Process for repairing metallic pieces especially turbine blades of a gas turbine motor

• US 20050120555A1
• Filed: 10/08/2004
• Published: 06/09/2005
• Est. Priority Date: 10/10/2003
• Status: Active Grant

• Current Assignee: Safran Aircraft Engine Company
• Original Assignee: Snecma Moteurs
• Inventors: Herault, Patrick, Boussaboun, Hassan, Caruana, Charles, Defrocourt, Gerard, Caux, Jean-Marc, Sampaio, Clement, Boulnois, Michel, Varin, Jean-Jacques, Chareyre, Francis, Boudereau, Christian
• Granted Patent: US 7,509,736 B2
• Time in Patent Office: Days
• US Class Current: 29/889.100
• CPC Class Codes: B23K 2101/001 Turbines
• CPC Class Codes: B23K 9/044 Built-up welding on three-dimensional surfaces
• CPC Class Codes: B23P 6/007 using only additive methods, e.g. build-up welding
• CPC Class Codes: F01D 5/005 Repairing methods or devices
• CPC Class Codes: Y10T 29/49318 Repairing or disassembling
• CPC Class Codes: Y10T 29/49725 by shaping
• CPC Class Codes: Y10T 29/49726 Removing material
• CPC Class Codes: Y10T 29/49728 and by a metallurgical operation, e.g., welding, diffusion bonding, casting
• CPC Class Codes: Y10T 29/49732 by attaching repair preform, e.g., remaking, restoring, or patching
• CPC Class Codes: Y10T 29/49746 by applying fluent material, e.g., coating, casting
• CPC Class Codes: Y10T 29/49748 by shaping, e.g., bending, extruding, turning, etc.

Abstract

The invention relates to a repair process of a metallic piece, in particular of a rotor or stator blade of a gas turbine motor comprising an anti-wear layer formed by loading by welding of an anti-wear material to a part of its surface and whereof said layer is partially machined, characterised in that it comprises a rectification stage of said layer in which a trace of said original anti-wear layer is left to subsist on at least part of the base of the rectified zone, and a stage in which a new layer of anti-wear material is deposited by welding. The invention in particular relates to turbine blades with a shroud and has the advantage of at the same time ensuring good adhesion of the new layer and preventing the appearance of defects in the metallic substrate.

Claims

1. A process for repair of a piece metallic of a gas turbine motor comprising an anti-wear layer formed by loading by welding an anti-wear material on a part of its surface and whereof said layer is partially machined, characterised in that it comprises a rectification stage of said layer in which a trace of said anti-wear layer is left to subsist on at least part of the base of the rectified zone, and a stage in which welding is employed to deposit a new layer of anti-wear material.

2. The process as claimed in the preceding claim, applied to a mobile blade or stator vane.

3. The process as claimed in the preceding claim, applied to a mobile turbine blade with shroud.

4. The process as claimed in the preceding claim, applied to a blade whereof the shroud of Z profile comprises a pit at the base of the profile.

5. The process as claimed in claim 1, in which said layer is rectified by means of a grinding wheel placed so as to remove a preset thickness of material relative to the initial side of the surface of said anti-wear layer.

6. The process as claimed in the preceding claim whereof the grinding wheel comprises a Z profile.

7. The process as claimed in the preceding claim whereof the grinding wheel is itself rectified continuously during the rectification stage of the layer.

8. The process as claimed in the preceding claim, comprising before deposit of a new layer of anti-wear material, a cleaning stage so as to eliminate any deposit of pollution and/or oxidation resulting from utilisation of the piece.

9. The process as claimed in the preceding claim whereof the cleaning stage comprises a chemical cleaning stage followed by a sand blasting stage.

10. The process as claimed in the preceding claim whereof the sand blasting is effected with a powder of low granulometry.

11. The process as claimed in the preceding claim, applied to a blade comprising surface cavities or evacuation orifices for cooling air, in which air is insufflated via the aerofoil portion and the sand blasting is performed dry, with the entrainment air being at a pressure below that of the insufflated air.

12. The process as claimed in claim 1, comprising a non-destructive control stage of the piece.