Advances in Metal Additive Manufacturing for Use in Railway Wheels
摘要
The present work continues the investigation on the use of Metal Additive Manufacturing (MAM) for its application on railway wheels. The aim of this investigation is to study this technique as a combination to turning reprofiling in order to extend the life service of the wheels, as well as trying to improve its performance. This major aspect of the rail system highlights the importance of wheel wear management and the need for cost-effective solutions to reduce maintenance expenses and increase the efficiency of railway operation. Certainly, MAM would be particularly interesting in wheels with localized severed flange wear, since it would avoid a considerable amount of material to be wasted during the turning process, thus extending the life of the wheel and reducing costs. In this work, three materials, AISI 4140, AISI 52100 and AISI H13, are studied as possible candidates for railway wheel reprofiling through the application of Direct Energy Deposition-Laser Beam (DEB-LB) technology. These materials are deposited on the surface of a worn tread of ER9 grade wheel, and their functionality is analysed in terms of hardness, residual stress, and wear and friction behaviour. The results show that these coatings can lead to an enhanced functionality of the wheel in these three different domains, specially, the AISI 4140 has been identified as the optimal candidate due to its superior combination of all characteristics. This indicates that DED-LB could effectively be used as a viable technique to produce superficial coatings on railway wheels.