Commonly used tungsten carbide with WC as the main component, according to whether to add other carbides and divided into the following categories:
(1) Tungsten Cobalt (WC+Co) cemented carbide (YG)
It is composed of WC and Co, has high bending strength toughness, good thermal conductivity, but poor heat resistance and wear resistance, mainly used for processing cast iron and non-ferrous metals. Fine grain YG class carbide (such as YG3X, YG6X), in the same cobalt content, its hardness and wear resistance than YG3, YG6 higher strength and toughness, suitable for processing hard cast iron, austenitic stainless steel, heat resistant alloy, hard bronze and so on.
(2) Tungsten titanium cobalt (WC+TiC+Co) Tungsten carbide (YT)
Since the hardness and melting point of TiC are higher than that of WC, compared with YG, its hardness, wear resistance and red hardness increase, the bonding temperature is high, the oxidation resistance is strong, and TiO 2 will be generated at high temperatures, which can reduce bonding. However, the thermal conductivity is poor and the bending strength is low, so it is suitable for processing ductile materials such as steel.
(3) Tungsten tantalum cobalt (WC+TaC+Co) cemented carbide (YA)
The addition of TaC(NbC) on the basis of YG class cemented carbide improves the hardness and strength at room temperature and high temperature, thermal shock resistance and wear resistance, and can be used for processing cast iron and stainless steel.
(4) Tungsten titanium tantalum cobalt (WC+TiC+TaC+Co)) carbide (YW)
The addition of TaC(NbC) on the basis of YT class cemented carbide improves the bending strength, impact toughness, high temperature hardness, oxygen resistance and wear resistance. It can process steel, cast iron and non-ferrous metals. Therefore, it is often called general purpose cemented carbide (also known as W energy cemented carbide). At present, it is mainly used for processing heat-resistant steel, high manganese steel, stainless steel and other difficult materials.
Performance characteristics of cemented carbide:
High hardness (86 ~ 93HRA, equivalent to 69 ~ 81HRC);
Good thermal hardness (up to 900 ~ 1000℃, maintain 60HRC);
Good wear resistance.
The cutting speed of cemented carbide tools is 4 to 7 times higher than that of high-speed steel, and the tool life is 5 to 80 times higher. Manufacturing mold, measuring tools, life than alloy tool steel 20 to 150 times higher. It can cut hard materials of about 50HRC. However, tungsten carbide is brittle, can not be cut, it is difficult to make a complex shape of the whole tool, so often made of different shapes of the blade, the use of welding, bonding, mechanical clamping and other methods installed in the tool body or die specific use.
