What types of corrosion that hot-dip galvanized sheets from China galvanized sheet factory can resist?

China galvanized sheet factory's commonly used anti-corrosion treatment is the hot dip galvanizing process. The reason why hot dip galvanizing is used is that zinc forms a good corrosion-resistant film on the surface in a corrosive environment. It not only protects the zinc layer itself, but also the steel base. Therefore, steel after hot-dip galvanizing greatly extends its service life.
Hot-dip galvanized national standard galvanized sheet requires a galvanized layer of about 85μm, which can effectively isolate water and air and protect the substrate from corrosion and rust. Hot-dip galvanized sheet is made by reacting the molten metal with the iron substrate to produce an alloy layer, thus combining both the substrate and the coating. Before hot-dip galvanizing, the steel sheet is pickled in order to remove the iron oxide on the surface of the sheet, china galvanized sheet factory then cleaned in aqueous ammonium chloride or zinc chloride bath, and then sent to the hot dip plating bath. Hot dip galvanizing has the advantages of uniform coating, strong adhesion, and long service life.
The service life is related to the zinc layer and the environment in which it is placed. This is confirmed by the atmospheric corrosion test conducted on hot-dip galvanized steel sheets, which have different corrosion rates in different environmental atmospheres, and theoretically, this corrosion may proceed in two different ways, namely chemical and electrochemical corrosion.

So what types of corrosion that galvanized sheets produced by china galvanized sheet factory can resist?
1. Chemical corrosion
Chemical corrosion is a direct chemical interaction between the metal and the surrounding medium.
For example, in dry (moisture) gas and non-conductive liquid medium (non-electrolyte), the chemical effect on zinc is called typical chemical corrosion, chemical corrosion is very harmful to the steel base, if not to do the corresponding protection life will be greatly reduced.
2. Electrochemical corrosion
Electrochemical corrosion refers to the metal in the moist gas and conductive liquid medium (such as electrolytes), due to the flow of electrons caused by the corrosion. For example, the corrosion of zinc in acid, alkali, salt solutions, and seawater and atmospheric corrosion of zinc in humid air belongs to electrochemical corrosion. An electrolyte is formed when moisture in the air accumulates in pits on the surface of the galvanized sheet and when carbon dioxide, sulfur dioxide, or other corrosive agents in the air dissolve in the water. In this way, a microcell is formed.
Whether it is chemical corrosion or electrochemical corrosion, we can avoid direct contact with the outside world by galvanizing the steel surface, which reduces the risk of corrosion, thus well protecting the steel base and china galvanized sheet factory ultimately extending the service life of galvanized sheet.