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Last edited 04 Apr 2022

Galvalume

Galvalume (GL) is a kind coating consisting of of 43.4% zinc, 1.6% silicon, and 55% aluminium that performs the role of protecting metals from oxidation.

Advantages:

Excellent resistance to corrosion. The corrosion resistance of galvalume products is mainly associated with the protective functions of aluminium. When the zinc starts to degrade, the aluminium will form a thick alumina layer which prevents further corrosion of the materials inside. Its corrosion resistance is 3 times that of galvanized sheet.
High heat reflectivity. The thermal reflectivity of GL sheet is very high, twice that of galvanized steel sheet, and it is often used as a thermal insulation material. roofing sheet is suitable for hot climates.
Heat resistance. Galvalume steel has impressive heat resistance that will withstand temperatures that exceed 300 degrees , so it is often used in chimney pipes, ovens, luminaires, and fluorescent lampshades.
Appearance: The surface of the GL steel sheet is smooth with beautiful and uniform spangles, and the base colour is silver white, so it can be used as cladding.
GL coating has good adhesion to paint film so it can be the substrate for PPGL (pre-painted galvalume) steel.
It has good processing performance and can be punched, sheared, welded, etc. for other uses.

Disadvantages:

High cost: GL coil is more expensive than galvanized, HR and CR coils.
Thickness: The option of coating thickness and coil thickness is limited. The sheet thickness ranges between 0.2-4mm generally.
Not-suited for livestock facilities: GL coil is widely used in building materials, household appliances, automobiles, machinery, ships and so on. But it should not be used for animal confinement spaces. Galvalume coil will corrode faster than galvanized metal when exposed to animal urine.