Production of areas with reduced strength in press-hardened components by means of a tempering station

通过回火站生产模压硬化部件中强度降低的区域

• 批准号: 313453754
• 负责人: Professor Dr.-Ing. Bernd-Arno Behrens
• 金额: --
• 依托单位: Institut für Umformtechnik und Umformmaschinen (IFUM)
• 依托单位国家: 德国
• 项目类别: Research Grants (Transfer Project)
• 财政年份: 2017
• 资助国家: 德国
• 起止时间: 2016-12-31 至 2021-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/313453754?language=en
• 关键词: Production; areas; reduced; strength; press

The transfer project shall adapt the methodology of a local temperature control of austenitized materials before or in between individual forming steps for the specific setting of a desired microstructure in a practical application using the example of press hardening. Tailored material properties shall b obtained in the press-hardened components based on locally adapted microstructures by employing the technology of a two-phase spray cooling process in collaboration with the project partner, Volkswagen AG. Press-hardened components that feature regions with locally reduced strength show increased joining properties and facilitate trimming. In the proposed transfer project, the microstructural adjustment shall take place through a targeted pre-cooling on localized component areas before the actual press hardening process. A suitable heat control unit must be developed to design such a pre-cooling by means of two-phase spray and simultaneous temperature control of component regions, which should not cool down and must be kept at a temperature above Ac3. For this purpose, numerical simulation models and experiences from the ongoing precedigng project ("Development of a microstructural suited forging technology for crank shafts") shall be applied. In the pre-cooled areas at first a temperature in the range of bainite or pearlite transformation should be adjusted to achieve a bainitic microstructural transformation during the subsequent and uniform cooling in the press-hardening tool. Areas quenched from a temperature level above Ac3 undergo a martensitic transformation due to cooling in the press-hardening tool. The advantage of this procedure is that no locally tempered press-hardening tools are required and short holding times during hot stamping can be used. Ultimately, it should be verified whether the tempering station is practically useful for the local formation of different microstructures by means of local cooling and maintaining the local austenitized state of the sheets at the same time. At Leibniz Universität Hannover, the design of the tempering station and the hot stamping is carried out at the Institute of Forming Technology and Machines, and the development of the pre-cooling device and the microstructure characterization is carried out at the Institut für Werkstoffkunde (Materials Science).

转移项目应在单个形成步骤之间或在实际应用中使用按压硬化的示例在实际应用中特定设置所需的微观结构的特定设置的单个形成步骤之前或之间的局部温度控制方法。量身定制的材料特性应通过与项目合作伙伴Volkswagen AG合作采用两阶段喷雾冷却过程的技术，该技术基于本地改编的微观结构在压制的组件中获得B。具有局部降低强度区域的压力固定组件显示结合性能增加并支撑修剪。在拟议的转移项目中，微观结构调整应通过在实际的压力硬化过程之前对局部组件区域进行的有针对性的预冷进行。必须开发一个合适的热控制单元，以通过两阶段喷雾和组件区域的简单温度控制设计这种预冷，该温度不应冷却，并且必须保持在AC3以上的温度下。为此，应采用正在进行的预先研究项目（“开发适合曲柄轴的微观结构”的数值模拟模型和经验）。首先，应调整Bainite或珠光体转换范围内的温度，以在随后的新闻硬化工具中的随后和均匀的冷却过程中进行贝恩氏微结构转换。从AC3高于AC3的温度水平淬火的区域会由于压力硬化工具中的冷却而经历了马氏体转化。此过程的优点是，不需要本地温度的压制工具，并且可以使用热冲压期间短的固定时间。最终，应该验证温度站是否通过局部冷却和维护局部的板块同时进行局部冷却和维护，这实际上对于局部形成了不同的微观结构。在莱布尼兹大学汉诺威（LeibnizUniversität），在形成技术和机器研究所进行了回火站和热冲压的设计，并开发了预冷装置和微观结构表征，并在InstitutfürFürWerkstoffkunde研究所进行。

项目成果

Tailoring Soft Local Zones in Quenched Blanks of the Steel 22MnB5 by Partial Pre-cooling with Compressed Air

• DOI: 10.1007/s11665-020-04916-5
• 发表时间: 2020-07
• 期刊: Journal of Materials Engineering and Performance
• 影响因子: 2.3
• 作者: O. Golovko;Max-Henry Stolte;K. Wölki;S. Hübner;B. Behrens;H. Maier;F. Nürnberger

Erzeugung duktiler Bereiche beim Formhärten*/Production of ductile areas in hot stamping – Creating areas with reduced strength using a tempering station

在模具硬化期间生成延性区域*/在热冲压中生成延性区域 â 使用回火站创建强度降低的区域

• DOI: 10.37544/1436-4980-2019-10-54
• 发表时间: 2019
• 期刊: wt Werkstattstechnik online
• 作者: Behrens;Hübner;Wölki;Golovko;Nürnberger
• 通讯作者: Nürnberger