When the stainless steel surface appears brown spot (point), people are very surprised: think "stainless steel is not rusty, rust is not stainless steel, may be steel problems." In fact, this is a lack of understanding of stainless steel a one-sided wrong view. Stainless steel will also rust under certain conditions.
Stainless steel has the ability to resist atmospheric oxidation-that is, corrosion resistance. However, the size of its anti-corrosion ability is changed with the chemical composition, processing state, conditions of use and type of environmental medium of its steel itself. Such as304L Stainless Steel Wire, In a dry and clean atmosphere, has an absolutely excellent anti-rust ability, but moved it to the seaside area, in the sea fog containing a lot of salt, quickly rusted, while 316 steel, it performed well. Therefore, not any kind of stainless steel, in any environment can withstand corrosion, do not rust.
Stainless steel is a very thin and sturdy and stable chromium oxide film (protective film) formed by its surface to prevent the continued infiltration and oxidation of oxygen atoms, and to obtain the ability to resist rust. One reason, however, the film has been constantly destroyed, air or liquid oxygen atoms will continue to seep in or metal iron atoms continue to analyze out, the formation of loose iron oxide, metal surface will be constantly corroded.
There are many forms of damage to this surface membrane, and there are several more common in everyday life:
1, stainless steel surface accumulation containing other metal elements of dust or heterogeneous metal particles of the attachment, in the moist air adhesion and stainless steel condensate, will be two connected into a micro-battery, triggered an electrochemical reaction, the protection film was damaged, called electrochemical corrosion.
2, stainless steel surface adhesion organic juice (such as melon vegetables, noodle soup, phlegm, etc.), in the case of water oxygen, constitute organic acid, long time organic acid on the metal surface corrosion.
3, stainless steel surface adhesion contains acid, alkali, salt substances (such as decoration walls of alkali water, lime water splash), causing local corrosion.
4, in the polluted air (such as containing a large number of sulfide, oxidized carbon, nitrogen oxides of the atmosphere), in case of condensate, the formation of sulfuric acid, nitric acid, acetic acid liquid point, causing chemical corrosion.
All the above conditions can cause the damage of stainless steel surface protective film to cause rust. Therefore, in order to ensure that the metal surface is permanently bright and not corroded, we recommend:
1, it is necessary to regularly clean and scrub the decorative stainless steel surface, remove the attachment, eliminate the external factors that cause the modification.
2, the seaside area to use 316 materials stainless steel, 316 materials can resist seawater corrosion.
3, the market some stainless steel chemical composition can not meet the corresponding national standards, up to 304 material requirements. Therefore, it will also cause rust, which requires users to carefully choose the products of reputable manufacturers.