Rate theory study of the proton-irradiation induced dislocation loops in modified 310S steels

Abstract

The evolution of dislocation loops in two types of modified 310S steel under proton irradiation are investigated with rate theory simulations. The growth of dislocation loops is promoted with the increase of irradiation dose and growth rate decreases at high dose, while the number density of the dislocation loops increases first with dose and then tends to be saturated gradually. At the initial stage of irradiation, large number of dislocation loops nucleate and the density increases rapidly. With the development of irradiation, the growth of dislocation loops gradually takes over. Simulation results are in good agreement with the experimental observations of transmission electron microscope. Present study shows that The irradiation resistance of Zr-added steel is slightly better than that of (Nb, Ta, W)-added steel, which may due to the smaller migration energy of interstitials and vacancies in Zr-added steel than that in the (Nb, Ta, W)-added one.