Innovative sample preparation for GDOES analysis of decarburized layers in cylindrical metal specimens

Glow discharge optical emission spectrometry (GDOES) is a technique widely used for depth profile analysis but there are two significant limitations: samples must have planar surfaces and profile analysis generally cannot go beyond a depth of 100 µm. A new method of sample preparation has been developed to overcome both of these limitations, consisting of plastic deformation of the curved sample by pressing it until a planar surface is obtained. Furthermore, after profile analysis, the surface surrounding the glow-discharged zone of the sample is ground to obtain a uniform layer levelled down to the bottom of the crater. Repeated grinding operations and profile analyses allow analysis of samples with practically unlimited thickness. An application of this method to determine the entity of the decarburized layer on a carbon steel rod sample is described in this paper. Copyright © 2001 John Wiley & Sons, Ltd.