Investigation of the thermomechanical interactions in the shear zone during the fine blanking of heated high strength sheet materials (HotFib)

研究加热高强度板材精冲过程中剪切区的热机械相互作用 (HotFib)

• 批准号: 372316085
• 负责人: Professor Dr.-Ing. Thomas Bergs, since 7/2019
• 金额: --
• 依托单位: Werkzeugmaschinenlabor - WZL
• 依托单位国家: 德国
• 项目类别: Research Grants
• 财政年份: 2017
• 资助国家: 德国
• 起止时间: 2016-12-31 至 2020-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/372316085?language=en
• 关键词: Investigation; thermomechanical; interactions; shear; zone

The research project is based on the research hypothesis that by means of inductive sheet heating, high-strength materials can be processed reliably, the cutting force can be significantly reduced and the component quality can be improved by fine blanking. Thus, the manufacturing process fine blanking may be capable of the thermo-mechanical mechanisms need to be understood and explained in the shear zone. Heating the sheet metal leads to a lower flow stress, which promotes the plastic material flow and reduces the necessary process forces during fine cutting. By lowering the blanking force, the fine blanking process will be qualified for processing thicker sheets and offers additionally the possibility to process ultra-high sheet metal materials. The interactions between the heating of the sheet material, the blanking force, the achievable component quality as well as the knowledge of the precise thermomechanical mechanisms is unknown for fine blanking. In order to confirm this research hypothesis experimental and numerical investigations will be carried out. By means of the system TTH25 different heating profiles will be applied to sheet metal materials (16MnCr5, 42CrMo4). Furthermore, different inductor designs will be tested in order to analyze the influence of the heat distribution during the fine blanking process. The thermomechanical mechanisms of action are described by analyzing the section quality (microstructure, surface quality) and their correlation with the heating profiles as well as the process characteristics (blanking force, v-ring force, counter force). The numerical FE process simulations support the experimental methods to allow further correlations with the stress-strain state and other difficult to measure quantities (true strain). All partial results (blanking force reduction, section quality, hydrostatic stress state, elongations) are combined with each other to form a holistic explanation model considering the sheet thickness, the sheet metal material and the thermomechanical mechanisms of action. The aim is to extend the calculation of blanking force, v-ring force and counter force for the fine blanking process with a temperature factor. This allows the analytical calculation of the process forces as a function of the temperature. Furthermore, different empirical-analytic function surfaces will be derived that reflect the functional relationship between heating temperature, part quality and part properties considering on the sheet material, the sheet thickness and the hydrostatic stress state. In this way, the postulated research hypothesis is examined and, in conjunction with the validation of the explanation model, the superior research objectives will be achieved.

该研究项目基于研究假设，即通过感应板料加热，可以可靠地加工高强度材料，可以显著降低切削力，并通过精冲提高零件质量。因此，制造工艺精冲可能能够在剪切区的热机械机制需要理解和解释。加热金属板可降低流动应力，从而促进塑性材料流动并减少精切过程中所需的加工力。通过降低冲裁力，精冲工艺将适合加工较厚的板材，并额外提供加工超高金属板材的可能性。板材加热、冲裁力、可实现的部件质量以及精确的热机械机制知识之间的相互作用对于精冲是未知的。为了证实这一研究假设，将进行实验和数值研究。通过TTH 25系统，不同的加热曲线将应用于金属板材（16 MnCr 5，42 CrMo 4）。此外，将测试不同的电感器设计，以分析精冲过程中热分布的影响。通过分析截面质量（显微组织、表面质量）及其与加热曲线的相关性以及工艺特性（冲裁力、V形环力、反力）来描述热机械作用机制。数值FE过程模拟支持实验方法，以允许与应力-应变状态和其他难以测量的量（真应变）的进一步相关性。所有的部分结果（冲裁力减少，截面质量，静水应力状态，伸长率）相互结合，形成一个整体的解释模型，考虑板厚度，金属板材料和热机械作用机制。其目的是将冲裁力、V形圈力和反力的计算推广到含温度因子的精冲过程。这允许作为温度的函数的过程力的分析计算。此外，不同的解析函数曲面将被导出，反映加热温度，零件质量和零件性能之间的函数关系，考虑板材料，板厚度和静水应力状态。通过这种方式，假设的研究假设得到检验，并与解释模型的验证相结合，将实现上级研究目标。