A corrosion inhibitor is a chemical substance or a mixture of several chemicals that exists in an appropriate concentration and form in an environmental medium and can prevent or slow down corrosion. Unlike the protective mechanism of chemical nickel plating based on sodium hypophosphate and nickel sulfate on metals, the corrosion inhibitor method mainly achieves the effect of metal corrosion prevention by containing elements such as phosphorus, molybdenum, silicon, and chromium.
The principle of action of corrosion inhibitors is to change the surface state of metals or act as catalysts to change the reaction mechanism of the corrosion process, thereby increasing the activation energy barrier of the reaction, reducing the reaction rate constant, and reducing the reaction rate of the entire corrosion process, achieving the goal of slowing down corrosion. In a corrosive environment, adding a small amount of corrosion inhibitor can cause physical and chemical reactions with the metal surface, significantly reducing the corrosion of metal materials.
According to chemical composition classification, corrosion inhibitors can be divided into three types: organic, inorganic, and composite. Organic corrosion inhibitors include organic amine corrosion inhibitors, phosphorus containing organic corrosion inhibitors, etc; Inorganic corrosion inhibitors include zinc salts, molybdates, chromates, phosphates, and polyphosphates; Composite corrosion inhibitors include zinc based composite corrosion inhibitors, silicate based (silicon based) composite corrosion inhibitors, phosphate based (phosphorus based) composite corrosion inhibitors, molybdate based (molybdenum based) composite corrosion inhibitors, chromate based (chromium based) composite corrosion inhibitors, and all organic corrosion inhibitors.
Different anti-corrosion methods are applied to different metal material surfaces, and * is a common method, which is to prepare a protective layer on the metal material surface that can prevent corrosion, block various conditions that cause metal corrosion and the contact between the metal substrate, and achieve anti-corrosion effect.