Characterization of the suitability of high manganese steels for the production of small sheet metal parts by multi-stage deep drawing

高锰钢多级拉深生产小型钣金零件的适用性表征

• 批准号: 423190740
• 负责人: Professor Dr.-Ing. Gerhard Hirt
• 金额: --
• 依托单位: Institut für Bildsame Formgebung (IBF)
• 依托单位国家: 德国
• 项目类别: Research Grants (Transfer Project)
• 财政年份: 2019
• 资助国家: 德国
• 起止时间: 2018-12-31 至 2020-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/423190740?language=en
• 关键词: Characterization; suitability; manganese; steels; production

In the automotive industry, relatively small, sometimes complicated and tube-shaped components with paramagnetic properties are required. They are used as components for valve drives or injection nozzles and are produced in multi-stage combined deep drawing and ironing drawing processes, e.g. by the Hubert Stüken GmbH. The currently used chromium-nickel steels show low strengths and a weak austenite stability. Hence, a replacement by austenitic high manganese steels (HMnS) is aimed. Preliminary tests of the application partner with a commercially available HMnS with a composition comparable to alloys investigated in the SFB 761 part project B2 have shown fundamental potential in terms of formability and increasing strength. Nevertheless, an unfavorable change of the microstructure during the multi-stage deep drawing process occurs due to twinning and martensite formation, which affects the mechanical and magnetic properties of the components. In the automotive industry, for example, common limit values of 2 - 5 A/cm must be kept for the magnetic properties. Already established methods for the design of deep-drawing processes cannot predict the change of the magnetic properties by martensitic transformation during multi-stage deep-drawing. The working hypothesis of this project is, that the formation of martensite is favored by very large deformations of φ>5 and/or multi-axial stress states occurring in the deep-drawing processes. The aim is therefore to systematically investigate the microstructure changes under these complex loads and to develop empirical models specifically in order to design process sequences targeting the final microstructure. For this, it is necessary to understand the underlying mechanisms under different multi-axial stresses and for different deformation states. Only the cooperation with the application partner enables an adequate definition of the requirements regarding the process-dependent material behavior and component properties. Based on this, a characterization method is to be developed which emulates the microstructure development occurring during multi-stage deep-drawing processes. On the basis of this basic experiment, an empirical model for the microstructure development in multi-stage deep drawing processes will be developed and validated. This model will then be used to design a suitable process sequence, e.g. for components without martensitic transformation, which will finally be produced experimentally at the industrial facilities of the application partner. The basic experiment developed in this project can help to validate material models for high strains with regard to future questions and thus contribute to the improvement of the simulative process design.

在汽车工业中，需要具有顺磁特性的相对较小、有时复杂的管状部件。它们被用作阀门驱动器或注射喷嘴的部件，并通过多阶段组合深拉和减薄拉深工艺生产，例如Hubert Stüken GmbH。目前使用的铬镍钢强度低，奥氏体稳定性差。因此，目标是用奥氏体高锰钢（HMnS）替代。该应用合作伙伴使用市售HMnS进行的初步测试表明，其成分与SFB 761部分项目B2中研究的合金相当，在可成形性和增加强度方面具有基本潜力。然而，由于孪晶和马氏体的形成，在多阶段拉深过程中发生了不利的组织变化，这影响了部件的机械和磁性能。例如，在汽车工业中，磁性能必须保持2 - 5 A/cm的常见极限值。已经建立的深冲工艺设计方法不能预测多级深冲过程中马氏体相变引起的磁性能变化。该项目的工作假设是，马氏体的形成有利于在深冲过程中发生的φ>5的非常大的变形和/或多轴应力状态。因此，我们的目标是系统地研究这些复杂的负载下的微观结构的变化，并专门开发经验模型，以设计针对最终微观结构的工艺序列。为此，有必要了解不同多轴应力和不同变形状态下的潜在机制。只有与应用合作伙伴的合作才能充分定义与工艺相关的材料行为和组件特性相关的要求。在此基础上，一个表征方法是要开发的模拟多阶段拉深过程中发生的微观结构的发展。在此基础实验的基础上，将开发和验证多阶段拉深过程中微观组织发展的经验模型。然后，该模型将用于设计合适的工艺顺序，例如，用于没有马氏体相变的部件，最终将在应用合作伙伴的工业设施中进行实验生产。本计画所发展之基本实验，可协助验证高应变下之材料模型，并有助于改善模拟制程设计。