不均質変形組織の特徴と役割

――せん断帯を中心にして

抄録

Microstructural characteristics developed by inhomogeneous plastic flow in fcc metals and alloys have been reviewed. The aspect of microstructural evolution due to plastic deformation in fcc materials is markedly influenced by the values of SFE. Particular emphasis is laid on the formation of shear bands in a cold-rolled low SFE metal such as 310S austenitic stainless steel. In cold-rolled 310S steel, deformation twinning easily occurs to form fine lamellar structure due to twin (T) and matrix (M). Further deformation causes shear band formation. In shear bands, fine-grained structures are formed with large orientation scattering. The multiplication of shear bands destroys the fine T-M lamellae to form fine-grained structures being similar to those due to severe plastic deformation. Shear bands are considered to be a microstructural instability where intense shear deformation occurs due to the local collapse of fully work-hardened structure.