Method of manufacturing corrosion-resistant welding electrodes made of tungsten or a tungsten alloy

Abstract

Corrosion-resistant welding electrodes made of tungsten or a tungsten alloy are produced. Prefabricated welding electrodes are heat treated at temperatures of between 300° C. and 500° C. in an oxidizing atmosphere. This results in the formation of oxide layers on the surface of the welding electrodes; these layers have good electrical conductivity and prevent the formation of unwanted corrosion layers with poor conductivity. Welding electrodes produced in this way demonstrate outstanding spark ignition and problem-free erosion.

We claim:  
     
         1 . A method of producing a corrosion-resistant welding electrode, which comprises: 
 providing a welding electrode of tungsten or tungsten alloy; and    heat treating the welding electrode at a temperature of between 300° C. and 500° C. in an oxidizing atmosphere.    
     
     
         2 . The method according to  claim 1 , which comprises heat treating at a temperature between 375° C. and 430° C.  
     
     
         3 . The method according to  claim 1 , which comprises heat treating over a period of between 2 and 8 hours.  
     
     
         4 . The method according to  claim 1 , wherein the oxidizing atmosphere is air.  
     
     
         5 . The method according to  claim 1 , which comprises adjusting oxidation conditions to form an oxide layer with a color corresponding to a color prescribed to identify the electrode material.