When brown spots appear on the surface of the stainless steel coil, people are surprised that the stainless steel coil will not rust, and the rust is not the stainless steel coil, it may be a problem with the steel. In fact, this is a one-sided misconception about the lack of understanding of stainless steel coils. Stainless steel coils will also rust under certain conditions.

Stainless steel coils have the ability to resist atmospheric oxidation, that is, non-rust, and also have the ability to resist corrosion in media containing acid, alkali, and salt, that is, corrosion resistance. However, the size of its corrosion resistance is changed with the chemical composition of the steel itself, the conditions of mutual use and the type of environmental media. For example, 304 has absolutely excellent corrosion resistance in a dry and clean atmosphere, but if it is moved to a seaside area, it will soon rust in the sea fog containing a lot of salt, while 316316l stainless steel coil is good performance. Therefore, it is not any kind of stainless steel coil that can resist corrosion and rust at any time.

The stainless steel coil is a very thin, firm and fine stable chromium-rich oxide film (protective film) formed on its surface. Prevent oxygen atoms from continuing to penetrate and continue to oxidize, and obtain anti-corrosion ability. Once the film is damaged continuously for some reason, the oxygen atoms in the air or liquid will be continuously separated out to form loose iron oxide, and the metal surface will be continuously corroded.