Repetitive Impact Wear Behaviors of the Tempered 25Cr3Mo2NiWV Fe-Based Steel

Abstract

This study aimed to reveal the impact wear behaviors of tempered 25Cr3Mo2NiWV steel. The specimens were subject to various heat treatment processes for generating different mechanical and wear properties. The impact wear tests were performed with an MLD-10 dynamic abrasive wear tester. Worn surface morphologies and micro-cracks of the cross-sections were analyzed by optical microscope and scanning electron microscope. The Vickers hardness of the sample and the impact wear mechanism were also analyzed. The steel with the best combination of hardness and toughness had the lowest wear. With the increase of wear time, the dominant wear mechanism varied from slight plastic deformation to micro-cutting and adhesive wear. Finally, micro fatigue peeling occurred. After impact wear, the cracks could initiate from the surface or the sub-surface. Micrographs of the crack in the cross-section demonstrated two different propagation modes of fatigue fractures. The results showed that the strength and toughness of steel affected the crack propagation, surface spalling, and wear failure mechanism during impact wear.