defined in the mold liner assembly.  
     
     
         7 . An assembly according to  claim 6 , wherein said selective cooling means is further constructed and arranged to direct cooling at varying intensities by accordingly varying the length of deepened slot portions according to the amount of cooling that is desired at a particular area in the moldface.  
     
     
         8 . An assembly according to  claim 1 , wherein said selective cooling means is constructed and arranged to direct cooling at varying intensities by accordingly varying the length of deepened slot portions according to the amount of cooling that is desired at a particular area in the moldface.  
     
     
         9 . A method of operating a continuous casting machine of the type having a mold liner assembly that has an inner surface defining a casting space in which molten metal may be shaped and cooled, comprising steps of: 
 (a) introducing molten metal into the casting space; and    (b) selectively cooling the mold liner assembly in varying intensities at different portions of the inner surface of the mold liner assembly according to predetermined circulation patterns in the molten metal, whereby heat transfer inequality as a result of convection is accommodated over the inner surface of the mold liner assembly, product quality is enhanced and mold life is lengthened.    
     
     
         10 . A method according to  claim 9 , wherein the mold liner assembly comprises a funnel-type mold for making a thin slab casting, said funnel type mold comprising a relatively wide central region, relatively narrow end regions, and transition regions between said central region and said end regions.  
     
     
         11 . A method according to  claim 10 , wherein step (b) is performed to direct enhanced cooling to said transition regions.  
     
     
         12 . A method according to  claim 10 , wherein step (b) is performed to direct diminished cooling to said central region.  
     
     
         13 . A method according to  claim 9 , further comprising providing enhanced cooling to a portion of the inner surface of the mold liner assembly that corresponds to where the meniscus of the molten metal will be positioned during casting.  
     
     
         14 . A method according to  claim 9 , wherein step (b) is performed by varying distances between the inner surface of the mold liner assembly and the bottoms of cooling slots that are defined in the mold liner assembly.  
     
     
         15 . A method according to  claim 14 , wherein step (b) is further performed by varying the length of a deepened cooling slot according to the amount of additional cooling that is desired to be directed to an area of the mold liner assembly.  
     
     
         16 . A method according to  claim 9 , wherein step (b) is performed by varying the length of a deepened cooling slot according to the amount of additional cooling that is desired to be directed to an area of the mold liner assembly