Galvanization is the process of coating metals with zinc to prevent corrosion and rusting. This process typically involves cleaning the metal surface from grease, then treating it with acid to remove impurities before applying a flux coating, followed by immersion in a bath of molten zinc. Additionally, upon customer request, passivation treatment can be applied. Galvanization serves to protect metals such as steel by providing a zinc coating that acts as a barrier against corrosive elements, thereby extending the metal's lifespan.
There are three main methods of galvanization:
Hot-Dip Galvanization: Involves dipping the metal into a bath of molten zinc. The metal must first undergo mechanical or chemical cleaning to ensure a strong bond between the metal and zinc. Fluxing is then applied to remove any remaining oxides before immersion in the zinc bath. Hot-dip galvanization is known for its economic efficiency, speed, and applicability to complex shapes.
Pre-Galvanization: Similar to hot-dip galvanization, but primarily used for pre-shaped metal products. The metal undergoes the same cleaning process before being passed through a bath of molten zinc, followed by recoiling. While pre-galvanization offers faster galvanization of large steel sheet coils compared to hot-dip galvanization, it may result in exposed areas when the metal is cut during manufacturing.
Electrogalvanization: Differs from hot-dip galvanization and pre-galvanization as it does not involve immersion in molten zinc. Instead, an electrolyte solution and electric current are used to deposit zinc onto the metal surface. Electrogalvanization ensures a uniform coating thickness, but it may not provide as robust corrosion protection as hot-dip galvanization.
In galvanization, after cleaning the metal surface from grease and treating it with acid, followed by flux coating, the metal undergoes hot-dip galvanization. Additionally, passivation treatment can be applied upon customer request. For further details, please contact us.