Structure and Properties of the S49 Rail after a Long Term Outdoor Exposure

Abstract

The subject of the research in this work was the S49 rail made of R260 rail steel (1.0623). The carried out investigations concern microstructure tests and tests of mechanical properties of rails after several years of exposure in the open air without usage. The purpose of the work was to determine on the basis of the results of research the possibilities of using the tested rail for usage and application for the construction of tracks on railway sidings. For investigations there were used diverse techniques reaching such engineering materials investigations like light or scanning electron microscope for microstructure investigations, as well as hardness and microhardness test were performed for determinations of the microstructural changes occurred in the upper area of the rails surface. The microstructure changes concerns especially the ferritic and pearlitic structure and the breaks in the present carbide mesh. During investigations it was found out that the tested railway rails are fully useful for application, after machining to achieve required dimensional parameters. It is also of high importance, of the economical point of view, that their price, also in case of earlier installation of the rails, may be lower than the current price off ered on the marked for a entire new product. The price diff erence reaches dimensions in the range of 5-10%.

Evolution of the Lamellar Pearlite Structure of Rail Steel under Tension

“…В современных условиях высоких нагрузок на ось и скоростей движения поверхностные слои рельсов при длительной эксплуатации испытывают интенсивные пластические деформации, приводящие к повреждениям и, как следствие, к изъятию рельсов [1,2]. Как известно, зарождение и развитие микротрещин в пластичных материалах обусловлено эволюцией дефектной субструктуры, которая во многом определяет их механические свойства [3].…”

Evolution of Cementite Substructure of Rails from Hypereutectoid Steel during Operation

“…This has made it possible to analyze the mechanisms of wear, the degradation of rail properties and the reasons for their failure. The formed data bank, as well as the results of recent studies [14][15][16][17][18][19] of the patterns of structure formation, phase composition and dislocation substructure can be considered as achievements in the physics of hypoeutectoid pearlite steels. New steel grades have been sought for several years in order to limit contact fatigue and wear.…”