Flexible rolling of light metals

Abstract

A method of flexibly rolling a metal strip or a metal sheet bar, wherein the metal strip or metal sheet bar is rolled in the longitudinal direction of the rolling operation along its entire length from a starting thickness to an end thickness which is variable along its length. The strip or sheet bar material used is in the form of light metals, more particularly aluminum or magnesium.

1 . A method of flexibly rolling a metal strip or a metal sheet bar wherein the metal strip or metal sheet bar is rolled in the longitudinal direction of the rolling operation along its entire length from a starting thickness to an end thickness which is variable along its length, and wherein the strip or sheet bar material used is in the form of light metals, wherein said end thickness comprises at least three different thickness stages.  
   
   
       2 . A method according to  claim 1 , wherein the thickness of the material is reduced along its entire length by at least 5% with reference to the starting thickness of 100%.  
   
   
       3 . A method according to claims  1  or  2 , wherein differences in end thickness of the material of different thickness stages are at least 10%, which thickness stages adjoining one another in respect of thickness, with reference to the starting thickness of 100%.  
   
   
       4 . A method according to claims  1  or  2 , wherein the thickness of the greatest thickness stage ranges between 95% and 75% with reference to the starting thickness of 100%.  
   
   
       5 . A method according to claims  1  or  2 , wherein the thickness of the second greatest thickness stage ranges between 85% and 45%, with reference to the starting thickness of 100%.  
   
   
       6 . A method according to claims  1  or  2 , wherein the thickness of the second greatest thickness stage ranges between 85% and 45% with reference to the starting thickness of 100% and wherein the thickness of the third greatest thickness stage ranges between 75% and 30% with reference to the starting thickness of 100%.  
   
   
       7 . A method according to  claim 6 , wherein different thickness stages alternate periodically, but in any optional sequence.  
   
   
       8 . A method according to  claim 6 , wherein the changes in thickness between the individual thickness stages are carried out with a gradient γ of at most 1:40 and of at least 1:4000.  
   
   
       9 . A method according to  claim 8 , wherein the thickness of the material is reduced by a maximum of 70% with reference to the starting thickness of 100%.  
   
   
       10 . A method according to  claim 6 , wherein if aluminum is used, the material, prior to being rolled, is heated to a temperature of at least 350°-470° C.  
   
   
       11 . A method according to  claim 6 , wherein if magnesium is used, the material, prior to being rolled, is heated to a temperature of 180°-280° C.  
   
   
       12 . A method according to  claim 6 , wherein use is made of strip or sheet bar with a width in excess of 1400 mm transversely to the direction of rolling.  
   
   
       13 . A metal strip or metal sheet bar which, by being flexibly rolled in the longitudinal direction of the rolling operation, is rolled along its entire length from a starting thickness to an end thickness, which end thickness is variable along its length, wherein the strip or sheet bar material is used in the form of light metals, wherein the end thickness comprises at least three different thickness stages.  
   
   
       14 . A metal strip or metal sheet bar according to  claim 13 , wherein there exists differences in end thickness of the materials between thickness stages adjoining one another in respect of size of at least 10% with reference to the starting thickness of 100%.  
   
   
       15 . A metal strip or metal sheet bar according to any one of claims  13  or  14 , wherein the thickness of the greatest thickness stage ranges between 95% and 75% with reference to the starting thickness of 100%.  
   
   
       16 . A metal strip or metal sheet bar according to  claim 15 , wherein the thickness of the second greatest thickness stage ranges between 85% and 45% with reference to the starting thickness of 100%.  
   
   
       17 . A metal strip or metal sheet bar according to  claim 16 , wherein the thickness of the third greatest thickness stage ranges between 75% and 30% with reference to the starting thickness of 100%.  
   
   
       18 . A metal strip or metal sheet bar according to  claim 17 , wherein the changes in thickness between the individual thickness stages take place with a gradient γ of at most 1:40 and of at least 1:4000.  
   
   
       19 . A metal strip portion or a metal sheet bar according to  claim 18  which produces a deformed planar element consisting of sheet metal.  
   
   
       20 . A metal strip portion or a metal sheet bar according to  claim 19  which produces a hollow profile or tube consisting of sheet metal.