Orientation-dependent plastic deformation in transformer steel: Experiments and dislocation dynamics simulations

Abstract

The anisotropic tensile response of fully processed cold-rolled grain-oriented (CRGO) steel was studied for two crystallographic orientations: (110) 〈001〉 and (110) 〈11¯1〉. They showed remarkably different stress–strain behavior and corresponding developments in deformed microstructures. The (110) 〈001〉 oriented CRGO steel specimens retained their orientation stability until ε (true strain)=0.07. On the other hand, (110) 〈11¯1〉 oriented specimens underwent significant reorientation and displayed formation of strain localizations by ε=0.03. Discrete dislocation dynamics (DDD) simulations were carried out – three-dimensional (3-D) for “limited” (∼10−4) plastic strain and two-dimensional (2-D) for the experimentally imposed strain – to investigate the orientation effects on the tensile response of the CRGO steel specimens. 2-D DDD simulations were able to provide qualitative and quantitative estimates of the post-yield tensile behavior of (110) 〈001〉 and (110) 〈11¯1〉 samples. Direct comparison between experimental and simulation results confirmed the orientation effect on the overall macroscopic response of the specimens. It was observed that the response of (110) 〈11¯1〉 specimens showed features of reorientation and textural softening and these were captured by the Taylor type deformation simulations.