For a long time, many industry professionals considered hard alloys synonymous with tungsten steel. Today, we are going to discuss the differences between hard alloys and tungsten steel.
I. Hard League
A hard alloy is an extremely hard alloy material created through a powder metallurgy process from hard compounds of refractory metal and binding metals.
Tungsten carbide (WC) is the main component of the hard alloy, accounting for 70%-97% of the total composition. The binder metal, typically comprising 3% to 30%, serves as the binder in the alloy.
During the sintering process, it envelops tungsten carbide powder and binds it tightly; after cooling, it forms a hard alloy.
Consequently, commonly used hard alloys are classified into three categories based on their composition and performance characteristics: tungsten-cobalt, tungsten-titanium-cobalt, and tungsten-titanium-tantalum (niobium) types.
The most commonly used in production are hard tungsten-cobalt and tungsten-titanium-cobalt alloys.
1. Tungsten and cobalt hard alloy
The main components are tungsten carbide (WC) and cobalt. The content is represented by the code YG, followed by the percentage of cobalt. For example, YG6 represents a hard tungsten-cobalt alloy with 6% cobalt content and 94% tungsten carbide.
2. Tungsten titanium cobalt hard alloy
The main components are tungsten carbide (WC), titanium carbide (TiC) and cobalt. The grade is represented by the code YT, followed by the percentage of titanium carbide. For example, YT15 represents a hard alloy of tungsten, titanium and cobalt with 15% titanium carbide content.
3. Hard tungsten titanium tantalum (niobium) alloy
This type of hard alloy, also known as universal hard alloy or versatile hard alloy, is mainly composed of tungsten carbide (WC), titanium carbide (TiC), tantalum carbide (TaC) or niobium carbide (NbC) and cobalt . The note is represented by the code YW followed by a sequence number.
Table 1: Common hard alloy classes and chemical compositions
| Note | Chemical composition% | |||
| Bathroom | Tic | TaC | co | |
| YG3X | 96.5 | – | <0.5 | 3 |
| YG6 | 94.0 | – | – | 6 |
| YG6X | 93.5 | – | <0.5 | 6 |
| YG8 | 92.0 | – | – | 8 |
| YG8N | 91.0 | – | 1 | 8 |
| YG11C | 89.0 | – | – | 11 |
| YG15 | 85.0 | – | 15 | |
| YG4C | 96.0 | – | – | 4 |
| YG6A | 92.0 | – | two | 6 |
| YG8C | 92.0 | – | – | 8 |
| YT5 | 85.0 | 5 | – | 10 |
| YT14 | 78.0 | 14 | – | 8 |
| YT30 | 66.0 | 30 | – | 4 |
| YW1 | 84~85 | 6 | 3-4 | 6 |
| YW2 | 82~83 | 6 | 3-4 | 8 |
Note: The “X” after the grade indicates a fine-grain alloy, “C” indicates a coarse-grain alloy, and no letter indicates a general-grain alloy.
II. The Difference Between Tungsten Steel and Hard Alloy
Generally, tungsten steel is produced by adding tungsten material to molten steel in the steel refining process, also known as high-speed steel or tool steel, with a typical tungsten content of 15-25%.
In addition to producing high-speed steel by melting, there are also high-speed steels for powder metallurgy, which avoid the segregation of carbides caused by the melting method that leads to reduced mechanical properties and distortion from heat treatment.
Hard alloy, on the other hand, is made through a powder metallurgy process with tungsten carbide as the main body and cobalt or other binding metals for sintering, and its tungsten content is generally greater than 80%.
Simply put, any alloy with a hardness greater than HRC65 can be called a hard alloy. Thus, tungsten steel is a type of hard alloy. However, strictly speaking, a hard alloy is not necessarily tungsten steel.
