After the equipment is welded, what are the white and red paints on the welds?
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What are the white and red substances left at the welds of the company’s equipment?
Reply to 1# Tan Xunqiang: It should be surface inspection, where a substance is sprayed on the welds; surface defects can be detected by color. I can’t remember exactly after such a long time; it might be penetrant testing. I also forgot whether that substance is sprayed first. Hope this helps.
Thank you. It should be penetrant testing; it seems to turn white first and then red
For surface flaw detection of equipment, the coloring method is used!
The red one is called a penetrant, and the white one is called a developer. After welding, certain fillet welds and welds that cannot be inspected internally are first polished clean. Then a penetrant (red) is sprayed on, followed by wiping away the penetrant with water or a cleaner. After that, a developer (white) is sprayed; if there are cracks in the weld, red marks will appear on the white surface.
Hehe. . . I know this: what is seen are the residues from penetrant testing. Penetrant testing is used to detect surface open defects in welds. The white you see is the developer, and the red is the penetrant. First, spray the penetrant; it must be removed completely before spraying the white developer. However, it is sufficient to ensure that the area between the weld and the heat-affected zone (15–25 mm) is thoroughly cleaned. So generally, the red color on the periphery is just left there. That’s the spray imaging agent. If there are no further processes after that. The NDT personnel left without cleaning up. It should be wiped normally. Corrosive to welds (weak).
It wasn’t cleaned properly after doing PT. The on-site management is poor; nothing is kept clean
Floors 6 and 7 are correct; they refer to the penetrant and developer used for penetrant testing
Thank you~~~~ Bow{:1_90:}