High strength, hot corrosion and oxidation resistant, equiaxed nickel base superalloy and articles and method of making

Abstract

Corrosion and oxidation resistant, high strength, directionally solidified superalloy alloys and articles are described. The articles have a nominal composition in weight percent of about 12.1% Cr, 9% Co, 1.9% Mo, 3.8% W, 5% Ta, 3.6% Al, 4.1% Ti, 0.013% B, 0.1% C, up to about 0.01 Zr, balance essentially nickel. The resultant articles have good hot corrosion resistance, oxidation resistance and creep properties. The articles are preferably cast as equiaxed articles such as gas turbine engine components.

1 . A high strength, corrosion and oxidation resistant nickel base superalloy consisting essentially of, in weight percent, of: 11-13.25% chromium; 8-10% cobalt; 1.5-2.5% molybdenum; 3.25-4.5% tungsten; 4.5-5.5% tantalum; 3.25-4% aluminum; 3.5-4.5% titanium; 0.005-0.02% boron; up to about 0.03 zirconium; 0.05-0.2% carbon; up to about 0.15% hafnium; and balance essentially nickel; said article having creep rupture at 1400° F. of at least roughly 2.5×, and at 1600° F. of at least roughly 2× compared to a similar equiaxed article having a nominal composition of 14 Cr, 4.9 Ti, 1.6 Mo, 3.8 W, 2.8 Ta, 3 Al, 9.5 Co, 0.01 B, 0.02 Zr, 0.1 C, and balance Ni.  
   
   
       2 . An article composed of the alloy of  claim 1 .  
   
   
       3 . The alloy of  claim 1  having stress rupture resistance sufficient to ensure that a load of about 27 ksi applied ruptures after more than about 75 hours, and also has a time to 1 % creep of more than 50 hours, at 1800° F.  
   
   
       4 . The alloy of  claim 3 , wherein stress rupture occurs only after more than 85 hours.  
   
   
       5 . The alloy of  claim 1 , further characterized by having about 11-13% chromium; 8.5-9.5% cobalt; 1.6-2.25% molybdenum; 3.25-4.25% tungsten; 4.75-5.25% tantalum; 3.25-4% aluminum; 3.75-4.35% titanium; 0.0075-0.02% boron, and 0.005-0.010 zirconium.  
   
   
       6 . The alloy of  claim 1 , having about 12% chromium; 9% cobalt; 1.9% molybdenum; 3.8% tungsten; 5% tantalum; 3.6% aluminum; 4.1% titanium; 0.01% boron; 0.01% zirconium; 0.1% carbon; balance essentially nickel.  
   
   
       7 . The article of  claim 2  comprising a gas turbine engine component.  
   
   
       8 . The article of  claim 7 , comprising a turbine blade or vane.  
   
   
       9 . A high strength, corrosion resistant, nickel base superalloy article adapted for use in equiaxed grain articles, comprising in weight percent 11-13.25% chromium; 8-10% cobalt; 1.5-2.5% molybdenum; 3.25-4.5% tungsten; 4.5-5.5% tantalum; 3.25-4% aluminum; 3.5-4.5% titanium; 0.005-0.02% boron; less than about 0.03% zirconium; 0.05-0.2% carbon; up to about 0.15% hafnium; and balance essentially nickel; said article having creep rupture at 1400° F. of at least roughly 2.5×, and at 1600° F. of at least roughly 2× compared to a similar equiaxed article having a nominal composition of 14 Cr, 4.9 Ti, 1.6 Mo, 3.8 W, 2.8 Ta, 3 Al, 9.5 Co, 0.01 B, 0.02 Zr, 0.1 C, and balance Ni.  
   
   
       10 . The article of  claim 9  comprising a gas turbine engine component.  
   
   
       11 . The article of  claim 10  comprising a turbine blade or vane.  
   
   
       12 . The article of  claim 1  having stress rupture resistance sufficient to ensure that a load of about 27 ksi applied ruptures after more than about 80 hours, and also has a time to 1 % creep of more than 40 hours, at 1800° F.  
   
   
       13 . The article of  claim 12 , wherein stress rupture occurs only after more than 85 hours.  
   
   
       14 . The article of  claim 9 , further characterized by having 11-13% chromium; 8.5-9.5% cobalt; 1.6-2.25% molybdenum; 3.25-4.25% tungsten; 4.75-5.25% tantalum; 3.25-4% aluminum; 3.75-4.35% titanium; 0.0075-0.02% boron; 0.01 % zirconium.  
   
   
       15 . The alloy of  claim 14 , having about 12% chromium; 9% cobalt; 1.9% molybdenum; 3.8% tungsten; 5% tantalum; 3.6% aluminum; 4.1 % titanium; 0.01 % boron; less than about 0.03% zirconium; 0.1% carbon; balance essentially nickel.  
   
   
       16 . The article of  claim 2  comprising a gas turbine engine component.  
   
   
       17 . The article of  claim 16 , comprising a turbine blade or vane.  
   
   
       18 . The article of  claim 9 , wherein the article is up to about 60 inches long.  
   
   
       19 . A method of producing an equiaxed, cast, high strength, corrosion resistant, nickel base superalloy article comprising the steps of: 
 melting an alloy consisting of in weight percent 11-13.25% chromium; 8-10% cobalt; 5-2.5% molybdenum; 3.25-4.5% tungsten; 4.5-5.5% tantalum; 3.25-4% aluminum; 3.5-4.5% titanium; 0.005-0.02% boron; less than about 0.03% zirconium; 0.05-0.2% carbon; up to about 0.15% hafnium; and balance essentially nickel; and    casting the alloy to form an article, wherein the article has creep rupture at 1400° F. of at least roughly 2.5×, and at 1600° F. of at least roughly 2× compared to a similar equiaxed article having a nominal composition of 14 Cr, 4.9 Ti, 1.6 Mo, 3.8 W, 2.8 Ta, 3 Al, 9.5 Co, 0.01 B, 0.02 Zr, 0.1 C, and balance Ni.    
   
   
       20 . The article of  claim 19 , further comprising the step of machining the article.  
   
   
       21 . The article of  claim 19 , further comprising the step of applying an oxidation and/or corrosion resistant coating to the article.  
   
   
       22 . The method of  claim 21 , where in the article has at least one internal passage, further comprising the step of applying an oxidation and/or corrosion resistant coating to the internal passage.  
   
   
       23 . The article of  claim 9 , further comprising a thermal barrier coating applied to one or more portions of the article.