What is the difference between tungsten steel and tungsten carbide in machining tool materials?

The terms "tungsten steel" and "tungsten carbide" are sometimes used interchangeably, but they refer to different materials in the context of machining tool materials. Let's clarify the distinctions between the two:

1. Tungsten Steel:

"Tungsten steel" is a term commonly used in China and certain regions to refer to high-speed steel (HSS) tools that contain tungsten as one of the alloying elements. High-speed steel is an alloy of iron (Fe), tungsten (W), molybdenum (Mo), chromium (Cr), and other elements.

Tungsten in high-speed steel contributes to hardness and wear resistance. High-speed steel tools are known for their ability to withstand high temperatures generated during machining processes.

2. Tungsten Carbide:

Tungsten carbide is a composite material composed of tungsten (W) and carbon (C) atoms, often formulated as tungsten carbide (WC) particles embedded in a cobalt (Co) matrix. Tungsten carbide is extremely hard and wear-resistant.

In the context of machining tools, cemented carbide or hard metal tools are commonly made from tungsten carbide. These tools are known for their exceptional hardness, wear resistance, and suitability for high-speed machining.

Key Differences:

1. Composition:

Tungsten steel (HSS) is primarily composed of iron, tungsten, molybdenum, chromium, and other alloying elements.

Tungsten carbide is composed of tungsten carbide (WC) particles and a binder phase, typically cobalt (Co).

2. Hardness:

Tungsten carbide is generally harder than tungsten steel (HSS). The hardness of tungsten carbide contributes to its superior wear resistance and suitability for cutting, drilling, and milling applications.

3. Wear Resistance:

Tungsten carbide exhibits higher wear resistance compared to tungsten steel. This makes tungsten carbide tools more durable in high-speed machining operations.

4. Applications:

Tungsten steel (HSS) tools are commonly used for a range of machining applications, including cutting, milling, and drilling. They are suitable for a variety of materials but may wear faster in demanding conditions.

Tungsten carbide tools are particularly well-suited for applications where hardness and wear resistance are crucial. They are widely used in high-speed machining of hard materials such as metals, alloys, and composites.

While tungsten steel and tungsten carbide serve similar purposes in machining, tungsten carbide tools are often preferred for applications demanding high hardness and wear resistance, especially in modern machining practices where cutting speeds and efficiency are critical.