Oxidation Behavior of AISI 430 Ferritic Stainless Steel Coated with Ni-Co-TiO2

Ferritic stainless steels are used in high- temperature applications like solid oxide fuel cells. Application of steels in these conditions will expose them to severe thermal cycles. Therefore, it is essential to protect them at high temperatures. One of the most effective methods for increasing the life of these components against oxidation is the application of composite and ceramic coatings. In the present study, Ni-Co-TiO2 composite coating was deposited on AISI 430 steel substrate by electroplating to investigate the oxidation behavior at operating conditions of solid oxide fuel cells. To observe the morphology, scanning electron microscopy (SEM) and to determine the phases, X-ray diffraction (XRD) was used. For investigating the oxidation behavior of steel isothermal and cyclic oxidation tests were performed at 800 °C on the samples. Results showed that in isothermal and cyclic oxidation tests, due to the formation of Ni-Co spinels, coated samples showed less weight gain than uncoated samples. Spinel prevented outward Cr diffusion which improved the oxidation resistance of AISI 430 steel.