Oxidation behavior and electrical properties of de-siliconized aisi 430 alloy with mn1.5co1.5o4 coating for solid oxide fuel cell interconnect

Bakhshi Zadeh, A ; Sharif University of Technology | 2020

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  1. Type of Document: Article
  2. DOI: 10.1007/s11085-020-09962-x
  3. Publisher: Springer , 2020
  4. Abstract:
  5. Abstract: The effect of de-siliconization on the oxidation behavior of AISI 430 stainless steel used for solid oxide fuel cell interconnect application was investigated. De-siliconization treatment was conducted via heating steel parts in an H2 environment. The de-siliconized substrates were then coated with a Mn1.5Co1.5O4 spinel coating, using wet spray method. For comparison, a similar coating process was applied on the as-received AISI 430 stainless steel specimens. Oxidation kinetics of coated interconnects were evaluated at 700, 800 and 900 °C in air. Results showed that the de-siliconization surface treatment decreased oxidation rates, with kinetic rates (g2 cm−4 s−1) of 4.39 × 10−14 at 700 °C, 1.71 × 10−13 at 800 °C and 1.62 × 10−12 at 900 °C, i.e., 55, 48 and 22% lower compared to the as-received coated substrates, respectively. Scanning electron microscopy images and EDS analysis confirmed the formation of SiO2-rich layer beneath the surface oxide scale for the oxidized specimens. The thickness of the formed scale for the de-siliconized specimens was noticeably lower than that of as-received ones. Step-wise electrical conductivity measurements showed that the de-siliconized specimens, compared to the as-received specimens, had higher electrical conductivity (~ 30–40%), implying lower oxidation degrees of the substrate and thus, better electrical performance under cathodic service condition of SOFC. Graphic Abstract: [Figure not available: see fulltext.]. © 2020, Springer Science+Business Media, LLC, part of Springer Nature
  6. Keywords:
  7. De-siliconization ; Electrical properties ; Interconnect ; Oxidation ; SOFC ; Spinel ; Coatings ; Cobalt alloys ; Electric conductivity ; Electric properties ; Manganese alloys ; Scale (deposits) ; Scanning electron microscopy ; Silica ; Stainless steel ; Steel research ; Substrates ; Surface treatment ; AISI-430 stainless steels ; Electrical conductivity ; Electrical conductivity measurements ; Interconnect applications ; Scanning electron microscopy image ; Siliconization ; Solid oxide fuel cells (SOFC)
  8. Source: Oxidation of Metals ; Volume 93, Issue 3-4 , 2020 , Pages 401-415
  9. URL: https://www.sciencedirect.com/science/article/abs/pii/S1387181120301189