Bainitic steel grade for solid wheels: metallurgical, mechanical, and in-service testing

Bainitic steel grades generally have superior rolling contact and thermal fatigue resistances, but poorer wear characteristics when compared with ‘conventional’ pearlitic steel wheels. To improve the wear characteristics, the manufacturing process of bainitic materials needs to be carefully controll...

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Bibliographic Details
Published in:Proceedings of the Institution of Mechanical Engineers, Part F: Journal of Rail and Rapid Transit
Main Authors: Gianni, Andrea, Ghidini, Andrea, Karlsson, Tord, Ekberg, Anders
Language:unknown
Published: 2009
Subjects:
Online Access:https://doi.org/10.1243/09544097JRRT217
https://research.chalmers.se/en/publication/92347
Description
Summary:Bainitic steel grades generally have superior rolling contact and thermal fatigue resistances, but poorer wear characteristics when compared with ‘conventional’ pearlitic steel wheels. To improve the wear characteristics, the manufacturing process of bainitic materials needs to be carefully controlled. In this article, the manufacturing process of the ‘MICRALOS’ bainitic steel grade has been described. The main focus is on metallurgical testing activities performed in order to compare the new steel grade with standard pearlitic steels and to predict the service behaviour of the solid bainitic wheels. Further, on-going field tests on the iron ore line between Luleå and Narvik have been reported, with details about measurement methods and results. The performance of the wheels is reviewed and compared with the current scientific knowledge of bainitic steel grades and the deterioration of heavy haul wheels. Finally, benefits of and challenges for bainitic wheels in general and for the MICRALOS grade wheels in particular will be discussed.