stainless steel is a very thin, firm and fine stable chromium-rich oxide film formed on its surface (Protective film) To prevent the oxygen atoms from continuing to infiltrate and continue to oxidize, and to obtain the ability to resist corrosion. Once there is some reason, this kind of film is continuously destroyed, oxygen atoms in air or liquid will continuously penetrate into or iron atoms in metal will continuously separate out to form loose iron oxide, the metal surface is constantly rusted. There are many forms of damage to this mask, and there are several common ones:
dust containing other metal elements or attachments of stainless steel spheres containing heterogeneous metal particles are stored on the surface of stainless steel hollow spheres. In humid air, the condensed water between the attachment and the stainless steel connects the two into a micro-battery, which triggers an electrochemical reaction and damages the protective film, which is called electrochemical corrosion.
organic juice adhered to the surface of stainless steel hollow spheres (Such as melon, noodle soup, sputum, etc) In the case of water and oxygen, organic acids are formed, and the organic acids corrode the metal surface for a long time. Stainless steel surface adhesion contains acid, alkali, salt substances (Such as alkaline water, lime water splash on the wall), Causing local corrosion. In polluted air ( Such as the atmosphere containing a large amount of sulfide, carbon oxide, nitrogen oxide) In case of condensed water, sulfuric acid, nitric acid and acetic acid are formed, causing chemical corrosion.