Galvanized metal is a metal that has undergone the galvanizing process, which is a corrosion protection process for iron or steel in which the substrate is coated with zinc to prevent it from rusting. The galvanization process entails immersing clean, oxide-free iron or steel into molten zinc in order to form a zinc coating that is metallurgically bonded to the iron or steel's surface.
The zinc coating on the galvanized metal acts as a sacrificial anode.
Galvanized metal is simply iron or steel in some form that has received a thin coating of zinc oxide. Galvanizing is a one-time process that ensures maintenance-free use, long service life and virtually eliminates disruptive maintenance.
The zinc coating protects the surface against corrosion in two ways:
- The zinc coating shields the base metal from the atmosphere.
- Because zinc is more electronegative than iron or steel, it gives cathodic (sacrificial) protection.
Even if the surface becomes scratched and the base metal is exposed, the zinc is slowly consumed while the iron or steel remains protected from corrosion.
The value of galvanizing stems from zinc's corrosion resistance and long life. The galvanizing process produces a durable, abrasion-resistant coating of metallic zinc and zinc-iron alloy layers on the substrate and completely covers the work piece. No other steel coating matches galvanization's unique combination of properties and advantages.
The galvanization process for carbon steel produces numerous beneficial effects for manufacturing industrial parts, and it is available in many forms.
Galvanized steel is used to build:
- House framing materials
- Truck and bus bodies
- Household appliances
- Electrical towers
- Metal pails
- Air ducts
- Trash cans
- Many other daily use items
Although galvanization can be done with electrochemical and electrodeposition processes, the most common method is hot-dip galvanization, in which steel parts are submerged in a bath of molten zinc.
The hot-dip galvanizing process is adaptable to coating products such as:
- Pipes and tubes
- Wire cloth
- Structural assemblies