In the stainless steel submersible pump surface rust when the people are very strange: stainless steel is not rusty, how rust it, it is the quality of stainless steel submersible pump problem. "In fact, this view is wrong, stainless steel Under certain conditions will be rusty.
The main material of stainless steel is stainless steel, which has a stainless steel, but also in acid, alkali, salt, the corrosion resistance of the medium. But its corrosion resistance is the chemical composition of its steel itself, the use of conditions and the environment is different. Not any kind of stainless steel, in any environment can be resistant to corrosion, no rust.
Stainless steel is due to its surface of the chromium-rich oxide film, so as to prevent the continued infiltration of oxygen atoms, continue to obtain the ability to resist corrosion. But once the film has been constantly destroyed, the air or liquid oxygen atoms will continue to infiltrate or metal iron atoms continue to precipitate out to form loose iron oxide, metal surface will continue to rust. This surface film is damaged in the form of many, more common in daily life are the following:
1, stainless steel surface adhesion containing acid, alkali, salt substances (such as decorative walls of alkaline water, lime water splash), causing local corrosion.
2, stainless steel surface adhesion of organic juice (such as vegetables, soup, sputum, etc.), in the case of water and oxygen, constitute organic acids, long time the organic acid corrosion of metal surface.
3, in the contaminated air (such as containing a lot of sulfide, carbon oxides, nitrogen oxide atmosphere), in case of condensate, the formation of sulfuric acid, nitric acid, acetic acid liquid point, causing chemical rot
4, the surface of the stainless steel containing other metal elements of dust or heterogeneous metal particles attached to the wet air, between the attachment and stainless steel condensate, will
The two together into a micro-battery, triggering an electrochemical reaction, the protective film is damaged, called electrochemical corrosion.