We believe that zinc is easily soluble in acid and alkali, so it is called amphoteric metal. Zinc hardly changes in dry air. In humid air, a dense basic zinc carbonate film will be formed on the zinc surface. In the atmosphere containing sulfur dioxide, hydrogen sulfide and marine, the corrosion resistance of zinc is poor, especially in the atmosphere of high temperature and high humidity containing organic acid, the zinc coating is easily corroded. The standard electrode potential of zinc is -0.76V. For the steel substrate, the zinc coating is an anodic coating. It is mainly used to prevent corrosion of steel, and its protection performance has a great relationship with the thickness of the coating. After passivation treatment, dyeing or coating of light protectant, the zinc coating can significantly improve its protection and decoration.
Galvanizing process principle: In a rotating drum equipped with plating, glass balls, zinc powder [nonferrous business opportunity: zinc powder standard], water and accelerator, the glass ball as the impact medium rotates with the drum, and is plated Friction and hammering on the surface of the workpiece produce mechanical and physical energy. Under the action of the chemical accelerator, the coated zinc powder is "cold welded" onto the surface of the plated article to form a smooth, uniform and fine plating layer with a certain thickness.