Investigation on Grain Boundary Character Distribution During Dynamic Recrystallization of Austenitic Stainless Steel During Hot Deformation

The phenomenon of dynamic recrystallization (DRX) is central to the hot working and thermomechanical processing of austenitic stainless steel. This study aims to relate two distinct parameters that influence DRX: the content of interstitial atoms, such as nitrogen, and character of grain boundaries in the steel. 316LN austenitic stainless steel has been subjected to thermomechanical processing at 1,423 K through uniaxial compression at different strain rates. At these, the microstructure is fully recrystallized. The nature, character, and growth of DRX grains are studied using Electron Backscatter Diffraction (EBSD). EBSD is used to determine grain boundary character distribution and the Effective Grain Boundary Energy (EGBE) parameter. The evolution of EGBE and its relation to grain growth are analyzed. The concomitant development of special low-energy boundaries is correlated with the interstitial content in the steel, thus linking interstitial content to EGBE. The correlations so made are tested by examining the corrosion resistance of different boundaries formed at different deformation conditions.