Will there be pitting on the surface of tungsten carbide products during decarburization？

Decarburization is a process that involves the loss of carbon from the surface of a material, typically due to exposure to high temperatures in the presence of oxygen. Tungsten carbide, being a composite material of tungsten and carbon, is susceptible to decarburization under certain conditions. The extent of decarburization and the potential for pitting on the surface depend on various factors:

1. Temperature and Atmosphere:

High temperatures and exposure to oxidizing atmospheres can accelerate decarburization. The severity of decarburization increases with higher temperatures and prolonged exposure.

2. Heat Treatment Process:

Tungsten carbide products are often subjected to heat treatment processes for sintering and other purposes. The parameters of the heat treatment, such as temperature, duration, and atmosphere, can influence the degree of decarburization.

3. Protective Coatings:

Some tungsten carbide products may be coated with protective layers or coatings to minimize oxidation and decarburization during high-temperature processes. Coatings like titanium nitride (TiN) or other carbide-based coatings can provide a barrier against oxidation.

4. Carbon Content:

The initial carbon content of the tungsten carbide material can affect its susceptibility to decarburization. Higher carbon content may provide greater resistance to the loss of carbon during high-temperature processes.

5. Surface Finish:

The surface finish of the tungsten carbide product can influence its resistance to decarburization. A smooth and dense surface may provide better protection against oxygen penetration and carbon loss.

6. Cooling Rate:

The rate at which the tungsten carbide product is cooled after heat treatment can also impact decarburization. Rapid cooling can help minimize the extent of decarburization.

Pitting on the surface may occur as a result of uneven decarburization or oxidation. Pits can be formed due to localized loss of carbon, leading to a less uniform surface. Pitting can affect the mechanical and wear properties of the tungsten carbide product.

To minimize the risk of pitting and decarburization, manufacturers often employ controlled heat treatment processes, protective atmospheres, and coatings. Additionally, proper cooling procedures and attention to the specific requirements of the tungsten carbide grade used are crucial in maintaining the desired properties of the material.

It's advisable to consult with the manufacturer or supplier of the tungsten carbide products for specific information on their heat treatment processes, protective measures, and recommendations for minimizing decarburization-related issues.