楔横轧多楔轧制高铁空心车轴壁厚均匀性

在空心轴楔横轧多楔轧制中，控制壁厚均匀性是衡量车轴成形质量的重要标准。本文先分析空心轴楔横轧多楔轧制的稳定轧制条件，得到了确定空心车轴楔横轧压扁失稳的准则。在此基础上，基于DEFORM-3D软件，建立楔横轧多楔同步轧制高铁空心车轴的三维刚塑性有限元模型，分析展宽角、成形角等工艺参数对壁厚均匀性的影响，获得了工艺参数影响轧制空心车轴壁厚变化的规律。结果表明：成形角越大，壁厚均匀性越好；展宽角越大，壁厚均匀性越好，但在展宽角大于10。时，壁厚均匀性反而下降。基于多楔轧制实验，轧制1：5缩比的空心车轴，测量了轧制力矩和轧制空心轴的壁厚，与仿真结果作比较，相对误差均在10%以内，验证了所建有限元模型的正确性。

Wall thickness uniformity of railway hollow shafts by cross-wedge rolling

Wall thickness uniformity is an important quality criterion of railway hollow shafts by multi-wedge synchrostep cross wedge rolling. The stable rolling condition of railway hollow shafts in this rolling process is analyzed, and a flattening instability criteri-on is presented. Based on this result, a rigid-plastic finite element model of hollow railway shafts by multi-wedge synchrostep rolling is established with DEFORM-3D software, the influence of processing parameters such as broadening angle and forming angle on the wall thickness uniformity is discussed, and the change law of wall thickness is obtained by changing these processing parameters. The big-ger the forming angle, the more uniform the wall thickness is;the bigger the spreading angle, the more uniform the wall thickness is, but when the spreading angle is more than 10., the wall thickness uniformity will decrease. A 1:5 ratio high-speed railway hollow shaft is rolled based on multi-wedge synchrostep cross wedge rolling experiment. Rolling torque measurements and wall thickness com-parisons between experimental and simulated results show that the relative error is controlled within 10%, which verifies the validity of this finite element model.