Why does the stainless steel mesh belt rust?
The stainless steel mesh belt has the ability of atmospheric oxidation resistance, namely rustless property, and it has the ability of corrosion resistance in medium containing acid, alkali and salt, namely corrosion resistance. However, the corrosion resistance of the TD-YWD varies with its chemical composition, additive state, service conditions and the type of the ambient medium. For example, the 304 TD-YWD has perfect corrosion resistance in dry and clean atmosphere, but if it is moved to the coastal area, it will rust soon in the sea fog containing a lot of salt, while the 316 TD-YWD performs well. Therefore, is not any kind of stainless steel, the ability corrodes under any environment, does not rust.
There are many forms of destruction of the surface film, the following are common in everyday life.
The stainless steel mesh belt prevents oxygen atoms from continuous infiltration and its oxidation to obtain the corrosion resistance by a very thin, solid, fine and stable chromium-rich oxidation film (protective film) formed on its surface. Once the film is destroyed constantly due to some reason, oxygen atoms in air or liquid will infiltrate continuously or the iron atoms in the metal will be isolated continuously, which form loose iron oxide, and metal surface will be corroded constantly. There are many forms of destruction of the surface film, the following are common in everyday life.
1. The surface of the stainless steel mesh belt is deposited with dust containing other metallic elements or adhesives of different metal particles. In the damp air, the condensate water between the adhesives and the TD-YWD connect the two into a micro-battery, which causes electrochemical reaction and damages the protective film. It is called electrochemical corrosion.
2. The surface of the stainless steel mesh belt is adhered with organic juice (such as cucurbits and vegetables, water in which noodles have been boiled, phlegm, etc.). Under the condition of water and oxygen, the organic acid is formed, the organic acid will corrode the metal surface after a long time.
3. The surface of the stainless steel mesh belt is adhered with substances containing acid, alkali and salt (such as the splash of water containing soda and lime water while painting the walls), which causes local corrosion.
4. In polluted air (such as atmosphere containing a large amount of sulphide, carbon dioxide and nitrogen oxide), when condensate water comes into being, the liquid points of the sulfuric acid, nitric acid and acetic acid will cause chemical corrosion.