Grain size dependence of ductile-to-brittle transition temperature of a high-nitrogen Cr–Mn austenitic steel

With decreasing grain size, the yield and tensile strengths increased without a loss in ductility and the upper-shelf energy was also improved. However, the reduction of grain size had no beneficial influence on lowering the ductile-to-brittle transition temperature because it promoted the increase of yield stress with decreasing temperature.