Abstract
Erosion-corrosion possesses a serious problem for the mining and mineral processing industries. Handling and processing of silica-based solids results in extremely severe wear conditions. Simultaneous action of erosion, corrosion and their synergistic interactions accelerates the material damage. Chrome white irons (CWI) are extensively used in the oilsands industry for slurry handling equipment. Erosion-corrosion resistance of CWI’s depends on the chemical composition, matrix microstructure, types and volume fraction of carbides. In this study, high-Cr white irons were assessed using a slurry pot erosion-corrosion testing apparatus, where the total erosion-corrosion (E-C) rate as well as the separate components of synergy were determined. It was found that corrosion resistance of white irons largely depends on the amount of dissolved chromium in the matrix. On the other hand, erosion resistance is controlled by the type and volume fraction of carbides. During erosion-corrosion, corrosion enhanced erosion dominates the synergistic component. Material degradation rate depends on the involved wear mechanisms. SEM observation revels that cutting of the metal matrix by erodent at low impingement angles, micro-fracture of the carbides and spallation are the dominant mechanisms.
