Difference Between Aluminized Sheet and Aluminum-Zinc Steel Sheet
Difference Between Aluminized Sheet and Aluminum-Zinc-Plated Steel Sheet
Corrosion Resistance
The zinc coating on a galvanized steel sheet is more chemically active than aluminum-zinc alloy, leading to lower corrosion resistance. Tests show that aluminum-zinc-plated steel sheets last over four times longer than galvanized steel under the same outdoor conditions.
The aluminum-zinc alloy layer consists of 55% aluminum, 43.4% zinc, and 1.6% silicon, solidified at 600°C. This composition forms a dense quaternary crystal structure, which creates a strong barrier against corrosion.
Characteristics of Aluminum-Zinc-Plated Steel Sheet
Superior Corrosion Protection
The 55% aluminum-zinc coating provides barrier protection from aluminum and sacrificial protection from zinc. Zinc protects exposed edges and scratches, while aluminum forms an insoluble oxide layer to block further corrosion. Outdoor exposure tests over 20 years confirm that an aluminized sheet offers better edge protection than galvanized steel.
Heat Resistance
Aluminum-zinc-plated steel sheets withstand up to 315°C, offering superior oxidation resistance compared to galvanized steel.
High Reflectivity
These sheets reflect heat effectively, twice as much as galvanized steel, making them ideal for roofing and panels where energy efficiency is needed.
Better Paintability
Paint adheres directly to the zinc layer of aluminum-zinc steel sheets without the need for pretreatment, unlike galvanized steel, which requires weathering and priming before painting.
Uses of Galvanized and Aluminum-Zinc Steel Sheets
Galvanized Steel Sheet Applications:
- Distribution cabinets: 1.2-2mm thickness
- Solar water heaters: 0.32mm thickness
- Anti-theft door panels
- Home appliance back panels
Protective Features of Galvanized Steel
Hot-dip galvanizing is commonly applied to steel sheets, strips, and wires to prevent atmospheric corrosion. Since zinc is more reactive than iron, it sacrifices itself to protect the steel, prolonging its lifespan.
Advantages of Aluminum-Zinc-Plated and Aluminized Sheets
Compared to galvanized steel, aluminum-zinc-plated steel provides stronger corrosion resistance and longer service life. Its dense aluminum-iron-silicon-zinc structure acts as a barrier, effectively preventing corrosion.
For industries looking for durable steel sheets, an aluminized sheet, or a reliable aluminized supplier, aluminum-zinc-coated steel is a superior choice.
