STP1125: Irradiation Response and Annealing Behavior of Pressure Vessel Model Steels and Iron Ternary Alloys Measured with Positron Techniques

    Valo, M
    Research scientist, Technical Research Centre of Finland (VTT), Espoo,

    Krause, R
    Physicist, Sektion Physik der Martin-Luther-Universitat Halle-Wittenberg, Halle, Saale

    Saarinen, K
    Research fellow and professor, Laboratory of Physics, Helsinki University of Technology, Espoo,

    Hautojarvi, P
    Research fellow and professor, Laboratory of Physics, Helsinki University of Technology, Espoo,

    Hawthorne, JR
    Research metallurgist, Materials Engineering Associates, Inc., Lanham, MD

    Pages: 14    Published: Jan 1992


    Abstract

    Positron lifetime and annihilation gamma-line Doppler broadening measurements were used to study the irradiation response and postirradiation annealing behavior of pressure vessel model steels and ternary iron alloys. The steel samples had the basic composition of A533-B and A302-B type steels with varying key impurity elements, i.e., Cu, P, and Ni. The steels and the ternary iron alloys were neutron irradiated at 288°C into a fluence of 2.5 and 4.6 ˟ 1023 neutrons/m-2, E > 1 MeV, respectively.

    Due to irradiation, microvoids were formed in the ternary iron alloys but not in the steel samples. The irradiation response measured as the vacancy-type defect content of the specimens was found to be dependent on chemical composition. The vacancy defects annealed out in all the specimens in the temperature range of 400 to 500°C. In the annealing behavior, there were some smaller differences in details.

    Keywords:

    pressure vessel steel, radiation embrittlement, positron lifetime


    Paper ID: STP17868S

    Committee/Subcommittee: E10.08

    DOI: 10.1520/STP17868S


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