Galvanized Color Coated Plate Sheet Corrugated Steel Gi Iron Roofing 275g / ㎡

Types of Galvanized Iron Sheet

There are different types of GI sheets. For example, due to the different galvanizing methods, there are hot-dip galvanized sheets and electro-galvanized steel sheets.

Hot dipped galvanized sheet is mainly produced by the continuous galvanizing process. That is, the zinc coating is applied by continuously immersing the steel coil in the molten zinc bath at temperatures of 450 degrees. This process provides a thick zinc coating that freezes into crystallized zinc spangles. The thick zinc coating offers full protection for the base steel. That’s why its service life is more than 30 years under normal conditions. By the way, the zinc layer at Wanzhi Steel is Z40-275 g/m2.

Electro-galvanized sheet often uses cold rolled steel as the base metal. Then the zinc coating of the electro-galvanized sheet is applied by electro-deposition. The continuous electrolytic coating process offers a thin but very uniform zinc coating. So the electro-galvanized steel has a smoother appearance. However, its corrosion resistance is not as good as that of hot-dip galvanized steel.