Evolution of cellular dislocation structures and defects in additively manufactured austenitic stainless steel under ion irradiation

摘要

The evolution of irradiation-induced defects in additively manufactured (AM) austenitic stainless steel was investigated in situ by 1 MeV Kr ion irradiation at 450 and 600 degrees C in a transmission electron microscope. Cellular dislocation structure in AM steel act as sink/trap sites for the irradiation-induced defects, resulting in the lower density and smaller dislocation loops in AM steel than conventional forged (CF) steel at 450 degrees C. The higher stacking fault energy and local stress concentration induced by cellular dislocation structure in AM steel promotes the unfaulting process and the formation of network dislocation at 600 degrees C. (C) 2019 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.