Effect of KCl deposits in high‐temperature corrosion on chromium‐rich steels in SO2‐containing atmosphere

Abstract High‐temperature corrosion was studied under multiple chemical loads on ferritic‐austenitic model alloys (Fe–13Cr, Fe–18Cr–12Ni, and Fe‐25Cr–20Ni) with KCl deposit under 0.5% /99.5% Ar gas atmosphere at . Postexposure characterization was done by X‐ray diffraction and scanning electron microscopy. In a pure /Ar environment a protective scale was formed by all samples. The introduction of KCl deposits causes the scale to be nonprotective and multilayered, consisting of CrS, FeS, , and . The impact of the microstructure and alloying elements is discussed.