Modification of hot work tool steel surfaces by various thermochemical treatments

The surface of the hot work tool steel X37CrMoV5-1 (W300) was subjected to different thermochemical treatments in order to improve its mechanical properties, corrosion and wear resistance. Nitrocarburising with or without post-oxidation based on the TENIFER procedure and low temperature powder aluminising+nitrocarburising with or without post-oxidation were performed. Nitrocarburised and nitrocarburised+post-oxidised layers were characterised by testing their basic properties (compound layer thickness, nitrocarburising depth and microhardness) as well as their corrosion resistance. First, the microstructures of aluminised+nitrocarburised samples (with or without post-oxidation) were analysed by means of optical microscopy, and then the microhardness distribution across the surface layer. Finally, the corrosion resistance of aluminised+nitrocarburised samples (with or without post-oxidation) were examined. Glow discharge optical spectroscopy was employed to investigate the distribution of elements in the c...