Theory of radiation embrittlement and recovery of radiation damage in ferritic steels

Abstract

Utilizing theories developed to explain the behaviour of irradiated face-centred cubic metals, mechanisms are developed to explain neutron embrittlement and subsequent recovery of body-centred cubic metals (including ferritic steels). The proposed micro-mechanism is an adaptation of Seeger's damage theory combined with Makin's saturation effects concept and Cottrell's brittle fracture theory. It is suggested that annealing of the damage occurs by the thermally activated motion and coalescence of the damage zones as entities through surface diffusion of atoms on the zone interior surfaces. The overall zone motion is described by random-walk movement. The reasonableness of the model is demonstrated from various experimental data.