Work-hardening model for polycrystalline metals under strain reversal at large strains

The mechanical behaviours under reversed strain of low carbon steels and aluminium alloys are reviewed and modelled with a simple approach based on the evolutionary laws of two dislocation densities related respectively to the forward and the backward straining. In essence, it is the competition between the annihilation of the dislocations that were created during the prestrain and the storage of newly created dislocations that lead to the observed stagnation of the hardening rate. Textural effects as well as back stresses are shown to extend or to reduce the stress–strain plateau but are not responsible for it.