Deformation and damage behavior of additively manufactured medium-manganese steels featuring an in situ established multiphase microstructure

为了最大限度地减少全球变暖和保护不可再生能源，轻量化建筑、减排和资源效率已成为我们社会最重要的任务之一。这一趋势不仅要求开发新的高强度和高成形性结构材料，还要求通过应用新的生产技术来有效利用剩余资源。含锰钢是一类很有前途的高强度材料，同时也是一种高变形性材料，具有出色的能量吸收能力。除了纯位错滑动外，还通过激活二次变形机制实现了独特的机械性能组合。增材制造的特点使其在加工含锰钢时具有各自的优势。由于高冷却速率，可显著减少部件中的元素偏析。由于该工艺的固有特性是分层添加材料，因此循环热输入也可以用作原位热处理，从而最终确定AM工艺过程中材料中的相分布。在该项目中，将使用增材制造的缩短工艺路线制造微观结构复杂且具有工业前景的中锰钢。在此过程中，通过原位热处理，最终形成多相组织。在应用科学家和机构的互补专业知识和设备的基础上，该项目的目的是了解增材制造和随后的机械加载过程中的基本材料行为。基于所获得的基本理解，增材制造过程中中锰钢的微观结构发展将受到影响，从而可以定制变形和损伤行为。实验研究和计算机辅助多尺度方法的材料表征和模拟协同使用的项目。

The general trend toward lightweight construction, emission reduction and resource efficiency, with the aim of minimizing global warming and conserving non-renewable energy sources, has become one of the most important tasks of our society. This trend not only requires the development of new high-strength and highly formable structural materials, but also the efficient use of remaining resources through the application of new developments in production technology.Steels containing manganese represent a promising class of high-strength and, at the same time, highly deformable materials with excellent energy absorption capacity. The unique combination of mechanical properties is achieved through the activation of secondary deformation mechanisms occurring in addition to pure dislocation sliding.The characteristics of additive manufacturing lead to advantages when respective techniques are used for processing steels containing manganese. Due to the high cooling rates, element segregation in the component can be significantly reduced. Due to the process inherent characteristic of adding material in layers, the cyclical heat input can also be used as in situ heat treatment and, thus, ultimately set the phase distribution in the material during the AM process.In the project microstructurally complex and industrially promising medium-manganese steels are to be manufactured using a shortened process route employing additive manufacturing. The multi-phase microstructure finally is established by means of the in situ heat treatment during the process. On the basis of the complementary expertise and equipment of the applying scientists and institutions, the aim of the project is to understand the fundamental material behavior during additive manufacturing and subsequent mechanical loading. Based on the basic understanding gained, the microstructure development in medium-manganese steels during additive manufacturing is to be influenced in such a way that the deformation and damage behavior can be tailored. Experimental investigations and computer-aided multiscale approaches for material characterization and simulation are used synergistically in the project.