The effect of cold rolled reduction ratios on grain boundary character and mechanical properties of the SUS301L austenitic stainless steel

With the rapid development of the rail vehicle industry, SUS301L austenitic stainless steel becomes the main material of rail vehicles, due to its cold processing performance, which has attracted much attention. In order to study the effect of grain boundary feature distribution on the properties of 301L stainless steel during cold deformation. 301L stainless steel samples with a cold rolling reduction of 3%, 5%, 9%, and 24% were prepared. The microstructure, mechanical properties and corrosion resistance of samples with different grain boundary characteristics were studied by means of OM, EBSD, universal testing machine and three-electrode electrochemical workstation. The result shows that with the increasing of the cold rolling reduction, grain orientation 〈111〉 is significantly weakened, the grain boundary of small angles gradually increases. Meanwhile, the grain boundary of large angle the strong grain boundary of Σ ≤ 29 gradually decreases. 301L stainless steel high ductility and toughness can be improved by obtaining a frequency of low Σ values in the coincident site lattice(CSL) grain boundaries. The microstructure and grain size is gradually getting smaller. The strength increased, while ductility, toughness, and the corrosion resistance reduced. The grain boundary of Σ3 gradually decreases with the increase of cold rolling reduction, but the reduction range of 9%∼24% is not significant. (paper)