This study relates to an innovative method for forming rail car axles by skew rolling in a CNC 3-roll mill. The rolling mill was constructed at the Lublin University of Technology. The use of this machine makes it possible to produce elongated axisymmetric parts that are up to 55 mm in diameter and up to 1000 mm in length. Experimental rolling tests are performed (in 1:5 scale) using this machine. Two types of axles are analysed: one manufactured in accordance with North American standards (AAR Class E) and one manufactured in compliance with European standards (BA302). Diameters of produced axles have a dimensional accuracy of ± 0.4 mm. Produced axles are free from internal cracks, and their surface defects (shallow helical grooves) can easily be removed by machining. The major shortcoming of the proposed method is the presence of chucking allowance. To eliminate this allowance, it is proposed that the forming process should be performed in two operations: rolling extrusion and skew rolling. Results of a numerical analysis were performed using the Simufact.Forming program confirms that rail car axles can be formed by the proposed method.

中文翻译：

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CNC斜轧机中有轨车轴的成型

这项研究涉及一种通过在CNC三辊轧机中斜轧形成轨道车轴的创新方法。轧机是在卢布林工业大学建造的。使用该机器可以生产直径不超过55毫米，长度不超过1000毫米的细长轴对称零件。使用此机器进行了实验性滚动测试（以1：5的比例）。分析了两种类型的车轴：一种是按照北美标准制造的（AAR E级），另一种是按照欧洲标准制造的（BA302）。生产的车轴直径的尺寸精度为±0.4毫米。所生产的轴没有内部裂纹，并且其表面缺陷（浅螺旋凹槽）可以通过机械加工轻松去除。所提出的方法的主要缺点是存在夹紧力。为了消除这种余量，建议成形过程应分两个步骤进行：轧制挤压和斜轧。使用Simufact进行了数值分析的结果。成形程序确认可以通过所提出的方法来成形轨道车轴。