Corrosion test results and application of coil coated Galfan

CIM Bulletin, Vol. 80, No. 905, 1987

F.E. GOODWIN,International Lead Zinc Research Organization, Inc. New York, N.Y., A.F. SKENAZI, Centre de Recherches Metallurgiques Liege, Belgium and R.F. LYNCH, Zinc Institute Inc., New York, N.Y.

The Galfan alloy has been developed for continuous galvanizing of steel. The choice of the eutectic zinc-aluminum alloy with addition of mischmetal gives a coating with specific characteristics as far as structure, analysis, surface chemistry and surface morphology are concerned. The performance of the uncoated Galfan coating is superior when compared to conventional galvanized particularly for corrosion resistance and ductility. For coil coating applications, these two assets are of the utmost importance but in order to benefit from these two advantages, good paint adherence and high resistance to edge creep and blistering have to be obtained. Despite Galfan's unique features compared to other zinc based or aluminum-zinc based coatings, existing pretreatments and painting conditions are used with only minor modifications in order to assure good adherence and edge creep resistance. With compatible processing, Galfan can outperform galvanized and Galvalume as a substrate for coil coating as is demonstrated with various test results.

Keywords: Metallurgy, Galfan, Corrosion resistance, Coil coating, Galvalume.