Evaluation of electrodeposited Fe–Ni alloy on ferritic stainless steel solid oxide fuel cell interconnect

Fe–Ni alloy is electrodeposited on ferritic stainless steel for intermediate-temperature solid oxide fuel cell (SOFC) interconnects application. The oxidation behavior of Fe–Ni alloy coated steel has been investigated at 800 °C in air corresponding to the cathode environment of SOFC. It is found that the oxidation rate of the Fe–Ni alloy coated steel becomes similar to that of the uncoated steel after the first week thermal exposure, although the mass gain of the coated steel is higher than that of the uncoated steel. Oxide scale formed on the uncoated steel mainly consists of Cr2O3 with (Mn,Cr)3O4 spinel. However, a double-layer oxide structure with a Cr-free outer layer of Fe2O3/NiFe2O4 and an inner layer of Cr2O3 is developed on the Fe–Ni alloy coated steel. The scale area specific resistance (ASR) for the Fe–Ni alloy coated steel is lower than that of the scale for the uncoated steel.