The carbon contents in carburized steels were investigated by electron
probe microanalysis (EPMA) for a range of carbon levels in the solid
solution less than 1 wt%. This article describes the difficulties
encountered with the classic analytical procedure using the k
ratio of X-ray intensities and the φ(ρz) model. Here, a
suitable calibration curve method is presented with emphasis on the
metallographic study of standard specimens and on the carbon
decontamination of samples.