Hot-dip galvanized channel is a structural steel channel that has been hot-dip galvanized. Galvanizing is the process of protecting steel or iron from corrosion by coating it with zinc.
Here's how the process usually works:
- Surface Preparation: The steel channel is thoroughly cleaned to remove any corrosion, grease, or other pollutants that may interfere with the galvanizing process.
- Galvanizing Bath: The cleaned steel channel is immersed in a bath of molten zinc at temperatures of roughly 860°F (460°C). The immersion method allows the zinc to metallurgically bond with the steel, forming a protective layer.
- Alloy Layers: During immersion, zinc reacts with iron in the steel, forming a succession of zinc-iron alloy layers. These layers form a strong coating that helps to resist corrosion.
- Cooling and quenching: After immersion, the galvanized steel is withdrawn from the bath and left to cool. It is sometimes quenched with water or air to speed up the cooling process.
- Finishing: After cooling, the galvanized channel may go through additional procedures such as inspection, passivation (to improve corrosion resistance), or post-treatment coating if necessary for specific purposes.