Anti-corrosion Principle of Hot-Dip Galvanized Steel in Curtain Wall Engineering: Dual Protection for Long-Term Reliability

Modern curtain wall engineering facades are constantly exposed to rain, salt spray, and high humidity. Supporting steel structures are highly prone to corrosion. Hot-dip galvanized steel, with its superior anti-corrosion performance, has become the preferred material for glass curtain walls and unitized curtain walls keels and connectors — delivering 20–50 years of maintenance-free service.

1. Hot-Dip Galvanizing Process

Clean steel is immersed in molten zinc at approximately 450°C, forming a series of zinc-iron metallurgical alloy layers. Unlike paint or electroplating, the coating metallurgically bonds with the steel substrate, offering extremely strong adhesion. Typical coating thickness reaches 70–120 μm (well above the GB/T 13912 standard requirement of ≥70 μm) and is highly resistant to scratching.

2. Dual Anti-corrosion Mechanisms

1. Physical Barrier Protection The dense zinc layer completely isolates oxygen, moisture, and corrosive media, reducing steel corrosion rate to 1/20 of bare steel.

2. Sacrificial Anode (Cathodic) Protection Zinc has a more negative electrode potential than iron. When the coating is locally damaged, zinc corrodes preferentially, forming a stable passivation film that “self-heals” the damage and fully protects the underlying steel.

3. Application Advantages in Curtain Wall Engineering

In southern humid or coastal projects, hot-dip galvanized steel (square/rectangular tubes, angles) demonstrates outstanding durability, maintains original mechanical properties, and is ideal for factory prefabrication and fast on-site installation — significantly lowering lifecycle maintenance costs.

ShunChen Steel Group specializes in producing hot-dip galvanized angles, channels, square/rectangular tubes, and other products. We strictly control zinc layer thickness and uniformity and have supplied numerous curtain wall engineering projects. We offer custom processing and 7-day response service to help clients achieve green building goals.