What is the difference between stainless steel coating solution and pickling passivation?
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Is the effect of applying a stainless steel protective coating equivalent to that of acid washing and passivation? What’s the difference?
All metals react with oxygen in the atmosphere to form an oxide layer on their surfaces, and the iron oxide that forms on ordinary carbon steel continues to oxidize, causing rust to spread and eventually leading to the formation of holes. The surface of carbon steel can be protected by electroplating with paint or oxidation-resistant metals, but this protection is merely a thin film; if the protective layer is damaged, the steel beneath begins to rust again. The corrosion resistance of stainless steel depends on chromium; when the chromium content in the steel reaches 10.5%, its resistance to atmospheric corrosion increases significantly. Stainless steel is corrosion-resistant because an inert, dense layer of chromium-rich oxide forms on its surface in the atmosphere, protecting it from further oxidation. This oxide layer is extremely thin, allowing the natural luster of the steel surface to be visible through it, which gives stainless steel its unique appearance. If the chromium film is damaged, the chromium in the steel can react chemically with oxygen in the atmosphere to rapidly re-form a passive film that continues to provide protection. However, under certain environmental conditions, stainless steel can still corrode. 1. The protective solution and pickling passivation serve the same purpose: they form a protective film to prevent further oxidation of the iron elements within stainless steel ； 2. The key is to consider the condition of the membrane during the two processing steps and in its subsequent use, such as dissolution and decomposition, density, sensitivity to mechanical stress (scratches), and damage caused by salts and alkalis. It ultimately depends on the specifics of your own processing process
It is mainly used in contact with turbine lubricating oil at around 60°C. It is not known whether this method has an impact on the film-forming surface caused by the grease, and specific relevant information is desired