Advances in rail materials from conventional rail steels to those with higher yield points and the potential of additively manufactured laser clad coatings to improve the durability of railway track components presents a new challenge in characterisation. Many of these new and novel materials have either limited test samples available or are more resistant to strain and therefore present challenges in characterisation. The method reported here uses twin disc tests to simulate cyclic loading experienced by rail steel in service. A sample from a single test condition is analysed, measuring the shear yield stress and the accumulated shear strain at multiple depths below the contact surface, from which a Shear Yield Stress – Plastic Shear Strain (SYS-PSS) relationship is extracted. Knowledge of the stress history of a rail sample is not required to apply the method and minimal samples are required, providing a technique which can be used on rail steel samples removed from service.

铁路材料从传统的铁路钢到具有更高屈服点的铁路材料的进步，以及增材制造的激光熔覆涂层改善铁路轨道组件的耐久性的潜力，在表征方面提出了新的挑战。这些新型材料中的许多材料要么只能提供有限的测试样品，要么更能抵抗应变，因此在表征方面存在挑战。此处报道的方法使用双盘试验来模拟在役钢轨承受的循环载荷。分析来自单个测试条件的样品，测量接触面以下多个深度处的剪切屈服应力和累积剪切应变，从中提取剪切屈服应力与塑性剪切应变（SYS-PSS）的关系。