The paper presents results of research on gas nitriding and PA PVD-Arc technologies to form duplex layer on constructional and hot work tool steels. As a result a two layer structure of nitrided layer and CrN coating was obtained. Authors shown results of investigations of duplex layer: hardness, microstructures, wear and corrosion resistance. Duplex layer has thickness about 2-3 μm (CrN) and 150-400 μm (nitrided layer). The steel after nitriding consists of a white layer of about 2-15 μm or without it (only diffusion layer about 150-400 μm). The duplex layers possess a better corrosion and wear resistance like only nitrided layers. In the case of anticorrosion nitrided layer, oxidation and impregnation can be replaced by using CrN coats