I. impact of natural environment (different regions)
The choice of painted steel plates in different areas mainly considers the local snow load and corrosion environment. Wind and snow load is mainly concerned with the safety factor of the building, which is related to the mechanical properties of the painted steel plate, but more related to the shape and thickness of the pressed steel plate and the connection between the plates. It is difficult to describe the corrosion environment quantitatively. For example, temperature, humidity, temperature difference between day and night, duration and intensity of sunshine, rainfall and acidity of rainfall, wind direction and speed, corrosive deposition, etc.
Color coated steel corrosion factors
They are coating type, coating thickness, coating supplier, coating type, coating thickness, pretreatment type, steel plate thickness, coating structure, etc.
Influence of construction design on corrosion
Installation or processing quality: it is mainly reflected in whether the coating is damaged during processing, whether the coating is brittle under low temperature processing, dragging the steel plate during installation leads to damage, when the installation of the structure welding iron chips fell on the coating, construction is not finished cleaning the roof board, etc., which will cause corrosion of the material.
Based on the above introduction of corrosion factors of painted steel plates, feedback from users and analysis of exposure test results, our Suggestions for different areas are as follows:
Highland of the ultraviolet (uv) strong (southwest and northwest) and low latitudes (guangdong and south) consider colorized painting steel should choose superior durability of coating (PVDF coating layer, HDP coating, SMP, etc.), in high temperature and high humidity areas (where most of the southern coastal) coating and coating will choose superior corrosion resistance of the material, coating thickness and coating thickness must be at least meet the national standard requirements.
In the seaside use color coated steel plate, the need for thick coating color coated steel plate or coating relatively dense coating species, because the chloride ion permeability in seawater is very strong, it can be directly through the thin coating or not dense coating corrosion of the substrate coating, of course, the substrate must be galvanized or coated aluminum zinc material. Painted steel plates are not recommended where sea water can splash.
In the industrial environment, the main impact on color coating is acid rain, these areas concentrated in hunan, chongqing, jiangxi and other areas, contact the use of high zinc coating zinc substrate color coating, color coating is still required to be thick and dense. In other areas that do not belong to the above, the choice of color coated steel plate is relatively large, as long as it meets the color coated national standards.