A consideration is given to structure and behavior of austenite in Fe-Mn-Cr-C system alloys under conditions of quasistatic deformation and dynamic contact loading. Principles of basic composition selection for metastable austenitic steels intended for operation under above-mentioned conditions are substantiated. Three groups of basic compositions were selected to design commercial grades of steels, namely, 1) 0.4-0.7% C; 7-14% Mn; 0-5% Cr; 2) 0.75-0.95% C; 6-8% Mn; 2-4% Cr; 3) 1.0-1.4% C; 5-8% Mn; 0-2% Cr. Steels types 60G10Kh4(M)L, 60G14(Kh2)L, 80G7Kh3(F)L, 110G7KhL, 130G9KhFL were developed.