Corrosion resistance of Kanthal A-1 and Fe-12Cr-2Si alloy coatings in Cl-containing environment

Teemu Sarikka, Risto Ilola, Rami Pohja, Hannu Hänninen

    Research output: Chapter in Book/Report/Conference proceedingConference article in proceedingsScientificpeer-review

    Abstract

    Boiler and tubing materials used in biomass-fired energy production are susceptible to corrosion in severe corrosive environments caused by inorganic constituent such as chlorine at the operating temperatures. In conventional stainless steels, which rely on the formation of a chromia scale for protection against corrosion, the Cl present in the environment reacts with the Cr in the alloy to form volatile CrCl2 and CrCl3 compounds and, thus, reduces the formation of an external, stable chromia scale. The volatile CrCl2 and CrCl3 compounds formed on the surface of the alloy are not able to provide protection against further corrosion and due to the formation of these compounds the conventional stainless steels may lose their resistance to the Cl-containing environment. Alumina and silica forming alloys have been considered as possible solutions against corrosion in these types of applications. In this study, overlay weld coatings with FeCrAl and FeCrSi type consumables were manufactured on 10CrMo9-10 steel by gas-tungsten arc welding method. Kanthal A-1 with a nominal composition of 5.8 wt. % Al was chosen as an alumina-forming alloy and a silica-forming alloy was Fe-12Cr-2Si alloy with a nominal composition of 2.0 wt. % Si. Performance of the overlay coatings was tested in 168 h potassium chloride (KCl) exposure tests at 600°C in as-welded condition and after 24 h pre-oxidation at 950°C. Composition distributions of the coatings and the formed oxide layers in the KCl exposure were characterized with FEGSEM and EDS.
    Original languageEnglish
    Title of host publicationBaltica IX. International Conference on Life Management and Maintenance for Power Plants
    EditorsPertti Auerkari, Juha Veivo
    Place of PublicationEspoo
    PublisherVTT Technical Research Centre of Finland
    Pages500-512
    ISBN (Print)978-951-38-8025-5, 978-951-38-8026-2
    Publication statusPublished - 2013
    MoE publication typeA4 Article in a conference publication
    EventBALTICA IX - International Conference on Life Management and Maintenance for Power Plants - Helsinki-Stockholm, Finland
    Duration: 11 Jun 201313 Jun 2013

    Publication series

    SeriesVTT Technology
    Number106
    ISSN2242-1211

    Conference

    ConferenceBALTICA IX - International Conference on Life Management and Maintenance for Power Plants
    CountryFinland
    CityHelsinki-Stockholm
    Period11/06/1313/06/13

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  • Research Output

    • 1 Book (editor)

    Baltica IX: International Conference on Life Management and Maintenance for Power Plants

    Auerkari, P. (ed.) & Veivo, J. (ed.), 2013, Espoo: VTT Technical Research Centre of Finland. 683 p. (VTT Technology; No. 106).

    Research output: Book/ReportBook (editor)

    Open Access
  • Cite this

    Sarikka, T., Ilola, R., Pohja, R., & Hänninen, H. (2013). Corrosion resistance of Kanthal A-1 and Fe-12Cr-2Si alloy coatings in Cl-containing environment. In P. Auerkari, & J. Veivo (Eds.), Baltica IX. International Conference on Life Management and Maintenance for Power Plants (pp. 500-512). VTT Technical Research Centre of Finland. VTT Technology, No. 106 https://www.vtt.fi/inf/pdf/technology/2013/T106.pdf