Evaluation of Corrosion Resistance of WC-Co Based Alloys inH2SO4
Three cemented carbide specimens, i.e., WC-Co (Sample A), WC-Cr3C2-Co (Sample B) and WC-βt-Co (Sample C) in which βt indicates (Ti,W,Ta,Nb)C, are prepared by liquid phase sintering, and their corrosion behavior has been investigated by the electrochemical methods. The similar activation, passive state and over passive state regions as SUS304 stainless steel during the polarization test, and the preferential dissolution of Co were observed for all of the three specimens mentioned above. Both Cr3C2 and βt improved the corrosion resistance of WC-Co alloy, in which the effect of the former was better than that of the latter. Sample B also showed the best corrosion resistance in all the samples for the electrochemical impedance spectroscopy (EIS) test.
Young Won Chang, Nack J. Kim and Chong Soo Lee
S. Sunada et al., "Evaluation of Corrosion Resistance of WC-Co Based Alloys inH2SO4", Materials Science Forum, Vols. 561-565, pp. 2147-2150, 2007