Welding material, gas turbine blade or nozzle and a method of repairing a gas turbine blade or nozzle

Abstract

A welding material composition, which is a nickel based super alloy having γ′ phase and chromium carbides precipitated. The composition comprising 18 to 25% by weight of Co, 15 to 20% by weight of Cr, 1.5 to 5.5% by weight of Al, 5 to 14% by weight of W, 0.05 to 0.15% by weight of C, 0 to 0.02% by weight of B, 0 to 1% by weight of at least one of Ta, Nb, Ti, Mo, Re and Fe, 0 to 0.5% by weight of at least one of V, Zr, rare earth elements and Y, 0 to 1% by weight of Mn, 0 to 0.5% by weight of Si, and the balance being Ni.

1 . A welding material composition having gamma prime phase and precipitated chromium carbides comprising 18 to 25% by weight of Co, 15 to 20% by weight of Cr, 1.5 to 5.5% by weight of Al, 5 to 14% by weight of W, 0.05 to 0.15% by weight of C, 0 to 0.02% by weight of B, the balance being Ni, wherein the amounts of Al, W and Co meet the following relationship: 
       (GP×0.139+11)<[W]<(GP×0.139+16), 
     where GP=(90[Al]−5[Co])  
   
   
       2 . The welding material composition according to  claim 1 , wherein the welding material composition comprises 18 to 19% by weight of Co, 18 to 19% by weight of Cr, 4.5 to 5.5% by weight of Al, 6 to 8% by weight of W, 0.05 to 0.15% by weight of C, 0.005 to 0.02% by weight of B, the material being powder having a particle size of 80 to 170 micrometers.  
   
   
       3 . The welding composition according to  claim 1 , wherein the welding material composition comprises 20 to 24% by weight of Co, 17 to 19% by weight of Cr, 2 to 3% by weight of Al, 10 to 14% by weight of W, 0.05 to 0.15% by weight of C, 0.005 to 0.02% by weight of B, the material being of a wire form.  
   
   
       4 . A welded structure body composed of a mother metal body to which a welding material is welded to form a welded metal, wherein the welded metal is formed from a welding material that has gamma prime phase and precipitated chromium carbides and comprises 18 to 25% by weight of Co, 15 to 20% by weight of Cr. 1.5 to 5.5% by weight of Al, 5 to 14% by weight of W, 0.05 to 0.15% by weight of C, 0 to 0.02% by weight of B, the balance being Ni, wherein the amounts of Al, W and Co meet the following relationship: 
       (GP×0.139+11)<[W]<(GP×0.139+16), 
     where GP=(90[Al]−5[Co])  
   
   
       5 . The welded structure according to  claim 4 , wherein the welded metal is formed from a welding material powder comprising 18 to 19% by weight of Co, 17 to 19% by weight of Cr, 4.5 to 5.5% by weight of Al, 6 to 8% by weight of W, 0.05 to 0.15% by weight of C, 0.005 to 0.02% by weight of B, the welding material powder having a particle size of 80 to 170 micrometers.  
   
   
       6 . The welded structure according to  claim 4 , wherein the welded metal is formed from a welding material wire comprising 20 to 24% by weight of Co, 17 to 19% by weight of Cr, 2 to 3% by weight of Al, 10 to 14% by weight of W, 0.05 to 0.15% by weight of C, 0.05 to 0.02 by weight of B.  
   
   
       7 . A turbine blade having a blade with a top portion to which a welding material is welded to form a welded metal, the welding material having a composition, which has gamma prime phase and precipitated chromium carbides and comprises 18 to 25% by weight of Co, 15 to 20% by weight of Cr. 1.5 to 5.5% by weight of Al, 5 to 14% by weight of W, 0.05 to 0.15% by weight of C, 0 to 0.02% by weight of B, the balance being Ni, wherein the amounts of Al, W and Co meet the following relationship: 
       (GP×0.139+11)<[W]<(GP×0.139+16), 
     where GP=(90[Al]−5[Co]).  
   
   
       8 . The gas turbine blade according to  claim 7 , wherein the welded metal is formed from a welding material powder comprising 18 to 19% by weight of Co, 17 to 19% by weight of Cr, 4.5 to 5.5% by weight of Al, 6 to 8% by weight of W, 0.05 to 0.15% by weight of C, 0.005 to 0.02% by weight of B, the welding material powder having a particle size of 80 to 170 micrometers.  
   
   
       9 . The turbine blade according to  claim 7 , wherein the welded metal is formed from a welding material wire comprising 20 to 24% by weight of Co, 17 to 19% by weight of Cr, 2 to 3% by weight of Al, 10 to 14% by weight of W, 0.05 to 0.15% by weight of C, 0.05 to 0.02% by weight of B.