How to pickle the surface of stainless steel equipment to achieve an attractive appearance
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I have a stainless steel device whose surface needs to be pickled. However, after pickling, the surface appearance is very unsatisfactory: for example, the areas where welding has taken place and those that are oxidized due to welding remain in their original color and turn yellow. Additionally, the areas that have been polished with a grinder become shiny after pickling, resulting in a very uneven surface texture. Is it because the pickling method is incorrect? How should acid cleaning be done correctly to ensure consistent color on the equipment surface!
What company are you from? You can ask me for advice.
Under normal circumstances, after pickling, the welds on stainless steel equipment (such as 304) appear whiter than other areas, while the color of the remaining parts does not change much. The surface of stainless steel equipment is generally polished as a whole, or only the welds are polished; it is not possible to polish one area while leaving another untreated, as this will cause uneven polishing. If the surface colors are consistent before pickling, then they should also be consistent after pickling. As you mentioned, inadequate pickling during the process is one issue; firstly, the welds are not properly pickled.
It is necessary to control the pickling time; if it is too long, yellowing will occur, and if it is too short, the pickling will not be effective
The issue of pickling and passivation on stainless steel surfaces has always been a focus of discussion.
The equipment manufactured by the previous company was small; after overall sandblasting and immersion in an acid wash tank, it looked quite nice.
The equipment manufactured by the previous company was small; after overall sandblasting and immersion in an acid wash tank, it looked quite nice.
This post was last edited by du*angyin on 2010-10-22 at 15:20. Reply to 3# zyz: It’s because, when manufacturing the equipment, different parts of the cylinder were sanded here and there; as a result, after acid washing, the areas that were sanded appeared different from the other areas, giving it an ugly appearance with those uneven patches. Also, the surface of the equipment isn’t polished; it was simply pickled. How can it be made to look better?
In my opinion, it might be impossible to avoid polishing during the manufacturing process; it’s probably a problem with the pickling process – in other words, the pickling time should be longer, around 3 hours
In my opinion, it might be impossible to avoid polishing during the manufacturing process; it’s probably a problem with the pickling process – in other words, the pickling time should be longer, around 3 hours
Reply to 8# du*angyin: In my experience, if a good appearance is necessary, the only option is to polish everything again (all areas)