STP978: Galvanic Corrosion Caused by Corrosion Products

    Wilhelm, SM
    Senior engineer, Cortest Laboratories, Inc., Cypress, TX

    Pages: 12    Published: Jan 1988


    Abstract

    Experiments were conducted to quantify the magnitude of galvanic currents and potentials that exist between metals (iron, copper, titanium, aluminum, chromium, and nickel) and their corrosion products in oxygen-containing environments. Current measurements using a zero resistance ammeter and potential measurements of metal electrodes and oxide electrodes are reported. The effects of solution and electrode compositions on galvanic currents and potentials were determined. A galvanic series of corrosion products was constructed.

    Galvanic interactions between metals and surface compounds are dependent on electronic conduction type (insulator, n-type, p-type, metallic) and thickness of corrosion product layers. It may be possible to modify semiconductor film conductivity by doping with impurity elements present as alloy constituents or via environmental addition and thereby mitigate galvanic corrosion.

    Keywords:

    galvanic corrosion, semiconductor oxides, metal oxides, metal sulfides, pitting, crevice corrosion


    Paper ID: STP26189S

    Committee/Subcommittee: G01.07

    DOI: 10.1520/STP26189S


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