Nickel base superalloy compositions being substantially free of rhenium and superalloy articles

Abstract

A nickel base superalloy composition substantially free of rhenium includes, in percentages by weight: about 5-8 Cr; about 7-8 Co; about 1.3-2.2 Mo; about 4.75-6.75 W; about 6.0-7.0 Ta; if present, up to about 0.5 Ti; about 6.0-6.4 Al; about 0.15-0.6 Hf; if present, from about 0.03-0.06 C; if present, up to about 0.004 B; if present, one or more rare earths selected from Y, La, and Ce up to about 0.03 total, the balance including nickel and incidental impurities. The superalloy composition is able to provide sustained-peak low cycle fatigue and/or oxidation resistance properties comparable to second generation superalloy compositions including at least about 3 wt % rhenium. Superalloy articles incorporating the compositions include nozzles, shrouds, and splash plates for gas turbine engines.

1 . A nickel base superalloy composition consisting of, in percentages by weight:
 about 5-6 Cr;   about 7-8 Co;   about 1.5 Mo;   about 6 W;   about 6.0-7.0 Ta;   if present, up to about 0.5 Ti;   about 6.0-6.4 Al;   about 0.15-0.6 Hf;   if present, from about 0.03-0.06 C;   if present, up to about 0.004 B;   if present, one or more rare earths selected from Y, La, and Ce up to about 0.03 total;   wherein the superalloy composition is substantially free of Re and exhibits a sustained-peak low cycle fatigue resistance exceeding 10,500 cycles to failure at 2000° F./18 ksi APS;   the balance of the superalloy composition being nickel and incidental impurities.   
     
     
         2 . The nickel base superalloy composition according to  claim 1  being characterized by a P-value of less than 3360, wherein the P-value is defined as: P=−200 Cr+80 Mo−20 Mo 2 −250 Ti 2 −50 (Ti×Ta)+15 Cb+200 W−14 W 2 +30 Ta−1.5 Ta 2 +2.5 Co+1200 Al −100 Al 2 +100 Re+1000 Hf−2000 Hf 2 +700 Hf 3 −2000 V−500 C−15000 B−500 Zr. 
     
     
         3 . The nickel base superalloy composition according to  claim 2  being characterized by a P-value of less than 3050. 
     
     
         4 . The nickel base superalloy composition according to  claim 1  wherein the superalloy composition is in the form of a single crystal article. 
     
     
         5 . The nickel base superalloy composition according to  claim 4 , wherein the single crystal article is a gas turbine engine component chosen from the group consisting of a nozzle, a shroud, and a splash plate. 
     
     
         6 . The nickel base superalloy composition according to  claim 1  having a nominal composition, in wt %: 6.2 Al, 6.5 Ta, 6 Cr, 6 W, 1.5 Mo, 0 Re, 7.5 Co, 0.03 C, 0.004 B, 0.15 Hf, the remainder being nickel and incidental impurities. 
     
     
         7 . (canceled) 
     
     
         8 . The nickel base superalloy composition according to  claim 12  having a nominal composition, in wt %: 6.2 Al, 6.5 Ta, 6 Cr, 6.5 W, 1.5 Mo, 0 Re, 7.5 Co, 0.03C, 0.004 B, 0.15 Hf, the remainder being nickel and incidental impurities. 
     
     
         9 - 10 . (canceled) 
     
     
         11 . The nickel base superalloy composition according to  claim 14  having a nominal composition, in wt %: 6.2 Al, 6.5 Ta, 6 Cr, 6 W, 2 Mo, 0 Re, 7.5 Co, 0.03 C, 0.004 B, 0.6 Hf, the remainder being nickel and incidental impurities. 
     
     
         12 . A nickel base superalloy composition consisting of, in percentages by weight:
 about 5-6 Cr;   about 7-8 Co;   about 1.5 Mo;   about 6.5 W;   about 6.0-7.0 Ta;   if present, up to about 0.5 Ti;   about 6.0-6.4 Al;   about 0.15-0.6 Hf;   if present, from about 0.03-0.06 C;   if present, up to about 0.004 B;   if present, one or more rare earths selected from Y, La, and Ce up to about 0.03 total;   wherein the superalloy composition is substantially free of Re and exhibits a sustained-peak low cycle fatigue resistance exceeding 2000 cycles to failure at 1600° F./70 ksi APS;   the balance of the superalloy composition being nickel and incidental impurities.   
     
     
         13 . The nickel base superalloy composition according to  claim 12  wherein, wherein the superalloy composition is in the form of a single crystal article. 
     
     
         14 . A nickel base superalloy composition consisting of:
 about 5-6 Cr;   about 7-8 Co;   about 2 Mo;   about 6 W;   about 6.0-7.0 Ta;   if present, up to about 0.5 Ti;   about 6.0-6.4 Al;   about 0.6 Hf;   if present, from about 0.03-0.06 C;   if present, up to about 0.004 B;   if present, one or more rare earths selected from Y, La, and Ce up to about 0.03 total;   wherein the superalloy composition is substantially free of Re and exhibits a sustained-peak low cycle fatigue resistance exceeding 10,500 cycles to failure at 2000° F./18 ksi APS;   the balance of the superalloy composition being nickel and incidental impurities.   
     
     
         15 . The nickel base superalloy composition according to  claim 14 , wherein the superalloy composition is in the form of a single crystal article. 
     
     
         16 . (canceled) 
     
     
         17 . The nickel base superalloy composition according to  claim 15 , wherein the single crystal article is a gas turbine engine component chosen from the group consisting of a nozzle, a shroud, and a splash plate. 
     
     
         18 . The nickel base superalloy composition according to  claim 13 , wherein the single crystal article is a gas turbine engine component chosen from the group consisting of a nozzle, a shroud, and a splash plate. 
     
     
         19 - 20 . (canceled)