Hot-dip galvanizing provides a zinc coating that helps protect steel from corrosion. When uncoated, steel is subject to corrosion. The amount of corrosion varies and depends on what the steel is exposed to. Air, water, concrete, and other elements all have different effects on steel corrosion. When there is potential for steel to corrode, providing a barrier coating is essential.
Hot-dip galvanizing is the process of cleaning steel and then dipping it into a bath of molten zinc. The method ensures a superior coating that provides barrier protection to the underlying steel. It creates a metallurgical bond between the zinc and steel, as well as a series of intermetallic layers. These layers are harder than the steel itself.
Hot-dip galvanizing is different than zinc plating because of the application process. While HDG steel is dipped in molten zinc, zinc plating is applied by electrodeposition. The steel is dipped into an acidic or alkaline bath that uses an electric current to deposit zinc ions onto the surface. The coating achieved by zinc plating is thinner than a galvanized coating and recommended for use in only mildly corrosive atmospheres.
Benefits of HDG Steel
HDG steel has many benefits, including durability, sustainability, and long-lasting corrosion protection. The exterior zinc layer will sacrifice itself to cover any damage to the surface. Additionally, the metallurgical bond created during the application process provides a tough and durable coating that covers all areas of the piece, including corners and threads (if the part is galvanized after threading). Both steel and zinc are infinitely recyclable materials, making the HDG process sustainable as well.