Electron-microscopic study on austenitic aging Fe-Ni-Mn steels with carbide-intermetallic strengthening

The fine structure and mechanical properties of nonmagnetic austenitic Fe-Mn steels alloyed with nickel, aluminium, vanadium, carbon are studied. In the course of aging at 600-700 deg C two types of excessive phases of vanadium carbide and Ni-Al base intermetallics are formed at the same time. Formation of the intermetallic phase realizes in two stages. At the first stage a three-dimensional periodical modulated structure of coherent equiaxial particles, at the second one - intermetallic plates (with the b. c. c. structure of the B2 type) appear. Simultaneous for-- mation of high-dispersed particles of VC, γ' and α' ensures a high level of mechanical properties of studied steels