2017 Volume 58 Issue 675 Pages 323-329
The tensile properties of a Japanese-sword-type steel sheet, which has a sandwich-type layered structure consisting of low and medium carbon steels, were clarified. The hard and soft center sheets were prepared by stacking 0.05%C steel as the soft layer and 0.44%C steel as the hard layer with different combinations of thickness, and plane-strain compression at 1000 °C was conducted for bonding. The yield stress and the tensile strength of the Japanese-sword-type steel sheets were independent of the layer structure regardless of the position of the hard center sheet or the soft center sheet, whereas the strength changed with a strong dependence on the volume fraction of the hard layers. When the hard-layer volume fraction was larger than 50%, the measured strength was better than the estimation based on the rule of linear mixture. On the other hand, the area reduction at a fracture of the hard-center sheets was larger than that of the soft-center sheet at any volume fraction of hard layers.
