High coating softening, corrosion medium easy to adhere, easy to penetrate into the color steel plate substrate, high temperature water oxygen content will increase, at a certain temperature corrosion speed.
The corrosion of the substrate at the notch and processing damage belongs to electrochemical corrosion, and it is not easy to form corrosion cell (i.e. electrochemical circuit) due to low humidity.
Three temperature difference
temperature difference is easy to condense, forming galvanic corrosion on the bare metal. In addition, large temperature difference also leads to frequent cold and hot deformation of the coating, which will accelerate the aging and loosening of the coating
of color steel plate, and the external corrosive medium is easy to penetrate into the substrate.
UV spectrum belongs to high frequency ray, which has more destructive power than low energy spectrum. X-ray can penetrate, γ -
ray can break chemical bond and produce free charged ions, which are fatal to organic matters. Therefore, it can be seen from the above that the time and intensity of sunlight affect the structural stability of the coating, especially in the areas with
Five. Rai water
Heavy rainfall and acidity will certainly corrode steel. However, the rainfall has a dual effect on the wall color steel plate and the roof color steel plate with large slope, which can clean the surface
of the steel plate and wash away the surface corrosion; but for the roof plate with low slope and the part with poor drainage, the rainfall is large, which is easy to cause the corrosion to intensify.
Six. Wind direction
Similar to water,
and often accompanied by it, it is a test for the connection parts of materials, because the wind will cause the connection parts to loosen, and rainwater will penetrate into the interior of the building.
such as chloride ions and sulfur dioxide, accelerate the corrosion. Most of these sediments occur in coastal areas and areas with serious industrial pollution (such as power plants, smelters, etc.).
8、 Link mode
Generally, there are overlapping,
undercutting and buckling. The selection of fastener material requires that its corrosion resistance is better than that of color steel plate, otherwise, according to the principle of large cathode and small anode, the interface will corrode and wear
out quickly. Secondly, the quality of sealant should also be guaranteed.
The orientation and slope of the building affect the sunshine time, thus affecting the durability of the coating. The slope also affects the settling time
of corrosive medium or dust on the color steel plate.