The color-coated steel sheet uses galvanized steel sheet as the base material. In addition to zinc protection, the organic coating on the zinc layer also plays a role of covering and isolating, which can prevent the steel sheet from rusting and has a longer service life than the steel sheet. It is said that the service life of coated steel sheet is 50% longer than that of galvanized steel sheet. Buildings or workshops made of color-coated steel sheets usually have a long service life when they are washed by rain, otherwise their use will be affected by sulfur dioxide gas, salt and dust. Therefore, in the design, if the slope of the roof is large, it is unlikely to accumulate dirt such as dust, and the service life is long. For those areas or parts that are not often washed by rain, they should be washed regularly with water.
However, the service life of color coated plates with the same amount of zinc plating, the same coating material and the same coating thickness will vary greatly in different areas and different use locations. For example, in industrial areas or coastal areas, due to the influence of sulfur dioxide gas or salt in the air, the corrosion rate increases and the service life is affected. In the rainy season, if the coating is soaked in rain for a long time or the temperature difference between day and night is too large, condensation will easily occur, the coating will corrode quickly, and the service life will be shortened.