Preferentially Deformed Grains during Micro-yielding in Duplex-grained Austenitic Steel

Micro-yielding occurs during macro-yielding in the steel, or polycrystalline material. In this phenomenon, some grains start to transform preferentially at lower strain, or the steel has preferentially deformed grains. However, this phenomenon has mostly been studied in uniform-grained steel so that the effect of duplex-grains is not clear. In this study, preferentially deformed grains during micro-yielding in duplex-grained austenitic steel are investigated. Rotation angle of every grain as deformation is analyzed with SEM-EBSD. Every preferential deformed grain has no trend for grain size and Schmid factor separately. In case grains which are in contact with a preferential grain have larger size and larger/smaller Schmid factor than it, it may be affected by around grains into deforming (Case I). On the other hand, in case grains which are in contact with a preferential grain has smaller size than it, it has larger size and larger Schmid factor (Case II).