Study on Mechanical Properties and Deformation Mechanism of TWIP Stainless Steel

In this study, based on the sensitivity of chemical composition fluctuation to thermodynamic parameter, which controls level stacking fault energy (SFE), a series high Cr–Mn–N twinning-induced plasticity (TWIP) stainless steels are designed by using sublattice model, and their mechanical properties micro deformation mechanism analyzed The formation twins (Mts) during makes test steel show perfect combination strength ductility after different solution treatments. Among them, treatment at 950 °C 1050 °C, 19Cr–0.7N 19CrSi–0.7N samples have maximum value with product reaching 60.7% 64.6%, 12Cr–CN has 1200 81.3%. SFE values were relatively high, 48 mJ·m−2 45 mJ·m−2, respectively. is 37 Mts grow rapidly maintain highest twinning density under same strain conditions. characterization tensile occurs deformations electron backscattered diffraction (EBSD) transmission microscope (TEM). results EBSD local misorientation difference angle analysis showed Silicon element addition good saturation rate. It observed from TEM that nucleation process difficult, emit inward along grain boundary present cross shape increase in strain. contribution strengthening (σ0), dislocation (σf), effect (σt) dynamic micro-refinement stress calculated. known certain amount strain, ratio σt σf changes increasing, when exceeds about 25%, reinforcement plastic dominated plane σf.