Effect of (La0.8Sr0.2)CrO3 Coating on Carbon Deposition onto a Stainless-Steel (SUS430) Substrate

In this study, a dense strontium‐doped lanthanum chromite (La0.8Sr0.2CrO3, LSC) thin layer was designed to protect a stainless‐steel (SUS430) substrate from carbon deposition. The LSC layer was coated onto an SUS430 substrate by a dipping technique from a precursor solution of La, Sr and Cr nitrates, acetylacetone (acac), and 2‐methoxyethanol. The effect of AcAc on the phase behavior and microstructure evolution of the LSC thin films was investigated. After being heat‐treated at 800°C in air, the thin film was found to consist of perovskite LaCrO3, Mn1.5Cr1.5O4, and Cr2O3 phases. The addition of a chelating agent, acac, to the precursor solution led to a reduction in the formation of the strontium chromite (SrCrO4) phase. As a consequence, a thin film having a dense microstructure could be obtained. It was confirmed by Fourier‐tranform Raman spectroscopic analysis and FESEM observations that the carbon deposited on the uncoated SUS430 substrate was amorphous with a spherical morphology. The LSC thin film thus obtained was found to be very effective at preventing carbon deposition when it was heat‐treated under a dry hydrocarbon atmosphere.