Microstructure, properties, and failure characteristics of medium-carbon steel subjected to severe plastic deformation

The paper deals with two-stage processing of medium-carbon steel 45 (0.45 % C; 0.27 % Si; 0.65 % Mn) via quenching and high pressure torsion. Such processing combination allowed producing a nanocomposite microstructure with a ferrite matrix and high-dispersed carbides. The ultimate tensile strength of the nanostructured steel is over 2500 MPa. The processing effect on the structure, mechanical properties and failure mechanisms of steel 45 samples is studied. The peculiarities of static fractures in the samples after HPT are demonstrated in comparison with those after quenching.