The effect of grain boundary character distribution on the mechanical properties at different strain rates of a 316L stainless steel

Grain boundary engineering was applied to a 316L stainless steel. The proportion of low-Σ coincidence site lattice boundaries was increased to more than 70% in the GBE specimen. The effect of grain boundary character distribution formed through GBE on the mechanical properties at different strain rates (4 × 10⁻², 4 × 10⁻³, 4 × 10⁻⁴, 4 × 10⁻⁵ s⁻¹) was studied by tensile test at room temperature. The results showed that the GBE specimens exhibited higher uniform elongation than the non-GBE specimens. With the strain rate decreasing, the uniform elongations of GBE specimens had a greater extent of increase. The local misorientation, average Schmid factor (\( \overline{m} \)) and Taylor factor (M) in GBE and non-GBE specimens at uniform plastic deformation area were studied by using electron backscatter diffraction. The results indicate that the micro-zone strain was more uniformly distributed and the activation process of the slip system was apt to happen in the GBE specimens.