Characterization of alumina scale formed on FeCrAl steel

Abstract

In this paper the morphology of the oxide scale formed at 850°C on the foil surface of FeCrAl steel is described. Two types of samples have been used: one covered with an Al nano-layer and the second without. Microscopic observations of the cross-sections of scales have demonstrated that in the case of foil without Al nano-layer there is a remnant of an amorphous Al 2O3 nano-layer, from which γ and θ crystallites of Al2O3 have been grown. In the case of foil covered with the Al nano-layer, α-Al2O3 phase is present and θ-phase forms a forest of whiskers on the surface.