Method of improving the properties of a repaired component and a component improved thereby

Abstract

A repaired component with improved material and mechanical properties and a method of improving the properties of a repaired component are provided. The repaired component comprises a body, a repaired area integral with the body, and an area of compressive residual stress wherein the area of compressive residual stress comprises at least a portion of the repaired area. One method for improving the fatigue performance, foreign object damage tolerance, and resistance to stress related failure mechanisms of a repaired component includes inducing a designed residual compressive stress distribution with a controlled amount of cold work in the repaired area to offset high-applied tensile stresses and stresses introduced as a result of the repair procedure as well as to improve the properties of the material added to the component during the repair.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

These and other features, aspects, and advantages of the present invention will become better understood with regard to the following description, appended claims, and accompanying drawings where:

FIG. 1 is a schematic diagram showing one embodiment of the repaired blading member of the present invention.

FIG. 2 is a flow diagram of the method of using residual stress to improve the fatigue life of a repaired component.

Claims

1. A method for improving the properties of a repaired component comprising the acts of: identifying an area of the component that comprises at least a portion of a repaired area of the component;inducing compressive stresses in the identified area.

2. The method of claim 1 wherein the identified area includes undamaged material surrounding the repaired area adversely affected by the repair process.

3. The method of claim 1 further comprising the acts of: determining the applied stress that the identified area is subject to during operation;determining the residual stresses present in the identified area after the repair process has been completed; anddesigning a residual stress distribution to be induced in the area of the repair to offset the effects of both the applied stresses and the residual stresses resulting from the repair process.

4. The method of claim 1 wherein the component has been repaired by removing the damaged area by machining or grinding.

5. The method of claim 4 further comprising the act of replacing the damaged area by joining new material to the component.

6. The method of claim 5 wherein the act of joining new material comprises welding a patch to the component.

7. The method of claim 5 wherein the act of joining new material comprises depositing successive layers of new material by welding or brazing.

8. The method of claim 5 wherein the act of joining consists of brazing, gas welding, arc welding, resistance welding, thermite welding, laser welding, linear friction welding, friction stir welding and electron-beam welding.

9. The method of claim 1 wherein the compressive stress is induced by a process selected from the list consisting of burnishing, deep rolling, pinch peening, impact peening, shot peening, glass bead peening, coining, and/or combinations thereof.

10. The method of claim 1 wherein the compressive stress is induced by burnishing.

11. A component with improved fatigue performance, increased tolerance of foreign object damage, and improved resistance to stress corrosion cracking, the blading member comprising: a body;at least one repaired area integral with said body; andat least one area of compressive residual stress, said at least one area of compressive residual stress comprising a portion of a repaired area;wherein said at least one area of compressive residual stress has been induced by burnishing.

12. The component of claim 11 wherein the area of compressive residual stress comprises the entire said repaired area.

13. The component of claim 11 wherein said at least one area of compressive residual stress extends through the thickness of said body.

14. The component of claim 11 wherein said at least one repaired area has been repaired by removing damage by machining or grinding.

15. The component of claim 11 wherein the component has been repaired by removing damage by machining or grinding, replacing the damage by joining new material to the component, and machining the new material to return the component to its original configuration.

16. The component of claim 15 wherein the act of joining comprises a process selected from the list consisting of brazing, gas welding, arc welding, resistance welding, thermite welding, laser welding, linear friction welding, friction stir welding and electron-beam welding.

17. The component of claim 15 wherein the act of joining new material comprises welding a patch to the component.

18. The component of claim 15 wherein the component has been repaired by depositing successive layers of material by welding or brazing.

19. The component of claim 15 is a blading member for use in turbo machinery.