Gi steel coil is common steel coil pickling, galvanizing, packaging and other processes from the processing, the surface of galvanized steel coil have galvanized layer and organic coating double protection, because of good corrosion resistance, it is widely used.
Hot dip galvanizing, also known as hot-dip galvanizing, is a method by which steel components are immersed in molten zinc to obtain a metal coating. Generally, the thickness of electric galvanizing (cold galvanizing) layer is 5 ~ 15 microns, while the thickness of the hot galvanizing layer is more than 35 microns, even up to 200 microns. Hot dip galvanized coating ability, coating density, no organic inclusion. As we all know, the mechanism of zinc resistance to atmospheric corrosion includes mechanical protection and electrochemical protection. Under the condition of atmospheric corrosion, ZnO, Zn(OH)2 and basic zinc carbonate protective film exists on the surface of zinc layer, which can slow down the corrosion of zinc to a certain extent, and the destruction of this protective film (also known as white rust) will form a new film. When the zinc layer is seriously damaged and endangers the iron matrix, zinc is dissolved as anode and iron are protected as a cathode when the zinc and iron form a micro battery. Obviously, the resistance to atmospheric corrosion of base metal iron by hot-dip galvanizing is better than that by electric galvanizing.
High quality cold rolled steel coil china, including plates and coils, are rolled from hot rolled coils at room temperature and below the recrystallization temperature. The surface of cold-rolled steel coil is mainly protected by anti-rust oil and gas-phase anti-rust paper.
So the main differences between the galvanized steel coil and cold-rolled steel coil are as follows:
1. Galvanized steel coil mechanical properties are better.
2. Galvanized steel coil better anticorrosive performance, not easy to fade.
3. Hot dip galvanized coating uniform, strong adhesion, not easy to delaminate.
4. Longer service life.