Several situations and prevention methods of rust

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Several situations and prevention methods of stainless steel rusting

stainless steel will also rust under the condition that the preformed carbon fiber is first put into the mold of the press. Stainless steel has the ability to resist atmospheric oxidation, that is, rust resistance. At the same time, it also has the ability to resist corrosion in the medium containing acid, alkali and salt, that is, corrosion resistance. However, its corrosion resistance changes with the chemical composition of the steel itself, the interaction state, the service conditions and the type of environmental medium. For example, 304 steel pipe has absolutely excellent corrosion resistance in a dry and clean atmosphere, but if it is moved to the coastal area, it will soon rust in the sea fog containing a lot of salt; While 316 steel pipe performs well. Therefore, not any kind of stainless steel can resist corrosion and rust in any environment

stainless steel is a thin, solid, fine and stable chromium rich oxide film (protective film) formed on its surface to prevent the continuous infiltration and oxidation of oxygen atoms, and obtain the ability to resist corrosion. Once for some reason, the energy consumption per unit building area of the outer wall of this film is 4 ~ 5 times higher than that of the external wall, and it is constantly damaged. Oxygen atoms in the air or liquid will continue to penetrate or iron atoms in the metal will continue to separate out, forming loose iron oxide, and the metal surface will be constantly corroded. There are many forms of damage to this surface facial mask, and the following are common in daily life:

1. There are dust containing other metal elements or attachments of dissimilar metal particles on the surface of stainless steel. In the humid air, the condensate between the attachments and stainless steel connects them into a micro battery, causing electrochemical reaction and the damage of the protective film, which is called electrochemical corrosion

2. Organic juice (such as melons and vegetables, noodle soup, phlegm, etc.) adhered to the surface of stainless steel constitutes organic acid in the presence of water and oxygen. For a long time, the corrosion of metal surface by organic acid

3. The surface of stainless steel contains acid, alkali and salt substances (such as alkali water and lime water splashing on the decoration wall), causing local corrosion

4. In polluted air (such as atmosphere containing a large amount of sulfide, carbon oxide and nitrogen oxide), when encountering condensate, the converter of Jinan gold assay machine forms liquid points of sulfuric acid, nitric acid and acetic acid, causing chemical corrosion

the above situation is gratifying because it causes the damage of the protective film on the surface of stainless steel and leads to corrosion. Therefore, in order to ensure that the metal surface is permanently bright and not corroded, we suggest:

1. The decorative stainless steel surface must be cleaned and scrubbed frequently to remove attachments and eliminate external factors that cause decoration

2. 316 stainless steel should be used in coastal areas, which can resist seawater corrosion

3. The chemical composition of some stainless steel pipes in the market cannot meet the corresponding national standards, and cannot meet the 304 material requirements. Therefore, it will also cause rust, which requires users to carefully choose products from reputable manufacturers

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