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 its significant change occurring at strain burst have been investigated by measuring the stress amplitude, the Bauschinger energy parameter, stress asymmetry and instability of stress amplitude. Under a plastic strain amplitude of 2×104, occurrences of two strain bursts were recognized as sudden huge reductions in stress amplitude. Such huge bursts were accompanied by sudden increase in the Bauschinger energy parameter and decrease in stress asymmetry. These simultaneous changes in the parameters can be understood by the dissociation of dislocation dipoles, which has been proposed by Neumann.