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Effect of KCl deposits in high‐temperature corrosion on chromium‐rich steels in SO 2 ‐containing atmosphere
Author(s) -
Kingsbery Phillip,
StephanScherb Christiane
Publication year - 2022
Publication title -
materials and corrosion
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.487
H-Index - 55
eISSN - 1521-4176
pISSN - 0947-5117
DOI - 10.1002/maco.202112901
Subject(s) - metallurgy , microstructure , materials science , chromium , atmosphere (unit) , corrosion , austenite , scanning electron microscope , high temperature corrosion , austenitic stainless steel , diffraction , composite material , optics , physics , thermodynamics
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%SO 2${\text{SO}}_{2}$ /99.5% Ar gas atmosphere at560 ° C $560^\circ {\rm{C}}$ . Postexposure characterization was done by X‐ray diffraction and scanning electron microscopy. In a pureSO 2${\text{SO}}_{2}$ /Ar environment a protectiveCr 2 O 3${\text{Cr}}_{2}{{\rm{O}}}_{3}$ scale was formed by all samples. The introduction of KCl deposits causes the scale to be nonprotective and multilayered, consisting of CrS, FeS,Cr 2 O 3 , Fe 3 O 4${\text{Cr}}_{2}{{\rm{O}}}_{3},{\text{Fe}}_{3}{{\rm{O}}}_{4}$ , andFe 2 O 3${\text{Fe}}_{2}{{\rm{O}}}_{3}$ . The impact of the microstructure and alloying elements is discussed.