Asia Pacific Industries

Hot-Dip Galvanising (HDG)

A corrosion protection process where fabricated steel is immersed in molten zinc to form a durable, metallurgically bonded coating.

Hot-dip galvanising is the most common corrosion protection method for structural steel in Australia. The process involves immersing clean, fabricated steel in molten zinc at approximately 450°C. The zinc reacts with the steel to form a series of zinc-iron alloy layers topped with a layer of pure zinc. This provides both barrier protection and galvanic (sacrificial) protection — the zinc corrodes preferentially to the steel. Coating thickness is specified by AS/NZS 4680, typically 45-85μm depending on the steel thickness.

Related Terms

Steel Corrosion ProtectionDuplex CoatingPaint Systems

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