Quantification of the Morphological Signature of Roping Based on Multiscale Analysis and Autocorrelation Function Description

Abstract

<jats:p>Roping or ridging is a visual defect affecting the surface of ferritic stainless steels, assessed using visual inspection of the surfaces. The aim of this study was to quantify the morphological signature of roping to link roughness results with five levels of roping identified with visual inspection. First, the multiscale analysis of roughness showed that the texture aspect ratio Str computed with a low-pass filter of 32 µm gave a clear separation between the acceptable levels of roping and the non-acceptable levels (rejected sheets). To obtain a gradation description of roping instead of a binary description, a methodology based on the use of the autocorrelation function was created. It consisted of several steps: a low-pass filtering of the autocorrelation function at 150 µm, the segmentation of the autocorrelation into four stabilized portions, and finally, the computation of isotropy and the root-mean-square roughness Sq on the obtained quarters of function. The use of the isotropy combined with the root-mean-square roughness Sq led to a clear separation of the five levels of roping: the acceptable levels of roping corresponded to strong isotropy (values larger than 10%) coupled with low root-mean-square roughness Sq. Both methodologies can be used to quantitatively describe surface morphology of roping in order to improve our understanding of the roping phenomenon.</jats:p>

Analysis and characterization of roping in AA6XXX automotive sheet

“…While the stoning process highly depends on the experience and is time-consuming. Some researchers have proposed using 3D morphological information to describe surface roping [1,4,[7][8][9], including morphological images obtained from the white light interferometer and grayscale images acquired by the optical camera. Engler et al [4] studied two Al-Mg-Si sheets with significant roping intensity differences using a white light interferometer.…”

Surface Inspection and Description in Metrology and Tribology—Vol.1

“…These aspects are particularly important for Industry 4.0 and its purely metrological part, Metrology 4.0 with all aspects and consequences [2]. Another important topic was the separation of different frequencies, i.e., different ideas of filtration and multiscale approach to analysis [3,4]. This is particularly important for different ways of machining [5] and the investigation of bodies in contact [6,7], where tribological behavior and chemical processes on the surface are to be considered [8,9].…”

3D Parametric and Nonparametric Description of Surface Topography in Manufacturing Processes

“…Different scales show the multiscale nature of different sorts of anisotropies. Continuing multiscale approach to surface topography, Marteau et al [ 19 ] present a study with the morphological signature of roping to link roughness results with five levels identified by a visual inspection. Roping or ridging is a visual defect affecting the surface of ferritic stainless steels, assessed using visual inspection of the surfaces.…”