The hardening and austenite stability as a result of nitrogen alloying steel type of Cr18Ni10 in the temperature range, which is usual for the application of such steels as corrosion-resistant structural heat-resistant and/or cryogenic ones was studied. It is shown that the nitrogen alloying is perspective for strengthening and increasing of stability of austenitic stainless steels. Additional strengthening due to the preliminary cold or warm deformation hardening increases a tendency to the martensite formation under load, which limits the operating temperature of these steels. High-strength non-magnetic nitrogen-alloyed steels on the base of Cr18Ni10 steels containing up to 0.22 % of nitrogen are suitable for cryogenic application of non-deformed articles only. Otherwise, a strain-induced martensite will always form in them at temperatures below -70 °С. High strength, ductility and toughness of these steels can be achieved simultaneously only as a result of the TRIP-effect or fine-grained structure formation.