Understanding the Affects of Increased Special Boundary Fraction on Dynamic Recrystallization
Deformations introduced into low to medium stacking fault energy materials at or above the recrystallization temperature cause simultaneous formation and annihilation of defects. Annihilation of defects by nucleating strain free grains is called dynamic recrystallization (DRX). Nucleation during DRX has been shown to occur more extensively on general (high angle) boundaries then on special (low angle) boundaries. Grain boundary engineering (GBE) is a process that improves the structural and functional properties of polycrystalline materials by manipulating the occurrence of low sigma or so called special grain boundaries. An iterative GBE cold rolling based process has been created to increase the occurrence of the Σ3 low angle special boundaries within stainless steel 316L (SS316L). The affect of increased Σ3 content on DRX has been studied on the MTS 810 Material Test System at elevated temperatures and strains specific to the creep regime. Analysis of a material’s microstructure, including grain boundary type and energy, has been performed with a crystallographic based microstructural characterization technique known as electron backscatter diffraction (EBSD). Through EBSD analysis, the affect of GBE SS316L, specifically to increase the Σ3 content, on DRX has been explored.