Effects of heating atmosphere and steel chemistry on delamination of the surface layer of aluminized steel

► Aluminized layer delaminates from steel after heating at 950 °C in N2-rich atmosphere. ► Voids forms in aluminized layer by diffusion between Al and Fe. ► N2 reacts with Al on the void surfaces to form AlN which spoils the adhesion. ► Steel chemistry also affects the occurrence of delamination. ► Delamination is suppressed for steel containing Cr and Mo.