Kinematical barriers enhanced dislocation strengthening mechanisms in cold-worked austenitic steels

We experimentally investigated microstructure evolution and strengthening behaviors of three cold-worked austenitic steels that deform via dislocations, twinning and stacking faults. The development of stacking faults and twins acting as kinematical barriers for dislocation motion was found to be influenced by stacking fault energy and accumulated dislocations simultaneously, which in turn accelerate dislocation storage rate, strengthen the alloys, and develop high strain hardening rate. We thus proposed a nonadditive strengthening equation to rationalize experimental observation by combining the dislocation-based two-internal-variable model coupled with kinematical barriers.

Automated summary

We experimentally investigated the microstructure evolution and strengthening behaviors of three cold-worked austenitic steels that deform via dislocations, twinning, and stacking faults. It was found that the development of stacking faults and twins acts as kinematical barriers for dislocation motion, which is influenced by stacking fault energy and accumulated dislocations. These factors accelerate the dislocation storage rate, strengthen the alloys, and develop a high strain hardening rate. Therefore, we proposed a nonadditive strengthening equation by combining the dislocation-based two-internal-variable model coupled with kinematical barriers to rationalize the experimental observations.