3330 超微細粒金属材料の特異な力学特性(S18-3 微細粒組織と強度,S18 材料の強度と組織)

抄録

Ultrafine grained steels having mean grain sizes much smaller than 1μm can be realized nowadays at least in laboratory scale. The present author has systematically studied the mechanical properties of the ultrafine grained steel sheets with wide range of mean grain sizes. Ultrafine grained steels perform peculiar mechanical properties, that are not only very high strength but also other nice aspects like excellent low-temperature toughness. Furthermore, quite unusual deformation behaviors that have not yet been reported in conventionally coarse grained metals can appear in the ultrafine grained metals All these features of the mechanical properties of ultrafine grained metallic materials will be reviewed.