Influence of dislocation structure on bcc metal creep under reactor irradiation

Creep iron at 600 deg C and commercial vanadium at 900 deg C with different types of dislocation structures produced by working and the succeeding annealing is investigated. The structures were determined by relation of dislocation length along the directions of the < 111 > type to general length of dislocation lines. This relation serves as a characteristic of the screw component fraction. It is shown that specimens with a higher fraction of screw component in the dislocation structure have higher resistance to plastic deformation under the neutron flux (phisub(t)=5x1019 n/cm2) at 0.5 Tsub(melt.) temperatures. Effectiveness of dislocation strengthening for an increase of bcc metal heat resistance is marked out