Structure of deformed ferrite–austenite stainless steel

AbstractThe examination covered two phase ferrite–austenite steel of coarse grained structure after 23, 43, and 85% deformation induced by rolling at room temperature. Optical and electron metallography have been used in the investigations and the formation of Neumann bands was revealed for reductions below 5%; for increased reductions the deformation of ferrite occurred by slip only. Ferrite deformation induces a rapid increase of dislocation density. In the dislocation structure, bands of increased dislocation density can be observed that are usually parallel to {110} planes and uni- or two directional in a given region. Increases in strain induce an increase of dislocation density as well as a decrease of the spacing between the bands. The formation of micro bands, microband clusters, and shear bands indicates ferrite non-homogeneous deformation. For low strains, austenite deformation occurs by slip only. In austenite, intensive twinning occurs for reductions between 20 and 40%, whereas for reductions ...