Sand is often used in rainy countries as friction modifier aimed at preventing wheel sliding due to low adhesion. Therefore, in this case it is considered a “friendly” factor. The growing number of railways in the deserts introduces a different point of view, as uncontrolled sand on rails is the new enemy to be tackled by dedicated research on materials and design. Many metallurgical investigations on full scale wheels tested in the desert have been carried out in the metallurgical laboratories of Lucchini RS in order to discover the main damage mechanisms. An in-depth research programme and laboratory investigations on the effect of desert sand on wear and RCF behaviour of various railway wheel steels has been carried out in cooperation with the University of Brescia, with special attention paid to the following topics: - optimization of coupling between wheel and rail in the presence of sand through FEM simulation; - rolling contact tests of various durations on different steel grades using a special two-disc testing machine with sand; - evaluation of the experimental results by means of elastic-plastic FEM analysis. The in-depth research and development work conducted by Lucchini RS with the cooperation of the University of Brescia allows to present a new class of steels grades called SANDLOS®, a set of three innovative steel grades for solid wheels able to run in the desert’s high temperatures and sandstorms. SANDLOS® materials exhibit an excellent performance in terms of resistance to wear in sandy environments, mainly due to their high mechanical properties, which confines extremely huge plasticisation phenomena to a “thin surface layer”, preventing sand penetration and incorporation. In case of interaction and coupling with different rail grades, the SANDLOS® family grades are arguably the best alternative to AAR Class B, C, D steels, not only in presence of sand and wear debris, but also in all the cases in which an increase in mechanical characteristics or a longer wheel life are required.
SANDLOS® wheels for desert environments
FACCOLI, Michela;MAZZU', Angelo
2017-01-01
Abstract
Sand is often used in rainy countries as friction modifier aimed at preventing wheel sliding due to low adhesion. Therefore, in this case it is considered a “friendly” factor. The growing number of railways in the deserts introduces a different point of view, as uncontrolled sand on rails is the new enemy to be tackled by dedicated research on materials and design. Many metallurgical investigations on full scale wheels tested in the desert have been carried out in the metallurgical laboratories of Lucchini RS in order to discover the main damage mechanisms. An in-depth research programme and laboratory investigations on the effect of desert sand on wear and RCF behaviour of various railway wheel steels has been carried out in cooperation with the University of Brescia, with special attention paid to the following topics: - optimization of coupling between wheel and rail in the presence of sand through FEM simulation; - rolling contact tests of various durations on different steel grades using a special two-disc testing machine with sand; - evaluation of the experimental results by means of elastic-plastic FEM analysis. The in-depth research and development work conducted by Lucchini RS with the cooperation of the University of Brescia allows to present a new class of steels grades called SANDLOS®, a set of three innovative steel grades for solid wheels able to run in the desert’s high temperatures and sandstorms. SANDLOS® materials exhibit an excellent performance in terms of resistance to wear in sandy environments, mainly due to their high mechanical properties, which confines extremely huge plasticisation phenomena to a “thin surface layer”, preventing sand penetration and incorporation. In case of interaction and coupling with different rail grades, the SANDLOS® family grades are arguably the best alternative to AAR Class B, C, D steels, not only in presence of sand and wear debris, but also in all the cases in which an increase in mechanical characteristics or a longer wheel life are required.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
