Estimates and experimental study of aluminum, carbon and nitrogen content effect for thermally and mechanically stable austenitic alloys based on Fe-(20–25)%Mn-(5–10)%Al-(0–10)%Ni-C-N, and hardening efficiency of these alloys by nitrogen addition are conducted. It is shown that the alloys based on the investigated system with C content of >1.2% for nickel-free system and ≥1.4 % for 5% and 10% of Ni can be proposed as high-strength non-magnetic cryogenic both in heat-treated and aged states. Nitrogen addition in the alloy containing 5% Al can be considered as micro-alloying, enhances dispersion of the cast structure. Ni enhances the dispersion hardening effect due to increase in carbide release rate resulted from the reduction of C solubility in austenite. Rational content of nickel equals to ~5%.