Degradation of structure and properties of rail surface layer at long-term operation

Abstract

Abstract:The microstructure evolution and properties variation of the surface layer of rail steel after passed 500 and 1000 million tons of gross weight (MTGW) have been investigated.The wear rate increases to 3 and 3.4 times after passed 500 and 1000 MTGW, respectively.The corresponding friction coefficient decreases by 1.4 and 1.1 times. The cementite plates were destroyed and formed the cementite particles of around 10-50 nm in size after passed 500 MTGW. The early stage dynamical recrystallization was observed after passed 1000 MTGW. The mechanisms for these have been suggested. The large number of bend extinction contours is revealed in the surface layer. The internal stress field is evaluated.

Manufacture of materials using external fields

“…Babutskyi et al presented the effect of magnetic pulses on Ti-alloys [15]. The evolution of structure and properties of pearlitic steels under long-term mechanical loading has been reported by Gromov et al [16]. Researchers from several UK industries, e.g.…”

Прочностные, Трибологические Свойства И Структурно-Фазовые Состояния Рельсовых Сталей

“…Важность информации о структурнофазовом состоянии, прочностных и трибологических свойствах новых видов рельсов определяется глубиной фундаментальных проблем физического материаловедения, с одной стороны, и практической значимостью проблемы, с другой, поскольку рельсы производятся из стали перлитного класса [2-7]. В работах [8][9][10][11][12][13][14] выполнены оценки механизмов упрочнения рельсов при различных сроках длительной эксплуатации, различных видах деформации и проанализированы стадии трансформации пластинчатого перлита [1,15,16].…”

Strain Stress Model of the Rail with Crack in its Head and Estimation of its Operational Lifetime

“…In the areas of the sharp crack edges a concentration of stresses can appear, consequently the crack will be developing in this direction rather quickly. The value of stresses in areas of concentration can exceed the yield strength, so the rail can be broken down soon [5,6]. Residual stresses appear within the processes of production, welding and installation [7][8][9].…”