Method and apparatus for repairing superalloy components

Abstract

A method of repairing a metallic component, such as a superalloy turbine blade or turbine nozzle, includes the step of preparing the component by stripping the protective coatings from the component. The component is then pre-conditioned for welding by a first hot isostatic process. Once the conditioning sequence is complete, the component is welded using any of a number of welding techniques and by adding weld fillers to the weld area. After the welding step, the component is sealed by a second hot isostatic process treatment performed at conditions similar to the first hot isostatic process. The component is finally prepared for re-entry into service.

1 - 21 . (canceled)  
   
   
       22 . A method of repairing a metallic component, comprising: 
 subjecting a metallic component to a first hot isostatic processing operation;    welding the metallic component with a first weld filler using gas tungsten arc welding;    sealing a micro-crack on the surface of the metallic component with a second weld filler; and    exposing the metallic component to a second hot isostatic processing operation.    
   
   
       23 . The method of  claim 22 , wherein the metallic component comprises a super-alloy metallic component.  
   
   
       24 . The method of  claim 22 , wherein the metallic component comprises a turbine blade.  
   
   
       25 . The method of  claim 22 , wherein the metallic component comprises a turbine-nozzle.  
   
   
       26 . The method of  claim 22 , wherein said subjecting and said exposing are performed at temperatures required for solution annealing.  
   
   
       27 . The method of  claim 22 , wherein said welding comprises traversing the metallic component at least once.  
   
   
       28 . The method of  claim 27 , further comprising repeating said traversing.  
   
   
       29 . The method of  claim 22 , wherein said first weld filler comprises a precipitation strengthened super-alloy.  
   
   
       30 . The method of  claim 29 , wherein said precipitation strengthened super-alloy comprises IN-939 or a derivative thereof.  
   
   
       31 . The method of  claim 29 , wherein said precipitation strengthened super-alloy comprises IN-738 or a derivative thereof.  
   
   
       32 . The method of  claim 29 , wherein said precipitation strengthened super-alloy comprises Rene 80 or a derivative thereof.  
   
   
       33 . The method of  claim 22 , wherein said sealing comprises welding with said second weld filler that comprises a solid-solution strengthened alloy filler.  
   
   
       34 . The method of  claim 33 , wherein said solid-solution strengthened alloy filler comprises a lower strength than said first weld filler.  
   
   
       35 . The method of  claim 33 , wherein said solid-solution strengthened alloy filler comprises IN-625.  
   
   
       36 . The method of  claim 22 , further comprising preparing the metallic component for repair prior to said subjecting.  
   
   
       37 . The method of  claim 36 , wherein said preparing comprises: 
 chemically stripping the metallic component;    machining the metallic component; and    grinding the metallic component.    
   
   
       38 . The method of  claim 22 , further comprising finishing the metallic component after said exposing.  
   
   
       39 . The method of  claim 38 , wherein said finishing comprises a process selected from the group consisting of grinding the metallic component, machining the metallic component, re-coating the metallic component, age heat treating the metallic component and combinations thereof.