Characterization and Utilization of Process-Induced Residual Stresses for the Manufacturing of Functional Surfaces by Near-Net-Shape-Blanking Processes

通过近净形冲裁工艺制造功能表面的工艺残余应力的表征和利用

• 批准号: 374524261
• 负责人: Professor Dr.-Ing. Karsten Stahl
• 金额: --
• 依托单位: Lehrstuhl für Maschinenelemente
• 依托单位国家: 德国
• 项目类别: Priority Programmes
• 资助国家: 德国
• 项目状态: 未结题
• 来源: https://gepris.dfg.de/gepris/projekt/374524261?language=en
• 关键词: Characterization; Utilization; Process; Induced; Residual

Near-Net-Shape Blanking processes are shear cutting processes that are able to manufacture parts with functional surfaces, that need no or only minimal post-processing. The functional surfaces are produced by plastic deformation, which can be used to control the residual stress state of the final component and thus its fatigue strength. The use of base materials with higher strength in combination with process-induced compressive residual stresses has considerable potential in terms of the targeted increase of the load carrying capacity with regard to the fatigue failure modes pitting and tooth root breakage. This offers the potential to replace cost- and time-intensive heat treatment in the manufacturing of power-transmitting gears by increasing the fatigue strength by locally adapted residual stresses. In the two-year follow-up project, this potential is to be investigated on a shear-cut pinion/wheel pair made from the previously used reference material and a higher strength steel. Fundamental relationships are systematically investigated with the models set up and validated by determining the tooth root bending strength in pulsator tests and the pit load carrying capacity in running tests.The residual stress states of the different gear variants are measured both before and after the fatigue tests. This allows to track process improvements but also ensures the predictability of the property improvements and the stability of the residual stresses. Thus, these measurements are used to extend the existing residual stress simulation model.By using a higher strength steel material, it will be shown that further improvements can be achieved in terms of tooth bending strength and pitting strength through process-induced residual stresses. Both experimental and numerical investigations are carried out for this purpose. In addition, the prediction of the respective load carrying capacity for the reference material and the higher strength material will be evaluated and if necessary improved. By integrating the results into the bidirectional model from the second funding period, it will be possible to design and manufacture shear cut gears of different materials and geometries with increased load carrying capacity by utilizing the positive effect of shear cutting process-induced residual stresses.The focus of the project is the design, layout and optimization of the NNSB processes with regard to an improved residual stress state for higher tooth bending strength and pitting strength, ensuring the predictability of the property improvements caused by residual stresses, and demonstrating residual stress stability in running tests under real operating conditions.

近净形冲裁工艺是能够制造具有功能表面的零件的剪切切割工艺，其不需要或仅需要最少的后处理。功能表面通过塑性变形产生，可用于控制最终部件的残余应力状态，从而控制其疲劳强度。使用具有更高强度的基础材料与工艺引起的压缩残余应力相结合，在针对疲劳失效模式点蚀和齿根断裂的承载能力的目标增加方面具有相当大的潜力。这提供了替代成本和时间密集型热处理的动力传动齿轮制造的潜力，通过增加疲劳强度的局部适应的残余应力。在为期两年的后续项目中，将在由先前使用的参考材料和更高强度钢制成的剪切切割小齿轮/齿轮副上研究这种潜力。通过对齿轮齿根弯曲强度的测定和齿轮运行试验中的点蚀承载能力的测定，系统地研究了齿轮疲劳试验的基本关系，并测量了不同齿轮在疲劳试验前后的残余应力状态。这允许跟踪工艺改进，但也确保了性能改进的可预测性和残余应力的稳定性。因此，这些测量结果被用来扩展现有的残余应力模拟模型。通过使用更高强度的钢材料，将表明，通过工艺引起的残余应力，可以进一步提高齿的弯曲强度和点蚀强度。为此目的，进行了实验和数值研究。此外，还将评估参考材料和高强度材料各自的承载能力预测，并在必要时进行改进。通过将结果整合到第二个资助期的双向模型中，将有可能设计和制造不同材料和几何形状的剪切齿轮，并通过利用剪切过程引起的残余应力的积极影响来提高承载能力。该项目的重点是设计，- NNSB工艺的设计和优化，以改善残余应力状态，提高齿弯曲强度和点蚀强度，确保由残余应力引起的性能改善的可预测性，并且在真实的操作条件下的运行测试中证明残余应力稳定性。