METHOD FOR REPAIRING A GAS TURBINE COMPONENT

• US 20110099810A1
• Filed: 10/29/2010
• Published: 05/05/2011
• Est. Priority Date: 10/30/2009
• Status: Abandoned Application

• Current Assignee: Alstom Technology Ltd. (Alstom SA)
• Original Assignee: Alstom Technology Ltd. (Alstom SA)
• Inventors: RICKENBACHER, Lukas, AMBROSY, Günter, HÖBEL, Matthias, STANKOWSKI, Alexander, HÖVEL, Simone
• Application Number:
  US12/916,032
• Publication Number:
  US 20110099810A1
• Time in Patent Office: Days
• US Class Current: 29/888
• CPC Class Codes: B22F 10/28 Powder bed fusion, e.g. selective laser melting [SLM] or electron beam melting [EBM]
• CPC Class Codes: B22F 2999/00 Aspects linked to processes or compositions used in powder metallurgy
• CPC Class Codes: B22F 7/062 involving the connection or repairing of preformed parts
• CPC Class Codes: B23K 2101/001 Turbines
• CPC Class Codes: B23P 6/005 using only replacement pieces of a particular form
• CPC Class Codes: F01D 5/005 Repairing methods or devices
• CPC Class Codes: F05D 2230/13 using lasers
• CPC Class Codes: F05D 2230/80 Repairing, retrofitting or upgrading methods
• CPC Class Codes: F05D 2250/20 Three-dimensional
• CPC Class Codes: Y02P 10/25 Process efficiency
• CPC Class Codes: Y10T 29/49229 Prime mover or fluid pump making

Abstract

A method for repairing an ex-service gas turbine component (10) includes the steps of: removing a damaged section (13) from the gas turbine component (10), manufacturing a 3-D article, which fits in the gas turbine component (10) to replace the removed damaged section (13), and joining the gas turbine component (10) and the 3-D article inserted therein. Reduced cost, improved flexibility and productivity, and simplified handling are achieved by removing the damaged section (13) in the form of a cut-out section along a split line (14) as one single cut-out piece (15), measuring the cut-out piece (15) to obtain the actual non-parametric geometry data set of the cut-out piece (15), and manufacturing the 3-D article based on the geometry data set of the cut-out piece (15).

Claims

1. A method for repairing an ex-service gas turbine component comprising:

removing a damaged section from said gas turbine component;

manufacturing a 3-D article which fits in said gas turbine component to replace the removed damaged section; and

joining said gas turbine component and said 3-D article inserted therein;

wherein removing the damaged section comprises removing in the form of a cut-out section along a split line as one single cut-out piece;

measuring the cut-out piece to obtain the actual non-parametric geometry data set of the cut-out piece; and

wherein manufacturing said 3-D article comprises manufacturing based on said geometry data set of the cut-out piece.

2. A method according to claim 1, further comprising:

creating a virtual 3-D article in the form of a CAD model from said measured geometry data.

3. A method according to claim 2, wherein creating a virtual 3-D article comprises virtually rebuilding damaged or missing areas of the cut-out piece to create, modify, extend, or combinations thereof, said CAD model.

4. A method according to claim 2, wherein the CAD model includes information about the inner surface, potential distortions, local wall thickness modifications, and positions of cooling air holes of the ex-service gas turbine component.

5. A method according to claim 1, further comprising:

adding an additional material surcharge around at least part of the split line to the geometry data set of the cut-out piece to allow for

a compensation of the material loss due to cutting,

the preparation of a split line surface,

a final or individual adaptation of a standard 3-D article geometry to the individual ex-service gas turbine component to be repaired,

or combinations thereof.

6. A method according to claim 1, wherein manufacturing the 3-D article comprises manufacturing by an additive manufacturing technology.

7. A method according to claim 6, wherein the additive manufacturing technology is selected from the group consisting of selective laser melting (SLM), selective laser sintering (SLS), and electron beam melting (EBM).

8. A method according to claim 1, wherein manufacturing the 3-D article comprises manufacturing by investment casting or milling.

9. A method according to claim 1, further comprising, before said joining the manufactured 3-D article into the ex-service gas turbine component:

recontouring the manufactured 3-D article into a recontoured 3-D article to reach optimum conditions of the split line surface, gap width for the final joining process, or both.

10. A method according to claim 9, wherein recontouring comprises removing a fixed thickness of material.

11. A method according to claim 9, wherein recontouring comprises individual adaptive machining.

12. A method according to claim 11, wherein said adaptive machining is based on the individually scanned ex-service gas turbine component, which is compared with the 3-D article geometry.

13. A method according to claim 11, wherein said adaptive machining uses a geometry data set based on the evaluation of a limited number of scanned gas turbine components of the same kind.

14. A method according to claim 9, wherein recontouring comprises a subtractive machining process.

15. A method according to claim 14, wherein said subtractive machining process is selected from the group consisting of milling, grinding, and electro chemical machining (ECM).

16. A method according to claim 9, wherein recontouring further comprises heat treatment, chemical cleaning of the surfaces, or both, of the 3-D article to make the 3-D article ready for insertion.

17. A method according to claim 1, wherein said joining of said gas turbine component and said 3-D article comprises brazing, welding, or a combination thereof.