The coating of the coated steel sheet cannot bypass its substrate, and by the way, we can also talk about galvanized sheet. The substrates of coated steel sheets can be divided into (commonly used, not introduced for the time being): cold rolling, electroplating (cold plating), hot-dip galvanizing and hot-dip galvanizing. In the specification of coated steel sheet, Z180 refers to: the amount of double-sided galvanized steel per square meter (/㎡) (the chemical symbol is Zn, and Z is its abbreviation) is 180g; AZ150 refers to the double-sided galvanized steel sheet per square meter (/㎡). The surface aluminum plating (its chemical symbol is Al, A is its abbreviation) zinc amount is 150g.
The color plate produced from the cold-rolled substrate has a smooth and beautiful appearance and has the processing performance of the cold-rolled plate; however, the small scratches on the surface coating will expose the cold-rolled substrate to the air, so that the exposed iron will be formed quickly. red rust. Therefore, such products can only be used for temporary isolation measures and interior materials with low requirements. The cold-rolled plate (corresponding to the “original plate” in the national standard) is a piece of iron, which is plated and coated layer by layer like clothing to prevent it from contacting with oxygen in the air. Therefore, the color-coated board is not easy to rust depends on whether the coating is thick or not and the quality is good.
Theoretically, if the coating and coating of the coated steel plate are not damaged, its service life is equal to the life of the test conclusion in the laboratory (a fog salt experiment with a conclusion of more than 20 years).
