Shaped direct chill aluminum ingot

Abstract

Method and apparatus for forming aluminum ingot having shaped ends to avoid alligatoring during rolling.

1 . A method of rolling an ingot of aluminum to avoid alligatoring as the ingot is reduced in thickness to produce a slab, the ingot being rolled in a rolling mill wherein the ingot is subject to multiple rolling passes, the method comprising: 
 (a) providing a rolling mill;    (b) providing an ingot to be rolled, the ingot having two large flat sides and at least one shaped end comprising: 
 (i) opposed surfaces tapered into said ingot towards said end to provide tapered surfaces, said tapered surfaces being provided in the direction of rolling, and being in the range of 2° to 20° from the surface to be rolled and extending towards said end, and  
 (ii) said end having a curved surface contiguous with said tapered surfaces, said curved surfaces extending transverse to said rolling direction to provide said formed end; and  
   (c) subjecting said ingot to multiple rolling passes in said rolling mill to reduce said ingot in thickness and extend the ingot in length to produce rolled material, said material being free of alligatoring.    
   
   
       2 . The method in accordance with  claim 1  wherein said tapered surfaces is in the range of 5° to 15°.  
   
   
       3 . The method in accordance with  claim 1  wherein said curve approximates a ½ circle.  
   
   
       4 . The method in accordance with  claim 1  wherein both ends of said ingot have tapered surfaces and provided with curved surfaces.  
   
   
       5 . The method in accordance with  claim 1  wherein at least one of said ends of said ingot is formed during casting from a shape of a bottom block onto which aluminum is poured during casting.  
   
   
       6 . The method in accordance with  claim 1  wherein at least one of said ends of said ingot is formed by machining after the ingot is formed.  
   
   
       7 . The method in accordance with  claim 1  wherein both ends of the ingot are formed during casting to provide said formed ends.  
   
   
       8 . A method of producing an aluminum ingot having a formed end to avoid alligatoring as the ingot is reduced in thickness during rolling, the ingot being rolled in a rolling mill wherein the ingot is subject to multiple rolling passes, the method comprising: 
 (a) providing a caster for casting aluminum ingot, said caster comprising a rectangular shaped mold and bottom block fitted therein to start casting said ingot having said formed end, said bottom block having an upper surface for receiving molten aluminum, said upper surface having two opposed faces tapered inwardly towards each other and terminating in a rounded end to provide a cast ingot for rolling, the cast ingot having at least one formed end comprising: 
 (i) opposed surfaces tapered into said ingot towards said end to provide tapered surfaces, said tapered surfaces being provided at an angle in the range of 2° to 20° from the surface to be rolled and extending towards said end, and  
 (ii) said end having a curved surface contiguous with said opposed surfaces, said curved surface extending transverse to said rolling direction to provide said formed end;  
   (b) providing a molten aluminum to be cast into an ingot;    (c) casting said ingot; and    (d) subjecting said ingot to multiple rolling passes in said rolling mill to reduce said ingot in thickness and extend the ingot in length to produce a rolled material free of alligatoring.    
   
   
       9 . The method in accordance with  claim 8  wherein said tapered surface is in the range of 5° to 15°.  
   
   
       10 . The method in accordance with  claim 8  wherein said curve approximates a ½ circle.  
   
   
       11 . The method in accordance with  claim 8  wherein both ends of said ingot are tapered and provided with curved surfaces.  
   
   
       12 . The method in accordance with  claim 8  wherein both ends of the ingot are formed during casting to provide said formed ends.  
   
   
       13 . A method of producing an aluminum ingot having a formed end to avoid alligatoring as the ingot is reduced in thickness during rolling, the ingot being rolled in a rolling mill wherein the ingot is subject to multiple rolling passes, the method comprising: 
 (a) providing a molten aluminum to be cast into an ingot;    (b) providing a caster for casting aluminum ingot, said caster comprising a rectangular shaped mold and bottom block fitted therein to start casting said ingot having said formed end, said bottom block having an upper surface for receiving molten aluminum in the mold, said upper surface having two opposed faces tapered inwardly towards each other and terminating in a rounded end to provide a cast ingot for rolling;    (c) casting said ingot, the cast ingot having at least one formed end, the formed end comprising: 
 (i) opposed surfaces having a taper provided in the direction of rolling, said taper being in the range of 2° to 20°, and  
 (ii) a rounded surface continuous with said taper, said rounded surface extending transverse to said rolling direction to provide said formed end;  
   (d) subjecting said ingot to multiple rolling passes in said rolling mill to reduce said ingot in thickness and extend the ingot in length to produce a slab free of alligatoring.    
   
