Effect of carbon content on the microstructure and properties of Cr-doped WC–15Co cemented carbide

WC–15Co–0.95Cr cemented carbide with various carbon content was fabricated via sintering hot isostatic pressing. The influences of carbon content on the microstructure, magnetic and mechanical properties, as well as corrosion behavior, were systematically investigated. The results show that the increases in carbon contribute to WC grain growth. (Cr, W)Cx phase would precipitate at the interface while excessive carbon is added. The coercive force and Vickers hardness gradually decreased with carbon content added, while the transverse rupture strength initially increased and then decreased. The higher carbon content cemented carbide exhibits inferior corrosion resistance in the sodium sulfate solution. The poor corrosion resistance of higher carbon content cemented carbide primarily ascribes to the precipitation of Cr-rich phase, which gave rise to the lack of Cr elements in the Co binder phase.