A CRITIQUE ON THE WEAR MECHANISM OF SURFACE ENGINEERED SUGAR MILL ROLLER SHELLS

SURFACE ENGINEERED sugar mill roller shells (SMRS) have historically been done by a welding process called ‘arcing’. The desired effects of the engineered surface on the SMRS are: to increase friction between the SMRS and the shredded sugar cane, to enhance the extraction of sucrose juice, to minimise the wear and to potentially enhance bagasse comminution. In this investigation, the surface of grey cast iron rollers were arced in the traditional way. A second set of grey cast iron rollers were hardfaced using similar welding electrodes. The engineered surfaces were characterised for their abrasion and corrosion wear resistance. The results of the study suggest that the predominant wear mechanism is corrosion associated with porosity and a depletion of Cr. The depletion of Cr on the welded globules, when compared to the manufacturer’s welding electrode specification, is quite significant. The results lead to the conclusion that the formulation of elemental additives to welding electrodes for arcing SMRS needs to be further investigated.