Cemented carbide, also known as tungsten steel, is made by high-quality tungsten carbide and cobalt powder which are compounded and blended and then pressed and sintered. It has a series of excellent properties such as high hardness, wear resistance, strength and toughness, heat resistance and corrosion resistance. Especially its high hardness and wear resistance, which remains basically unchanged even at a temperature of 500 °C, there is still a high hardness at temperature of 1000 °C. Cemented carbide as a tooth of modern industry, cemented carbide tools play a fundamental role in the development of the manufacturing industry.
Tungsten steel is classified according to grain size and can be classified into ordinary hard alloys, fine-grained hard alloys, and ultra-fine-grained hard alloys. The newly introduced double-crystalline cemented carbides are classified into major tungsten carbide-based hard alloys and titanium carbide-based hard alloys. Tungsten carbide-based hard alloys include tungsten-cobalt (YG), tungsten-cobalt-titanium (YT), and rare-carbonized (YW), each of which has advantages and disadvantages. The metal bonding phase commonly used for hard alloys of tungsten carbide (WC), titanium carbide (TiC), and niobium carbide (NbC) is Co. Titanium carbide-based cemented carbide is a hard alloy with TiC as its main component, and the commonly used metal bonding phases are Mo and Ni. Cemented carbide has high hardness (86～93HRA, equivalent to 69～81HRC), good thermal hardness (up to 900～1000°C, maintaining 60HRC); high flexural strength (MPa5100), good impact toughness and corrosion resistance extremely high chemical inertness and other characteristics not found in general alloy inserts.
