Media treatment of anti-corrosion technology
Change the nature of the corrosive medium to prevent or mitigate the corrosion of metal products or equipment by the medium. This method can only be used when the volume of corrosive media is limited. Environmental treatment can be divided into two categories:
The common methods to remove or reduce harmful components in the medium are: (1) dehumidifying and dust-proof to eliminate harmful components such as water vapor, sulfur dioxide and dust contained in the air; ② Deoxygenation is the main technology of boiler water treatment, which can effectively control the water corrosion of the boiler system; (3) Desalting, the various salts (such as magnesium chloride) contained in the crude oil before refining are reduced to a reasonable level to reduce the corrosion of refining equipment, which is an important process of crude oil treatment.
Add corrosion inhibitors Add a small amount of substances to the corrosive medium that can significantly reduce the rate of corrosion. Corrosion inhibitors are divided into inorganic and organic two categories. Inorganic corrosion inhibitors include nitrate, nitrite, chromate, bichromate and other oxidizing corrosion inhibitors. There are phosphate, silicate, carbonate and other non-oxidizing corrosion inhibitors. Organic corrosion inhibitors include amines, aldehydes, heterocyclic compounds, imidazolines and organic sulfides. Although the chemical structure of these inhibitors is different, the corrosion inhibition rate in acidic media is large. The use effect of corrosion inhibitor is closely related to the various parameters and conditions of the corrosive medium, and should be strictly selected when used. Some corrosion inhibitors are toxic and cannot be used in media associated with food preparation. In addition, vapor phase corrosion inhibitors (such as rust-proof paper, etc.) are also widely used to prevent atmospheric corrosion of metal products.
