Galvanized steel is a carbon flat rolled steel product that is covered in a zinc coating on its surface. This coating increases a steel coil’s, slit coil’s, or sheet’s resistance to corrosion. The most common method of galvanizing steel is the hot dip galvanized process.

Galvanizing is a metallurgical reaction process. From a microscopic point of view, the hot-dip galvanizing process has two dynamic balances: heat balance and zinc-iron exchange balance. When the steel workpiece is immersed in the molten zinc solution at about 450°C, the workpiece at room temperature absorbs the heat of the zinc solution. When the temperature reaches above 200°C, the interaction between zinc and iron is gradually obvious, and zinc penetrates into the surface of the iron workpiece. As the temperature of the workpiece gradually approaches the temperature of the molten zinc, alloy layers with different proportions of zinc and iron are formed on the surface of the workpiece to form a layered structure of the zinc coating. As time goes by, different alloy layers in the coating show different growth rates. From a macro point of view, the above process is manifested as the workpiece is immersed in the zinc liquid, and the zinc liquid surface appears to boil. When the zinc-iron reaction gradually balances, the zinc liquid surface gradually calms down. The workpiece is lifted out of the molten zinc surface, and when the temperature of the workpiece gradually drops below 200°C, the zinc-iron reaction stops, the hot-dip galvanizing layer is formed, and the thickness is determined.