Property-balanced nickel-base superalloys for producing single crystal articles

• US 6,074,602 A
• Filed: 07/05/1994
• Issued: 06/13/2000
• Est. Priority Date: 10/15/1985
• Status: Expired due to Term

• Current Assignee: General Electric Company
• Original Assignee: General Electric Company
• Inventors: Buchakjian, Leo Jr., Wukusick, Carl Stephen
• Primary Examiner(s): KASTLER, SCOTT R
• Application Number:
  US08/270,528
• Time in Patent Office: 2,170 Days
• Field of Search: 148/410, 148/428, 420/443, 420/448, 420/449, 420/450
• US Class Current: 420/443
• CPC Class Codes: C22C 19/057 with the maximum Cr content being less 10%

Abstract

The present invention is directed to the achievement of increased gas turbine engine efficiencies through further improvements in nickel-base superalloys used to make parts and components for gas turbine engines. The present invention comprises nickel-base superalloys for producing single crystal articles having a significant increase in temperature capability, based on stress rupture strength and low and high cycle fatigue properties, over single crystal articles made from current production nickel-base superalloys. Further, because of their superior resistance to degradation by cyclic oxidation, and their resistance to hot corrosion, the superalloys of this invention possess a balance in mechanical and environmental properties which is unique and has not heretofore been obtained.

Claims

1. A nickel-base single-crystal superalloy article consisting essentially of, in percentages by weight, 5-10 Cr, 5-10 Co, 0-2 Mo, 3-8 W, 3-8 Ta, 0-2 Ti, 5-7 Al, Re in an amount of up to 6, 0.08 to 0.2 Hf, 0.03-0.07 C, 0.003-0.006 B, and 0.0-0.04 Y, the balance being nickel and incidental impurities.

2. The superalloy article of claim 1 consisting essentially of, in percentages by weight, 6.75-7.25 Cr, 7.0-8.0 Co, 1.3-1.7 Mo, 4.75-5.25 W, 6.3-6.7 Ta, 0.02 max. Ti, 6.0-6.4 Al, 2.75-3.25 Re, 0.12-0.18 Hf, 0.04-0.06 C, 0.003-0.005 B, and 0.005-0.02 Y, the balance being nickel and incidental impurities.

3. The superalloy article of claim 2 consisting essentially of, in percentages by weight, 7 Cr, 7.5 Co, 1.5 Mo, 5 W, 6.5 Ta, 0 Ti, 6.2 Al, 3 Re, 0.15 Hf, 0.05 C, 0.004 B, and 0.01 Y, the balance being nickel and incidental impurities.

4. The superalloy article of claim 1, wherein the Co and Re contents are, in percentages by weight, 5-8 and up to 3.25, respectively.

5. The superalloy article of claim 1, wherein the Cr and W contents are, in percentages by weight, 5-9.75 and 3-7, respectively.

6. The superalloy article of claim 1, wherein the article is an airfoil member for a gas turbine engine.

7. The superalloy article of claim 2, wherein the article is an airfoil member of a gas turbine engine.

8. The superalloy article of claim 3, wherein the article is an airfoil member of a gas turbine engine.

9. The superalloy article of claim 4, wherein the article is an airfoil member of a gas turbine engine.

10. The superalloy article of claim 5, wherein the article is an airfoil member of a gas turbine engine.

11. The superalloy article of claim 1, wherein the superalloy has a gamma prime content of up to 60 volume percent.

12. The superalloy article of claim 1, wherein the superalloy is substantially free of a topologically close-packed phase that would cause microstructural instability.

13. The superalloy article of claim 1, wherein the superalloy exhibits no metal loss after 200 hours of high-velocity oxidation testing at about 2150°

F. with a gas velocity of Mach 1 and cooling to room temperature once each hour.

14. The superalloy article of claim 1, wherein the superalloy has a grain boundary mismatch of greater than 6 degrees.

15. The superalloy article of claim 1, wherein the Y content is, in percentage by weight, 0.005-0.03.

16. The superalloy article of claim 1, wherein the Y content is about 0 weight percent.

17. A gas turbine blade case from a nickel-base single-crystal superalloy consisting essentially of, in percentages by weight, 5-10 Cr, 5-10 Co, 0-2 Mo, 3-8 W, 3-8 Ta, 0-2 Ti, 5-7 Al, Re in an amount of up to 6, 0.08 to 0.2 Hf, 0.03-0.07 C, 0.003-0.006 B, and 0.0-0.04 Y, the balance being nickel and incidental impurities.

18. The gas turbine blade of claim 17, wherein the Co and Re contents are, in percentages by weight, 5-8 and up to 3.25, respectively.

