Corrosion and Highly Wear Resistant Hard Metals.

Hard metals based on WC-Co have a better combination of mechanical properties compared to WC-Ni grades, but their corrosion resistance is generally poor. Either by variation of the binder phase (Ni, Ni-Cr) or by variation of the carbide phase (grain size) the corrosion resistance of hard metals can be tailored to the specific application maintaining the good mechanical properties of WC-Co-grades. The mechanical, chemical and thermal properties of various hard metal compositions are given. Hard metals of modified composition are used for valve parts, seal rings, nozzles and as wear parts for other applications in chemical industry.