Definition - What does Galvanizing mean?
Galvanizing is a corrosion protection process for steel or iron, 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.
It can be applied on wide range of products and is also favored as a means of protective coating because of its low cost, ease of application and comparatively long maintenance-free service life. The coating normally lasts at least 20 to 40 years in industrial environments and 50 to 100 years in less aggressive atmospheres.
Corrosionpedia explains Galvanizing
Galvanizing is the coating of steel or iron with zinc. It is a one-time process, ensuring maintenance-free use, long service life and virtually eliminating disruptive maintenance.
The zinc coating protects the surface against corrosion by providing protection to the iron or steel in two ways:
- The zinc coating shields the base metal from the atmosphere.
- Because zinc is more electronegative than iron or steel, the zinc gives cathodic, or 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 the corrosion resistance and long life of zinc. The galvanizing process produces a durable, abrasion-resistant coating of metallic zinc and zinc-iron alloy layers to the substrate and completely cover the work piece. No other coating for steel matches galvanization's unique combination of properties and advantages.
The galvanization process for carbon steel produces numerous effects which help in manufacturing parts of industrial objects, and it is available in many forms. Galvanized steel is also used for building:
- Housing frames
- Truck and bus bodies
- Household appliances
- Electrical towers
- Metal pails
- Other various 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. In industry, common galvanized steel is used in many applications such as air ducts and trash cans.
The hot-dip galvanizing process is adaptable to coating nearly all types of fabricated and non-fabricated products such as:
- Pipes and tubes
- Wire cloth
- Structural assemblies