Cold-drawn seamless pipes have the ability to resist gas oxidation, namely stainless steel, and also have the ability to resist corrosion in components containing acids, alkalis and salts, that is, corrosion resistance. However, the external dimensions of its anti-corrosion ability are changed by the analysis and chemical composition of the steel itself of the high-precision parts, the mutual conditions, the application standard and the type of geographical environment chemical substances. Such as 304 raw material, in the dry and clear air, there is no doubt that it has excellent corrosion resistance, but if it is moved to the beach area, it will quickly rust in the sea fog containing a lot of salt. Therefore, not all cold-drawn seamless pipes are corrosion-resistant and non-corrosive at any time.
Cold-drawn seamless pipe is a layer of ultra-thin and firm and stable chromium-rich oxide film (protective film) formed on its surface to prevent oxygen atoms from entering again. Re-oxidation, CNC lathe WeChat public platform cncdar can resist Corrosive can. Once there are various reasons, this kind of plastic film is continuously damaged, and the vapor or liquid melted new oxygen atoms will continue to enter or the iron atoms in the metal composite material will continue to separate out, forming a loose chemical substance, and the surface layer of the metal composite material will continue to enter. It is constantly corroded. There are many ways to damage this kind of protective film. The following are the most common in daily life:
1. The surface layer of the cold-drawn seamless pipe stores dust containing other chemical molecules or the attachments of semi-animal metal composite particles. In the humid air, the condensed water between the attachments and the cold-drawn seamless pipe will separate the two. Combined into a micro rechargeable battery, the photocatalytic reaction is caused, and the protective film is damaged, which is called electrochemical corrosion.
2. The surface layer of the cold-drawn seamless pipe is attached with organic matter juices (such as melons, vegetables, noodle soup, sputum, etc.), which constitute organic compounds in the presence of ice and oxygen, and long-term corrosion of organic compounds on the surface of metal composite materials.
3. The surface layer of the cold-drawn seamless pipe contains acid, alkali and phosphate compounds (such as edible soda ash and lime powder spray test on the decoration wall in the room), which leads to some corrosion.
4. In the air with air pollution (containing a lot of potassium thiocyanate. Hydroxide. Hydrogen peroxide gas), when encountering condensed water, it forms sulfuric acid, sodium cyanide, and acetic acid liquid points, resulting in chemical corrosion.
