On the origin of deformation microstructures in austenitic stainless steel: Part II - Mechanisms

Deformation microstructures of austenitic stainless steels consist of profuse pile-up dislocations, stacking faults, nanotwins, and defect-reduced channels as demonstrated in the Part I companion paper of this title [Acta mater., 2001, 49(16), 3269-3276]. Yet the mechanisms of such microstructural evolution are poorly understood. Thus, a comprehensive study was conducted to understand the underlying physics of deformation in metals using radiation damage as a tool. It was found that, for energetic reasons, glide dislocations dissociated into Shockley partials during glide. Consequently, the interaction between a glide dislocation and radiation-induced defects occurs by a two-step reaction, first with the leading partial and then with the trailing partial. With this insight, the origin of deformation microstructures was explained by analyzing Shockley partial dislocations and their interactions with radiation-induced Frank loops.