Co-WO3 composite coating on ferritic stainless steel interconnects

Abstract

In order to apply Co-WO3 composite coating to SUS 430 steel interconnects for solid oxide fuel cell (SOFC) interconnects, a combination of electrophoresis and electroplating is used, followed by thermal energy exposure to ambient temperature at 800 ℃ for up to 5 weeks. The thermal growth of the oxide scale displays a tri-layer structure with a Cr2O3 layer in the inner part, a CoWO4 layer in the middle and (Co,Fe)3O4 and Co3O4 layer in the outer part. Co-WO3 coating produces an oxide layer that not only prevents Cr2O3 development and outward transport of Cr species but also enhances the electrical behavior of the surface scale.

Keywords

• Co-WO3 composite coating
• CoWO4
• Electrophoresis-electroplating
• Oxidation
• Area specific resistance