Color Coated Steel Sheet are also called organic coating sheet or pre-coated steel sheet.
As a continuous production method of coiled material, Color Coated Steel Sheet can be divided into two methods: electrogalvanizing and hot-dip galvanizing.
In the meantime, electrogalvanizing is the method of electroplating to make the gold-plated paint-"layer zn metal or zn alloy.
Hot-dip galvanizing, also called hot-dip galvanizing, is to immerse the metal product to be maintained in the molten zn metal, so that its appearance constitutes a maintenance metal coating. Compared with electroplating, the metal hot-dip coating is thicker; in the same environment Next, its lifetime is longer.
Corrosion of the hot-dip galvanized layer on the surface of steel is equivalent to that of pure zinc. The corrosion of zinc in the atmosphere is similar to the corrosion process of steel under atmospheric conditions. Chemical oxidation corrosion occurs, and electrochemical corrosion occurs on the surface of zinc with water film condensation. In a neutral or weakly acidic atmospheric environment, the corrosion products formed by the galvanized layer of steel plates are insoluble compounds (zinc hydroxide, zinc oxide, and zinc carbonate). These products will be separated by deposition and constitute Fine thin layer.
Generally it can reach a thickness of 8μm ". This film has a certain thickness, but it is not simply soluble in water, and has strong adhesion. Therefore, it can play a barrier effect between the atmosphere and galvanized sheet to prevent further corrosion. Damage to the galvanized layer during maintenance. Part of the steel surface is exposed to the atmosphere.
At this moment, zinc and iron constitute a microbattery. The potential of zinc is significantly lower than the potential of iron. Zinc, as an anode, has the effect of dedicating anode maintenance to the steel plate substrate to avoid the occurrence of corrosion of the steel plate.
Color-coated galvanized sheet is a liquid paint, which is applied on the clean metal surface by brush or roller coating. After heating and curing, a paint film with the same thickness can be obtained.
