Microstructural evolution and strain hardening behavior of AISI 316L type austenitic stainless steel

Abstract

Abstract The microstructural evolution of AISI 316L austenitic stainless steel subjected to interrupted uniaxial tensile testing is investigated in relation to the strain hardening behavior. The microstructural evolution is characterized by means of scanning electron microscopy equipped with electron backscattered diffraction, optical profilometry and atomic force microscopy. The experimental results show that the increase in level of deformation causes increased surface roughness, extrusion height, plastic strain value, fraction of low-angle grain boundaries and geometrically necessary dislocations. The tensile work hardening analysis reveals a three-stage behavior, where the deformation mechanism is dominated by localization of plastic strain in slip bands due to dislocation–dislocation interactions in stage II and by rotation of austenite grains and dynamic recovery which is due to dislocation annihilations in stage III.