Aluminized zinc steel sheets are widely used in various industries due to their excellent properties, particularly their high corrosion resistance. In fact, aluminized zinc sheets are three times more resistant to corrosion compared to pure galvanized sheets. Their surface features beautiful zinc flowers, and they are made from a combination of metallic elements like zinc and aluminum. If the zinc wears off over time, aluminum forms a dense oxide layer that prevents further corrosion, thereby extending the material’s lifespan. However, welding performance can be a bit challenging. The corrosion resistance of 55% aluminum-zinc alloy steel plates depends on the passivation layer formed by aluminum and the protective function of zinc. When zinc is scratched or damaged, aluminum forms an insoluble oxide layer on the steel’s surface, offering barrier protection. Tests in various regions such as rural areas, industrial zones, general coastal regions, and severe marine areas have shown that the corrosion resistance of 55% aluminum-zinc is 2-6 times better than that of galvanized steel, given the same coating thickness.
How Does Galvanized Steel Compare to Aluminized Zinc Steel in Terms of Performance?
Galvanized materials refer to metals or alloys coated with zinc, offering aesthetic appeal and rust prevention. The primary method for galvanization is hot-dip galvanizing, which results in a layer of zinc that protects the underlying steel from corrosion. Galvanized steel, commonly known as “white iron” in China, has been widely used in the construction industry and other applications. The galvanized coating reacts with oxygen, forming a protective oxide layer that isolates air and moisture to prevent further oxidation. Additionally, the galvanizing process provides cathodic protection, where zinc sacrificially corrodes to protect the exposed steel beneath.
Although most companies and factories use aluminized zinc in their products today, internally, some suppliers still consider galvanized steel a better option due to its faster self-healing ability. Galvanized steel provides greater protection after cutting, scratching, and other damage, while aluminized zinc may take longer to recover. Galvanized steel also offers significant advantages in preventing rainwater corrosion during transport.
What Makes Aluminized Zinc Steel Sheets Stand Out?
Aluminized zinc sheets are often made from G550 grade materials, and while there is no major difference in the material coefficients, aluminized zinc is generally more expensive than galvanized steel, depending on the market situation. As the use of aluminized zinc continues to rise, the production of galvanized steel has decreased, leading to lower inventory levels of galvanized steel in the market.
Key Characteristics of Aluminized Zinc Steel Sheets:
- High Thermal Reflectivity
Aluminized zinc steel sheets have a thermal reflectivity twice that of galvanized steel, making them an excellent choice for heat insulation applications. - Excellent Heat Resistance
These sheets can withstand temperatures exceeding 300°C, similar to the high-temperature oxidation resistance of aluminized steel. They are frequently used in chimneys, ovens, lighting equipment, and lampshades. - Superior Corrosion Resistance
The corrosion resistance of aluminized zinc steel sheets is primarily due to the protective function of aluminum. When zinc is worn off, aluminum forms a dense oxide layer that prevents further corrosion. - Cost-Effectiveness
Since the density of 55% aluminum-zinc alloy is lower than that of zinc, aluminized zinc steel sheets offer over 3% more surface area than galvanized steel of the same weight and coating thickness. - Paint Adhesion
Aluminized zinc sheets have excellent adhesion to paint and do not require pre-treatment or weathering processes. This makes them ideal for use in applications like signage and general-purpose sheets. - Aesthetic Appeal
The aluminized zinc steel sheets feature a sleek, silver-white surface that enhances the visual appeal of products. - Comparable Processing and Coating Performance
Aluminized zinc steel sheets offer similar processing and coating properties as galvanized steel, making them suitable for a wide range of applications.
