Work rolls having an engineered surface texture prepared by controlled surface modification after chrome coating

Abstract

Apparatus and methods of texturing the surfaces of work rolls and the rolls produced thereby which are used in the manufacture of sheet metals and other sheet materials. The working surface of each roll is processed in a series of steps which include the steps of chrome coating followed by controlled surface modification. Texturing can optionally precede controlled surface modification or chrome coating and intervening process steps can be used. Either or both process steps of chrome coating or controlled surface modification can be carried out once or more than once as long as each process step is used at least once and as long as a controlled surface modification step follows a chrome coating step. The work rolls produced by the method exhibit improved performance and extended life.

1 . A method of preparing the surface of a roll for use in a mill, the roll having a cylindrical outer surface, comprising chrome coating the surface and then controlled surface modification of the chrome coated surface.  
   
   
       2 . The method of  claim 1  wherein controlled surface modification of the surface is also carried out prior to chrome coating the surface.  
   
   
       3 . The method of  claim 1  wherein chrome coating is carried out in two or more than two distinct processing steps.  
   
   
       4 . The method of  claim 1  wherein controlled surface modification is carried out in two or more than two distinct processing steps.  
   
   
       5 . The method of  claim 1  wherein controlled surface modification is superfinishing.  
   
   
       6 . The method of  claim 1  wherein controlled surface modification of the chrome coated surface is the last step of texturing the roll before it is run in a mill.  
   
   
       7 . The method of  claim 1  wherein media blasting the surface is the first step of texturing or cleaning the roll after it is returned from a mill for reconditioning.  
   
   
       8 . The method of  claim 1  wherein controlled surface modification of the surface is the first step of texturing the roll after it is returned from a mill for reconditioning.  
   
   
       9 . The method of  claim 1  wherein a further step of chrome coating is carried out after controlled surface modification.  
   
   
       10 . An apparatus for texturing a roll having a cylindrical outer surface comprising 
 i) a chrome coating bath capable of uniformly chrome coating the outer surface;    ii) a means for contacting the outer surface with a controlled surface modification apparatus.    
   
   
       11 . A roll having a cylindrical outer surface which surface has been textured by a method comprising chrome coating the surface and then controlled surface modification of the surface.  
   
   
       12 . A method of preparing the surface of a roll for use in a mill, the roll having a cylindrical outer surface, comprising coating the surface with a coating selected from the group consisting of nickel, electroless nickel, nickel iron, cobalt, tungsten carbide and alloys and then controlled surface modification of the coating.