Analysis of the Wear Mechanism and the Influence of the Chemical Composition and Repair Welds of the Pig Iron Wagon Wheels

The aim of the present study was to develop a concept for the inverse analysis of wear mechanisms in cast steel wheels of a pig iron wagon after long-term operation. Samples were taken from the flange and the tread edge area of fourteen wheels. The impact of wheel parameters and repair methods on their wear was assessed. An analysis was carried out to determine whether welds were made as part of casting correction or as repair welds. Changes in the microstructure of the weld area, the heat-affected zone, and the parent material resulting from operation were determined. The main wear mechanism in the area of the welds and the parent material is the plastic flow of the material resulting from high unit pressures. The hardness of the material is found to be contingent upon its chemical composition, the microstructural components, and the degree of plastic deformation resulting from wear (it has been established that increasing alloying results in increased hardness; a comparable effect is observed in the formation of non-equilibrium structures (bainite)). The increase in hardness is attributed to strain hardening, a consequence of exploitation. Research and analytical methods have been developed to differentiate the results of repair processes for wear effects in a highly loaded friction node with non-stationary lubrication conditions from repair processes applied to castings of large structural components.