STP380: Effects of Irradiation on A302-B Steel Subjected to a Multiaxial Stress Distribution

    Trozera, T. A.
    Staff member and staff associate, General Dynamics Corp., San Diego, Calif.

    Flynn, P. W.
    Staff member and staff associate, General Dynamics Corp., San Diego, Calif.

    Pages: 13    Published: Jan 1965


    Changes in mechanical properties of A302-B reactor-grade, pressure-vessel steel due to various combinations of neutron irradiation, biaxial stress fields, and temperature were studied. Capsules containing tube, tension, and Charpy specimens were irradiated to doses from 1.6 x 1018 to 1.14 x 1020 nvt. Results of the Charpy tests are within the well-known scatter band of Steele, Naval Research Laboratory. Tube tests were performed at principal stress ratios of 1:1 and 2:1 at temperatures up to 149 C. The experimental results have been analyzed on the basis of the Hencky-Von Mises strength theory. A reduction of uniform elongation to less than 1 per cent was observed for tubes tested at 66 C, dose about 8 x 1018 nvt, and a stress ratio of 1:1. This should be compared with a uniform strain of 2 1/2 per cent for a tube tested in simple tension under the same conditions of temperature and dosage. The strain predicted from a simple instability criterion is about 2 per cent. The results indicate that the simple geometric methods generally used to predict instability under combined stresses greatly overestimate measured strains for this material. At doses of about 8 x 1019 nvt, yielding of tension bars was followed by large amounts of localized deformation indicating good ductility, but a condition of instability in a pressure vessel application.

    Paper ID: STP43538S

    Committee/Subcommittee: E10.07

    DOI: 10.1520/STP43538S

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