Hot galvanizing is a kind of alloy layer produced by the reaction of molten metal and iron substrate. Hot galvanizing is a process of pickling iron and steel parts, in order to remove iron oxide on the surface of iron and steel parts. After pickling, it is cleaned through ammonium chloride or zinc chloride aqueous solution or mixed water solution of ammonium chloride and zinc chloride, and then sent to the hot dip bath. Hot galvanizing has the advantages of uniform coating, strong adhesion and long service life.

The most widely used steel materials in industry are corroded to varying degrees when used in the atmosphere, seawater, soil and building materials. According to statistics, approximately one third of the world's total production of steel is lost to corrosion each year. In order to guarantee the normal use of steel products and extend their service life, the anti-corrosion protection technology of steel has been widely paid attention to.