When brown rust spots (spots) appear on the surface of stainless steel pipes, some people believe that "stainless steel does not rust, rust is not stainless steel, it may be a problem with the steel quality.". In fact, some materials with low nickel content in stainless steel are rusty, so the rusted ones may also be stainless steel. Nowadays, stainless steel pipes are widely used. Stainless steel can also rust under certain conditions.
Stainless steel has the ability to resist atmospheric oxidation, namely rust resistance, and also has the ability to resist corrosion in media containing acid, alkali, and salt, namely corrosion resistance. But the magnitude of its corrosion resistance varies with the chemical composition, additive state, usage conditions, and type of environmental medium of the steel itself. For example, 304 steel pipes have absolutely excellent rust resistance in a dry and clean atmosphere, but when moved to coastal areas, they will quickly rust in sea mist containing a large amount of salt. Therefore, not any type of stainless steel can withstand corrosion and rust in any environment.
Stainless steel is a stable chromium rich oxide film (protective film) formed on its surface, which is extremely thin, sturdy, and fine, preventing the continued infiltration and oxidation of oxygen atoms, and obtaining the ability to resist corrosion. Once for some reason, this thin film is constantly damaged, and oxygen atoms in the air or liquid will continuously infiltrate or iron atoms in the metal will continuously separate, forming loose iron oxide, and the metal surface will also be constantly corroded. This kind of surface facial mask is damaged in many ways, and the following types are common in daily life:
1. Dust containing other metal elements or attachments of dissimilar metal particles accumulate on the surface of stainless steel. In humid air, the attachment and the condensate between the attachment and stainless steel form a micro battery, triggering an electrochemical reaction and damaging the protective film, which is called electrochemical corrosion.
2. The surface of stainless steel adheres to organic juices (such as melons, vegetables, noodle soup, phlegm, etc.), which form organic acids in the presence of water and oxygen. Over time, organic acids corrode the metal surface.
3. The surface of stainless steel adheres to substances containing acids, alkalis, and salts (such as alkaline water and lime water splashing during wall decoration), causing local corrosion.
4. In polluted air (such as atmospheres containing large amounts of sulfides, carbon oxides, and nitrogen oxides), when encountering condensation water, sulfuric acid, nitric acid, and acetic acid droplets form, causing chemical corrosion.
The above situations can cause damage to the surface protective film of stainless steel chemical pumps, leading to corrosion. So, to ensure that the metal surface is permanently bright and not corroded, we recommend:
1. It is necessary to regularly clean and scrub the surface of the decorative stainless steel chemical pump to remove attachments and eliminate external factors that may cause modification.
2. In coastal areas, 316 stainless steel pipeline pumps should be used, which can resist seawater corrosion.
3. Some stainless steel pipes on the market do not meet the corresponding national standards for chemical composition and cannot meet the requirements of 304 material. Therefore, it can also cause rusting, which requires users to carefully choose products from reputable manufacturers.
