锌层上的有机涂层除了起到保护锌的作用外，还起到了对以镀锌钢板为底板的彩钢板进行覆盖和隔离的作用，可以防止钢板生锈，使用寿命比镀锌钢板长。据报道，涂层钢板的使用寿命比镀锌钢板长50%。但是，同一镀锌量、同一涂层、同一涂层厚度的彩涂板在不同区域、不同使用部位的使用寿命会有很大的差异。

例如，在工业区或沿海地区，由于二氧化硫气体或空气中的盐的影响，腐蚀速度加快，使用寿命受到影响。在雨季，如果长期被雨水浸湿或昼夜温差过大且不可凝结，涂层会迅速腐蚀，降低使用寿命。用彩钢板建造的建筑物或工厂经常在雨水冲刷下使用寿命更长。否则会受到二氧化硫气体、盐和灰尘的影响。

因此，在设计中，屋顶越倾斜，越不容易积垢和其它污垢，使用寿命越长。对于不受雨水冲刷的区域或部件，应使用常规水进行冲洗。

What fields are the good anticorrosion properties of coloured steel sheets widely used in?

Coloured steel sheet has light weight, beautiful appearance, good anticorrosion performance, and can be directly processed. It provides a new raw material for construction, shipbuilding, vehicle manufacturing, furniture, electrical industry, etc. It has played a good role in replacing wood with steel, efficient construction, energy saving and pollution prevention.

In addition to zinc protection, the organic coating on the zinc layer acts as a covering and isolation function for the color steel plate with galvanized steel plate as its base plate, which can prevent the steel plate from rusting and has a longer service life than that of galvanized steel plate. It is reported that the service life of the coated steel plate is 50% longer than that of galvanized steel plate. However, the service life of color coated sheets with the same galvanizing amount, the same coating and the same coating thickness will vary greatly in dfferent areas and different parts of use.

For example, in industrial areas or coastal areas, due to the effect of sulfur dioxide gas or salt in the air, the corrosion rate is accelerated and the service life is affected. During the rainy season, the coating will be corroded quickly and its service life will be reduced if it is wetted by rainwater for a long time or where the temperature difference between day and night is too large and condensable. Buildings or factories made of coloured steel plates often have longer service life when washed by rainwater. Otherwise, they will be affected by sulfur dioxide gas, salt and dust.

Therefore, in the design, the more inclined the roof is, the less easy it is to accumulate dirt and other dirt, and the longer the service life. For those areas or parts that are not washed by rainwater, regular water should be used to wash them.