Structure and properties of surface layers prepared by ion nitriding

Chemical and structural analysis of thin surface layers was carried out on tool steel and maraging steel prepared by ion nitriding and magnetron deposition. The nitrogen highest surface saturation was achieved after cathodic ion nitriding. The maximum effect of strengthening of the surface was found in steel 17321 because of the chromium nitride formation. Complete ion nitriding of the titanium layer was not achieved. Material transport from supporting electrodes to nitrided samples seems to be probable during the process of plasma nitriding. Tungsten, molybdenum, chromium and aluminium supporting electrodes were checked. Both anodal and alternate nitriding were applied. Technically pure iron was choosen for surface treatment. Applied experimental methods consisted of X-ray diffraction analysis, topography of sample surface, globe discharge optical spectrometry, metallographical investigation, hardness measurement, etc. Experiments proved, that the material transport takes part from all checked electrodes to the surface of samples during anodal as well as alternate nitriding.