1. The surface layer of the cold-drawn seamless pipe has accumulated smoke and dust rich in other chemical molecules or the appendages of the semi-animal metal material composite material inhalable particulate matter. The two form a micro-rechargeable lithium battery, which leads to electrochemical corrosion and damage to the protective film, which is called the principle of primary battery.
2. The surface layer of the cold-drawn seamless pipe is attached to the organic compound juice (such as melon and vegetables, cold noodles, sputum, etc.), which forms sodium tripolyphosphate in the presence of ice and oxygen. etch.
3. There are acid, alkali and polyphosphate chemicals on the surface of the cold drawn seamless pipe (such as edible soda ash and quicklime powder splashing on the wall decoration in the house), causing a part of the erosion.
4. In the air with environmental pollution (such as the vapor with a lot of potassium thiocyanate, carbon dioxide, and sulfur oxide), when it encounters condensed water, it will lead to hydrochloric acid, sodium cyanide, and acetic acid liquid point, resulting in chemical corrosion.