Strengthening of austenitic stainless steel by formation of nanocrystalline γ-phase through severe plastic deformation during two-dimensional linear plane-strain machining

Austenitic stainless steel was severely plastically deformed at room temperature using plane-strain machining for two different processing conditions. Using X-ray diffraction, magnetometry, conventional transmission electron microscopy, including a transmission electron microscope based orientation imaging microscopy technique, and hardness measurements, microstructure changes were related to mechanical properties. The observed hardness increase is attributed to the machining-induced grain refinement and stored strain. Depending on the processing condition, dynamic recovery and recrystallization were observed.