Overview of Dynamic Strain Aging and Associated Phenomena in Fe-Mn-C Austenitic Steels

This paper presents an overview of the recent works on dynamic strain aging (DSA) of Fe-Mn-C austenitic steels including Hadfield and twinning-induced plasticity (TWIP) steels. First, a model of the DSA mechanism and its controlling factors are briefly explained in terms of Mn-C coupling and dislocation separation. Then, we introduce the effects of DSA on mechanical properties such as work hardening capability, uniform elongation, post-uniform elongation, and fatigue strength. Specifically, we note (1) the pinning effect on extended dislocation for the work hardening, (2) the Poretvin-Le Chatelier banding effect on damage evolution for the tensile elongation, and (3) the crack tip hardening/softening effect on crack resistance for the fatigue strength. We believe that this overview will help in designing advanced high strength steels with superior ductility and fatigue resistance.