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Keywords: railway, early-damage, head checks, laboratory scale testing, wear.

Summary

The aim of the study, presented in this paper, was the experimental modeling of a cyclic wheel-rail contact at a laboratory scale to investigate wear behaviour and crack initiation. For this purpose, a novel test rig using a transverse oscillating movement was developed to reproduce the unidirectional loading that occurs on real rail tracks. The tests were carried out at the gauge corner of rail samples in order to reach similar contact stresses as in the real system. The counterbody was a model wheel with its contour adjusted to the rail section. The influence of bending, pitch and surface pre-conditioning (as-rolled and milled) on wear and crack initiation were investigated using two different rail materials (R260 and R350HT) tested during an increasing number of loading cycles. The experimental simulation of head checks, regular cracks on the gauge corner of the rail, on the rail track samples could be achieved successfully. The results showed that the distance between the surface micro-cracks and the size of the micro-cracks decreases with increasing hardness of the rail. Micro-crack initiation and growth rate are strongly correlated with the wear rate of the rails. Furthermore, the surface condition of the rails showed a strong influence on micro-crack initiation. While milled rail surfaces without decarburization the near-surface zone showed crack initiation after a higher number of testing cycles, as-rolled rails underwent micro-crack initiation and growth at an earlier stage.

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Front Page Browse CCP CSETS CTR IJRT Other Authors Search Purchase Guide FAQ Contact us	Civil-Comp Proceedings ISSN 1759-3433 CCP: 110 PROCEEDINGS OF THE THIRD INTERNATIONAL CONFERENCE ON RAILWAY TECHNOLOGY: RESEARCH, DEVELOPMENT AND MAINTENANCE Edited by: J. Pombo Paper 152 The Influence of Attack Angle and Rail Surface Condition on Early-Damaging A. Trausmuth¹, E. Badisch¹, M. Rodriguez Ripoll¹, T. Lebersorger¹, D. Künstner² and S. Scheriau² ¹Austrian Center of Competence for Tribology, AC2T Research GmbH, Wiener Neustadt, Austria ²Voestalpine Schienen GmbH, Leoben, Austria doi:10.4203/ccp.110.152 purchase the full-text of this paper Full Bibliographic Reference for this paper , "The Influence of Attack Angle and Rail Surface Condition on Early-Damaging", in J. Pombo, (Editor), "Proceedings of the Third International Conference on Railway Technology: Research, Development and Maintenance", Civil-Comp Press, Stirlingshire, UK, Paper 152, 2016. doi:10.4203/ccp.110.152 Keywords: railway, early-damage, head checks, laboratory scale testing, wear. Summary The aim of the study, presented in this paper, was the experimental modeling of a cyclic wheel-rail contact at a laboratory scale to investigate wear behaviour and crack initiation. For this purpose, a novel test rig using a transverse oscillating movement was developed to reproduce the unidirectional loading that occurs on real rail tracks. The tests were carried out at the gauge corner of rail samples in order to reach similar contact stresses as in the real system. The counterbody was a model wheel with its contour adjusted to the rail section. The influence of bending, pitch and surface pre-conditioning (as-rolled and milled) on wear and crack initiation were investigated using two different rail materials (R260 and R350HT) tested during an increasing number of loading cycles. The experimental simulation of head checks, regular cracks on the gauge corner of the rail, on the rail track samples could be achieved successfully. The results showed that the distance between the surface micro-cracks and the size of the micro-cracks decreases with increasing hardness of the rail. Micro-crack initiation and growth rate are strongly correlated with the wear rate of the rails. Furthermore, the surface condition of the rails showed a strong influence on micro-crack initiation. While milled rail surfaces without decarburization the near-surface zone showed crack initiation after a higher number of testing cycles, as-rolled rails underwent micro-crack initiation and growth at an earlier stage. purchase the full-text of this paper (price £22) go to the previous paper go to the next paper return to the table of contents return to the book description purchase this book (price £85 +P&P)
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