Orientation topography and ridging phenomenon in ferritic stainless steel sheets

The ridging phenomenon occurring in ferritic stainless steel sheets in the case of elongation or deep drown is the subject of investigations. The resu lting deterioration of the surface quality is a severe, long known problem in industrial processing. This problem is here investigated by the SEM-EBSD technique (Electron Backscattering Diffraction in the Scanning Electron Mi croscope). Orientation topography acquired using this technique shows that the sheet is composed of two macro-elements of different anisotropy, thin, {100}[011] oriented bands lying parallel to the former rolling direction an d the matrix with orientations: {112} [110], {111}[134] and {111}[112], mix ed on the local scale. From the analysis of the ropes results that their ge ometry is formed by two kinds of superimposed effects, namely the macro-rid ging on the millimeter scale and micro-ridging on the micrometer scale. The first of them is directly related to inhomogeneity of the texture and it c an be interpreted according to the mechanism proposed by Wright [6]. Then t he micro-ridging can be explained by the anisotropic interaction between sa mple symmetry related variants of the same component, particularly of the t ype {112}[110], which roughly corresponds to the model of Appel-Lucke [in 5 ].