Investigations on the influence of machining and sulphur content on the fatigue strength of the quenched and tempered steel 42CrMo4+QT

机械加工和硫含量对调质钢42CrMo4 QT疲劳强度的影响研究

• 批准号: 320296624
• 负责人: Professor Dr.-Ing. Dirk Biermann
• 金额: --
• 依托单位: Institut für Spanende Fertigung
• 依托单位国家: 德国
• 项目类别: Research Grants
• 财政年份: 2016
• 资助国家: 德国
• 起止时间: 2015-12-31 至 2019-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/320296624?language=en
• 关键词: Investigations; influence; machining; sulphur; content

Quenched and tempered steels are common material for industrial applications, especially for components exposed to high mechanical or cyclic loads. One of the best known examples of this material class is the quenched and tempered steel AISI 4140 (42CrMo4+QT). It is used in the automotive industry, for example in powertrain components such as connecting rods and crankshafts, but also in general mechanical engineering such as high-pressure pumps for hydraulic systems. Technological trends, such as the downsizing of components in combus-tion engines or increased mechanical and dynamic loads within the area of application, are increasing the demands on the load capacity of these components. Within the scope of the joint research project between the Institute of Machining Technology (ISF) and the Depart-ment of Materials Test Engineering (WPT) of the TU Dortmund University, experimental and theoretical investigations on manufacturing technology and mechanical material behaviour are brought together aiming to improve the fatigue behaviour of deep-drilled components through an optimised machining process. Furthermore, a prediction and description of the fatigue behaviour through innovative characterisation methods is possible. This very success-ful cooperation is to be continued in a second project phase with the aim of further improving the understanding of the targeted surface layer influence, which was developed in the first phase. The aim is to further increase the fatigue strength of deep-drilled components and to improve the non-destructive damage assessment. On the one hand, this will be achieved by extending the analysis methods used during deep drilling. In addition to the mechanical ef-fects, which were the focus of the investigations in the first project phase, thermal influences on the integrity of the bore surface layer will be considered in a detailed way. From this, the fundamental understanding of the thermomechanical effects on the bore surface layer and the resulting mechanical and dynamic strength of the components can be extended. On the other hand, the method of Barkhausen noise analysis will be further developed by compre-hensive microstructural investigations, which should allow an improved assessment of the damage condition of the samples.

淬火和回火钢是工业应用的常用材料，特别是用于暴露于高机械或循环载荷的部件。这类材料最著名的例子之一是淬火和回火钢AISI 4140（42CrMo4+QT）。它用于汽车工业，例如动力总成组件，如连杆和曲轴，但也用于一般机械工程，如液压系统的高压泵。技术发展趋势，如内燃机部件的小型化或应用领域内机械和动态负载的增加，对这些部件的负载能力提出了更高的要求。在机械加工技术研究所（ISF）和多特蒙德大学材料测试工程系（WPT）的联合研究项目范围内，对制造技术和机械材料行为进行了实验和理论研究，旨在通过优化的机械加工工艺改善深孔部件的疲劳性能。此外，通过创新的表征方法预测和描述疲劳行为是可能的。这一非常成功的合作将在项目的第二阶段继续进行，目的是进一步提高对第一阶段开发的目标表层影响的理解。其目的是进一步提高深钻部件的疲劳强度，并改善非破坏性损伤评估。一方面，这将通过扩展深钻期间使用的分析方法来实现。除了第一个项目阶段研究的重点机械效应外，还将详细考虑对孔表面层完整性的热影响。由此，可以扩展对孔表面层的热机械效应以及由此产生的部件的机械和动态强度的基本理解。另一方面，巴克豪森噪声分析的方法将进一步发展的微观结构调查，这应该允许一个更好的评估样本的损坏情况。