| Résumé | A significant fraction of operational cost in oil sands mining is directly or indirectly related to undercarriage component wear. One of the strategies to minimize the cost is to repair/rebuild the worn components. Recent advancement of welding technology offers an economical way to achieve this goal. Depending on the involved wear mechanisms, the selection of appropriate overlay material can considerably extend the service life of worn undercarriage components. Due to their excellent wear resistance, tungsten carbide based overlays is a unique choice for this purpose. In this study, three WC-based overlays with different carbide types were selected for evaluation. Wear resistance was assessed via low-stress abrasion (ASTM G65) and rolling contact abrasion (RCA). RCA tests were conducted with two slip ratios, where 0.3% slip ratio simulates pure rolling/high-stress contact fatigue, and a 3.0% slip combines fatigue and abrasion as observed in undercarriage components. Based on the wear test results, it was found that, despite their good low-stress abrasion resistance, WC-based overlays display high rolling contact abrasion damage and is not suitable for the restoration of undercarriage components. SEM observation on wear scars correlates the wear performance with carbide type and corresponding mechanisms. |
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