Understanding the Deformation Mechanisms in Austenitic Iron-Manganese Steels with Changes in Stacking Fault Energy, Strain Rate and Tempeature

了解奥氏体铁锰钢随堆垛层错能、应变率和温度变化的变形机制

• 批准号: 1309258
• 负责人: James Wittig
• 金额: $ 35.29万
• 依托单位: Vanderbilt University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2013
• 资助国家: 美国
• 起止时间: 2013-06-01 至 2018-05-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1309258&HistoricalAwards=false
• 关键词: Understanding; Deformation; Mechanisms; Austenitic; Iron

TECHNICAL SUMMARYTo understand the complex deformation mechanisms exhibited by austenitic iron-manganese steels, which include transformation-induced plasticity (TRIP), twinning-induced plasticity (TWIP), and dislocation glide, requires systematic mechanical testing with materials characterization down to the atomic scale. Changes in stacking-fault energy (SFE) with composition and temperature strongly influence the active deformation mechanism. Although the determination of SFE is challenging and most investigations rely on calculated values, careful experimental methods using weak-beam dark field (WBDF) imaging of partial dislocation separation can provide accurate SFE measurements. In addition to the composition and deformation temperature, important microstructural and processing parameters include grain size and strain rate. Correlation of the SFE with the mechanical behavior is a critical aspect for developing a basic understanding of the structure-property-processing relationships that will allow for future advances in the design of new high-manganese austenitic steels.NON-TECHNICAL SUMMARYIn the last five years, there has been a significant increase in the research activity associated with high-manganese austenitic steels as evidenced by both the number of scientific publications and patent applications. These steels are excellent candidates for applications requiring high formability and energy absorption such as cold-stamping of automotive parts owing to their exceptional ductility, strain-hardening, and toughness. This proposal describes collaboration between Vanderbilt University, the Ohio State University, the RWTH University and the Max-Planck-Institut für Eisenforschung in Germany, and the Oak Ridge National Laboratory to address the basic science involved with the future development of high-manganese austenitic steels. This international collaboration not only allows the combined expertise of the individual investigators to be focused on understanding the complex deformation mechanisms in these alloys, but it will also promote the education of graduate students who will benefit from the international experience. Student education and training will be enhanced through international collaborations. Educational opportunities enabled by these activities will be made available to under-represented groups through the Vanderbilt-Fisk Bridge program.

技术摘要为了了解奥氏体铁锰钢表现出的复杂变形机制，包括相变诱发塑性 (TRIP)、孪晶诱发塑性 (TWIP) 和位错滑移，需要进行系统的机械测试，并在原子尺度上进行材料表征。 堆垛层错能（SFE）随成分和温度的变化强烈影响主动变形机制。 尽管 SFE 的确定具有挑战性，并且大多数研究依赖于计算值，但使用部分位错分离的弱光束暗场 (WBDF) 成像的仔细实验方法可以提供准确的 SFE 测量。 除了成分和变形温度外，重要的微观结构和加工参数还包括晶粒尺寸和应变速率。 SFE 与机械行为的相关性是发展对结构-性能-加工关系的基本了解的一个关键方面，这将有助于新型高锰奥氏体钢设计的未来进步。非技术摘要在过去五年中，与高锰奥氏体钢相关的研究活动显着增加，科学出版物和专利申请的数量证明了这一点。 这些钢具有出色的延展性、应变硬化和韧性，是需要高成形性和能量吸收的应用（例如汽车零件的冷冲压）的绝佳选择。 该提案描述了范德比尔特大学、俄亥俄州立大学、RWTH 大学和德国马克斯普朗克研究所以及橡树岭国家实验室之间的合作，以解决高锰奥氏体钢未来发展所涉及的基础科学问题。这项国际合作不仅使各个研究人员的综合专业知识能够集中于了解这些合金的复杂变形机制，而且还将促进从国际经验中受益的研究生的教育。将通过国际合作加强学生教育和培训。这些活动带来的教育机会将通过范德比尔特-菲斯克桥计划向代表性不足的群体提供。