Investigation of the influence of rail hardness on the wear of rail and wheel materials under dry conditions (ICRI wear mapping project)
Investigation of the influence of rail hardness on the wear of rail and wheel materials under dry conditions (ICRI wear mapping project)
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DOI：
10.1016/j.wear.2019.05.030
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发表时间：
2019-07-15
期刊：
影响因子：
5
通讯作者：
Lewis, S. R.
中科院分区：
文献类型：
--
作者：
Lewis, R.;Christoforou, P.;Lewis, S. R.
一些铁路管理者和从业人员担心，引入优质铁路材料会对使用该线路的火车车轮产生不利影响。已经对实验室和现场所有规模的相关调查进行了审查。这表明，随着钢轨硬度的增加，其磨损和整个系统的磨损会减少。车轮磨损确实会随着轨道硬度的增加而增加，但仅限于在比它们更软的轨道上运行的车轮。所有研究中都观察到了类似的趋势，因此看来这种担心是没有根据的。虽然磨损趋势似乎已得到很好的表征，但已经发现了一些问题。其中之一涉及轮轨材料不同的加工硬化能力。通常只引用体积硬度，但加工硬化可以将材料表面硬度提高多达 2.5 倍，并使最初较软的材料比相反的材料更硬。另一个相关问题是测试长度。重要的是要应用足够的循环，以使材料达到稳态磨损，即加工硬化达到其极限的点。在之前的工作中，并不总是清楚是否已达到稳态磨损。目前的知识库中已经发现了一些差距，其中最大的差距是未能确定哪些机制导致了所见的磨损趋势。通过对钢轨盘和优质钢轨材料上不同熔覆层的最新研究进行分析，可以解决其中一些差距。结果表明，相对的车轮材料硬化到相同水平，与钢轨硬度无关。因此，车轮磨损是在使用条件下由应力驱动的，并且仅由车轮材料特性决定。在较高的滑移水平下，关系变得不太清楚，但这里温度和因此热硬度的影响最大，并且尚未表征。
Some railway managers and practitioners fear that introducing premium rail materials will have a detrimental effect on the wheels of trains that use the line. A review of relevant investigations across all scales in the laboratory, and in the field has been carried out. This showed that, as rail hardness increases, its wear, and overall system wear reduces. Wheel wear does increase with increasing rail hardness, but only for wheels running on rails that are softer than them. Similar trends were observed in all studies, so it seems that the fears were unfounded.While the wear trends appear well characterised some issues have been identified. One relates to the varying work hardening capability of wheel and rail materials. Often only bulk hardness is quoted, but work hardening can increase material surface hardness by up to 2.5 times and make materials that were initially softer, harder than the opposing material. Another related issue is test length. It is essential that enough cycles are applied such that the materials reach steady state wear, i.e., the point at which work hardening has reached its limit. In previous work it is not always clear that steady state wear has been reached. Some gaps have been identified in the current knowledge base, the largest of which is the failure to determine which mechanisms lead to the wear trends seen.Analysis of recent work on different clad layers on rail discs and premium rail materials allowed some of these gaps to be addressed. Results indicated that opposing wheel material hardened to the same level independent of rail hardness. Wheel wear is therefore stress driven under the conditions used, and dictated by the wheel material properties only. At higher slip levels relationships become less clear, but here temperature and therefore hot hardness is most influential and is as yet uncharacterised.