Dynamic tensile properties of a novel high strength and high toughness bolt steel: Constitutive models and microstructures

• DOI: 10.1016/j.jmrt.2024.04.169
• Publication Date: 2024-05-03T03:42:11Z
• Authors: Min Xia; Wentao Wu; Zhaojiang Xue; Wenjie Fan; Shuyu Nie; Jie Tang; Naisheng Jiang; Hongyan Guo; Manchao He
• Keywords: Split Hopkinson Pressure Bar; Elongation; Tension (geology); Dynamic Tension

With the continuous increase of depth in underground engineering, rock bursts or explosions can cause instantaneous shock load and result engineering disasters. To solve these problems, a novel high strength toughness (HSHT) bolt steel with constant resistance large deformation is proposed. This study aims to investigate dynamic constitutive models microstructure HSHT under extreme loading conditions. A series tension tests were conducted using Split Hopkinson Tensile Bar (SHTB) system high-speed camera. The results revealed that exhibited positive strain rate effect. As increased from 1000 s-1 5000 s-1, yield ultimate gradually. However, no obvious changes uniform elongation. Specifically, strength, elongation at 1100 MPa, 1170 30%, respectively. According SHTB tests, modified Johnson-Cook model was Additionally, we investigated through microscopic characterization techniques. number fine deep dimples observed near fracture loading. Moreover, demonstrates significant presence nano-twins, which effectively impedes crack propagation both within grain interior along boundaries. above findings reveal relationship between mechanical behavior conditions, providing valuable insights for design engineering.