Influence of axial and torsional cyclic loading on the fatigue behavior of 304LN stainless steel using solid and hollow specimens

Effect of loading path and geometry on fatigue behavior was evaluated for 304LN stainless steel using solid and thin walled hollow specimens. Hollow specimens were subjected to both axial and shear loading under strain control. Solid specimens were used only for strain controlled axial loading. Fatigue life was highest for shear loading despite the higher stress response and the least for the axial loading for hollow specimens. The cyclic deformation behavior marked by Masing behavior, cyclic stress strain curves and probability density function analysis was found to be remarkably different for shear loading. All disparities in the cyclic deformation behavior due to difference in loading path has been accounted by the dislocation dynamics and martensitic transformation investigated through TEM.