1.What is the protective principle of the galvanized layer?
Barrier protection: The dense zinc layer physically isolates the steel substrate from the corrosive media (oxygen, water, salt).
Sacrificial anode protection: Zinc has a more negative potential than iron. When the coating is damaged or scratched, zinc will corrode first, thus protecting the steel substrate and inhibiting the spread of rust even at small damage.
Passivation: Zinc corrosion products (such as basic zinc carbonate) form a dense, relatively stable protective film on the surface, slowing down further corrosion.
2.What challenges does the windy and sandy environment pose to galvanized steel supports?
Abrasive wear: High-speed wind carrying sand particles continuously impacts the surface of the bracket (especially the windward side and the part close to the ground), constantly grinding the galvanized layer and its corrosion product protective film like sandpaper.
Synergistic corrosion effect: Wear-corrosion coupling: Wear destroys the protective layer and accelerates corrosion; corrosion products (such as loose zinc salts) are more easily worn away by wind and sand, forming a vicious cycle.
Corrosive substances in sand particles: Sand and dust may contain salt (coastal, saline-alkali land), acidic or alkaline substances (industrial pollution, special soil), hygroscopic particles, which adhere to the worn surface or embed in the wear marks, which will significantly accelerate local corrosion.
Impact damage: Larger sand or gravel in strong winds may cause mechanical damage (pits, scratches) to the galvanized layer, becoming the starting point for corrosion.
3.What are the key factors affecting anti-wind and sand performance?
Galvanizing layer thickness (the most important factor): A thicker hot-dip galvanizing layer must be used! Common standards require a local minimum thickness of ≥ 85μm, and an average thickness of ≥ 100μm, or even as high as 120-150μm. The thicker the zinc layer, the stronger its wear resistance and long-term corrosion resistance.
Galvanizing quality: Uniformity: The zinc layer must cover all surfaces (including corners, welds, and inner surfaces) without defects such as missing plating, bubbles, and sagging.
Bonding strength: The zinc layer must be firmly bonded to the steel substrate and not easily peeled off under wear.
Steel matrix composition and surface condition: Standard bracket steel.
Surface treatment (pickling, plating assistance) before plating must be thorough to ensure the quality of the coating.
4.How does galvanized steel compare to other corrosion protection systems?
Better than ordinary carbon steel (uncoated): This is a qualitative leap. Ordinary carbon steel will quickly rust and perforate in a windy and sandy environment.
Better than ordinary anti-corrosion paint: The paint coating is easily worn and peeled off under strong wind and sand abrasion. Once damaged, the damaged point will quickly rust and spread. Even if the galvanized layer is worn, the sacrificial anode protection is still in effect.
5.What are the measures to improve the ability of galvanized steel supports to resist wind and sand?
Specify a sufficiently thick hot-dip galvanizing layer: This is the basic and most important measure (≥85μm local thickness).
Choose a high-performance coating: In projects with extremely severe wind and sand or requiring a life of more than 25 years, consider using zinc-aluminum-magnesium coating.
Strict quality control: Ensure that the thickness, uniformity and adhesion of the galvanizing layer meet the standards.