Galvalume Steel Coil and Galvanized Steel Coil DX51D+Z DX53D+Z DX54D+Z

Al-Zn Coated Steel Coil is a common metal material widely used in construction, home appliances, automobile manufacturing and other fields. It combines the strength of steel with the corrosion resistance of aluminum and zinc by coating an aluminum-zinc alloy layer on the surface of a steel substrate.

• Basic composition of Al-Zn Coated Steel Coil

The substrate of Al-Zn Coated Steel Coil is a cold-rolled steel sheet, and a layer of aluminum-zinc alloy is coated on the surface through a hot-dip coating process. The typical coating composition is 55% aluminum, 43.4% zinc and 1.6% silicon. The addition of silicon helps to improve the bonding strength between the coating and the steel substrate and prevent the coating from peeling off. The coating thickness of Al-Zn Coated Steel Coil is

usually between 10 and 30 microns, depending on the application requirements.

• Comparison between Al-Zn Coated Steel Coil and Other Coated Steel Coil

(1) Comparison with Galvanized Steel Coil

The coating composition of galvanized steel coil is pure zinc. Although it has good corrosion resistance, it corrodes faster in certain environments (such as high humidity and high salt environments). In contrast, the aluminum-zinc alloy layer of galvanized steel coils can form a denser oxide film, with stronger corrosion resistance and longer service life. The addition of aluminum makes galvanized steel coils more stable in high temperature environments, while pure zinc is easily oxidized and ineffective at high temperatures.

(2) Comparison with aluminum-coated steel coils

The coating of aluminum-coated steel coils is pure aluminum, and its high temperature resistance is worse than that of galvanized steel coils, but its corrosion resistance in normal atmospheric environments is not as good as that of galvanized steel coils. The zinc in the aluminum-zinc alloy can provide cathodic protection. Even if the coating is partially damaged, the zinc will corrode first and protect the steel base from rust. The pure aluminum coating does not have this property. Once damaged, the steel base is prone to rust.

(1) Strong corrosion resistance

The corrosion resistance of galvanized steel coils is better than that of ordinary galvanized steel coils, especially in coastal areas or environments with heavy industrial pollution. Experimental data show that under the same environment, the service life of galvanized steel coils can reach 2 to 4 times that of ordinary galvanized steel coils.

(2) Good heat resistance

Alu-zinc coated steel coils can withstand temperatures around 300°C, while ordinary galvanized steel coils are easily oxidized and fail at high temperatures. This feature makes them suitable for certain occasions that require high temperature resistance, such as chimneys, oven shells, etc.

(3) Beautiful surface

The surface of the galvanized steel coil has a unique silver-gray metallic luster, which is more beautiful than ordinary galvanized steel coils and is suitable for use in places such as building exterior walls and roofs where high aesthetic requirements are required.