Habib Saadi A, Meredith Christopher S, Khan Akhtar S
National Institute of Standards and Technology, 100 Bureau Drive, Gaithersburg, MD, USA.
U.S. Army Research Laboratory, Aberdeen Proving Ground, MD, USA.
Int J Mech Sci. 2021 Dec;211. doi: 10.1016/j.ijmecsci.2021.106774.
The mechanical response of an advanced high strength and corrosion resistant 10 % Cr nanocomposite steel (ASTM A1035CS Grade 120) is measured under uniaxial tension and compression at the strain rates of 10 s, 10 s, 10 s, 700 s, and 3000 s. The experiments are performed at 22 °C as well as 80 °C to investigate the material behavior at the expected temperature rise due to adiabatic deformation at 15 % strain. Additionally, different compression-shear hat-shaped specimens are tested at quasi-static and dynamic strain rates to investigate the localization behavior of this material. The material exhibits small strain rate sensitivity (SRS) during quasi-static loading, but a pronounced SRS between quasi-static and dynamic strain rates. Tension-compression asymmetry is also observed at both temperatures. Experiments at 80 °C reveal a decrease in flow stress in both tension and compression indicating the material is sensitive to thermal softening due to adiabatic heating. Load-Unload-Reload (LUR) and strain rate jump experiments are performed to investigate the reasoning behind the approximate rate insensitivity of ASTM A1035CS steel during quasi-static strain rates. A new constitutive model is also developed using a novel rate dependent material model with a modified Hockett-Sherby (MHS) hardening model and incorporating Lode angle dependence to capture the tension-compression asymmetry. The model is also used to predict the LUR and strain rate jump experiments. Finally, reasoning behind the unique rate dependent thermo-mechanical behavior of ASTM A1035CS steel is discussed in regards to adiabatic heating, strain-partitioning, and phase transformation.
对一种先进的高强度耐腐蚀 10% Cr 纳米复合钢（ASTM A1035CS 120 级）在 10⁻³ s⁻¹、10⁻² s⁻¹、10⁻¹ s⁻¹、700 s⁻¹ 和 3000 s⁻¹ 的应变速率下进行单轴拉伸和压缩试验，测量其力学响应。试验在 22 °C 和 80 °C 下进行，以研究材料在 15%应变下绝热变形导致的预期温度升高时的行为。此外，还对不同的压缩 - 剪切帽形试样在准静态和动态应变速率下进行测试，以研究该材料的局部化行为。该材料在准静态加载过程中表现出较小的应变速率敏感性（SRS），但在准静态和动态应变速率之间表现出明显的 SRS。在两个温度下均观察到拉伸 - 压缩不对称性。80 °C 下的实验表明，拉伸和压缩时的流动应力均降低，这表明材料对绝热加热引起的热软化敏感。进行了加载 - 卸载 - 再加载（LUR）和应变速率跳跃试验，以研究 ASTM A1035CS 钢在准静态应变速率下近似速率不敏感性背后的原因。还使用一种新的速率相关材料模型和改进的霍克特 - 谢尔比（MHS）硬化模型，并纳入洛德角依赖性，开发了一个新的本构模型，以捕捉拉伸 - 压缩不对称性。该模型还用于预测 LUR 和应变速率跳跃试验。最后，讨论了 ASTM A1035CS 钢独特的速率相关热机械行为背后的原因，涉及绝热加热、应变分配和相变。
