Protective coatings for AISI 430 stainless steel at high temperatures using perovskite oxides La0.6Sr0.4CoO3 on spinel type oxide NiFe2O4

Although oxide coatings of perovskite type deposited on ferritic stainless steel AISI 430 provide an efficient barrier to oxygen diffusion, they have shown degradation at high temperatures by formation of intermediate phases with chrome. Other coatings, such as oxide of spinel type, form an effective barrier to the diffusion of chromium; however, they do not prevent oxygen diffusion into the substrate. In this context, in order to protect against oxidation at high temperatures ferritic stainless steel AISI 430 for application as interconnects in ITSOFC, the present work aimed to develop dual layer coatings obtained by deposition of a perovskite oxide, La0.6Sr0.4CoO3, on the coating of a spinel oxide NiFe2O4. The results showed that the combination of oxide coatings increases oxidation resistance of the ferritic stainless steel and it tends to prevent degradation of the perovskite, which is caused by the diffusion of chromium from substrate to coating creating undesired phases.