Abstract For their versatile microstructure controlling techniques, advanced high strength steels (AHSSs) show great potential to be tailored for various application scenarios. The unique microstructure of AHSSs renders their complex plasticity behaviors and mechanical properties. In this work, uniaxial tensile tests combined with a 3D digital image correlation system were carried out to capture the mechanical anisotropy evolution of a cold-rolled dual-phase AHSS (DP980) sheet. In contrast to the conventional body centered cubic (BCC) steel sheets, the studied DP980 sheet shows much smaller Lankford coefficients and a mild strength anisotropy. The Lankford coefficients depend significantly on tensile directions and vary obviously with deformation; they increase with deformation first and then decrease after macroscopic strain localization takes place. Postmortem experimental characterizations as well as microstructure based full-field crystal plasticity simulations were employed to uncover the underneath mechanisms. Plasticity heterogeneities and micromechanical interactions between the soft ferrite matrix and hard martensite islands primarily account for the mechanical anisotropy of the studied steel sheet.

中文翻译：

---

先进高强钢板塑性各向异性研究：实验及基于微观结构的晶体塑性建模

摘要 由于其多功能的微观结构控制技术，先进高强度钢 (AHSS) 显示出为各种应用场景量身定制的巨大潜力。AHSS 独特的微观结构使其具有复杂的塑性行为和机械性能。在这项工作中，进行了结合 3D 数字图像相关系统的单轴拉伸试验，以捕捉冷轧双相 AHSS (DP980) 板的机械各向异性演变。与传统的体心立方 (BCC) 钢板相比，所研究的 DP980 钢板显示出更小的兰克福德系数和温和的强度各向异性。Lankford 系数显着依赖于拉伸方向，并且随变形变化明显；它们随着变形先增加，然后在宏观应变局部化发生后减少。采用验尸实验表征以及基于微观结构的全场晶体塑性模拟来揭示底层机制。软铁素体基体和硬马氏体岛之间的塑性异质性和微观机械相互作用主要解释了所研究钢板的机械各向异性。