Positron annihilation study of irradiated China domestic A508-3 steels

AbstractChina domestic A508-3 steels are irradiated by protons with energy of 240 keV under the damage doses of 0.26 dpa, 0.50 dpa and 1.00 dpa, respectively. The results from positron lifetime spectrum analysis and microharness test show that τ1, τ2 lifetimes of A508-3 steels increase with increasing radiation dose. The variation of short lifetime value of τ1 from 120 ps to 151 ps means that monovacancies and divacancies emerge in the steels after proton radiation. The variation of long lifetime value of τ2 from 226 ps to 262 ps means that micro voids containing several vacancies are produced by radiation damage. The average diameter of voids under the three damage level is 0.41nm, 0.45nm, and 0.45nm, respectively. Radiation hardening is due to the improvement of dislocation motion resistance which is caused by radiation defects such as vacancies, voids and possible copper enriched clusters