Hot Cracking Susceptibility Coefficient
The hot cracking susceptibility coefficient indicates how likely solidification cracks are to form during cooling of weld metal. It takes into account the concentrations of sulfur, phosphorus, and carbon.
Physicochemical mechanism of action
The hot cracking susceptibility coefficient (WAK) measures the risk of solidification cracks in the weld metal. These cracks occur due to rapid cooling and the formation of low-melting eutectic films at the grain boundaries of the steel. Sulfur, phosphorus, and carbon influence the melting behavior and the susceptibility to cracking.
Metallurgical relevance & risks during welding
A high WAK means an increased risk of solidification cracks, especially during cooling. This can lead to failed weld attempts and dangerous crack formation. A low WAK reduces the risk of these problems.
Workshop practice & instructions
To minimize the risk of hot cracking, the melting process should be designed so that cooling is slow and controlled. This can be achieved through optimized welding parameters. With a high WAK, it is advisable to install additional cooling systems or extend the melting process.