The discontinuous Euler transformation behavior inside grains leading to low residual stress regions during plastic deformation

Studying the texture evolution behavior and orientation transition path during plastic deformation can help understand the deformation mechanism of materials and improve the prediction accuracy of crystal plastic finite element simulations. However, the mechanism of Euler angle transformation behavior inside grains during plastic deformation remains unclear. In this paper, the discontinuous Euler transformation behaviors of non-oriented electrical steel with body-centered cubic (BCC) lattice during uniaxial tensile deformation were studied in detail by electronic backscatter diffraction (EBSD). It is shown that the discontinuous Euler transformation behavior regions highly overlapped with the low residual stress regions in a wide plastic deformation region with high Schmid factors. Two types of discontinuous Euler transformation behaviors were identified: one occurring near the junction between 0° and 360° of Euler 1, where cyclic characteristics were observed; and the other resulting from concentrated change, replacing the required long-distance accumulation process. These discontinuous Euler transformation behaviors decreased the cumulative level of misorientation, leading to the formation of low residual stress regions. This study proposed a novel framework for analyzing the evolution of residual stress during plastic deformation on the basis of the Euler transformation behavior, and illustrated the relationship between the Euler transformation behavior and the low residual stress characteristic. In addition, this mechanism can be extended to clarify the deformation texture evolution behavior and orientation transition path of materials with other crystal structures or mixed crystal structures.