Co/LaCrO3 composite coatings for AISI 430 stainless steel solid oxide fuel cell interconnects

Rapidly decreasing electronic conductivity, chromium volatility and poisoning of the cathode material a re the major problems associated with inevitable growth of chromia on ferritic stainless steel interconnects of solid oxide fuel cells (SOFC). This work evaluates the performance of a novel, electrodeposited composite Co/LaCrO3 coating for AISI 430 stainless steel. The oxidation behaviour of the Co/LaCrO3-coated AISI 430 substrates is studied in terms of scale microstructure and growth kinetics. Area-specific resistance (ASR) of the coated substrates has also been tested. The results showed that the Co/LaCrO3 coating forms a triple-layer scale consisting of a chromia-rich subscale, a Co-Fe spinel mid-layer and a CO3O4 spinel top layer at 800 degrees C in air. This scale is protective, acts as an effective barrier against chromium migration into the outer oxide layer and exhibits a low, stable ASR of similar to 0.02 Omega cm(2) after 900 h at 800 C in air. (c) 2008 Elsevier B.V. All rights reserved.