Which is harder, chromium steel or tungsten carbide?

Tungsten carbide is generally harder than chromium steel. Let's look at the properties of both materials to understand why:

1. Tungsten Carbide:

Tungsten carbide is a composite material composed of tungsten (W) and carbon (C) atoms. The primary form is tungsten carbide (WC) particles embedded in a cobalt (Co) matrix. Tungsten carbide is renowned for its exceptional hardness, wear resistance, and strength.

Hardness: Tungsten carbide typically has a hardness in the range of 800 to 2,000 HRA (Rockwell Hardness A scale) or approximately 90 to 92 HRC (Rockwell Hardness C scale). The hardness depends on factors such as the specific grade, cobalt content, and manufacturing processes.

2. Chromium Steel:

Chromium steel, often referred to as high-chromium steel or tool steel, is an alloy of iron (Fe) with varying amounts of chromium (Cr) and other alloying elements. The addition of chromium enhances the hardness, wear resistance, and corrosion resistance of the steel.

Hardness: The hardness of chromium steel varies based on the alloy composition and heat treatment. Typically, chromium steels have hardness values in the range of 50 to 65 HRC (Rockwell Hardness C scale).

In summary, tungsten carbide generally has a higher hardness than chromium steel. The combination of tungsten and carbon, along with the specific microstructure of tungsten carbide, contributes to its outstanding hardness and wear-resistant properties. Tungsten carbide is often used in applications where extreme hardness and resistance to wear and abrasion are critical, such as cutting tools, drilling bits, and wear-resistant components.

When choosing between these materials for a specific application, factors such as the intended use, operating conditions, and the required combination of properties (hardness, toughness, wear resistance) should be considered.