Dx51d garde Gi steel coil is mild steel with a coating of zinc The zinc protects the steel by providing cathodic protection to the exposed steel, so should the surface be damaged the zinc will corrode in preference to the steel Galvanised steel is one of the most widely used products, used extensively in the building sector, automotive, agricultural and other areas where the steel needs to be protected from corrosion 

Hot-Dip Galvanizing or HDG is a process in which zinc bonds to steel at the molecular level to produce a four-layer corrosion-resistant finish. The first three layers are zinc-iron alloy layers that are actually harder than the base steel. The fourth or top layer is pure zinc.