HARDENING OF AUSTENITIC STEELS WITH HIGH Mn AND Al CONTENT
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%.