When the surface of stainless steel tableware is rusted, people are surprised: "Stainless steel does not rust, it is not stainless steel." In fact, this is a misunderstanding of the lack of understanding of stainless steel. Stainless steel cutlery can rust in some cases.
Stainless steel is resistant to atmospheric oxidation (i.e. does not rust) and also has the ability to corrode in acids, alkalis and salt-containing media (i.e. corrosion resistance). However, its corrosion resistance varies with the chemical composition of the steel itself, the state of mutual addition, the use conditions and the type of environmental media. For example, 430 steel pipe has absolutely excellent anti-corrosion ability in a dry and clean environment, but when it is moved to the seaside area, it will quickly rust in the sea mist containing a lot of salt; 304 steel pipe has good performance.
Therefore, it is not any kind of stainless steel that is resistant to corrosion and will not rust in any environment. There are many forms of damage to the surface of stainless steel. In daily life, the following situations are more common: Stainless steel relies on an extremely thin, strong, dense and stable chromium-rich oxide film formed on its surface to prevent oxygen atoms from continuing to penetrate and continue to oxidize, thereby gaining corrosion resistance. Once the membrane is broken continuously for some reason, the oxygen atoms in the air or liquid will continue to penetrate, or the iron atoms in the metal will continue to separate out, forming loose iron oxide, and the metal surface will continue to rust.
There are many forms of damage to this surface film. In daily life, the following are more common: Dust accumulates on stainless steel surfaces, which contain attachments of other metal elements or foreign metal particles. In humid air, condensate between the accessory and the stainless steel connects the two into a tiny battery, which triggers an electrochemical reaction and damages the protective membrane, known as electrochemical corrosion. The surface of stainless steel adheres to the organic juice, which forms organic acid in the presence of water and oxygen, and the organic acid corrodes the metal surface for a long time.
The surface of stainless steel adheres to substances containing acids, bases and salts, such as lye and lime water splashed on decorative walls, causing localized corrosion. Sulfuric acid, nitric acid and acetic acid liquids are formed in polluted air such as the atmosphere that contains large amounts of sulfides, carbon monoxide and nitric oxide. The stainless steel tableware used on the dining table is made of the above-mentioned stainless steel raw materials, and the stainless steel tableware used by people rarely encounters corrosive liquids.
So pay attention to cleaning and storage, generally can be used for a long time. Among the raw materials of stainless steel tableware, the best material is 304 (18/10 stainless steel), and its quality is higher than 430 (18/0 stainless steel). Stainless steel cutlery made from better raw materials will give people peace of mind! .