Tribological properties of hardened high strength boron steel at combined rolling and sliding conditions
2008 (English)In: Proceedings of NORDTRIB 2008: 13th Nordic Symposium on Tribology / [ed] Jaakko Kleemola; Arto Lehtovaara, Tampere University of Technology, 2008Conference paper (Refereed)
The use of hardened high strength steel is found in applications where high wear resistance is required. The wear properties of high strength boron steel are well known in applications with abrasive wear from stones, ore and other hard material. A unique concept of wear protection of rails is newly presented, a wear resistant cap made of hardened high strength boron steel. Reducing the wear of rails and wheels and controlling the frictional behaviour in the wheel/rail contact are two key issues for railway owners in order to reduce the increasing costs related to higher axle loads, higher speeds, more frequent traffic etc. The cost of the rail material when replacing a section of the rail is just a small portion of the total cost. Planning, disturbance of traffic and loss of income during the maintenance are some of the larger parts of the total costs. Likewise, the large difference in frictional behaviour in the wheel/rail contact of materials used today creates huge problems. Friction at the rail head needs to be high enough to withstand the traction force when accelerating and braking while the friction at the gauge corner should be low to save energy and give good steering capability of the train. The low friction at the gauge face can be achieved by using rail lubrication but the controlled friction at the rail head at different temperatures and other weather conditions is still a problem. In order to reduce the total costs it is therefore crucial to reduce the time for replacing the rail and increasing the service life of the rail. The ReRail rail cap has the potential to do both.There are almost no results published regarding the tribological properties of Boron steel in contact with other metallic materials for mechanical engineering applications. Therefore, the aim of this work has been to investigate the tribological properties of boron steel in contact with Blue Light wheel steel under dry and water lubricated conditions in a two-disc tribometer. Advanced analytical instruments including 3D optical surface profiler, micro hardness indenter, light microscope and SEM/EDS were used to analyse the results.Results from the experiments show that the friction coefficient in tests with boron steel is more stable both in dry and water lubricated conditions than tests including UIC 1100 rail steel used in todays application. Surface damages seen from water lubricated tests on UIC 1100 rail steel are not seen on the surface of the boron steel discs. In all tests, the wear decreased when water was added in the contact and friction was slightly decreased.
Place, publisher, year, edition, pages
Tampere University of Technology, 2008.
Research subject Machine Elements
IdentifiersURN: urn:nbn:se:ltu:diva-29397Local ID: 2de506b0-3d38-11dd-ab50-000ea68e967bISBN: 978-952-15-1959-8OAI: oai:DiVA.org:ltu-29397DiVA: diva2:1002621
Nordic Symposium on Tribology : 10/06/2008 - 13/06/2008
Godkänd; 2008; 20080618 (elka)2016-09-302016-09-30Bibliographically approved