Influence of Nb and V Addition on Abrasive and Impact Wear Properties of 16%Cr–3%Mo White Cast Iron

Investigations were conducted on the microstructure and behaviors of abrasive wear and impact wear of 16%Cr–3%Mo white cast iron without and with 2.7%Nb–1%V addition heat-treated at 1253 K followed by forced-air cooling to clarify the difference between two kinds of wear mechanisms. Microstructures were analyzed by means of scanning electron microscope equipped with energy dispersive X-ray spectrometer, X-ray diffractometer and ferrite meter. Results reveal that since MC spheroidal carbides are formed by addition of Nb and V, the other primary carbides are refined and martensite in the matrix becomes more stable. Such microstructure improves abrasive wear resistance, but deteriorates impact wear resistance. Under the severe test condition, self-tempering softening of martensite in the matrix caused by the impact energy of abrasive media and it increases the impact wear rate.