Origin of hardening and deformation mechanisms in irradiated 316 LN austenitic stainless steel

The effects of displacement damage and trapped helium on deformation micros tructures in AISI 316 LN austenitic stainless steel were studied by applyin g a newly developed disk bend method to specimens irradiated with 360 keV H e ions at 200 degreesC. Radiation damage microstructures consisted of an in timate mix of black dots, dislocation loops, and very small helium filled c avities. In the unirradiated specimens, the deformation mode upon straining was planar glide with cross-slip. With increasing dose, cross-slip was pro gressively restricted. Correspondingly, deformation microstructure changed from dislocation network dominant to channeling dominant. The channel bands were composed of piled-up dislocations, stacking faults, and twinned layer s. Published by Elsevier Science B.V.