The ductility and strong anti-corrosion properties of galfan make it a coating highly suited for deep-drawn parts and parts requiring a high level of corrosion protection. In some applications, a 10 micron galfan coating can replace a 20 micron galvanized coating, providing better weldability, drawability, and corrosion resistance. Galfan can thus reduce costs, simplifying secondary processes and eliminating the need for post-treatment. It can be used to replace thick galvanized coating and post-galvanizing treatments.
Galfan has a cellular surface which appears mottled. Unpainted galfan acquires a patina over time, its initial metallic appearance dulls to a matte gray.
Cellular surface appearance - galfan
The coating, composed of 95% zinc and 5% aluminum, has a eutectic structure lending it excellent ductility and the thin intermetallic layer at the steel/coating interface guarantees excellent coating adhesion. These two properties enable galfan to be used for making components that are particularly difficult to form.
Micrographic cross-section and structure
The three surface finishes defined in the EN 10327 standard are available to suit customer requirements.
The standard galfan coating values and corresponding thicknesses are as follows:
|µm per side||Minimum nominal
g/m² both sides (3 pts)
Galfan is obtained by continuous hot-dip coating in a bath of molten metal made up of approximately 95% zinc and 5% aluminum.
In general, galfan has a higher corrosion resistance compared to a standard galvanized product. Sacrificial protection provides effective corrosion resistance at the sites of mechanical damage (impact, scratches, stone chipping) and also prevents corrosion of cut edges. Its superior corrosion resistance enables galfan to be an alternative to thicker galvanized coatings and post-galvanization treatments.
Full-side corrosion resistance during an automotive cyclical corrosion test
Example of resistance to salt spray: 5% NaCl
Due to its eutectic structure and the thin intermetallic layer, galfan is a ductile coating suitable for deep-drawing operations, without risk of cracking, delamination or contamination of the equipment by powdering. The use of pre-lubricating oils can further improve drawing properties.
Galfan performs well in spot welding with:
This advantage arises mainly in the case of applications where the corrosion resistance specified would require very high zinc values when using hot-dipped galvanized.
Comparison of electrode life