A novel insight on the anisotropic Lüders strain of DP780 steel at cryogenic temperature

Anisotropic mechanical behavior and Lüders strain are frequently observed during the deformation of dual-phase (DP) steels. The present study investigates the anisotropic Lüders strain behavior exhibited by DP780 steel under cryogenic temperature tensile testing at varying strain rates. Based on electron backscattering diffraction (EBSD) technology, the effects of the texture evolution of the samples loaded in different directions and the Taylor factor distribution on the anisotropic Lüders strain were revealed. It is found that the formation of anisotropic Lüders strain is affected by the {110} slip system with lower dislocation slip resistance. For the first time, the mechanism of anisotropic Lüders strain of DP780 steel at cryogenic temperature was revealed from the perspective of texture evolution and main activated slip systems.