Process for repairing turbine components

• US 7,051,435 B1
• Filed: 06/13/2003
• Issued: 05/30/2006
• Est. Priority Date: 06/13/2003
• Status: Active Grant

• Current Assignee: General Electric Company
• Original Assignee: General Electric Company
• Inventors: Subramanian, Pazhayannur Ramanathan, Ruud, James Anthony, Cretegny, Laurent
• Primary Examiner(s): JIMENEZ, MARC QUEMUEL
• Application Number:
  US10/459,805
• Publication Number:
  US 20060117562A1
• Time in Patent Office: 1,082 Days
• Field of Search: 298/891, 298/897, 298/892, 294/020.3, 294/020.4, 294/020.5, 294/020.6, 294/020.7, 294/020.9, 294/021.1, 294/021.3, 294/021.6, 228/119
• US Class Current: 29/889.1
• CPC Class Codes: B23K 1/0018 Brazing of turbine parts
• CPC Class Codes: B23K 1/008 Soldering within a furnace B23K1/012 takes precedence
• CPC Class Codes: B23K 1/19 taking account of the properties of the materials to be soldered
• CPC Class Codes: B23K 1/20 Preliminary treatment of work or areas to be soldered, e.g. in respect of a galvanic coating preparation of surfaces in particular ways, see the relevant classes for the treatments or the materials treated, e.g. C04B, C23C
• CPC Class Codes: B23K 11/0033 Welding locally a thin plate to a large piece
• CPC Class Codes: B23K 2101/001 Turbines
• CPC Class Codes: B23P 6/005 using only replacement pieces of a particular form
• CPC Class Codes: Y10T 29/49318 Repairing or disassembling
• CPC Class Codes: Y10T 29/49336 Blade making
• CPC Class Codes: Y10T 29/49734 and removing damaged material
• CPC Class Codes: Y10T 29/49737 Metallurgically attaching preform

Abstract

A process for repairing a turbine component comprises overlaying a preform of a brazing material onto a surface of the turbine component, wherein the surface comprises a damaged portion; securing the preform of a brazing material to the surface; and heating the turbine component to a temperature effective to form a brazed joint between the brazing material and the turbine component. Also disclosed is a repaired turbine component repaired by the process.

Claims

1. A process for repairing a turbine component, comprising:

removing a damaged portion from a surface of the turbine component to form a recessed portion in the surface;

overlaying a preform consisting of brazing material onto the recessed portion;

securing the preform; and

heating the turbine component to a temperature effective to form a brazed joint between the brazing material and the turbine component, wherein heating the turbine component comprises stepwise heating to a temperature greater than a melting temperature of the brazing material and less than a melting temperature of the turbine component.

2. A process for repairing a turbine component, comprising:

removing a damaged portion from a surface of the turbine component to form a recessed portion in the surface;

overlaying a preform consisting of brazing material onto the recessed portion;

securing the preform to the surface, wherein securing the preform to the surface comprises spot welding; and

heating the turbine component to a temperature effective to form a brazed joint between the brazing material and the turbine component.

3. The process according to claim 2, further comprising machining the turbine component to return the turbine component to its original dimensions.

4. The process according to claim 2, further comprising protecting the turbine component with an inert gas prior to spot welding the preform to the surface of the turbine component.

5. The process according to claim 2, further comprising protecting the turbine component with a reducing gas prior to spot welding the preform to the surface of the turbine component.

6. The process according to claim 4, wherein the reducing gas is hydrogen gas.

7. The process according to claim 2, wherein the brazing material consists of at least one of an alloy or a superalloy of two or more metals.

8. The process according to claim 2, wherein heating the turbine component comprises heating in a vacuum and an inert atmosphere.

9. A process for repairing a turbine component, comprising:

removing a damaged portion from a surface of the turbine component to form a recessed portion in the surface;

spot welding at least one preform consisting of a brazing material to the recessed portion, wherein the preform has lateral dimensions about equal to lateral dimensions of the recessed portion; and

heating the turbine component to a temperature sufficient to form a brazed joint between the brazing material and the turbine component.

10. The process according to claim 9, further comprising machining the turbine component to return the turbine component to its original dimensions.

11. The process according to claim 9, further comprising protecting the turbine component with an inert gas prior to spot welding the preform.

12. The process according to claim 9, further comprising protecting the turbine component with a reducing gas prior to spot welding the preform.

13. The process according to claim 12, wherein the reducing gas is hydrogen gas.

14. The process according to claim 9, wherein heating the turbine component comprises stepwise heating to a temperature greater than a melting temperature of the brazing material and less than a melting temperature of the turbine component.

15. The process according to claim 9, wherein the brazing material comprises an alloy of two or more metals.

16. The process according to claim 9, wherein heating the turbine component comprises a vacuum and an inert atmosphere.