LAUSR

Abstract The present work aims to examine the low cycle fatigue (LCF) behavior of dual-phase (DP590) steel subjected to different pre-straining (uniaxial and equi-biaxial) paths. The LCF tests reveal all specimens showed continuous cyclic softening throughout the fatigue life. However, the rate of cyclic softening is higher for the equi-biaxial pre-strain specimen. The rotation of one maximum shear stress plane during fatigue cycling after equi-biaxial pre-straining introduces non-proportional loading conditions, thereby significantly reducing the fatigue life. The larger lattice rotation and in-grain misorientation due to the non-proportional loading is notable for the equi-biaxial pre-strain specimen.