Galvanization reaction
Hot dip galvanizing - Principle

Galvanization coating is not simply a deposit of zinc on the surface of steel, as paint might be. Since steel is dipped in liquid zinc, it is a metallurgical reaction of double diffusion between zinc and iron. This diffusion leads to the formation of layers of intermetallic compound alloys.

The galvanization coating is therefore composed of:

• one or more layers of intermetallic compounds, depending on the nature of the bath (presence of aluminum in particular) and the technological process;

• a final layer of external zinc, zinc drawn to the part's surface by capillary action.