Method for manufacturing seamless conical rings with defined inclination angles on radial-axial ring rolling mills

该研究项目的总体目标是研究在传统的径向环轧机上不使用异形工具制造可重复盘形环的轧制策略。在第一个资助阶段，开发了一个有限元模型，可以真实地模拟环攀爬过程。因此，关于爬升过程的额外信息，对于更深入的过程理解是必要的，是可用的。可以确定的是，攀登与环内部较高的切向拉伸有关。此外，在模拟和实验中都观察到，对于盘形环和高轴向进给，在半径上变化的接触长度足以支持环内部更大的拉伸。该研究的另一个结果是认识到，为了可重复地制造盘形环，必须启动环攀爬的不稳定性。在环开始爬升后，应通过稳定环的位置来减少所获得的倾斜角的局部变化。对于这两者，攀爬的起始和稳定环的位置不同的概念已经发展。这些导致了在有限元模拟中环几何形状均匀性的显着改善。基于总体目标和前人的研究结果，通过有限元分析确定的启动环爬升和稳定环位置的措施是有希望的，并将在进一步应用的项目期间进行实际检验和试验。根据仿真结果，提出了实现这两个目标的实际实施概念。一方面，这些概念要求对轧环机进行相对简单的修改，特别是对导辊和主辊进行修改。另一方面，基于有限元模拟的轧制策略必须通过干预轧机的控制算法来实现。预计在模拟中，最终几何形状的均匀性可以通过这些措施大大改善，因此可以轧制具有小公差的可重复盘形环。

The global objective of this research project is to investigate rolling strategies for manufacturing reproducibly dish shaped rings on conventional radial-axial ring rolling mills without using profiled special tools.In the first funding period, a FEM model was developed, which allows to simulate the ring climbing process realistically. Therefore, additional information about the climbing process, necessary for a deeper process understanding, is available. It could be confirmed that, climbing is associated with a higher tangential stretching of the rings inner part. Furthermore, it was observed in simulation as well as in experiment that for disk shaped rings and a high axial feed the varying contact length over the radius is sufficient in order to support a greater stretching of the rings inner part. Another result of the study is the knowledge that the instability of ring climbing must be initiated in order to manufacture dish shaped rings reproducibly. The local variations of the achieved inclination angle should be reduced by stabilizing the position of the ring after the ring started climbing. For both, the intended initiation of climbing and the stabilization the position of the ring different concepts have been developed. These resulted in a significant improvement with respect to the uniformity of the ring geometry in the FEM-simulation.Based on the global objective and the previous results, the measures for the initiation of ring climbing and stabilizing the position of the ring, which were confirmed to be promising by the FEM, will be examined and tested in reality within the further applied project period.Based on the simulation results concepts for the practical implementation to achieve both objectives have been developed. On the one hand, these concepts require relatively simple modifications of the ring rolling machine, especially of the guide rolls and the main roll. On the other hand, the rolling strategy according to the FEM-simulation has to be implemented in the industrial ring rolling mill by intervention in the control algorithms of the machine. It is expected that as in the simulation the uniformity of the final geometry can be improved considerably by these measures and therefore reproducible dish-shaped rings with small tolerances can be rolled.