1. Corrosion Resistance
The corrosion resistance of 55% Al-Zn coated steel coils stems from the barrier protection provided by the aluminum and the sacrificial protection provided by the zinc. While zinc offers sacrificial protection at cut edges, scratches, and coating abrasions, the aluminum forms an insoluble oxide layer that acts as a protective barrier. Outdoor exposure tests spanning over 20 years in various atmospheric environments have confirmed that 55% Al-Zn coated steel sheets offer superior cut-edge protection compared to galvanized steel sheets and 5% Al-Zn coated steel sheets. The highly durable anti-corrosion coating ensures structural integrity for 90 years.
2. Heat Resistance
55% Al-Zn alloy coated steel sheets exhibit better heat resistance than galvanized steel sheets, with high-temperature oxidation resistance comparable to that of aluminized steel sheets. They can be used in high-temperature environments reaching up to 315°C.
3. Reflectivity
55% Al-Zn alloy coated steel sheets possess high reflectivity, serving as an effective heat barrier. Their thermal reflectivity is nearly double that of galvanized steel sheets; consequently, using them for roofing and paneling-even without painting-can achieve energy-saving results.
4. Paintability
Due to the excellent adhesion between the coating layer and paint, 55% Al-Zn coated steel sheets can be painted without the need for pre-treatment or weathering when used for signage or general applications, whereas galvanized steel sheets require both weathering and pre-treatment.
