The precise measurement of carbon profiles after thermochemical treatment of PM steels is of extreme importance, but challenging. The usual methods like combustion analysis after selective milling is laborious and only applicable with simple geometries, sensitivity of SEM-EDX is not sufficient. Porosity excludes the application of GD-OES. In this work the use of LIBS for laterally resolved analysis of C in PM steels is presented. Quick and quantitative analysis with LIBS offers massive benefits, because exact C-profiles can be provided right at the desired regions, which might be important for further simulation of the process.
The method development includes the production of proper standards to identify influences of the production route. Different prealloyed steels (Mo, Cr & Cr+Mo) are used to produce standards with defined C content. The thoroughly characterized standards were used for optimization of measurement conditions. Finally the method is successfully tested on serial PM parts.