Deformation Mechanisms of Twinning-Induced Plasticity Steel under Shock-Load: Investigated by Synchrotron X-ray Diffraction

Abstract

As an ideal candidate material for automobiles, twinning-induced plasticity (TWIP) steels possess excellent formability, high strength and high energy absorption ability during collision. This is attributed to its deformation mechanism of mechanical twinning, resulting in a high work hardening rate. In the current study, deformation mechanisms of low-stacking fault energy TWIP steel, under different strain rates between 0.01/s to 1581/s, were investigated by high-energy X-ray diffraction. After compression, grains with {110}||compression direction became favourable. Higher intensity was observed near brass and A components in the selected orientation distribution function (ODF) section (φ2 = 45°) for all the compressed specimens. The activity of twinning was found to be the highest in the specimens that had been compressed with medium−high strain rates (e.g., 100/s and 10/s), while the texture component related to slip had stronger intensity in the specimen deformed with a quasi-static strain rate (0.01/s).

Keywords

• twinning-induced plasticity steel
• high-energy X-ray diffraction
• deformation mechanisms