Impact pad for a tundish

Abstract

A tundish impact pad formed from refractory material, the impact pad ( 1 ) comprising a base ( 3 ) having an impact surface ( 5 ) which in use faces upwardly to receive molten metal poured onto the impact pad, and a wall ( 7 ) extending upwardly from the base around at least part of the periphery of the impact surface, the wall including an overhang ( 9 ) projecting over a peripheral region ( 11 ) of the impact surface ( 5 ), the overhang ( 9 ) including a plurality of protrusions ( 13 ) which project further over the impact surface ( 5 ) than the remainder of the overhang ( 5 ).

1 . A tundish impact pad formed from refractory material, the impact pad comprising a base having an impact surface which in use faces upwardly to receive molten metal poured onto the impact pad, and a wall extending upwardly from the base around at least part of the periphery of the impact surface, the wall including an overhang projecting over a peripheral region of the impact surface, the overhang including a plurality of protrusions which project further over the impact surface than the remainder of the overhang.  
     
     
         2 . An impact pad according to  claim 1 , in which the impact surface has at least two corners over which a respective protrusion projects.  
     
     
         3 . An impact pad according to  claim 2 , in which at least one of the corners is formed at the convergence of substantially straight sides of the impact surface.  
     
     
         4 . An impact pad according to  claim 2  or  claim 3 , in which the impact surface is substantially polygonal.  
     
     
         5 . An impact pad according to  claim 4 , in which the impact surface is substantially quadrangular, preferably substantially rectangular or square.  
     
     
         6 . An impact pad according to  claim 4  or  claim 5 , in which a protrusion projects over each corner of the polygonal impact surface.  
     
     
         7 . An impact pad according to any preceding claim, in which the distance by which the overhang extending between two said protrusions projects over the impact surface is substantially uniform along at least most of its length.  
     
     
         8 . An impact pad according to any preceding claim, in which the overhang extending between two said protrusions is substantially straight along at least most of its length.  
     
     
         9 . An impact pad according to any one of  claims 1  to  6 , in which the distance by which the overhang extending between two said protrusions projects over the impact surface is substantially non-uniform along at least most of its length.  
     
     
         10 . An impact pad according to  claim 9 , in which one or more overhang(s) extending between two protrusions is curved in plan view  
     
     
         11 . An impact pad according to any preceding claim, in which the maximum distance by which the or each protrusion projects over the impact surface is at least 110% of the maximum distance by which the remainder of the overhang projects over the impact surface.  
     
     
         12 . An impact pad according to any preceding claim, in which the maximum distance by which the or each protrusion projects over the impact surface is no more than 600% of the maximum distance by which the remainder of the overhang projects over the impact surface.  
     
     
         13 . An impact pad according to any preceding claim, in which the height of the overhang above the impact surface is non-uniform along its length.  
     
     
         14 . An impact pad according to  claim 13 , comprising at least three said protrusions, the height of the overhang extending between two of the protrusions being different to that of the overhang extending between one of the two protrusions and another protrusion, or between two other protrusions.  
     
     
         15 . An impact pad according to  claim 13  or  claim 14 , in which at least one portion of the overhang which is lower than that of another portion of the overhang projects a greater distance over the impact surface than does the other, higher, portion of the overhang.  
     
     
         16 . An impact pad according to any preceding claim, in which the peripheral region of the impact surface comprises a trough extending around at least part of a central region of the impact surface.  
     
     
         17 . A tundish containing an impact pad according to any preceding claim.  
     
     
         18 . A tundish according to  claim 17 , also containing one or more dams extending across its width, the or each dam having a top surface with a central portion which is lower in height than laterally peripheral portions on each side of it.