A New Quantitative Representation of Surface Roughness and Its Application to the Analysis of Light Scattering from Steel Sheet Surfaces

Abstract

An automatic analysis system for surface roughness has been developed by incorporating a roughness measuring instrument of the probe type to a laboratory automation system. This system facilitates the measurement and statistical analysis of random profiles of rough surfaces which require a great deal of work and time.
1) First a new quantitative representation of surface roughness was established in this system and the statistical characteristics of surface profiles of cold rolled steel sheet were analysed.
2) Next the spatial intensity distribution of laser beam scattering from the same surfaces was examined by a photogoniometer.
From these experiments the relation between surface roughness and light scattering characteristics of dull finished sheet was obtained.
This result suggests the possibility of non-contacting, on-line inspection technique of surface roughness.
This system will be useful for the investigation of surface characteristics of steel products, such as the surface appearance, paint adhesion, plating, and drawing qualities.