Method for establishing a location of an elevated stress region

• US 8,291,589 B2
• Filed: 08/08/2007
• Issued: 10/23/2012
• Est. Priority Date: 08/08/2007
• Status: Active Grant

• Current Assignee: Rtx Corporation
• Original Assignee: United Technologies Corporation (Rtx Corporation)
• Inventors: Davis, Ephraim C., Bischof, Christopher J.
• Primary Examiner(s): Taousakis, Alexander P
• Application Number:
  US11/835,452
• Publication Number:
  US 20090038151A1
• Time in Patent Office: 1,903 Days
• Field of Search: 298/891, 298/897, 294/020.1, 294/020.9, 294/021.8, 294/070.1, 294/070.5, 737/60, 737/62, 737/94, 737/99, 738/04, 738/47, 703/7, 703/113, 427 8- 10
• US Class Current: 29/889.1
• CPC Class Codes: B23P 6/002 Repairing turbine components, e.g. moving or stationary blades, rotors, B23P6/045 takes precedence
• CPC Class Codes: F01D 5/005 Repairing methods or devices
• CPC Class Codes: F05D 2230/80 Repairing, retrofitting or upgrading methods
• CPC Class Codes: F05D 2260/94 Functionality given by mechanical stress related aspects such as low cycle fatigue [LCF] of high cycle fatigue [HCF]
• CPC Class Codes: F05D 2270/44 active, predictive, or anticipative
• CPC Class Codes: Y10T 29/49318 Repairing or disassembling
• CPC Class Codes: Y10T 29/49336 Blade making
• CPC Class Codes: Y10T 29/49718 Repairing
• CPC Class Codes: Y10T 29/49725 by shaping
• CPC Class Codes: Y10T 29/49771 Quantitative measuring or gauging

Abstract

A method for use in repairing gas turbine engine components includes applying a stress to a first gas turbine engine component to cause surface cracking on the first gas turbine engine component and establishing a location of an elevated stress region of a second gas turbine engine component based upon the location of the surface cracking on the first gas turbine engine component.

Claims

1. A method for use in repairing gas turbine engine components, comprising:

a. applying a stress to a first gas turbine engine component to cause surface cracking on the first gas turbine engine component; and

b. based upon a magnitude of the stress applied to the first gas turbine engine component that causes the surface cracking, establishing a maximum magnitude of a stress that is applied in a repair process to a second gas turbine engine component.

2. The method as recited in claim 1, wherein said step (a) includes applying a torque stress.

3. The method as recited in claim 1, wherein said step (a) includes applying a magnitude of the stress that is greater than a yield strength and less than an ultimate strength of the gas turbine engine component and greater than an ultimate strength of a protective coating on the gas turbine engine component.

4. The method as recited in claim 3, wherein the gas turbine engine component comprises a nickel alloy and the protective coating comprises aluminum.

5. The method as recited in claim 4, wherein the protective coating comprises a diffused aluminide coating.

6. The method as recited in claim 4, wherein the protective coating comprises MCrAlY, where the M includes at least one of nickel, cobalt, iron, or a combination thereof, Cr is chromium, Al is aluminum and Y is yttrium.

7. The method as recited in claim 1, wherein said step (a) includes applying the stress to cause the surface cracking in a protective coating on the first gas turbine engine component.

8. The method as recited in claim 1, wherein step (b) includes visually identifying the location of the surface cracking using a dye penetrant.

9. The method as recited in claim 1, wherein said step (a) includes holding a platform section of the first gas turbine engine component within a first fixture and holding an end of the first gas turbine engine component within a second fixture.

10. The method as recited in claim 1, wherein the first gas turbine engine component comprises a protective coating that includes aluminum, and the stress applied to the first gas turbine engine component causes the surface cracking in the protective coating.