Degreasing Cleanliness
Degreasing cleaning removes oil and grease from the component surface to ensure optimal wettability for dye penetrant testing.
Physicochemical mechanism of action
Degreasing refers to the process of removing oil and grease from a metal surface. This is done by chemical or mechanical methods that dissolve and remove the greasy film from the surface.
Metallurgical relevance & risks in welding
If degreasing is not carried out properly, residual grease can impair the wettability of the dye penetrant. This leads to uneven or missing dye distribution on the surface and can cause visual defects in the final product. In addition, grease can also interfere with the chemical reaction between the dye and the metal, which in turn reduces the effectiveness of the dye penetrant inspection.
Workshop practice & instructions
To ensure successful degreasing, the following steps should be taken:
1. Mechanical cleaning: Use a fine lint-free cloth or a mechanical cleaning tool to wipe the surface of the part and remove any dirt or soot.
2. Chemical cleaning: Apply a degreasing solution to the surface and let it sit for a few minutes. This can be a solution of water and a mild detergent.
3. Drying: After cleaning, the surface should be thoroughly dried to remove any residue or leftover cleaning agent.
4. Wetting: Make sure the surface is completely dry and ready for applying the penetrant.