Improved oxidation resistance of ferritic steels with LSM coating for high temperature electrochemical applications

The effect of single layer La0.85Sr0.15MnO3−δ (LSM) coatings on high temperature oxidation behaviour of four commercial chromia-forming steels, Crofer 22 APU, Crofer 22 H, E-Brite and AL 29-4C, is studied. The samples were oxidized for 140–1000 h at 1123 K in flowing simulated ambient air (air + 1% H2O) and oxygen and corrosion kinetics monitored by mass increase of the materials over time. The oxide scale microstructure and chemical composition are investigated by scanning electron microscopy/energy-dispersive spectroscopy. The kinetic data obey a parabolic rate law. The results show that the LSM coating acts as an oxygen transport barrier that can significantly reduce the corrosion rate.

► The LSM coating is dense and evenly distributed on the sample surface.
► The parabolic rate constant for steel oxidation is significantly reduced.
► The LSM coating serves as a transport barrier for oxygen.