Improved oxidation resistance of a nanocrystalline chromite-coated ferritic stainless steel

An economical dip coating process was developed to synthesize uniform, crack-free, and adherent thin nanocrystalline LaCrO₃ films on a ferritic stainless steel substrate for the solid oxide fuel cell interconnect applications. LaCrO₃ perovskite phase was formed after annealing in air at 800 °C for 1 h for both the LaCrO₃ and La₂O₃ precursors. The effectiveness of the coating in improving the oxidation resistance of the alloy was demonstrated by both isothermal and cyclic oxidation tests. The LaCrO₃ coatings were found to cause a pronounced reduction in oxidation rate of the alloy, especially with low La-content precursors. The area-specific resistance of the oxide scales formed on the bare and coated alloy substrates was also evaluated and discussed.