Wear resistance of D2 cold work tool steel after gas nitriding combined with deep cryogenic treatment
Gas nitriding with subsequent heat treatment in combination with deep cryogenic treatment (DCT) produces nitrided layers with specific properties. Layers with unique properties result from the dissolution of subsurface layers of iron nitrides and subsequent nitrogen diffusion into the substrate during austenitization. Process of deep cryogenic treatment takes place between the quenching and tempering steps. Fine precipitates of carbonitrides eventually form during DCT and the tempering process. This research is based on comparison of novel nitrided layers with conventionally nitrided layers. The experimental steel was AISI D2 cold work tool steel with equivalents DIN 1.2379 / X153CrMoV12. The thermochemical treatment methods were evaluated and compared based on hardness measurement and the extensive wear testing by the pin-on-disc method in different conditions of testing.