Stainless steel pipes can not be less than the amount of chromium
General stainless steel chromium content is generally not less than 12%, high even up to 18%. Steel added elements such as chromium, can change the performance of the steel, such as the molecular structure of steel more uniform on the surface of the steel is more easily to form a layer of dense oxide protective film, thereby greatly improving the ability of corrosion-resistant stainless steel. Therefore, stainless steel can resist fire, water, acid, alkali and various solutions to its corrosion, not rust. The scientists found that the internal structure of the steel is more uniform, various components more closely linked to the corrosion of the more difficult the invasion, also attached to the surface with a layer of oxide film, like iron and steel to wear armor, was not naturally easy to rust. Why is stainless steel rust? When the stainless steel tube surface appear brown rust (point) when people are surprised: stainless steel does not rust, rust is stainless steel, steel may be a problem. In fact, this is a lack of understanding of stainless steel one-sided misconceptions. Stainless steel will rust under certain conditions. Stainless steel has the ability to resist atmospheric oxidation - that is, stainless steel, and also has the ability to corrode in medium containing acids, alkalis, and salts - that is, corrosion resistance. But its corrosion resistance is changed with the chemical composition, the mutual state, the condition of use and the type of environmental medium.
The chromium content of stainless steel is generally not less than said first why stainless steel tube is not easy to rust 12%-304 stainless steel tube, then why stainless steel will rust stainless steel is not easy to have a great relationship with the composition of stainless steel rust. In addition to iron, stainless steel contains chromium, nickel, aluminum, silicon and so on.
304 stainless steel tube as 304 steel pipe, in the dry clean atmosphere, have absolutely excellent anti-corrosion ability, but it will be moved to the beach area, with large amounts of sea salt fog, will rust quickly; and the good performance of 316 steel pipe. Therefore, it is not any kind of stainless steel, capable of corrosion and rust in any environment. Stainless steel is a very thin layer formed on the surface and the stability of the fine solid chromium rich oxide film (protective film), to prevent the infiltration of oxygen atoms, to oxidation, and the ability to obtain anti-corrosion. Once there are some reasons, this film was constantly destroyed, air or liquid oxygen atoms will continue to infiltrate or metal atoms of iron to keep out from the loose formation of iron oxide, the metal surface will be continuously corroded. Many of the surface damage form, more common in daily life are as follows: 1. stainless steel surface deposited dust or heterogeneous metal particles containing other metal elements of the attachment, in the humid air, condensed water and adhesion between the stainless steel, the two together into a micro battery, cause the electrochemical reaction, the film has been destroyed, called electrochemical corrosion. 2. stainless steel surface adhesion of organic juice (such as vegetables, soup, sputum), oxygen in the water under the circumstances, a long time, organic acid, organic acid on the surface of metal corrosion. 3., stainless steel surface adhesion contains acid, alkali and salt substances (such as decoration wall caustic soda, lime water splash), causing local corrosion. 4., in polluted air (such as containing large amounts of sulfide, carbon dioxide and nitrogen oxides in the atmosphere), in case of condensation water, the formation of sulfuric acid, nitric acid, acetic acid liquid point, causing chemical corrosion.
