Galvanizing is a process whereby steel is immersed into a bath of molten zinc (865°F/460°C) to form a metallurgicallybonded zinc coating. This same hot dip immersion process is also used to produce aluminum-zinc alloy coatings.
Most cold-formed steel is galvanized by unwinding coils of cold rolled steel and feeding the sheet continuously through a molten zinc bath at speeds up to 600 feet per minute (200 meters/minute). As the steel exits the molten zinc bath, air “knives” blow off the excess coating from the steel sheet and control the coating thickness to the specification requirement. The coated sheet steel is chemically treated (passivated) to protect against storage stain and, if requested, oiled and recoiled for shipment to the fabricator