| Abstract Scope |
This study examines the impact of precipitates on the in-plane tensile behavior, including strain hardening, of hot-rolled X-65 Line pipe steel. Tensile samples were prepared from four directions on the RD-TD plane (0°, 30°,
60°, and 90° to the RD). The 90° sample exhibited superior mechanical properties, with better yield continuity and an optimal strength-ductility balance. The yielding behavior and tensile response are explained by grain boundary
characteristics, dislocation-precipitation interactions, and elastic-plastic incompatibility at grain boundaries. The interaction of dislocations with fine precipitates and differences in Elastic Modulus (EM) and Schmid Factor (SF) across
high-angle grain boundaries (HAGBs) significantly contribute to the enhanced properties of the 90° sample. |