Inclusion mapping and estimation of inclusion contents in ferrous materials by fast scanning laser-induced optical emission spectrometry.
In: Journal of Analytical Atomic Spectrometry (J.Anal.At.Spectrom.), Jg. 20 (2005) ; Nr. 8, S. 730-735
Zeitschriftenaufsatz / Fach: Chemie
Fast scanning laser-induced optical emission spectrometry (scanning laser OES) is applied to est. the content of nonmetallic inclusions in ferrous materials within a few tens of minutes. The emission intensity after each single laser pulse is recorded in 41 element channels. Signals of inclusion related elements are evaluated by different statistical algorithms. The goal of the data treatment is to distinguish between emission peaks representing laser pulses focussed on the nonmetallic inclusions and the class of low intensity signals from the element share dissolved in the metallic matrix. Criteria for the distinction are the 3-sigma (plus mean) threshold, the skewness of the histogram by Pearson, and a modified outlier test based on the Nalimov test. Correlations between the statistical approaches for signal evaluation and the inclusion contents in synthetic Fe-base stds. are discussed.