19. The gas turbine engine component of claim 17, wherein the Cr and W contents are, in percentages by weight, 5-9.75 and 3-7, respectively.

20. The gas turbine engine component of claim 17, wherein the superalloy has a gamma prime content of up to 60 volume percent.

21. The gas turbine engine component of claim 18, wherein the superalloy has a gamma prime content of up to 60 volume percent.

22. The gas turbine engine component of claim 19, wherein the superalloy has a gamma prime content of up to 60 volume percent.

23. The gas turbine engine component of claim 17, wherein the superalloy is substantially free of a topologically close-packed phase that would cause microstructural instability.

24. The gas turbine engine component of claim 18, wherein the superalloy is substantially free of a topologically close-packed phase that would cause microstructural instability.

25. The gas turbine engine component of claim 19, wherein the superalloy is substantially free of a topologically close-packed phase that would cause microstructural instability.

26. The gas turbine engine component of claim 17, wherein the superalloy exhibits no metal loss after 200 hours of high-velocity oxidation testing at about 2150°

F. with a gas velocity of Mach 1 and cooling to room temperature once each hour.

27. The gas turbine engine component of claim 18, wherein the superalloy exhibits no metal loss after 200 hours of high-velocity oxidation testing at about 2150°

F. with a gas velocity of Mach 1 and cooling to room temperature once each hour.

28. The gas turbine engine component of claim 19, wherein the superalloy exhibits no metal loss after 200 hours of high-velocity oxidation testing at about 2150°

F. with a gas velocity of Mach 1 and cooling to room temperature once each hour.

29. The gas turbine engine component of claim 17, wherein the superalloy has a grain boundary mismatch of greater than 6 degrees.

30. The gas turbine engine component of claim 18, wherein the superalloy has a grain boundary mismatch of greater than 6 degrees.

31. The gas turbine engine component of claim 19, wherein the superalloy has a grain boundary mismatch of greater than 6 degrees.

32. The gas turbine engine component of claim 17, wherein the Y content is, in percentage by weight, 0.005-0.03.

33. The gas turbine engine component of claim 18, wherein the Y content is, in percentage by weight, 0.005-0.03.

34. The gas turbine engine component of claim 19, wherein the Y content is, in percentage by weight, 0.005-0.03.

35. The gas turbine engine component of claim 17, wherein the Y content is about 0 weight percent.

36. The gas turbine engine component of claim 18, wherein the Y content is about 0 weight percent.

37. The gas turbine engine component of claim 19, wherein the Y content is about 0 weight percent.

38. A gas turbine engine component cast from a nickel-base single-crystal superalloy consisting essentially of, in percentages by weight, 6.75-7.25 Cr, 7.0-8.0 Co, 1.3-1.7 Mo, 4.75-5.25 W, 6.3-6.7 Ta, 0.02 max. Ti, 6.0-6.4 Al, 2.75-3.25 Re, 0.12-0.18 Hf, 0.04-0.06 C, 0.003-0.005 B, and 0.005-0.02 Y, the balance being nickel and incidental impurities.

39. The gas turbine engine component of claim 38, wherein the superalloy has a gamma prime content of up to 60 volume percent.

40. The gas turbine engine component of claim 38, wherein the superalloy is substantially free of a topologically close-packed phase that would cause microstructural instability.

41. The gas turbine engine component of claim 38, wherein the superalloy exhibits no metal loss after 200 hours of high-velocity oxidation testing at about 2150°

F. with a gas velocity of Mach 1 and cooling to room temperature once each hour.

42. The gas turbine engine component of claim 38, wherein the superalloy has a grain boundary mismatch of greater than 6 degrees.

43. The gas turbine engine component cast from a nickel-base single-crystal superalloy consisting essentially of, in percentages by weight, 7 Cr, 7.5 Co, 1.5 Mo, 5 W, 6.5 Ta, 0 Ti, 6.2 Al, 3 Re, 0.15 Hf, 0.05 C, 0.004 B, and 0.01 Y, the balance being nickel and incidental impurities.

44. The gas turbine engine component of claim 43, wherein the superalloy has a gamma prime content of up to 60 volume percent.

45. The gas turbine engine component of claim 43, wherein the superalloy is substantially free of a topologically close-packed phase that would cause microstructural instability.

46. The gas turbine engine component of claim 43, wherein the superalloy exhibits no metal loss after 200 hours of high-velocity oxidation testing at about 2150°

F. with a gas velocity of Mach 1 and cooling to room temperature once each hour.

47. The gas turbine engine component of claim 43, wherein the superalloy has a grain boundary mismatch of greater than 6 degrees.