   
       14 . The method in accordance with  claim 13  wherein said rounded surface comprises a half circle.  
   
   
       15 . The method in accordance with  claim 13  wherein said taper is in the range of 5° to 15°.  
   
   
       16 . In an improved system of producing an aluminum ingot having a formed end to avoid alligatoring as the ingot is reduced in thickness during rolling, the ingot being rolled in a rolling mill wherein the ingot is subject to multiple passes, the improvement comprising: 
 (a) a bottom block for inserting into a rectangular shaped mold to start vertical casting of ingot, the bottom block having: 
 (i) a top surface for receiving molten aluminum whereon the molten aluminum solidifies; and  
 (ii) the top surface having two opposed faces having a taper and terminating in a rounded section, said surfaces having a taper provided in a rolling direction of said ingot, the taper being in a range of 2° to 20° from the surface to be rolled.  
   
   
   
       17 . The method in accordance with  claim 16  wherein said rounded surface comprises a half circle.  
   
   
       18 . A method of rolling an ingot of aluminum to avoid alligatoring as the ingot is reduced in thickness to produce a slab, the ingot being rolled in a rolling mill wherein the ingot is subject to multiple rolling passes, the method comprising: 
 (a) providing a rolling mill;    (b) providing an ingot to be rolled, the ingot having two large flat sides and at least one shaped end comprising opposed surfaces tapered into said ingot towards said end, said tapered surfaces provided in the direction of rolling, and being in the range of 2° to 20° from the surface to be rolled and extending towards said end; and    (c) subjecting said ingot to multiple rolling passes in said rolling mill to reduce said ingot in thickness and extend the ingot in length to produce rolled material, said material being free of alligatoring.    
   
   
       19 . The method in accordance with  claim 18  wherein said tapered surface is provided at an angle in the range of 5° to 15°.  
   
   
       20 . The method in accordance with  claim 18  wherein both ends of said ingot are tapered.  
   
   
       21 . The method in accordance with  claim 18  wherein at least one of said ends of said ingot is formed during casting from a shape of a bottom block onto which aluminum is poured during casting.  
   
   
       22 . The method in accordance with  claim 18  wherein a second tapered surface is formed extending from said first tapered surfaces.  
   
   
       23 . The method in accordance with  claim 22  wherein said second tapered surface is provided at an angle in ranges of 50° to 80°.  
   
   
       24 . A method of producing an aluminum ingot having a formed end to avoid alligatoring as the ingot is reduced in thickness during rolling, the ingot being rolled in a rolling mill wherein the ingot is subject to multiple rolling passes, the method comprising: 
 (a) providing a caster for casting aluminum ingot, said caster comprising a rectangular shaped mold and bottom block fitted therein to start casting said ingot having said formed end, said bottom block having an upper surface for receiving molten aluminum, said upper surface having two opposed faces having tapers formed inwardly towards each other and terminating in an end to provide a cast ingot for rolling, the cast ingot having at least one formed end comprising: 
 (i) opposed surfaces having first tapers formed into said ingot towards said end, said tapers being provided in a direction of rolling, and being in the range of 2° to 20° from the surface to be rolled and extending towards said end, and  
 (ii) said end having second tapers contiguous with said first tapers, said second tapers extending in the rolling direction to provide said formed end;  
   (b) providing a molten aluminum to be cast into an ingot;    (c) casting said ingot; and    (d) subjecting said ingot to multiple rolling passes in said rolling mill to reduce said ingot in thickness and extend the ingot in length to produce a rolled material free of alligatoring.    
   
   
       25 . The method in accordance with  claim 24  wherein said first taper is in the range of 5° to 15°.  
   
   
       26 . The method in accordance with  claim 24  wherein said second taper is in the range of 50° to 80°.  
   
   
       27 . The method in accordance with  claim 24  wherein both ends of the ingot are formed during casting to provide said formed ends.  
   
   
       28 . A cast ingot for rolling into flat rolled product, the cast ingot having at least one formed end, the formed end comprising: 
 (a) opposed surfaces having a taper provided in a direction of rolling, said taper being in the range of 2° to 20°, and    (b) a rounded surface continuous with said taper, said rounded surface extending across said ingot to provide said formed end.    
   
   
       29 . A cast aluminum ingot having at least one formed end comprising: 
 (a) opposed surfaces having first tapers formed into said ingot towards said end, said tapers formed in a direction of rolling, and being in the range of 2° to 20° from the surface to be rolled and extending towards said end, and    (b) said end having second tapers contiguous with said first tapers, said second tapers being in the rolling direction to provide said formed end.