An alternative model for the strain hardening of FCC alloys that twin, validated for twinning-induced plasticity steel

A new explanation for the stress–strain behaviour of austenitic TWIP steels (or other low stacking-fault alloys deforming by twinning) is presented, that emphasizes the key contribution of the reinforcement of austenite by the thin (nanometric) deformation twins both to the macroscopic strain hardening and to the development of forward and backward internal stresses in respectively twin and matrix regions. The model is an alternative to current models only based on a “dynamic Hall–Petch effect” that treat mechanical twinning as a slip-like mechanism.