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

该研究项目的全球目标是研究在不使用异型专用工具的情况下在传统径向-轴向环轧米尔斯机上制造可重复生产的碟形环件的轧制策略。在第一个资助期内，开发了一个有限元模型，可以逼真地模拟环件的爬升过程。因此，关于爬升过程的附加信息是更深入地理解过程所必需的。可以确认，爬升与环内部的较高切向拉伸相关。此外，在模拟和实验中观察到，对于盘形环和高轴向进给，半径上变化的接触长度足以支持环内部的更大伸展。该研究的另一个结果是，为了可重复地制造碟形环，必须启动环攀爬的不稳定性。在吊环开始爬升后，应通过稳定吊环的位置来减小所获得的倾角的局部变化。对于这两种情况，已经发展出了预期的爬升起始和环的位置的稳定的不同概念。基于全局目标和前人的研究结果，提出了有限元模拟中有效的环爬升起始和稳定环位置的措施，将在未来的应用项目期间进行实际检查和测试。根据模拟结果，实现这两个目标的实际实施概念，开发了一方面，这些概念要求对环件轧制机、尤其是对引导辊和主辊进行相对简单的修改。另一方面，根据FEM仿真的轧制策略必须通过干预机器的控制算法在工业环轧机中实施。可以预期的是，在模拟中，最终几何形状的均匀性可以通过这些措施得到相当大的改善，因此可以轧制出具有小公差的可再现的盘形环。

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.