High-Temperature Plasticity Enhanced by Multiple Secondary Phases in a High-Si Austenitic Stainless Steel

An austenitic stainless steel with 6 wt% Si and multiple secondary phases was produced the aim to achieve enhanced plasticity during hot deformation. The microstructure of after fracture characterized via electron back-scattered diffraction, transmission Kikuchi diffraction scanning microscopy. From tail gage necking region, material evolved from low-angle grain boundaries (LAGBs) mixtures LAGBs high-angle (HAGBs), fine equiaxed recrystallized grains. elongation failure in tensile test exceeds 167%. During deformation, continuous dynamic recrystallization matrix promoted by phases. dislocations introduced were rearranged continuously transformed into HAGBs. initially coarse grains (30.5 μm) refined ultra-fine (1 μm), which contributed significantly deformation steel. In area sample, twins nucleated stress concentration regions accommodated local strain discontinuous recrystallization, also beneficial improving plasticity.