INFLUENCE OF CORROSION ON THE ABRASION RESISTANCE OF CEMENTED CARBIDES

摘要

Cemented carbides are technologically important materials because they possess unique combinations of wear resistance, strength, and fracture toughness. They are typically employed in demanding applications including tools for metalcutting, metalforming, oil/gas drilling, woodworking, as well as a host of other wear applications. Traditionally, the most common cemented carbide grades have been based on WC as the hard dispersed phase and Co as the binder or continuous phase. In general Co-WC based cemented carbides exhibit outstanding abrasion resistance when employed under dry conditions. However, the corrosion resistance of these materials is somewhat limited while in contact with corrosive fluids, particularly acids. The abrasion resistance of Co-WC based cemented carbides thus tends to degrade significantly when they are employed while in contact with corrosive acids. The purpose of this study was to examine the effects of improving the corrosion resistance of cemented carbides as a way of improving their abrasion resistance. This paper discusses the development of advanced corrosion resistant grades based on Ni and Cr additions. Data are presented showing the dramatic influence of the alloying additions in improving wear resistance, particularly in situations where abrasion and corrosive conditions are present simultaneously.