CYCLIC RESPONSE AND BURST PHENOMENA IN CYCLICALLY DEFORMED SINGLE-CRYSTALS OF A FERRITIC STAINLESS-STEEL

Cyclic stress-strain response of Fe-30%Cr alloy single crystals and it s significant change occurring at strain burst have been investigated by measuring the stress amplitude, the Bauschinger energy parameter, s tress asymmetry and instability of stress amplitude. Under a plastic s train amplitude of 2x10(4), occurrences of two strain bursts were reco gnized as sudden huge reductions in stress amplitude. Such huge bursts were accompanied by sudden increase in the Bauschinger energy paramet er and decrease in stress asymmetry. These simultaneous changes in the parameters can be understood by the dissociation of dislocation dipol es, which has been proposed by Neumann. (C) 1998 Elsevier Science S.A. All rights reserved.