Experimental study on the mechanical characteristics of a novel high-strength-and-high-toughness steel

Abstract

To effectively control large deformation disasters, our team has developed a novel high-strength and high-toughness (HSHT) steel. This study aims to conduct a comparative analysis of the mechanical properties of HSHT steel and typical commercial steel under tension and impact. Testing was carried out using a universal testing machine and a self-developed drop-hammer-type longitudinal impact dynamic mechanical tester, with dynamic axial force sensors and infrared equipment utilized for monitoring. The results of the experiments are as follows: In the tensile test, HSHT steel exhibited superior performance in terms of tensile strength, elongation, and uniform deformation, particularly in radial deformation. The strength-ductility product of HSHT steel was more than two times that of typical commercial steel, indicating better energy-absorbing properties. Infrared data analysis showed that HSHT steel bars displayed uniform warming throughout their entire length. In the impact test, HSHT steel reinforcement demonstrated higher mechanical properties compared to commercial steel. Following failure, HSHT steel bars did not exhibit significant necking at the fracture site and showed a larger area of impact deformation. The axial forces experienced by the different steel bars were similar under various conditions. Data fitting analysis revealed an exponential relationship between the static tensile maximum strains of all bar types and the number of cyclic impacts. For HSHT steel bars, the number of impacts was also exponentially related to displacement, cyclic height, and energy absorbed prior to failure. Additionally, HSHT bars exhibited better uniform heating characteristics during cyclic impacts, with higher heating temperatures compared to typical commercial steels.