Protectiveness of Mn-Co Oxide Coating on Type 430 Stainless Steel for an SOFC Interconnect Application Using an Anodic Electrodeposition Technique

Ferritic stainless steels are widely used as interconnects of solid oxide fuel cells (SOFCs) due to their high temperature stability and thermal expansion similar to that of the electrolyte. To help commercialise SOFCs, commercial-grade ferritic stainless steel with a coating, i.e., Type 430, has been considered a promising material for this application. In this work, we developed a Mn-Co oxide coating via anodic electrodeposition followed by heat treatment processes in Ar and oxygen at 800 °C. The proposed coating helped reduce the formation of Cr-rich oxide at the interface between the coating and substrate relative to a sample coated without annealing in Ar. It also provided a relatively dense coating layer and better withstood the applied load, provoking the first spallation of the coating layer assessed by the scratch test. A diagram used to assess the effects of pore density and size on the coating’s protectiveness is included in the manuscript.