The effect of Cr₂O₃ scale on electrical conductivity of Cobalt-spinel-coated ferritic stainless steel

One of the most effective approaches to improve the interconnect properties is to apply surface coatings to provide better conductivity, reduced scale growth and Cr volatility. In this study AISI 430 ferritic stainless steel interconnect was coated in a cobalt-base pack mixture by pack cementation. The effect of oxide thickness on the Electrical conductivity was investigated by applying isothermal oxidation. This effect was also investigated in different temperatures (400–700°C). The formation of MnCo₂O₄, CoCr₂O₄, CoFe₂O₄ and Co₃O₄ spinels during oxidation improved oxidation resistance and electrical conductivity. Results exhibited that the increase of isothermal oxidation time and increase of temperature, increased the oxide thickness and this decrease the electrical conductivity.