A study of the void surface healing mechanism in 316LN steel

Abstract

The behavior of void surface healing in 316LN steel samples undergoing thermal plasticity deformation was investigated using the Gleeble 1500 thermomechanical simulator. The characterization of the void surface after plastic deformation was analyzed under different deformation temperatures, deformation amounts, and holding time durations. The morphology evolution and microstructure of the void surface healing zone during thermal plasticity deformation and holding time duration stage were analyzed using electron back scatter diffraction imaging. The mechanism of void surface healing under thermal plasticity deformation was investigated. It was found that the degree of void surface healing increases with the degree of deformation and the duration of the holding time. Dynamic recrystallization occurred continuously at the void surface, resulting in a plethora of crystal defects and a substantial amount of energy. These conditions were conducive to atomic diffusion and migration, thereby promoting the healing process of the void surface. Maintaining high temperature after deformation can continue to provide energy for the diffusion and migration of atoms, promotes the growth of recrystallized grains, and gradually heals the void surface.