Abstract Forming processes play a key role in the manufacturing of metal components. They allow for the economical production of geometrical shapes with reproducibly high quality. Strain hardening and residual stresses affect the performance of the produced parts. These factors are controllable and can even be utilized to increase the performance of the component. This, however, does not apply to damage. Damage in metals describes the decrease of the load-bearing capacity due to the appearance and evolution of voids. The aim is to analyse, predict, and control the evolution of damage in cold forging, to allow for a production of cold forged components with a defined, load-adapted performance. It was investigated numerically to what extent the load path, which is responsible for the damage evolution, is affected in cold forging. Subsequently, the effect of load path changes on the product performance was determined experimentally in the region of the central axis where the load path is affected most by the extrusion parameters. Hereby, a correlation between the occurring triaxiality during forming and the product performance by means of number of cycles to failure in multi-step fatigue tests, impact energy and Young’s modulus was observed.

中文翻译：

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冷锻件损伤引起的性能变化

摘要 成型工艺在金属部件的制造中起着关键作用。它们允许以可重复的高质量经济地生产几何形状。应变硬化和残余应力会影响所生产零件的性能。这些因素是可控的，甚至可以用来提高组件的性能。但是，这不适用于损坏。金属损坏描述了由于空隙的出现和演变导致的承载能力下降。目的是分析、预测和控制冷锻损伤的演变，以允许生产具有定义的、适应负载的性能的冷锻部件。数值研究了导致损伤演化的载荷路径在冷锻中受到多大程度的影响。随后，负载路径变化对产品性能的影响是在中心轴区域通过实验确定的，在该区域负载路径受挤压参数影响最大。因此，通过多步疲劳试验中的失效循环数、冲击能和杨氏模量，观察了成形过程中出现的三轴性与产品性能之间的相关性。