At high temperature, the coating is easy to soften, and the corrosive medium is easy to adhere. It is easy to penetrate into the substrate, the oxygen content of the water will increase at high temperature, and the corrosion rate will be accelerated at a certain temperature.
The corrosion of the substrate at the incision and processing damage of the color-coated plate belongs to electrochemical corrosion, and it is not easy to form a corrosion battery (ie, an electrochemical circuit) when the humidity is low.
The temperature difference between day and night.
A large temperature difference is easy to condense, forming galvanic corrosion conditions on the exposed metal. In addition, a large temperature difference also leads to frequent hot and cold deformation of the coating, which will accelerate the aging of the coating and loosen, and the external corrosive medium will easily penetrate into the substrate.
Sunshine time and sunshine intensity.
Orientation and slope affect the duration of sunlight, which in turn affects the durability of the coating. The slope also affects the settling time of corrosive media or dust on the steel plate. Sunlight is an electromagnetic wave, which is divided into gamma rays, X rays, ultraviolet rays, visible light, infrared rays, microwaves and radio waves according to the level of energy and frequency. Waves and radio waves have low energy and do not interact with matter. Infrared is also a low-energy spectrum, and it can only stretch or bend the chemical bonds of substances, not break them. Visible light gives everything a rich color. UV-ultraviolet spectrum is a high-frequency ray, which has greater destructive power than low-energy spectrum. Skin dark spots and skin cancer as we know are caused by the sun’s ultraviolet rays. Likewise, UV can break the chemical bonds of substances, breaking them. It depends on the wavelength of the UV and the chemical bond strength of the substance. X-rays have a penetrating effect, and gamma rays can break chemical bonds and generate free charged ions, which are deadly to organic matter. Fortunately, these rays are rare in sunlight. Therefore, it can be seen from the above that the duration and intensity of sunlight affects the structural stability of the coating, especially in areas with strong UV rays.
Rainfall and rainfall acidity.
Rainfall acidity is undoubtedly detrimental to corrosion resistance. However, rainfall has a dual effect. For wall panels and roof panels with large slopes, rainfall has the effect of cleaning the surface of steel plates and washing away surface corrosion products, but for low-slope roof panels and parts with poor drainage, heavy rainfall It is easy to cause corrosion aggravation.
Wind direction and wind speed.
The effect of wind direction and speed is similar to that of water, and it is 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, sulfur dioxide, etc., all have an accelerated effect on corrosion, and these sediments mostly occur in the seaside and areas with serious industrial pollution (such as power plants, smelters, etc.).