Method Of And Molten Metal Feeder For Continuous Casting

Abstract

The invention provides a feeder for delivery of molten metal into a mold formed between confronting casting surfaces of a continuous casting machine. The feeder comprises a projecting nozzle tip having at least a lower wall provided with a molten metal-contacting inner surface, a generally flat outer surface and an end surface at an outer extremity of the tip extending between the inner and outer surface. The inner surface is generally flat and preferably slopes towards the outer surface considered in a direction moving towards the extremity of the tip at an angle of slope of no more than 8 degrees. The end surface is generally flat and extends from the inner surface to the outer surface at an acute angle of less than 88°, e.g. in the range of 15 to 80 degrees, relative to the inner surface in a direction away from the extremity of the tip. The feeder casts a metal sheet article having reduced surface defects caused by rupture of the metal oxide during casting.

1 . A feeder for delivery of molten metal into a mold formed between confronting casting surfaces of a continuous casting machine, the feeder comprising: 
 a nozzle having a projecting tip including at least one wall provided with a molten-metal-contacting inner surface, an outer surface, and an end surface at an outer extremity of the tip extending between the inner and outer surfaces,    characterized in that the inner surface and the end surface interconnect at a line and form an included angle of less than 88°, and said at least one wall has a thickness adjacent to said line in the range of 0.5 to 3 mm.    
     
     
         2 . A feeder according to  claim 1 , characterized in that said included angle is in the range of 15 to 85 degrees.  
     
     
         3 . A feeder according to  claim 1 , characterized in that said included angle is in the range of 15 to 80 degrees.  
     
     
         4 . A feeder according to  claim 3 , characterized in that said included angle is in the range of 15 to 75 degrees.  
     
     
         5 . A feeder according to  claim 3 , characterized in that said included angle is selected from a range of 30 to 70 degrees.  
     
     
         6 . A feeder according to  claim 1 , characterized in that said thickness is 1±0.5 mm.  
     
     
         7 . A feeder according to  claim 3 , characterized in that the tip has two of said walls aligned with each other with said metal-contacting inner surfaces confronting each other across a metal-conveying channel.  
     
     
         8 . A feeder according to  claim 7 , characterized in that said walls of said tip diverge from each other in a direction extending towards said outer extremity.  
     
     
         9 . A feeder according to  claim 8 , characterized in that said walls diverge from a longitudinal axis of the tip at an angle of about 8 degrees.  
     
     
         10 . A continuous casting machine, comprising: 
 a pair of endless casting surfaces confronting each other across a casting cavity;    a means for moving the casting surfaces in the same direction at the same speed; and    a feeder for introducing molten metal into said casting cavity at one end of said cavity;    wherein said feeder comprises a nozzle having a projecting tip including at least one wall provided with a molten-metal-contacting inner surface, an outer surface, and an end surface at an outer extremity of the tip extending between the inner and outer surfaces,    characterized in that said inner surface and said end surface interconnect at a line and form an included angle of less than 88 degrees, said at least one wall has a thickness adjacent to said line in the range of 0.5 to 3 mm, and said line is held during casting at a spacing from an adjacent one of said casting surfaces within a range of 0.5 to 3 mm.    
     
     
         11 . A casting machine according to  claim 10 , characterized in that said included angle is in the range of 15 to 85 degrees.  
     
     
         12 . A casting machine according to  claim 10 , characterized in that said included angle is in the range of 15 to 80 degrees.  
     
     
         13 . A casting machine according to  claim 12 , characterized in that said included angle is in the range of 15 to 75 degrees.  
     
     
         14 . A casting machine according to  claim 12 , characterized in that said included angle is within the range of 30 to 70 degrees.  
     
     
         15 . A casting machine according to  claim 10 , characterized in that said spacing is 1±0.5 mm.  
     
     
         16 . A casting machine according to  claim 12 , characterized in that the tip has two of said walls aligned with each other with said metal-contacting inner surfaces confronting each other across a metal-conveying channel.  
     
     
         17 . A casting machine according to  claim 16 , characterized in that said walls of said tip diverge from each other in a direction extending towards said outer extremity.  
     
     
         18 . A casting machine according to  claim 17 , characterized in that said walls diverge from a longitudinal axis of the tip at an angle of about 8 degrees.  
     
     
         19 . A process of continuous strip casting a molten metal to form a cast metal strip article, which process comprises feeding a molten metal, which develops an oxide layer when in contact with air, from a nozzle having a projecting nozzle tip onto at least one moving casting surface such that the metal forms a meniscus having a surface coating of metal oxide between an extremity of the tip and the casting surface, characterized in that said metal is fed from a tip having an inner surface and an end surface that interconnect at a line and form an included angle of less than 88 degrees, said at least one wall has a thickness adjacent to said line in the range of 0.5 to 3 mm, and said line during casting is positioned at a spacing from an adjacent one of said casting surfaces within a range of 0.5 to 3 mm.  
     
     
         20 . A process according to  claim 19 , characterized in that the final contact between the molten metal and the tip is confined to a fixed position on the tip by providing the tip with an inner metal-contacting surface and an end surface that interconnect at a line and have an included angle selected from a range of 15 to 80 degrees, and causing the molten metal to flow over said interconnecting line onto said casting surface.