What is galvanizing?

Zinc is a silver-white metal with a slight bluish tinge. Metal zinc is relatively brittle, and it has a certain ductility only when 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 impurities with positive potential, the dissolution rate of zinc is faster. However, 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 steel products as a protective coating. The standard electrode potential of zinc is -0.76V, which is negative than that of iron, and is an anodic coating. The galvanized layer on the surface of steel has both mechanical protection and chemical protection, and the galvanized layer forms a rainbow or white passivation film after passivation, which hardly changes in the air, and is also stable in the humid air containing gasoline or carbon dioxide, but the corrosion resistance of the galvanized layer is poor, especially at high temperatures, especially in the wet air containing S02, H2S, Marine atmosphere and seawater. The corrosion resistance of galvanized layer 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 in the corrosion resistant coating of steel parts. As a protective coating, the production is the largest, accounting for about 50% of the total output of electroplating. It is widely used in electromechanical, light industry, instrumentation, agricultural machinery, building hardware and national defense industry. The protective and decorative properties of the recently developed bright galvanized layer are further improved after coating the protective film.