Stainless steel blue spot inspection

Thread Content

1. Design requirements: The inner surface of the stainless steel storage tank must be cleaned of dirt and oil, and subjected to acid washing and passivation. Additionally, a blue-spot inspection must be carried out on the passivation layer; no blue spots indicate compliance with the standards. 2. Baidu’s methods for detecting blue spots – there are 4 such methods: (1) Visual inspection; (2) Illumination with a light source: Using a specific light source to shine on the stainless steel surface, blue spots will exhibit significant reflection under light of a particular wavelength. This method can help identify blue spots in stainless steel materials, but it requires specialized equipment and technical skills. (3) Magnetic testing (4) Chemical analysis: It should be carried out in accordance with the standards in the attachments. 3. I would like to ask: Has anyone used detection by irradiating with a light source (such as a UV lamp)? If so, what method was used? How effective is it? Are there any specific requirements for the passing criteria of the testing? The suggested answer provided by the artificial intelligence software is as follows: When using ultraviolet light to check the effectiveness of stainless steel pickling and passivation, the following standards can generally be used as a reference: 1. Surface cleanliness: The surface of the stainless steel after pickling and passivation should be free from any visible contaminants such as dirt, grease, or oxides. Under ultraviolet light, the surface should exhibit uniform fluorescence, with no distinct dark areas or bright spots. 2. Passivation film quality: A qualified passivation film should exhibit uniform and continuous fluorescence under ultraviolet light. If there are defects in the passivation film, such as cracks, pores, or irregularities, different fluorescence characteristics may be observed. 3. Color and brightness: The fluorescent color and brightness of the stainless steel surface after pickling and passivation under ultraviolet light can be used as a reference. Generally, the fluorescence color should be uniform with moderate brightness, and there should be no significant color differences or dark areas. 4. Comparative reference: The stainless steel that has been pickled and passivated can be compared with untreated stainless steel or samples that are known to be of satisfactory quality. By comparing the fluorescence behavior under ultraviolet light, it is possible to determine whether the pickling and passivation effect meets the requirements. It should be noted that ultraviolet light testing is only an auxiliary method, and it cannot be relied on entirely to determine the effectiveness of pickling and passivation. Other testing methods, such as visual inspection and chemical analysis, should also be employed to obtain a more accurate assessment.