Galvanizing refers to the application of a layer of zinc to the surface of a metal, alloy or other material, which has the function of aesthetics and rust prevention. Zinc is soluble in acids as well as bases, so it is called an amphoteric metal. Zinc does not change much in dry air. In humid air, zinc surface forms alkaline zinc carbonate film.

Zinc in the containing sulfur dioxide, hydrogen sulfide and marine atmosphere corrosion resistance is poor, especially in the high temperature and high humidity and organic acids in the atmosphere, zinc coating is easy to be corroded. Its protective properties are closely related to the thickness of the coating. Zinc coatings can significantly improve their protective and decorative properties when passivated, dyed or coated with a gloss protectant.

There are many different types of galvanizing. However, in terms of the pH value of the galvanizing bath, the two main types are alkaline galvanizing and acid galvanizing. The alkaline galvanizing process means that the pH of the bath is alkaline. However, depending on the cooperating agent, it is divided into cyanide galvanizing and zinc acid galvanizing. Cyanide galvanizing is an old galvanizing process. The plating solution consists of three main components: zinc oxide as the main salt, sodium cyanide as the compounding agent, and sodium hydroxide, commonly known as caustic soda, as the conductive salt.

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