Conduction mechanism of the anodic film on Fe-Cr alloys in sulfate solutions

Martin Bojinov, Gunilla Fabricius, Timo Laitinen, Kari Mäkelä, Timo Saario, Göran Sundholm

    Research output: Contribution to journalArticleScientificpeer-review

    38 Citations (Scopus)

    Abstract

    The passive state of Fe‐12% Cr and Fe‐25% Cr alloys in 1 M sulfate solutions of pH 0 and 5 was studied with a combination of electrochemical techniques: impedance spectroscopy, photoelectrochemistry, and dc resistance measurements by the contact electric resistance technique. The investigations were supported by studies on pure metal constituents (Fe, Cr) in the same solutions. As a result, the steady‐state passive film on the alloys (and on pure Cr) can be described as a thin, essentially insulating layer. Polarization of the steady‐state metal/anodic film/electrolyte system to negative and positive potentials away from the potential region corresponding to the highest electronic resistance was concluded to lead to the generation of lower or higher valency defects at the interfaces via solid‐state electrochemical reactions. These reactions result in a substantial increase of the conductivity in the first layers adjacent to either the metal/film or the film/electrolyte interface. At very negative (or very positive) potentials the film is transformed into a conductor allowing active (or transpassive) dissolution to take place. A quantitative physical model of the conduction mechanism on the basis of the surface charge approach is proposed and compared with experimental data.
    Original languageEnglish
    Pages (from-to)3238-3247
    Number of pages10
    JournalJournal of the Electrochemical Society
    Volume146
    Issue number9
    DOIs
    Publication statusPublished - 1999
    MoE publication typeA1 Journal article-refereed

    Fingerprint

    Sulfates
    Metals
    Electrolytes
    Electric contacts
    Surface charge
    Dissolution
    Spectroscopy
    Polarization
    Defects

    Cite this

    Bojinov, Martin ; Fabricius, Gunilla ; Laitinen, Timo ; Mäkelä, Kari ; Saario, Timo ; Sundholm, Göran. / Conduction mechanism of the anodic film on Fe-Cr alloys in sulfate solutions. In: Journal of the Electrochemical Society. 1999 ; Vol. 146, No. 9. pp. 3238-3247.
    @article{0f86b82ba8b846bb91495f52db5af255,
    title = "Conduction mechanism of the anodic film on Fe-Cr alloys in sulfate solutions",
    abstract = "The passive state of Fe‐12{\%} Cr and Fe‐25{\%} Cr alloys in 1 M sulfate solutions of pH 0 and 5 was studied with a combination of electrochemical techniques: impedance spectroscopy, photoelectrochemistry, and dc resistance measurements by the contact electric resistance technique. The investigations were supported by studies on pure metal constituents (Fe, Cr) in the same solutions. As a result, the steady‐state passive film on the alloys (and on pure Cr) can be described as a thin, essentially insulating layer. Polarization of the steady‐state metal/anodic film/electrolyte system to negative and positive potentials away from the potential region corresponding to the highest electronic resistance was concluded to lead to the generation of lower or higher valency defects at the interfaces via solid‐state electrochemical reactions. These reactions result in a substantial increase of the conductivity in the first layers adjacent to either the metal/film or the film/electrolyte interface. At very negative (or very positive) potentials the film is transformed into a conductor allowing active (or transpassive) dissolution to take place. A quantitative physical model of the conduction mechanism on the basis of the surface charge approach is proposed and compared with experimental data.",
    author = "Martin Bojinov and Gunilla Fabricius and Timo Laitinen and Kari M{\"a}kel{\"a} and Timo Saario and G{\"o}ran Sundholm",
    year = "1999",
    doi = "10.1149/1.1392461",
    language = "English",
    volume = "146",
    pages = "3238--3247",
    journal = "Journal of the Electrochemical Society",
    issn = "0013-4651",
    number = "9",

    }

    Bojinov, M, Fabricius, G, Laitinen, T, Mäkelä, K, Saario, T & Sundholm, G 1999, 'Conduction mechanism of the anodic film on Fe-Cr alloys in sulfate solutions', Journal of the Electrochemical Society, vol. 146, no. 9, pp. 3238-3247. https://doi.org/10.1149/1.1392461

    Conduction mechanism of the anodic film on Fe-Cr alloys in sulfate solutions. / Bojinov, Martin; Fabricius, Gunilla; Laitinen, Timo; Mäkelä, Kari; Saario, Timo; Sundholm, Göran.

    In: Journal of the Electrochemical Society, Vol. 146, No. 9, 1999, p. 3238-3247.

    Research output: Contribution to journalArticleScientificpeer-review

    TY - JOUR

    T1 - Conduction mechanism of the anodic film on Fe-Cr alloys in sulfate solutions

    AU - Bojinov, Martin

    AU - Fabricius, Gunilla

    AU - Laitinen, Timo

    AU - Mäkelä, Kari

    AU - Saario, Timo

    AU - Sundholm, Göran

    PY - 1999

    Y1 - 1999

    N2 - The passive state of Fe‐12% Cr and Fe‐25% Cr alloys in 1 M sulfate solutions of pH 0 and 5 was studied with a combination of electrochemical techniques: impedance spectroscopy, photoelectrochemistry, and dc resistance measurements by the contact electric resistance technique. The investigations were supported by studies on pure metal constituents (Fe, Cr) in the same solutions. As a result, the steady‐state passive film on the alloys (and on pure Cr) can be described as a thin, essentially insulating layer. Polarization of the steady‐state metal/anodic film/electrolyte system to negative and positive potentials away from the potential region corresponding to the highest electronic resistance was concluded to lead to the generation of lower or higher valency defects at the interfaces via solid‐state electrochemical reactions. These reactions result in a substantial increase of the conductivity in the first layers adjacent to either the metal/film or the film/electrolyte interface. At very negative (or very positive) potentials the film is transformed into a conductor allowing active (or transpassive) dissolution to take place. A quantitative physical model of the conduction mechanism on the basis of the surface charge approach is proposed and compared with experimental data.

    AB - The passive state of Fe‐12% Cr and Fe‐25% Cr alloys in 1 M sulfate solutions of pH 0 and 5 was studied with a combination of electrochemical techniques: impedance spectroscopy, photoelectrochemistry, and dc resistance measurements by the contact electric resistance technique. The investigations were supported by studies on pure metal constituents (Fe, Cr) in the same solutions. As a result, the steady‐state passive film on the alloys (and on pure Cr) can be described as a thin, essentially insulating layer. Polarization of the steady‐state metal/anodic film/electrolyte system to negative and positive potentials away from the potential region corresponding to the highest electronic resistance was concluded to lead to the generation of lower or higher valency defects at the interfaces via solid‐state electrochemical reactions. These reactions result in a substantial increase of the conductivity in the first layers adjacent to either the metal/film or the film/electrolyte interface. At very negative (or very positive) potentials the film is transformed into a conductor allowing active (or transpassive) dissolution to take place. A quantitative physical model of the conduction mechanism on the basis of the surface charge approach is proposed and compared with experimental data.

    U2 - 10.1149/1.1392461

    DO - 10.1149/1.1392461

    M3 - Article

    VL - 146

    SP - 3238

    EP - 3247

    JO - Journal of the Electrochemical Society

    JF - Journal of the Electrochemical Society

    SN - 0013-4651

    IS - 9

    ER -