In-situ texture analysis and crystallographic aspects of pearlitic steel subjected to pure shear in uniaxial stress

Abstract

In-Situ synchrotron X-ray diffraction experiments were conducted on pearlitic steel sample with a carbon content of 0.74% by weight. Specimens were subjected to shear deformation in two-dimensional diffraction patterns were acquired during uniaxial loading to investigate the crystallographic changes. Rietveld refinement was used to analyze the evolution of Dislocation Density, Lattice Microstrain in the ferritic phase and the crystallographic texture was investigated in both phases. The analysis revealed that texture from {110}<113>α component to {113}<121>α component and then, stabilizing in {013}<uvw>α fiber components. The cementite showed a {100, 010, and 001}θ texture planes and one strong preferential reorientation to planes close the same directions. Additionally, dislocation nucleation of interface α/θ promotes the amorphization of cementite and the activation of slip along non-compact directions in {310}α planes due to meeting interfacial defects. The orthorhombic phase orientation limits the rotation in the α-BCC, does not possibility the accommodation of defects to activation new reflections more stable. The increase of Dislocation Density promoted by activation of slip systems in ferrite, contributes to the macroscopic hardening of the pearlite. The influence of microstructural changes on mechanical properties is discussed.