Characteristics of tram wheel wear: Focus on mechanism identification and surface topography

Assessment of durability and reliability of ET41 series locomotive wheels based on laboratory tests

“…Wheel and track wear occurs when rollingsliding friction takes place. There are three varieties of wear regimes: mild wear, severe wear and catastrophic wear [25,26]. The dominant mechanism of mild wear is oxidation when the material loss is negligible.…”

“…Catastrophic wear consists in spalling and fatigue cracking in the subsurface [25]. Spalling occurs when, as a result of the wheel sliding along a track, enough heat is released in the contact zone to heat up the surface to over 730 O C for at least a few seconds [26]. In this case, a transformation of pearlite into the fragile martensite occurs.…”

“…The process occurs when the wheel's rolling surface heats up to over 300 O C for at least a few minutes. This weakens the material, in which the contact stresses created by the wheel-rail interaction can initiate the formation of microcracks [26]. Their formation may be facilitated by contamination of contact surfaces, such as water, sand or dust [26].…”

“…This weakens the material, in which the contact stresses created by the wheel-rail interaction can initiate the formation of microcracks [26]. Their formation may be facilitated by contamination of contact surfaces, such as water, sand or dust [26]. As a result of both spalling and shelling, shallow craters are formed on the surface from which flake-like wear debris is removed [26].…”

“…Their formation may be facilitated by contamination of contact surfaces, such as water, sand or dust [26]. As a result of both spalling and shelling, shallow craters are formed on the surface from which flake-like wear debris is removed [26]. During severe wear, the mechanism changes from oxidation to flaking and fatigue cracking [25].…”