Corrosion Mechanism of Low-Alloyed Steel in High-Temperature Water: Effect of Additives and Time of Exposure

Konsta Sipilä, Martin Bojinov (Corresponding Author), Wolfgang Mayinger, Timo Saario, Maxim Selektorc

    Research output: Contribution to journalArticleScientificpeer-review

    4 Citations (Scopus)

    Abstract

    The present paper investigates the effect of exposure time, chloride and sulfate additions on the corrosion mechanism of low-alloyed steel in a cladding flaw of a nuclear reactor pressure vessel using in-situ electrochemical impedance spectroscopy coupled to exsitu characterization of the oxides by surface analytical techniques. A quantitative interpretation of impedance spectra using the Mixed-Conduction Model for oxide films formed in high-temperature water allows for a discrimination between the rates of inner layer formation and cation transmission through that layer. The values of the inner layer thickness and cation release estimated from impedance measurements are in good agreement with those stemming from ex-situ analysis. At short exposure times, higher film formation and cation release rates of LAS are measured in the presence of chloride and sulfate additives. However, the effect of exposure time itself appears to be stronger than that of the impurities, and the protective ability of the oxides at longer exposure times starts to dominate the overall corrosion process.
    Original languageEnglish
    Pages (from-to)C530-C538
    JournalJournal of the Electrochemical Society
    Volume163
    Issue number9
    DOIs
    Publication statusPublished - 2016
    MoE publication typeA1 Journal article-refereed

    Fingerprint

    Steel
    Cations
    Positive ions
    Corrosion
    Oxides
    Sulfates
    Water
    Chlorides
    Nuclear reactors
    Pressure vessels
    Electrochemical impedance spectroscopy
    Temperature
    Oxide films
    Impurities
    Defects

    Keywords

    • chloride and sulfate impurities
    • high-temperature water
    • impedance spectroscopy
    • kinetic model
    • low-alloyed steel

    Cite this

    @article{2606ee5e95a143a5967d804d0a9b314f,
    title = "Corrosion Mechanism of Low-Alloyed Steel in High-Temperature Water: Effect of Additives and Time of Exposure",
    abstract = "The present paper investigates the effect of exposure time, chloride and sulfate additions on the corrosion mechanism of low-alloyed steel in a cladding flaw of a nuclear reactor pressure vessel using in-situ electrochemical impedance spectroscopy coupled to exsitu characterization of the oxides by surface analytical techniques. A quantitative interpretation of impedance spectra using the Mixed-Conduction Model for oxide films formed in high-temperature water allows for a discrimination between the rates of inner layer formation and cation transmission through that layer. The values of the inner layer thickness and cation release estimated from impedance measurements are in good agreement with those stemming from ex-situ analysis. At short exposure times, higher film formation and cation release rates of LAS are measured in the presence of chloride and sulfate additives. However, the effect of exposure time itself appears to be stronger than that of the impurities, and the protective ability of the oxides at longer exposure times starts to dominate the overall corrosion process.",
    keywords = "chloride and sulfate impurities, high-temperature water, impedance spectroscopy, kinetic model, low-alloyed steel",
    author = "Konsta Sipil{\"a} and Martin Bojinov and Wolfgang Mayinger and Timo Saario and Maxim Selektorc",
    note = "Project code: 101687",
    year = "2016",
    doi = "10.1149/2.0401609jes",
    language = "English",
    volume = "163",
    pages = "C530--C538",
    journal = "Journal of the Electrochemical Society",
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    Corrosion Mechanism of Low-Alloyed Steel in High-Temperature Water: Effect of Additives and Time of Exposure. / Sipilä, Konsta; Bojinov, Martin (Corresponding Author); Mayinger, Wolfgang; Saario, Timo; Selektorc, Maxim.

    In: Journal of the Electrochemical Society, Vol. 163, No. 9, 2016, p. C530-C538.

    Research output: Contribution to journalArticleScientificpeer-review

    TY - JOUR

    T1 - Corrosion Mechanism of Low-Alloyed Steel in High-Temperature Water: Effect of Additives and Time of Exposure

    AU - Sipilä, Konsta

    AU - Bojinov, Martin

    AU - Mayinger, Wolfgang

    AU - Saario, Timo

    AU - Selektorc, Maxim

    N1 - Project code: 101687

    PY - 2016

    Y1 - 2016

    N2 - The present paper investigates the effect of exposure time, chloride and sulfate additions on the corrosion mechanism of low-alloyed steel in a cladding flaw of a nuclear reactor pressure vessel using in-situ electrochemical impedance spectroscopy coupled to exsitu characterization of the oxides by surface analytical techniques. A quantitative interpretation of impedance spectra using the Mixed-Conduction Model for oxide films formed in high-temperature water allows for a discrimination between the rates of inner layer formation and cation transmission through that layer. The values of the inner layer thickness and cation release estimated from impedance measurements are in good agreement with those stemming from ex-situ analysis. At short exposure times, higher film formation and cation release rates of LAS are measured in the presence of chloride and sulfate additives. However, the effect of exposure time itself appears to be stronger than that of the impurities, and the protective ability of the oxides at longer exposure times starts to dominate the overall corrosion process.

    AB - The present paper investigates the effect of exposure time, chloride and sulfate additions on the corrosion mechanism of low-alloyed steel in a cladding flaw of a nuclear reactor pressure vessel using in-situ electrochemical impedance spectroscopy coupled to exsitu characterization of the oxides by surface analytical techniques. A quantitative interpretation of impedance spectra using the Mixed-Conduction Model for oxide films formed in high-temperature water allows for a discrimination between the rates of inner layer formation and cation transmission through that layer. The values of the inner layer thickness and cation release estimated from impedance measurements are in good agreement with those stemming from ex-situ analysis. At short exposure times, higher film formation and cation release rates of LAS are measured in the presence of chloride and sulfate additives. However, the effect of exposure time itself appears to be stronger than that of the impurities, and the protective ability of the oxides at longer exposure times starts to dominate the overall corrosion process.

    KW - chloride and sulfate impurities

    KW - high-temperature water

    KW - impedance spectroscopy

    KW - kinetic model

    KW - low-alloyed steel

    U2 - 10.1149/2.0401609jes

    DO - 10.1149/2.0401609jes

    M3 - Article

    VL - 163

    SP - C530-C538

    JO - Journal of the Electrochemical Society

    JF - Journal of the Electrochemical Society

    SN - 0013-4651

    IS - 9

    ER -