Nickel base superalloys and turbine components fabricated therefrom

Abstract

A nickel base superalloy suitable for the production of a large, crack-free nickel-base superalloy gas turbine bucket suitable for use in a large land-based utility gas turbine engine, comprising, by weight percents: Chromium 7.0 to 12.0 Carbon 0.06 to 0.10 Cobalt 5.0 to 15.0 Titanium 3.0 to 5.0 Aluminum 3.0 to 5.0 Tungsten 3.0 to 12.0 Molybdenum 1.0 to 5.0 Boron 0.0080 to 0.01 Rhenium 0 to 10.0 Tantalum 2.0 to 6.0 Columbium 0 to 2.0 Vanadium 0 to 3.0 Hafnium 0 to 2.0 and remainder nickel and incidental impurities.

What is claimed is:  
     
         1 . A nickel base superalloy suitable for the production of a large, crack-free nickel-base superalloy gas turbine bucket suitable for use in a large land-based utility gas turbine engine, comprising, by weight percents: 
 Chromium 7.0 to 12.0    Carbon 0.06 to 0.10    Cobalt 5.0 to 15.0    Titanium 3.0 to 5.0    Aluminum 3.0 to 5.0    Tungsten 3.0 to 12.0    Molybdenum 1.0 to 5.0    Boron 0.0080 to 0.0130    Rhenium 0 to 10.0    Tantalum 2.0 to 6.0    Columbium 0 to 2.0    Vanadium 0 to 3.0    Hafnium 0 to 2.0 and    remainder nickel and incidental impurities.    
     
     
         2 . The nickel base superalloy according to  claim 1 , wherein boron is present in an amount of about 0.008-0.010 weight percent.  
     
     
         3 . The nickel base superalloy according to  claim 1 , wherein boron is present in an amount of about 0.009 weight percent.  
     
     
         4 . The nickel base superalloy according to  claim 1 , wherein hafnium is present in an amount of about 0.015-0.45 weight percent.  
     
     
         5 . A nickel base superalloy suitable for the production of a large, crack-free nickel-base superalloy gas turbine bucket suitable for use in a large land-based utility gas turbine engine, comprising, by weight percents 
 Chromium 9.50-10.00    Cobalt 7.00-8.00    Aluminum 4.10-4.30    Titanium 3.35-3.65    Tungsten 5.75-6.25    Molybdenum 1.30-1.70    Tantalum 4.60-5.00    Carbon 0.06-0.10    Zirconium 0.01 max    Boron 0.008-0.010    Iron 0.20 max    Silicon 0.20 max    Manganese 0.01 max    Copper 0.10 max    Phosphorus 0.005 max    Sulfur 0.003 max    Columbium 0.40-0.60    Oxygen 0.002 max    Nitrogen 0.0015 max    Vanadium 0.10 max    Hafnium 0.10-0.20    Platinum 0.15 max    Rhenium 0.10 max    Rhenium+Tungsten 6.25 max    Magnesium 0.0035 max    Palladium 0.10 max    Nickel Remainder    
     
     
         6 . A method of making a cast and heat treated article of a nickel-base superalloy, comprising the steps of: 
 (a) providing a superalloy of the composition of  claim 1;     (b) heating the superalloy to develop at least 60 percent solutioning of gamma prime precipitate; and    (c) cooling to room temperature.    
     
     
         7 . The method according to  claim 6  wherein the article is heated to a temperature of about 2260° F.-2300° F. but at least about 25° F. below the incipient melting temperature of the superalloy.  
     
     
         8 . The method according to  claim 6  wherein the article is cooled by a furnace cool at a rate of about 35° F./minute to about 2050° F.  
     
     
         9 . The method of  claim 6  wherein the wherein the article is cooled by a gas fan cool at a rate of about 100-150° F./minute from below about 2050° F.  
     
     
         10 . The method of  claim 6 , wherein said heating is carried out in an argon atmosphere.  
     
     
         11 . The method of  claim 6  wherein said heat treating comprises the steps of: 
 (a) heating said article to a temperature of about 1400° F. at a rate of 25° F./minute and holding for about 10 minutes;  
 (b) heating said article in (a) to a temperature of about 2225° F. at a rate of 25° F./minute and holding for about 8 hours;  
 (c) heating said article in (b) to a temperature of about 2250° F. at a rate of 25° F./minute and holding for about 4 hours;  
 (d) heating said article in (c) to a temperature of about 2280° F. at a rate of 30° F./minute and holding for about 2 hours; and  
 (e) cooling to room temperature.  
 
     
     
         12 . The method according to  claim 11  wherein the article is cooled by a furnace cool at a rate of about 35° F./minute to about 2050° F.  
     
     
         13 . The method of  claim 11  wherein the wherein the article is cooled by a gas fan cool at a rate of about 100-150° F./minute from below about 2050° F.  
     
     
         14 . The method of  claim 6  wherein said article is a large turbine bucket.  
     
     
         15 . The method of  claim 6  wherein said article is a large aero engine turbine blade.  
     
     
         16 . An article produced by the method of  claim 6 .  
     
     
         17 . An article of  claim 16  which is directionally solidified.  
     
     
         18 . An article of  claim 16  which is conventionally cast.  
     
     
         19 . An article of  claim 16  which is single crystal cast.  
     
     
         20 . A gas turbine engine containing an article of  claim 16.