Detailed Metallographic Analysis of the Surface Layer Structure of Carbonitrided Case-Hardening Steels after Varied Tempering Treatments

This work aimed at performing a more in-depth analysis of the influence of the tempering temperature on the microstructure development in carbonitrided case-hardening steels. To this end, X-ray measurements are performed alongside various metallographic methods. It was, above all, due to the unusually high tempering temperature of 280 °C for case-hardened samples that the conventional characterization methods initially did not yield satisfying results. Therefore, examinations in the scanning and the transmission electron microscope as well as EBSD investigations were performed alongside the light microscopy analyses. The motivation for the examinations was and is the challenge or rather the desire to gain better understanding of the correlation between load capacity results and the respective surface layer microstructures.