What is Galvalume Sheet (Aluminized Steel)?

Galvalume sheet, also known as aluminized steel, is a type of metallic coated steel product. While the previous text described the 55% aluminum alloy (ASTM A792), this specific type—often referred to as Type 1 Aluminized Steel—features a coating consisting of 90% aluminum and 10% silicon.

This material is manufactured through a hot-dip process similar to galvanization but offers superior performance in high-temperature and corrosive environments.

Composition and Structure

The coating is primarily composed of:

• 90% Aluminum: Provides excellent barrier protection and heat resistance.
• 10% Silicon: Improves the adhesion of the coating to the steel substrate.

Key Performance Characteristics

1. Heat Resistance
Thanks to the unique combination of the steel substrate and the aluminum-silicon coating, galvalume sheet exhibits exceptional耐高温性.

• It maintains a high reflectivity at temperatures up to 450°C.
• The coating remains intact and protects the steel from oxidation up to 650°C.

2. Thermal Reflectivity
At high temperatures (e.g., 480°C), the material can reflect approximately 80% of incoming heat. This makes it an ideal choice for thermal reflectors and insulation barriers in furnaces and heaters, allowing for rapid temperature rise within the chamber.

3. Mechanical Strength

• At room temperature, its mechanical strength matches that of the base steel.
• At elevated temperatures (480°C), its strength is 10 times that of pure aluminum. This allows for the use of thinner gauges (reducing thickness by at least 30%) while maintaining structural integrity.

4. Corrosion Resistance
During the manufacturing process, the molten aluminum instantly reacts with oxygen in the air to form a dense Al₂O₃ (aluminum oxide) protective layer. This layer is:

• Stable and insoluble in water.
• Self-healing: If the surface is scratched, the aluminum in the coating will oxidize to repair the damaged area, preventing further corrosion.

5. Eco-Friendly Properties

• Non-toxic: Unchemically钝化的 (passivated) aluminized steel is harmless to human health, making it suitable for food processing equipment (ovens, bread boxes, cookware).
• Recyclable: It is fully recyclable and considered an environmentally friendly product.
• Cost-Effective: It offers performance comparable to stainless steel at roughly one-third the cost.

6. Workability

• Welding: Can be welded using standard MAG and TIG welding techniques.
• Forming: Suitable for drawing, stamping, and tube drawing processes.
• Appearance: The coating maintains a lasting luster and superior weatherability.

Applications

Due to its excellent耐蚀性, heat resistance, and strength, it is widely used in:

• Automotive: Mufflers, exhaust pipes, and oil tanks.
• Industrial Equipment: Burners, heat exchangers, dryers, and air conditioners.
• Household Appliances: Water heaters, gas stoves, microwave ovens, food processing machinery, and cooking utensils.
• Construction: Roofing, walls, ceilings, and other insulation components.