Influence of oxide scale thickness on electrical conductivity of coated AISI 430 steel for use as interconnect in solid oxide fuel cells

Abstract

The use of conductive coating on interconnect ferritic stainless steel can reduce electrical resistivity. In this study, an AISI 430 ferritic stainless steel interconnect was coated with a manganese base pack mixture by pack cementation. The effect of oxide scale thickness on electrical conductivity was evaluated by applying isothermal oxidation at 750 °C. This effect was also investigated at different temperatures (400–900 °C). The formation of manganese spinels during annealing improved the oxidation resistance and electrical conductivity. Results showed that the increase in isothermal oxidation time and temperature increased the oxide thickness, and this resulted in the relatively low values of electrical conductivity. Manganese spinels enhanced the electrical conductivity and oxidation resistance of coated substrates as compared to uncoated substrates.