Stress-state dependence of dynamic strain aging: Thermal hardening and blue brittleness

Abstract This study aims to discover the stress-state dependence of dynamic strain aging (DSA) effect on deformation and fracture behavior high-strength dual-phase (DP) steel at different temperatures (25–400°C) reveal damage mechanisms under these various configurations. To achieve stress states, predesigned specimens with geometric features were used. Scanning electron microscopy was applied analyze modes (e.g., dimple or shear mode) underlying mechanism investigated material. DSA is present in this DP steel, showing Portevin-Le Chatelier (PLC) serrated flow behavior, thermal hardening, blue brittleness phenomena. Results show that state contributes distinctly terms magnitude hardening pattern brittleness. Either low triaxiality Lode angle parameter promotes DSA-induced Accordingly, also states conjunction effect.