Microscopic investigation of surface layers on rails

A Kinetic Model for Tribological Surface Transformations Occuring on the Railroads: Irreversible Near-Surface Metallurgical Transformations

“…For the last twenty years, the weight and velocity of freight trains have been increasing steadily, resulting in the development of "Tribological Surface Transformations" (TSTs) or "White Etching Layers" (WELs) [1][2][3][4] (see Figure 1(a)). TSTs are the irreversible solid-solid phase transformations which occur both at the surface and in depth, in the immediately vicinity of the wheels of passing trains.…”

The Mössbauer Spectroscopy Studies of ϵ to Cementite Carbides Transformation during Isothermal Heating from As-Quenched State οf High Carbon Tool Steel

“…On the account of a possibility of using the data from [11][12][13][14][15][16][17][18], concerning the value of the hyperfine field on 57 Fe nuclei, located in various ferromagnetic phases or in chemical compounds occurring in the steels, the easiest way was to attribute the individual components of the experimental Mössbauer spectra to phases and chemical compounds occurring in the microstructure of the tempered steel. Figure 2 presents changes in hyperfine magnetic field (H) for a component corresponding with iron carbides vs. tempering time.…”

“…Many works [11][12][13][14][15][16][17][18] showed that the Mössbauer spectroscopy gives a possibility to obtain new data, which may help more detailed interpretation of the phenomena connected with phase transformations during tempering.…”

Surface Integrity – Definition and Importance in Functional Performance

“…For example, microscopic investigation of surface layers on rails showed severe plastic deformation due to the normal pressure as well as shearing, together with a rapid change of temperature at service conditions lead to decomposition of the initial pearlite structure accompanied by surface oxidation, defect formation, carbon clustering, precipitation of nanosize carbide particles and austenitization of the material [15]. SEM study of fracture surfaces and fatigue crack initiation due to low-temperature irradiation showed that this radiation causes an increase in stress amplitude and a reduction in fatigue lifetime corresponding to radiation hardening and loss of ductility [16].…”