At present, the main anti-corrosion steel of the solar mounting bracket is hot-dip galvanized 55-80μm, and the aluminum alloy is anodized 5-10μm.
In the atmosphere, the aluminum alloy is in the passivation zone, and a dense oxide film is formed on the surface, which hinders the contact of the surface of the active aluminum substrate with the surrounding atmosphere, so it has very good corrosion resistance and the corrosion rate increases with time. And decrease.
Steel under normal conditions (C1-C4 environment), 80μm galvanized thickness can guarantee the use of more than 20 years, but in high humidity industrial area or high salinity beach or even temperate sea water, the corrosion rate is faster, the galvanizing amount needs 100μm, Above and requires regular maintenance every year.
Aluminum is far superior to steel in terms of corrosion protection.
Second, other aspects of comparison
(1) Appearance: There are many kinds of surface treatment methods for aluminum solar panel mounting brackets, such as anodizing, chemical polishing, fluorocarbon spraying, and electrophoretic painting. The appearance is beautiful and can adapt to a variety of environments with strong corrosive effects.
Steel solar racking is generally hot dip galvanized, surface sprayed, painted and coated. The appearance is worse than the aluminum alloy profile. It is also inferior to aluminum profiles in terms of corrosion protection.
(2) Cross-section diversity: The general processing methods of aluminum alloy profiles include extrusion, casting, bending, and stamping. Extrusion production is the current mainstream production method. By opening the extrusion die, any arbitrary section profile can be produced, and the production speed is relatively fast.
Steel is generally rolled, cast, bent, stamped, etc. At present, roll pressing is the mainstream production method for producing cold-formed steel. The cross-section needs to be adjusted by the roller set, but the general machine can only produce similar products after the shaping, the size is adjusted, and the cross-sectional shape can not be changed, such as C-section steel, Z-shaped steel and other sections. The rolling production method is relatively fixed and the production speed is relatively fast.
Third, the comprehensive performance comparison
(1) The aluminum alloy profile is light in weight, beautiful in appearance and excellent in corrosion resistance. It is generally used for roof power stations and strong corrosive environments where load bearing is required. For example, Baowei color steel plate system and chemical plant power station use aluminum alloy as the bracket. There will be better results.
(2) The steel has high strength and is less deformed under load, and is generally used for power stations under normal conditions or for components with relatively large forces.
(3) Cost: Under normal circumstances, the basic wind pressure is 0.6kN/m2 and the span is less than 2m. The cost of the aluminum alloy bracket is 1.3-1.5 times that of the steel structure bracket. In the small-span system, the cost of the aluminum alloy bracket and the steel structural bracket (such as the color steel roof) is relatively small, and the aluminum alloy is much lighter than the steel bracket in terms of weight, so it is very suitable for the roof power station.