WE CLAIM
1. A gamma-prime nickel-base superalloy comprises, by weight:
16.0 to 30.0% cobalt;
9.5 to 12.5% chromium;
4.0 to 6.0% tantalum;
2.0 to 4.0% aluminum;
2.0 to 3.4% titanium;
3.0 to 6.0% tungsten;
1.0 to 4.0% molybdenum;
1.5 to 3.5% niobium;
up to 1.0% hafnium;
0.02 to 0.20% carbon;
0.01 to 0.05% boron;
0.02 to 0.10% zirconium;
the balance essentially nickel and impurities;
wherein the superalloy has a W+Nb-Cr value of at least -6, is free of observable amounts of sigma and eta phases, and exhibits a time to 0.2% creep at 1300°F and 100 ksi of at least 1000 hours.
2. The gamma-prime nickel-base superalloy according to claim 1, wherein the chromium content is 10.0 to 12.5 weight percent.
3. The gamma-prime nickel-base superalloy according to claim 1, wherein the niobium content is 1.8 to 2.2 weight percent.
4. The gamma-prime nickel-base superalloy according to claim 1, wherein the tungsten content is 3.0 to 5.0 weight percent.
5. The gamma-prime nickel-base superalloy according to claim 1, wherein the chromium content is 10.0 to 12.5 weight percent, the niobium content

is 1.8 to 2.2 weight percent, and the tungsten content is 3.0 to 5.0 weight percent.
6. The gamma-prime nickel-base superalloy according to claim 1, wherein the titanium content is 2.5 to 2.9 weight percent.
7. The gamma-prime nickel-base superalloy according to claim 1, wherein the molybdenum content is 2.5 to 3.0 weight percent.
8. The gamma-prime nickel-base superalloy according to claim 1, wherein the gamma-prime nickel-base superalloy consists of, by weight:
16.0 to 30.0% cobalt;
9.5 to 12.5% chromium;
4.0 to 6.0% tantalum;
2.0 to 4.0% aluminum;
2.0 to 3.4% titanium;
3.0 to 6.0% tungsten;
1.0 to 4.0% molybdenum;
1.5 to 3.5% niobium;
up to 1.0% hafnium;
0.02 to 0.20% carbon;
0.01 to 0.05% boron;
0.02 to 0.10% zirconium;
the balance essentially nickel and impurities.
9. The gamma-prime nickel-base superalloy according to claim 8, wherein the chromium content is 10.0 to 12.5 weight percent.
10. The gamma-prime nickel-base superalloy according to claim 8, wherein the niobium content is 1.8 to 2.2 weight percent.
11. The gamma-prime nickel-base superalloy according to claim 8,

wherein the tungsten content is 3.0 to 5.0 weight percent.
12. The gamma-prime nickel-base superalloy according to claim 8, wherein the chromium content is 10.0 to 12.5 weight percent, the niobium content is 1.8 to 2.2 weight percent, and the tungsten content is 3.0 to 5.0 weight percent.
13. The gamma-prime nickel-base superalloy according to claim 8, wherein the titanium content is 2.5 to 2.9 weight percent and the molybdenum content is 2.5 to 3.0 weight percent.
14. A component formed of the gamma-prime nickel-base superalloy of claim 8.
15. The component according to claim 14, wherein the component is a powder metallurgy component chosen from the group consisting of turbine disks and compressor disks and blisks of gas turbine engines.
16. A gamma-prime nickel-base superalloy consisting of, by weight:
17.0 to 20.5% cobalt;
10.0 to 12.5% chromium;
4.5 to 5.5% tantalum;
3.0 to 3.4% aluminum;
2.5 to 2.9% titanium;
3.0 to 5.0% tungsten;
2.5 to 3.0% molybdenum;
1.8 to 2.2% niobium;
up to 0.6% hafnium;
0.048 to 0.068% carbon;
0.015 to 0.04% boron;
0.04 to 0.06% zirconium;
the balance essentially nickel and impurities;

wherein the superalloy has a W+Nb-Cr value of at least -6, is free of observable amounts of sigma and eta phases, and exhibits a time to 0.2% creep at 1300°F and 100 ksi of at least 1000 hours.
17. The gamma-prime nickel-base superalloy according to claim 16, wherein the chromium content is a maximum of 12.0 weight percent.
18. The gamma-prime nickel-base superalloy according to claim 16, wherein the chromium content is 10.02 to 12.08 weight percent, the niobium content is 1.97 to 2.99 weight percent, and the tungsten content is 3.1 to 4.6 weight percent.
19. A component formed of the gamma-prime nickel-base superalloy of claim 16.
20. The component according to claim 19, wherein the component is a powder metallurgy component chosen from the group consisting of turbine disks and compressor disks and blisks of gas turbine engines.