Tungsten carbide hard phase formation
Tungsten carbide hard-phase formation creates hard tungsten carbides in the matrix, drastically improving wear resistance under abrasive conditions.
Physico-Chemical Action Mechanism
Tungsten carbide hard phase formation occurs when tungsten and carbon react in the weld. This leads to the formation of tungsten carbides (WC), which are very hard crystals.
Metallurgical Relevance & Risks in Welding
Hard phase formation increases the strength and wear resistance of the weld, which is especially helpful under hard or abrasive stress. However, too high a concentration of tungsten carbides can lead to puckering and graininess, which can reduce hardness.
Shop Practice & Action Instructions
To promote tungsten carbide hard phase formation, the tungsten content in the weld pool should be set to 0.5 to 1.0 %. The cooling time should be between 3 and 5 seconds to ensure optimal hard phase formation.