Repair nickel-based superalloy and methods for refurbishment of gas turbine components

Abstract

A nickel-based superalloy includes, in terms of weight, about 0.06% to about 0.10% carbon, about 6.0% to about 6.4% aluminum, about 5.8% to about 6.3% tantalum, about 6.5% to about 7.0% chromium, about 8.8% to about 9.3% cobalt, about 0.6% to about 1.0% molybdenum, about 2.4% to about 2.8% rhenium, about 4.8% to about 5.3% tungsten, about 0.3% to about 0.80% hafnium, about 0.01% to about 0.03% zirconium, about 0.10% to about 0.18% silicon, and nickel. A method for repairing a surface of a turbine component includes the step of applying the nickel-based superalloy to a damaged area of the component surface. Post-deposition processes are also performed as necessary.

1 . A nickel-based superalloy, comprising in terms of weight: 
 about 0.06% to about 0.10% carbon;    about 6.0% to about 6.4% aluminum;    about 5.8% to about 6.3% tantalum;    about 6.5% to about 7.0% chromium;    about 8.8% to about 9.3% cobalt;    about 0.6% to about 1.0% molybdenum;    about 2.4% to about 2.8% rhenium;    about 4.8% to about 5.3% tungsten;    about 0.3% to about 0.8% hafnium;    about 0.01% to about 0.03% zirconium;    about 0.10% to about 0.18% silicon; and    nickel.    
   
   
       2 . The nickel-based superalloy of  claim 1 , further comprising in terms of weight: 
 about 0.008% to about 0.014% boron; and    about 0.008% to about 0.015% yttrium.    
   
   
       3 . The nickel-based superalloy of  claim 1 , wherein in terms of weight at least 12% is aluminum and tantalum combined.  
   
   
       4 . The nickel-based superalloy of  claim 1 , wherein in terms of weight at least 8.0% is molybdenum, tungsten, and rhenium combined.  
   
   
       5 . The nickel-based superalloy of  claim 1 , wherein the superalloy is prepared in the form of a powder.  
   
   
       6 . The nickel-based superalloy of  claim 1 , wherein the superalloy is a prepared in the form of a weld wire.  
   
   
       7 . The nickel-based superalloy of  claim 5 , wherein the powder comprises substantially spherical particles.  
   
   
       8 . A method for repairing a surface of a turbine component, comprising the step of: 
 applying a nickel-based superalloy to a damaged area of the component surface, the nickel-based superalloy comprising in terms of weight:    about 0.06% to about 0.10% carbon;    about 6.0% to about 6.4% aluminum;    about 5.8% to about 6.3% tantalum;    about 6.5% to about 7.0% chromium;    about 8.8% to about 9.3% cobalt;    about 0.6% to about 1.0% molybdenum;    about 2.4% to about 2.8% rhenium;    about 4.8% to about 5.3% tungsten;    about 0.3% to about 0.8% hafnium;    about 0.01% to about 0.03% zirconium;    about 0.10% to about 0.18% silicon; and    nickel.    
   
   
       9 . The method of  claim 8 , wherein the nickel-based superalloy further comprises in terms of weight: 
 about 0.008% to about 0.014% boron; and    about 0.0080% to about 0.015% yttrium.    
   
   
       10 . The method of  claim 8 , wherein in terms of weight at least 12% of the nickel-based superalloy is aluminum and tantalum combined.  
   
   
       11 . The method of  claim 8 , wherein in terms of weight at least 8.0% of the nickel-based superalloy is molybdenum, tungsten, and rhenium combined.  
   
   
       12 . The method of  claim 8 , wherein the nickel-based superalloy is prepared in the form of a powder.  
   
   
       13 . The method of  claim 8 , wherein the nickel-based superalloy is prepared in the form of a weld wire.  
   
   
       14 . The method of  claim 12 , wherein the powder comprises substantially spherical particles.  
   
   
       15 . The method of  claim 8 , wherein the nickel-based superalloy is applied to the damaged area while performing a welding process on the damaged area.  
   
   
       16 . The method of  claim 8 , wherein the nickel-based superalloy is applied to the damaged area using a cold gas dynamic spraying process.  
   
   
       17 . The method of  claim 8 , wherein the nickel-based superalloy is applied to the damaged area using a thermal spraying process.  
   
   
       18 . The method of  claim 17 , wherein the thermal spraying process is selected from the group of processes consisting of high velocity oxygen fuel thermal spraying, and low pressure plasma spraying.  
   
   
       19 . The method of  claim 8 , further comprising the step of: 
 subjecting the component to a hot isostatic pressing process after applying the nickel-based superalloy to the damaged area.    
   
   
       20 . The method of  claim 8 , further comprising the step of: 
 heat treating the turbine component after applying the nickel-based superalloy to the damaged area.