High Temperature Oxidation Effect on the Dissolution Rate of Hot-Dip Aluminized Steel in Aluminum Melt

Abstract

Hot dip aluminizing of low carbon steel followed by high temperature oxidation in air was carried out to evaluate the dissolution rate of coated sample in molten aluminum. The microstructure of oxide and aluminide layers was investigated using scanning electron microscopy and X-ray diffraction methods. The characterization of the coating showed that Fe2Al5 has been the major phase formed on the surface of specimen before high temperature oxidation. Isothermal oxidation of the coating as resulted in the formation of Al2O3 while Fe2Al5 phase transformed into FeAl and Fe3Al phases. The coated samples were further subjected to corrosion in molten aluminum. It was proved that the oxide layer formed on the coating and developed FeAl and Fe3Al intermetallic phases play the major role in protecting the specimen from corrosion in molten aluminum.