Oxide scale behaviour on aluminium and steel under hot working conditions

Elevated temperature exposure to air of aluminium alloys and steel during thermomechanical processing inevitably results in oxide scales forming on the surface. With carbon and low alloy steels, the oxide scale is distinct and relatively easily removed from the surface in between hot rolling passes or when cooling down after rolling. The scale can behave in a brittle or ductile manner. The oxide scale that forms on aluminium alloys is much more tenacious. There is also strong evidence of the plastic deformation which results in intermixing of the surface metal and oxide scale, leading to a complex subsurface layer. This paper contrasts these two metals’ behaviour, based on laboratory measurements and computer-based simulations