Effect of Pre-strain on Microstructure, Texture, and Strengthening of Fully Pearlitic Steel

The changes of microstructure, crystallographic texture, and phase/boundary interface in fully pearlitic industrial steel, under coiling and uncoiling process were comprehensively investigated. The scanning electron microscopy investigation showed that localized stress accumulation at the ferrite-cementite interface promotes cementite fragmentation. The macro texture analysis revealed that the as-received material demonstrated a {001}, {110} and {112} texture parallel to the normal direction. After the coiling and uncoiling process, the {112} grains partially rotated into {110} and {111} grains oriented along the normal direction. This led to a significant increase in dislocation density due to the lattice distortion and localized stored energy as determined by the point-to-point Kernel misorientation analysis. Multiplication of ferrite-cementite interfaces and increase in crystallographic defects and pile-ups influenced the effective shear stress, leading to a brittle fracture mode.