Why does stainless steel rust? One day, you suddenly see your stainless steel products rusted, you look shocked. I think I got some fake stainless steel. You immediately ask the seller, "Why does stainless steel rust?" The seller tells you, just like there is no wife in the wife cake, there is no Lei Feng in the Leifeng tower, there is no money in the bag, stainless steel will rust.
So why does stainless steel rust?
Why does stainless steel rust?
Stainless steel is formed on the surface of a layer of a very thin and fine and stable solid rich inscription, oxide film (protective film), prevent oxygen to infiltration, continue to oxidation, and ability to resist corrosion, once you have some reason, this film have to constantly break, air or oxygen atoms in the liquid will constantly infiltration or metallic iron atom separation out unceasingly, the formation of porous oxide Iron, the surface of the metal is constantly corroded. The surface coating damage in the form.
1. Deposited on the surface of the stainless steel contain other metal elements of attachments, or heterogeneous metal particles of dust in the moist air, attachments and stainless steel, the condensed water between the both together as a micro battery, triggers the electrochemical reaction, protective film is damaged, to call the electrochemical corrosion
2. Stainless steel surface adhesion organic juice (such as melon and vegetables, noodle soup, disease, etc.), in the case of water, oxygen, organic acid, long time is caused by organic acid corrosion on the metal surface.
3 stainless steel surface adhesion contains acid, alkali, salt substances (such as the decoration of the wall of alkali water. Lime water injection), causing local corrosion.
4. In polluted air (air with lots of sulfides, carbon oxides, oxidized air), condensation water, sulfuric acid, nitric acid, acetic acid liquid points, chemical corrosion.
5. stainless steel bridge and iron and other dissimilar metal contact, explosive connection, stainless steel and dissimilar metal contact will cause iron ion pollution of stainless steel, resulting in stainless steel corrosion resistance, easier to rust.
How to protect stainless steel grid bridge?
Stainless steel rust reasons we understand, that how to avoid stainless steel rust? Let's take our stainless-steel grid bridge as an example.
1.Stainless steel storage and transportation should be separated from other metal materials, keep clean to prevent dust, oil, rust pollution of stainless steel resulting in late surface rust, is prohibited to drag, avoid knock, scratch.
2.The stainless-steel surface should be cleaned regularly to remove the surface attachment (metal particles, etc.) and eliminate the external factors causing rust.
3. Choose different types of stainless steel in the application environment, such as seaside projects, ship projects, etc., to choose 316L stainless steel material that can resist seawater corrosion.
4. Some stainless-steel chemical composition on the market cannot meet the corresponding national standards, not up to the material requirements, so it will easily cause rust, which requires users to carefully choose the products of reputable manufacturers.
5. stainless steel and dissimilar metal contact, welding, due to dissimilar metal corrosion potential, different, resulting in welding contact part of the anode metal priority electrochemical corrosion. The solution is to select the welding rod (such as A102 electrode) and appropriate welding method according to the dissimilar steel welding rules according to the contact medium.
