Prediction of Microstructure and Resulting Rolling Forces by Application of a Material Model in a Hot Ring Rolling Process
Prediction of Microstructure and Resulting Rolling Forces by Application of a Material Model in a Hot Ring Rolling Process
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DOI：
10.4028/www.scientific.net/kem.622-623.970
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发表时间：
2014-09
期刊：
影响因子：
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通讯作者：
Gideon Schwich;T. Henke;J. Seitz;G. Hirt
中科院分区：
文献类型：
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作者：
Gideon Schwich;T. Henke;J. Seitz;G. Hirt
环件轧制是一种多用途的增量体积成形工艺。由于该过程的增量特性，它包括大量的变形和停留步骤。体积成形过程的有限元（FE）模拟能够预测载荷、应力和材料流动。近年来，环件轧制过程的有限元分析在计算时间以及运动自由度的闭环控制方面都变得可行[1]。因此，现在关注的焦点包括微观结构演变的预测。这种数值模拟的准确性在很大程度上取决于表征材料行为和边界条件的模型。本文采用有限元模拟方法研究了传递时间、辐射、传热和摩擦等边界条件对环件轧制过程目标值的影响。模拟研究的结果进行了比较，环轧制实验上的工业规模的环轧制设备。观察到外径和径向力的演变具有良好的一致性。在模拟研究中，检测并考虑了整个过程中转移时间对力的强偶然性。在后处理步骤中，考虑到动态和静态再结晶以及晶粒生长的微观结构的演变计算使用有限元结果。计算得到的晶粒尺寸与轧制前后钢领的显微组织观察结果吻合较好。此外，工艺参数对晶粒尺寸的演变的影响进行了研究。
Ring rolling is a versatile incremental bulk forming process. Due to the incremental character of the process, it consists of a large number of deformation and dwell steps. Finite element (FE) simulations of bulk forming processes are capable of predicting loads, stresses and material flow. In recent years, the finite element analysis of ring rolling processes has become feasible both in terms of calculation time as well as regarding the closed loop control of the kinematic degrees of freedom [1]. Accordingly, the focus of interest now includes the prediction of the microstructure evolution. The accuracy of such numerical simulations strongly depends on the models characterizing the material behavior and boundary conditions. In this paper, a finite element based simulation study was conducted, in order to evaluate the impact of boundary conditions such as transfer time, radiation, heat transfer and friction on the target values of the ring rolling process. The results of the simulation study were compared to ring rolling experiments on an industrial size ring rolling device. A good accordance regarding the evolution of the outer diameter and radial force was observed. Strong contingencies of transfer time on the forces throughout the process were detected and considered in the simulation study. In a post processing step, the evolution of the microstructure considering the dynamic and static recrystallization as well as the grain growth was calculated using the FE results. The calculated grain sizes show good accordance with the experimentally observed microstructure of the ring before and after the rolling. Furthermore, the impact of process parameters on the evolution of the grain size was investigated.