Definition - What does Galvanized Coating mean?
Galvanized coating is the application of zinc coating to prevent corrosion or rusting from the steel or iron structure. The application of zinc on a steel structure is a process called ''galvanization.'' This process was first invented and developed in France and England in 1837, in which a sheet of iron or steel was dipped in a molten zinc bath and cooled (a method called "hot dip galvanization").
Corrosionpedia explains Galvanized Coating
The most common method of applying a galvanized coating is hot dip galvanization; however, there are various other processes that are also used, such as:
- Zinc electroplating – In this method, a steel sheet is dipped into the zinc ion solution and an electric current is passed through it, which uniformly spreads zinc ion solution on the metal sheet.
- Mechanical plating – In this method, zinc powder along with glass beads and a special reducing agent are coated on the metal sheet, which bonds zinc particles on the surface of sheet.
- Sherardizing – In this method, a metal sheet is heated up to a temperature of 752°F (400°C) and passed through zinc powder. At this high temperature, diffusion between zinc and steel molecules occurs.
- Continuous strip galvanizing and galvanized wire – In this method, a metal strip or metal wire is passed through a solution of molten zinc at a high speed of 590 feet (180 meters) per minute in a controlled air pumping. This applies a zinc coat on the metal sheet.
- Zinc metal spray – In this method, a metal sheet is cleaned to Class III level and then zinc powder is sprayed on top of it with the help of a plasma flame gun.