Crystallographic orientation and spatially resolved damage for polycrystalline deformation of a high manganese steel

Stress Evaluation Method by Neutron Diffraction for HCP-Structured Magnesium Alloy

“…Moreover, the orthogonal directions of [hkl]//TD grains are not always parallel to the LD. This issue has already been mentioned in several papers [51][52][53]. Stress conversions using the lattice strains for the TD without careful consideration of the development of texture in the LD and TD are, therefore, messy and require caution.…”

Effect of Grain Size on the Plastic Deformation Behaviors of a Fe-18Mn-1.3Al-0.6C Austenitic Steel

“…where σ T is the mechanical twinning critical nucleation stress, σ T0 is the lattice friction, K T is the coefficient related to the average grain size d, and A is a constant (0.5 < A < 1). Equation (13) shows that the critical nucleation stress for mechanical twinning is inversely proportional to the grain size; when the grain size was decreased from 103.4 µm to 6.8 µm in this experiment, the value of (σ T − σ T0 ) increased approximately 4~15 times due to the decrease in the average grain size d. This makes it more difficult to nucleate mechanical twins in small-sized grains, and mechanical twins are generated later in the plastic deformation process and are suppressed at a higher plastic strain. In summary, the increase in grain size can effectively promote the generation and proliferation of mechanical twins, thus contributing to the TWIP effect, increasing the plasticity of the sample and enhancing the work-hardening ability.…”

“…Fine-grain strengthening, which is a strengthening method that can simultaneously improve the strength and toughness of metallic materials, has a great impact on the overall performance of high-manganese austenitic steels. It is widely accepted that, to a certain extent, the mechanical properties improve with a decrease in grain size and an increase in grain boundary area, as grain refinement has a better strengthening effect on metallic materials [12,13]. High-manganese steel can be annealed after cold deformation to obtain different grain sizes by controlling the annealing temperature and holding time.…”

“…The results of Ueji et al [15] also confirmed that twins were more likely to form in large grains, and the high density of twins enhanced the pinning effect on dislocations, resulting in higher work-hardening properties of coarse-grained high-manganese steels. In most of the previous studies [12][13][14][15][16][17][18], the focus has been on the effect of grain size on the workhardening behavior, and less attention has been paid to the effect of the interaction of twinning behavior and dislocation proliferation during various stages of work-hardening.…”