Product details table:

Physical and chemical properties:

Physical properties

Appearance:

Galvanized steel sheets typically have a metallic silver-gray appearance, with a smooth surface and a distinctive glossy finish due to the zinc coating. The surface can be further treated with processes like chromating or painting to achieve different aesthetic effects or enhance corrosion resistance.

Density:

The density of galvanized steel sheets is generally around 7.85 g/cm³, which is slightly higher than that of pure iron due to the added zinc layer. For example, the density of a standard galvanized steel sheet is approximately 7.85 g/cm³, making it heavier than some other coated metals but still suitable for structural applications.

Melting point:

The melting point of galvanized steel sheets depends on the base steel material, typically ranging between 1370-1510℃. The zinc coating itself has a much lower melting point (around 420℃), but the steel substrate ensures stability in high-temperature environments.

Coefficient of thermal expansion:

The coefficient of thermal expansion is relatively moderate. For galvanized steel sheets, the coefficient of thermal expansion is approximately 11.7×10⁻⁶/℃ (at room temperature). This characteristic allows them to maintain dimensional stability under varying temperatures, though care must be taken during extreme temperature changes to avoid warping.

Thermal conductivity:

The thermal conductivity of galvanized steel sheets is relatively high compared to stainless steel, with a coefficient of about 50-60 W/(m·K). This makes them effective in applications requiring heat dissipation, though they are not as thermally conductive as pure copper or aluminum.

Electrical conductivity:

Galvanized steel sheets have low electrical conductivity due to the insulating effect of the zinc coating. The electrical conductivity is significantly lower than that of pure copper, making them unsuitable for electrical transmission but still useful in grounding applications.

Chemical properties

Corrosion resistance:

One of the key advantages of galvanized steel sheets is their excellent corrosion resistance. The zinc coating acts as a sacrificial anode, protecting the underlying steel from rust and oxidation. For example, galvanized steel sheets perform well in outdoor environments exposed to rain, humidity, and mild chemical exposure. However, in highly corrosive environments such as marine or industrial settings, additional protective coatings may be required.

Antioxidation:

Galvanized steel sheets exhibit good oxidation resistance due to the protective zinc layer. At room temperature, the zinc coating forms a stable oxide film that prevents further oxidation of the steel substrate. However, at high temperatures above 200℃, the zinc layer may degrade, reducing its protective properties.

Chemical stability:

In general chemical environments, galvanized steel sheets show moderate chemical stability. They resist mild acids, alkalis, and atmospheric pollutants effectively. However, strong acids (e.g., sulfuric acid) and bases can damage the zinc coating, compromising the sheet’s corrosion resistance.

Passivation:

While galvanized steel sheets do not undergo traditional passivation like stainless steel, the zinc coating naturally forms a protective layer when exposed to air. This layer can self-heal minor scratches or damages, providing continuous protection. Additional treatments, such as chromate passivation, can further enhance the durability and corrosion resistance of the zinc coating.

Application:

Galvanized steel sheets are widely used across various industries due to their excellent corrosion resistance, cost-effectiveness, and ease of fabrication. In construction, they are commonly used for roofing, wall cladding, and structural framing, offering durability and weather resistance. In the automotive industry, they are used for car bodies and components to prevent rust. In the agricultural sector, they are used for silos, fences, and water tanks due to their resistance to environmental exposure. Additionally, galvanized steel sheets are indispensable in manufacturing appliances, HVAC systems, and electrical enclosures, where they provide reliable performance in diverse working conditions.