Method for the non-destructive testing of workpiece surfaces
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.
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 .