Effect of shear deformation on refinement of crystal grains

Ferrite grain structures created through transformation from deformed austenite under different deformation modes have been investigated for a low carbon Si–Mn steel. To introduce a large plastic strain, a specimen is compressed by a pair of anvils with edges controlled to keep the strain rate constant by using a compression type simulator. An explicit finite element analysis was carried out to evaluate the non-uniform strain distribution quantitatively in the specimen induced by anvil compression. The ferrite grain size was plotted as a function of the numerically obtained data of the equivalent plastic strain ϵ_eq for areas with and withoutshear deformation, respectively. An interesting effect of the shear deformation is discussed from the viewpoint of the formation of finer ferrite grains.