Reversible martensitic transformation produced by severe plastic deformation of metastable austenitic steel

摘要

The peculiarities of martensitic transformations and formation of nanostructured states in metastable austenitic steel (Fe-18Cr-8Ni-Ti) after severe plastic deformation by high pressure torsion are investigated. It is shown that during severe plastic deformation with increased strain rate not only direct (γ→α'') but also reverse (α'→γ) martensitic transformations occur, which is revealed by the changes in the volume content of a' - martensite during deformation. The fragments thought to be formed by direct and reverse martensitic transformations and those of dynamic recrystallization of austenite are observed.