STP1132: Precipitate Behavior in Zircaloy-2 Oxide Films and Its Relevance to Corrosion Resistance

    Kubo, T
    Nippon Nuclear Fuel Development Co. Ltd., Ibaraki-ken,

    Uno, M
    Nippon Nuclear Fuel Development Co. Ltd., Ibaraki-ken,

    Pages: 21    Published: Jan 1991


    Abstract

    The a-c impedance measurements were made for oxide films formed in high temperature steam on Zry-2 with varying precipitate distributions. TEM and EDX analyses were also carried out on precipitates in oxide films. The electrical resistivity of oxide films tends to increase with an increase in nodular corrosion resistance, with the β-quenched samples having the highest resistivity. The resistivity tended to increase with a decrease in average precipitate size. EDX analyses showed that precipitates in oxide films dissolved into oxide matrix during the corrosion process in high temperature steam. Very fine precipitates in β-quenched Zry-2 would have disappeared early in the corrosion process. The improvement in corrosion resistance by β-quenching was attributed not to short-circuit effects of precipitates but to a change in oxide properties induced by an increase in the amount of alloying elements retained in the matrix.

    Keywords:

    zirconium alloys, nodular corrosion, oxide films, corrosion resistance, electrical resistivity, precipitate, dissolution


    Paper ID: STP25523S

    Committee/Subcommittee: B10.02

    DOI: 10.1520/STP25523S


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