Post-fire mechanical properties of low yield steel in uniaxial tension

Low yield point (LYP) steel is characterized by low yield strength, high ductility, and excellent energy dissipation capacity, making it widely used in structural energy dissipation components for engineering applications. However, the possible reduction of LYP steel's post-fire mechanical performances remains a concern for practical application. This study investigates 42 LYP160 specimens subjected to high-temperature exposure, ranging from ambient temperature to 800 °C, followed by either air cooling or water immersion cooling. Uniaxial tensile tests are performed to obtain stress-strain curves and evaluate the mechanical properties of the specimens. Additionally, the fracture morphologies and metallurgical structures are analyzed under different cooling methods. Based on these observations, predictive equations for the post-fire mechanical properties of LYP160 are developed, providing a scientific foundation and theoretical guidance for engineering applications.