Cyclic polycrystalline visco-plastic model for ratchetting of 316L stainless steel

Based on a cyclic crystal visco-plastic model developed in previous work for face-centered cubic (FCC) single crystals, a new polycrystalline visco-plastic model is constructed to describe the ratchetting of 316L stainless steel. In the constructed model, a combined nonlinear kinematic hardening rule is employed to describe the resolved shear back stress of each active slip system, and a simplified version of Bassani–Wu latent hardening model is used to capture the interaction of dislocation slip. An explicit scale-transition rule is adopted to obtain the polycrystalline behavior of metal materials. Comparing the simulated results with the experimental ones shows that the developed cyclic polycrystalline visco-plastic model provides reasonable description for the uniaxial ratchetting of 316L stainless steel. The dependence of ratchetting deformation on crystallographic orientation in intra-granular scale can be also reflected correctly by the developed model, and the applicability of the model to multiaxial ratchetting is also discussed.

Research highlights▸ We employ a new hardening rule to describe the ratcheting in intra-granular scale. ▸ Simplified Bassani-Wu model is used to describe the orientation dependence. ▸ The proposed model provides a reasonable prediction to the ratcheting of the steel. ▸ We emphasize to simulate the ratcheting of single crystal grain reasonably.