Hot forming tool

Abstract

Disclosed is a hot forming tool ( 1 ) which consists of a main tool member ( 2 ) having an at least partial surface coating ( 4 ) and which can be obtained by providing the main tool member with a raised metal relief that is then entirely or partly oxidized and converted into a protective layer.

1 . A hot forming tool comprising a tool body having at least pro rata surface coating, obtainable in that the basic body is provided with a raised metallic relief, which is subsequently completely or partially oxidized and converted into a protective layer. 
     
     
         2 . The tool according to  claim 1 , wherein it is a piercing plug, a forging mandrel or a rolling mandrel. 
     
     
         3 . The tool according to  claim 1 , wherein the basic body is made of metal, preferably steel. 
     
     
         4 . The tool according to  claim 1 , wherein the raised relief on the base body is a wire wrapping. 
     
     
         5 . The tool according to  claim 1 , wherein the raised relief on the base body is a metal fabric. 
     
     
         6 . A method for producing a hot forming tool comprising a tool body having at least pro rata surface coating, in which
 (a) the body is provided with a raised metallic relief, and   (b) successively the metallic relief is completely or partially oxidized and converted into a protective layer.   
     
     
         7 . The method according to  claim 6 , wherein the raised relief is applied on the base body by winding a wire. 
     
     
         8 . The method according to  claim 6 , wherein the raised relief is applied on the base body by covering with a metal fabric. 
     
     
         9 . The method according to  claim 8 , wherein the metal fabric is preformed by deformation on the shape of the tool and then put onto the basic body. 
     
     
         10 . The method according to  claim 7 , wherein the wire or the metal fabric is welded to the base body. 
     
     
         11 . The method of  claim 6 , wherein the raised relief is applied on the base body by Chemical/Physical Vapor Phase Deposition. 
     
     
         12 . The method according to  claim 6 , wherein the raised relief is applied on the base body by thermal spraying. 
     
     
         13 . The method according to  claim 6 , wherein the base body consists of metal, preferably steel, and the material forming the raised relief, is capable of at least partly forming an oxide layer. 
     
     
         14 . The method according to  claim 6 , comprising complete or partial conversion of the metallic reliefs in an oxidic protective layer by flame spraying, plasma spraying, or Is carried out by a thermochemical process. 
     
     
         15 . A method for the manufacture of seamless tubes or hot-forging tubular workpieces of metal, comprising using the tool according to  claim 1 .