For a long time, many people in the industry have believed that cemented carbide is tungsten steel. Today we will talk about the difference between cemented carbide and tungsten steel.
01 Carbide
Cemented carbide is made from hard compounds of refractory metals and bonding metals through a powder metallurgy process. It is an alloy material with extremely high hardness. Tungsten carbide (WC) is the main component of cemented carbide, accounting for 70% to 97% of the total composition; the bonding metal is used to bond the alloy, and its content is usually 3% to 30%. During the sintering process, It can surround tungsten carbide powder and bond it tightly together, and after cooling, it becomes a cemented carbide.
Therefore, commonly used cemented carbide is divided into three categories based on composition and performance characteristics: tungsten-cobalt, tungsten-titanium-cobalt, and tungsten-titanium-tantalum (niobium). The most widely used cemented carbides in production are tungsten-cobalt and tungsten-titanium-cobalt.
1) Tungsten-cobalt cemented carbide
The main components are tungsten carbide (WC) and cobalt. The brand name is represented by the code YG (prefixed by the Chinese pinyin of "hard" and "cobalt"), followed by the percentage value of the cobalt content. For example, YG6 represents a tungsten-cobalt cemented carbide with a cobalt content of 6% and a tungsten carbide content of 94%.
2) Tungsten titanium cobalt carbide
The main components are tungsten carbide (WC), titanium carbide (TiC) and cobalt. The brand name is represented by the code YT (prefix of the Chinese pinyin of "hard" and "titanium"), followed by the percentage value of titanium carbide content. For example, YT15 represents a tungsten-titanium-cobalt carbide with a titanium carbide content of 15%.
3) Tungsten titanium tantalum (niobium) carbide
This type of cemented carbide is also called universal cemented carbide or universal cemented carbide. Its main components are tungsten carbide (WC), titanium carbide (TiC), tantalum carbide (TaC) or niobium carbide (NbC) and cobalt. The brand name is represented by the code YW (prefixed by the Chinese pinyin of "hard" and "wan") followed by an ordinal number.
Commonly used cemented carbide grades and chemical compositions:
Note: "X" after the grade indicates fine-grained alloy, "C" indicates coarse-grained alloy, and nothing indicates general-grained alloy.
02 The difference between tungsten steel and cemented carbide
Generally speaking, tungsten steel is smelted by adding tungsten raw materials to molten steel using a steelmaking process. It is also called high-speed steel or tool steel. Its tungsten content is generally 15% to 25%. In addition to using the smelting method to produce high-speed steel, there is also powder metallurgy high-speed steel, which avoids the reduction in mechanical properties and heat treatment deformation caused by carbide segregation caused by the smelting method.
Cemented carbide is made by sintering tungsten carbide as the main body and cobalt or other bonding metals using a powder metallurgy process. Its tungsten content is generally above 80%.
Simply put, all alloys with a hardness exceeding HRC65 can be called cemented carbide, so tungsten steel belongs to cemented carbide; but strictly speaking, cemented carbide is not necessarily tungsten steel.
