Effect of initial grain size on the dynamic recrystallization behaviours of austenite

The effect of initial grain size on the recrystallization behaviour of a type 304 austenitic stainless steel was investigated using hot torsion. Refinement of the initial grain size to 8 μm had a considerable effect on the flow curve shapes, peak and critical strains and also on DRX kinetics, compared with an initial grain size of 35 μm. Microstructural investigations using EBSD suggest a transition from conventional (discontinuous) to continuous dynamic recrystallization with decreasing initial grain size. Also, there was a moderate effect of initial grain size on the DRX grain size.