The new idea is to produce specimens by forward rod extrusion, where in the core of the extrudate a deviatoric tension-loading is present, which is superposed by an adjustable hydrostatic pressure. Various damage levels are hence possible in the extrudate. Conducting tensile and upsetting tests with the pre-strained specimens both the influence of a load reversal as well as the material weakening through ductile damage on the resulting flow curve is explored. Not only can the results be utilized to identify flow curves of materials up to high strains (ε > 1.7), but also to get new insights into the plastic material behaviour, which can be used for generating or adapting new damage models as well as kinematic hardening models under cold forging conditions. The proposed method was first assessed by means of analytical and numerical methods and then validated experimentally, by the example of the typical cold forging steel 16MnCrS5.

新的想法是通过前向杆挤压来生产试样，其中在挤压物的芯中存在偏斜的拉伸载荷，该载荷由可调节的静水压力叠加。因此在挤出物中可能有各种损伤程度。研究了对预应变试样​​进行的拉伸和up锻试验，既研究了载荷逆转的影响，也发现了由于延展性破坏而使材料变弱对最终流动曲线的影响。结果不仅可以用于识别高应变（ε > 1.7），还可以使您对塑性材料的行为有新的认识，该行为可用于生成或适应新的损伤模型以及冷锻条件下的运动硬化模型。首先通过分析和数值方法对提出的方法进行了评估，然后以典型的冷锻钢16MnCrS5为例进行了实验验证。