Galvalumecoated

Galvalume-coated refers to steel or iron base metal that has been coated with an alloy of aluminum and zinc, typically 55% aluminum, 43.4% zinc, and 1.6% silicon. The coating is applied by a continuous hot-dip process, producing a protective layer that combines aluminum’s barrier properties with zinc’s sacrificial protection, improving corrosion resistance compared with plain zinc coatings.

Coated steel produced this way is commonly formed into coils or sheets for construction and manufacturing. The coating thickness and final finish are specified by product grades and market standards, and the material can be fabricated into panels, profiles, and other components. Galvalume coatings can be painted or left unpainted, depending on the application.

Uses include roofing and wall panels for commercial and residential buildings, metal roofing sheets, and other exterior components; automotive panels, appliances, and ductwork in some markets. It is valued for durability, ease of fabrication, and a bright, corrosion-resistant finish suitable for outdoor exposure.

Advantages include higher corrosion resistance than conventional galvanized steel in many environments, good formability, and heat reflectivity. The long-term performance depends on coating thickness, environment, and maintenance practices. Limitations can include storage-related issues such as white rust and paint adhesion challenges if the surface is not properly prepared before finishing.

Standards for galvalume-coated steel are defined in specifications such as ASTM A792/A792M, which covers aluminum-zinc-coated steel by the hot-dip process. Other regional standards may apply depending on market and application.