Method for the non-destructive testing of workpiece surfaces

Patent metadata

Field	Value
Publication number	US-9535012-B2
Application number	US-201414323183-A
Country	US
Kind code	B2
Filing date	Jul 3, 2014
Priority date	Jul 9, 2013
Publication date	Jan 3, 2017
Grant date	Jan 3, 2017

Abstract

Disclosed is a method for the non-destructive testing of workpiece surfaces of a workpiece by means of fluorescent penetrant testing or dye penetrant testing. The method comprises applying a penetrant to the region of the workpiece surface to be examined, thereby allowing the penetrant to penetrate into possible recesses in the workpiece surface, applying a developer to the region of the workpiece surface to be tested; bleaching the penetrant by a gaseous or liquid oxidant; and visually assessing the penetrant that has remained in the recesses present in the workpiece surface.

First claim

What is claimed is:

1. A method for the non-destructive testing of a workpiece surface of a workpiece by fluorescent penetrant testing or dye penetrant testing, wherein the method comprises:
(a) cleaning a region of the workpiece surface which is to be examined;
(b) applying a liquid fluorescent penetrant or a liquid non-fluorescent dye penetrant to the region of the workpiece surface which is to be examined, thereby allowing the penetrant to penetrate into possible recesses in the workpiece surface;
(c) removing excess penetrant from the workpiece surface;
(d) applying a developer to the region of the workpiece surface which is to be examined and from which excess penetrant has been removed;
(e) bleaching the penetrant by a gaseous or liquid oxidant in a layer formed by applied developer on the workpiece surface; and
(f) visually assessing penetrant that has remained in the recesses present in the workpiece surface.

2. The method of claim 1 , wherein the oxidant comprises ozone.

3. The method of claim 2 , wherein in (e) the workpiece with the workpiece surface is introduced into a chamber or container filled with ozone.

4. The method of claim 2 , wherein in (e) the workpiece with the workpiece surface is exposed to an ozone stream at least in a region of the workpiece surface.

5. The method of claim 2 , wherein in (e) the workpiece with the workpiece surface is exposed to an oxygen stream and at the same time to UV radiation for forming the ozone at least in a region of the workpiece surface.

6. The method of claim 2 , wherein (b) to (f) are repeated after conclusion of (f).

7. The method of claim 1 , wherein in (e) the oxidant is heated.

8. The method of claim 1 , further comprising (d1) a first visual assessment of the workpiece surface prior to (e).

9. The method of claim 8 , wherein in (d1) the workpiece surface to be examined is irradiated with UV light.

10. The method of claim 1 , wherein in (f) the workpiece surface to be examined is irradiated with UV light.

11. The method of claim 1 , wherein a further operation for bleaching the fluorescent penetrant or the non-fluorescent dye penetrant in a developer layer by the gaseous or liquid oxidant is carried out after or during the visual assessment of (f).

12. The method of claim 1 , wherein (b) to (f) are repeated after conclusion of (f).

13. The method of claim 1 , wherein the workpiece surface is a surface of a turbomachine.

14. The method of claim 1 , wherein the workpiece surface is a surface of a component of a gas turbine.

15. The method of claim 1 , wherein the penetrant comprises a fluorescent dye penetrant.

16. The method of claim 1 , wherein the penetrant comprises a non-fluorescent dye penetrant.

17. A method for the production of a component of a turbomachine, wherein the method comprises carrying out the method of claim 1 .

18. The method of claim 1 , wherein the workpiece surface is a surface of a component of a gas turbine.

19. A method for the maintenance of a component of a turbomachine, wherein the method comprises carrying out the method of claim 1 .

Assignees

• MTU Aero Engines AG

Inventors

• Satzger Wilhelm
• Bamberg Joachim
• Hessert Roland
• Schuster Robert
• Hess Thomas

Classifications

• G01N21/6447

  by visual observation · CPC title

• G01N21/33

  using ultraviolet light (G01N21/39 takes precedence) · CPC title

• G01N21/91 Primary

  using penetration of dyes, e.g. fluorescent ink · CPC title