Introduction to galvanizing

Zinc is a silver-white metal with a slight bluish tinge. Zinc is brittle and has no malleability until it is heated to 100-150 degrees. Zinc has low hardness and poor wear resistance. Zinc is an amphoteric metal soluble in both acids and bases. Especially when zinc contains positive impurity zinc dissolution rate is faster. But the electrogalvanizing layer has high purity and uniform structure, so the galvanizing layer has high chemical stability at room temperature. Zinc coating is mainly coated on the surface of iron and steel products as a protective coating. The standard electrode potential of zinc is -0.76V, which is negative than that of iron. In steel surface galvanized layer both mechanical protection, and chemical protection, galvanized layer after passivation formed rainbow color or white passivation film, almost no change in the air, in gasoline or carbon dioxide humid air is also very stable, but in the containing S02, H2S, Marine atmosphere and sea water in the corrosion resistance of galvanized layer is poor, especially at high temperature, The corrosion resistance of galvanized coating is very poor in high humidity and atmosphere containing organic acid. Electrogalvanizing is one of the earliest electroplating processes used in production, and the process is relatively mature, easy to operate, less investment, and the lowest cost of corrosion resistance coating in iron and steel parts. The production of protective coating is the largest, accounting for about 50% of total electroplating production. It is widely used in mechanical and electrical, light industry, instrumentation, agricultural machinery, building hardware and national defense industry. The newly developed bright galvanized layer has been further improved in both protection and decoration after being coated with protective film.