SUBMICROCRYSTALLINE STRUCTURES DEVELOPED IN 18-7 STAINLESS STEEL UNDER SEVERE DEFORMATION

摘要

Deformation microstructures evolved in a ferritic stainless steel (Fe-18Cr-7Ni) were studied in bar rolling followed by swaging at ambient temperature. The severe deformed microstructures were composed of highly elongated (sub)grains. At strains of around 3, the transverse (sub)grain size (as measured on the sections parallel to the swaging rolling/axis) approached its minimal value of about 70 nm, which slightly increased with further deformation. These severe deformed microstructures were characterised by considerable internal distortions in spite of relatively low dislocation densities evolved in the (sub)grain interiors.