LAUSR

Blade curving caused by quenching of the Japanese sword has been recognized by swordsmiths through the ages. In the late 1920s, Denzaburo Hattori noted that, based on his experimental results using cylindrical specimens, sword curving is induced not only by martensitic transformation expansion in the near-edge region but also nonuniform elastic and plastic strains distributed in this section. The presented research is an updated explanation on the subject of prepared Japanese sword (JS)-type specimens made of the same steel and by the same process as the Japanese sword, and model JS-type specimens with almost the same shape as JS-type specimens, which were machined from commercial carbon steel and austenite stainless steel bars. All specimens quenched by a swordsmith using the traditional way showed a usual curved shape with different curvatures. The curving, temperature, hardness, microstructure, and residual stress of the specimens were examined to prepare future simulation works.