Tungsten carbide formation
Tungsten carbide forms in high-alloy materials and provides extreme hardness and resistance to wear and thermal stress.
Physico-Chemical Action Mechanism
Tungsten carbides (WB) form through the reaction of tungsten with carbon. This process is typical for highly alloyed materials such as steel with a high tungsten content. The formation of WB leads to a strong increase in strength and hardness because the carbide crystals are very hard.
Metallurgical Relevance & Risks in Welding
The formation of tungsten carbides increases hot hardness and wear resistance of the materials. However, too high a concentration of WB can lead to cracking, especially if the material cools too quickly. This can result in hot cracks or shear cracks in the structure.
Shop Practice & Action Instructions
To take advantage of the benefits of tungsten carbide formation, it is important to weld the material at the correct temperatures and speeds. Too fast a cooling should be avoided, as it can lead to cracking. Recommended cooling time: at least 10 seconds per cm of steel thickness. For special materials such as high-alloy steels, it is advisable to follow the manufacturer's instructions.