Characterization of the wear of nodular cast iron rollers in contact with wire ropes

The present work describes the major findings of a wear mechanism analysis based on optical and scanning electron microscopy on rollers made from nodular cast iron that had rolled under partial slip against steel wire ropes in field service and in wear tests using rollers and wire ropes. Various wear modes were identified on the wire rope groove surfaces. The findings will be utilized in the modeling and testing work to support product development activities. In the roller surfaces and sub-surface zones, evidence of several wear mechanisms occurred. The microscopy of the worn rope groove surfaces revealed deformation tongues caused by plastic deformation and crack growth in sub-surface zones that had been subjected to contact pressure under rolling and micro-slip in tangential direction of the roller and sliding motion in the radial direction of the roller. To large extent, the cracks originated from graphite nodules that had been elongated by the surface material flow. The deformation tongues were oriented in the direction of the net sliding motion between the contact pair. High contact pressure levels activated crack growth opposite to the sliding direction.