When stainless steel sanitary accessories surface brown rust (point), people are surprised: that "pure copper, stainless steel is not rust, rust must be the quality of the problem." In fact, this is a lack of understanding of pure copper, stainless steel, a one-sided wrong view. Pure copper, stainless steel will rust under certain conditions.

Why does stainless steel bathroom hardware rust?

Pure copper, stainless steel has the ability to resist atmospheric oxidation - that is, rust, but also has the ability to corrode in the medium containing acid, alkali, salt - that is, corrosion resistance. However, its corrosion resistance is changed with the chemical composition of the steel itself, the mixing state, the service conditions and the type of environmental media. Such as 304 steel pipe, in the dry and clean atmosphere, has excellent corrosion resistance, but it is moved to the seaside area, in the sea fog containing a lot of salt, will soon rust; 316 steel pipe is good performance. Therefore, not any kind of stainless steel, in any environment can resist corrosion, does not rust.

Stainless steel is formed on the surface of a very thin and solid fine stable chromium-rich oxide film (protective film), prevent oxygen atoms continue to penetrate, continue to oxidize, and obtain the ability to resist corrosion. Once, for some reason, the film is constantly damaged, oxygen atoms in the air or liquid will continue to penetrate or iron atoms in the metal continue to decompose, forming loose iron oxide, the metal surface is constantly corroded. This kind of surface film is damaged in many forms, which are commonly seen in daily life as follows:

1 pure copper, stainless steel surface deposit containing other metal elements of dust or heterogeneous metal particles of attachment, in the humid air, between the attachment and stainless steel condensate, the two together into a micro battery, triggered the electrochemical reaction, protective film is damaged, called electrochemical corrosion.

2 pure copper, stainless steel surface adhesion organic juice (such as melons and vegetables, noodle soup, sputum, etc.), in the case of water oxygen, organic acid, organic acid corrosion on the metal surface for a long time.

3 pure copper, stainless steel surface adhesion containing acid, alkali, salt substances (such as the decoration of the wall of alkali water, lime water splash), cause local corrosion.

4. In polluted air (such as the atmosphere containing a large number of sulfide, carbon oxide, nitrogen oxide), the condensation of water, the formation of sulfuric acid, nitric acid, acetic acid liquid point, causing chemical corrosion.

The above conditions can cause pure copper, stainless steel fittings surface protective film damage caused by corrosion.