Coating characterization of nitrocarburized steels

In this investigation, a systematic characterization of the diffusion coatings was carried out. These coatings, developed by different nitrocarburizing processes, namely salt-bath, gas and plasma nitrocarburizing, were conducted on various steel substrates. The tested substrates were St 52-3, Ck 45, 42 CrMo 4, 30 CrNiMo 8 and X 20 Cr 13. The thickness of compound layers and their porosity were measured using optical microscopy. The structure of compound layers was characterised using an X-ray diffractometer and their surface roughness by a stylus profilometer. The surface hardness measurements and hardness profiles were carried out according to the Vickers principle.