Misorientation dependence of grain boundary segregation under electron irradiation in an austenitic stainless steel

The effect of grain boundary misorientation on intergranular Radiation-Indu ced Segregation (RIS) in an Fe-15Cr-20Ni alloy was studied using a high vol tage electron microscope (HVEM) at Hokkaido University HVEM facility and a rate equation model for RIS which incorporated grain boundary sink strength . The < 110 > tilt grain boundaries were chosen for the present study. It w as observed that after electron irradiation with 3x10(-3) dpa/s to 3 dpa at both temperatures of 623 K and 723 K, RIS was enhanced as the tilt angle i ncreases but was suppressed at coincidence grain boundaries (Sigma 9 and Si gma 3). The present result indicates that one needs explicitly to consider the grain boundary sink strength for point defects as an important factor a ffecting radiation induced grain boundary phenomena.