Galvalume is a high-performance metallic coating applied to steel, though technically it is not galvanizing, but an alloy coating process that is gaining traction for certain tubular applications.
Composition and Superiority
Galvalume, is an alloy coating composed of approximately Aluminum, Zinc, and Silicon. The process is similar to hot-dip galvanizing, where the steel is immersed in a molten bath, but the bath composition is fundamentally different.
The addition of aluminum provides a superior barrier layer, which slows down the rate of corrosion compared to pure zinc (galvanized) coatings.
Dual Protection: Galvalume provides barrier protection (from the aluminum) and sacrificial (cathodic) protection (from the zinc).
Application: Due to its exceptional corrosion resistance, Galvalume is highly favored for roofing, siding, and certain structural tubing where longevity in aggressive environments is paramount, often outlasting standard galvanized steel by several years.
While standard galvanizing (pure zinc) is more common for welded pipe where deep penetration is needed, Galvalume offers solution for pre-coated strip used in formed tubing.