The influence of the nitrogen treatment under the laser action in nitrogen flow, under xenon lamp irradiation in the air medium, in electrolytic plasma or at ion implantation on mechanical, electrochemical as well as corrosion properties of the treated steel surface is considered. It is shown that the enrichment of the surface layers by nitrogen independently on the way of the nitrogen doping promotes to an increase of the microhardness as well as to the passivation in neutral media of the steels having a moderate carbon concentration. It has been noticed that the treatment leads to a considerable increase of the corrosion resistance. Corrosion resistivity of the surface layers turns to be considerable more for the nitrogen implanted steel comparing with the steels nitrided both in the electrolytic plasma or the nitrogen flow. Obviously, the latter is a consequence of the uniform nitrogen distribution along the surface provided by the ion implantation. Substantial increase of the corrosion resistance allows to use nitriding in anode electrolytic heating for hardening of machine parts and tools. The developed express methods allow to estimate the corrosion resistance of nitrided steels fast and effectively.