Publish Time: 2023-01-11 Origin: Site
Because of the name stainless steel, many people believe that stainless steel does not rust. In fact, however, this is a very one-sided idea. Stainless steel also shows signs of rusting under certain conditions.
Definition of stainless steel: An iron-based alloy with a chromium content of 12% or more is called stainless steel.
Stainless steel is a corrosion and heat-resistant alloy that does not rust easily, which has a lot to do with its composition. Stainless steel is made up of crystal solids that resemble patchwork toys generally arranged by atoms. In addition to iron, stainless steel has chromium, nickel, aluminum, and silicon in its composition. Chromium, nickel elements with anti-rust function, steel added to chromium and other elements, it can make the steel structure more uniform, thus changing the performance of steel, so that the invasion of corrosion becomes difficult, from the metallographic point of view of analysis, because stainless steel contains chromium and make the surface form a very thin chromium film, this film isolated from the invasion of oxygen inside the steel, played a corrosion-resistant role, just like to steel wear an armor, naturally not easy to rust The steel is not prone to rust. And in order to maintain the inherent corrosion resistance of stainless steel, the steel must contain more than 12% chromium.
The following four corrosion conditions can cause stainless steel to rust:
2. when the stainless steel surface is attached to organic juice (such as vegetables, noodle soup, etc.), in the role of water oxygen, the two will constitute an organic acid, with the passage of time, organic acid will cause corrosion on the surface of stainless steel.
3. when the stainless steel surface is attached to acid, alkali, or salt substances (such as alkaline water, lime, etc.), will also cause local corrosion of stainless steel.
4. When the air contains a large number of sulfides, carbon dioxide, nitrogen oxide, and other substances, that is, contaminated air, stainless steel encounter condensation, will form sulfuric acid, nitric acid, acetic acid, etc., causing chemical corrosion, will also lead to stainless steel rust.