Laboratory tests for seizure of rail and wheel steels

Abstract

In the last decade side wear of rails and wheels was increasing in many countries. Topographic features of wearing surfaces of the rail gauge face and wheel flange lead to the assumption that seizure makes a heavy contribution to side wear especially at small radius curves. The exploration of seizure as a form (mode) of wear has been made. Two mechanisms of seizure designated as scoring and galling were observed in the laboratory tests. It is shown that the main peculiarity of scoring is local plastic deformation of both surfaces with formation of riders—hard movable centres consisting of two wedges with hardness ∼1.6 times greater than the basic metal. The main peculiarity of galling is plastic deformation of one surface only with formation of welding incrustation (protrusion) on the countersurface. An attempt was made to find the boundary of the scoring and galling area in the hardness–pressure–slippage–sliding velocity–environment space. Ways of counteracting side wear of rails and wheels following from the scoring mechanism of seizure are suggested.