Cluster porosity
Birdnest porosity consists of small, densely packed pores in the weld caused by local overheating or sudden parameter changes during arc welding. They weaken the material and can lead to cracks.
Physicochemical mechanism of action
Birdnest pores form from local overheating or sudden changes in arc parameters during welding. These conditions can lead to rapid cooling and thus pore formation.
Metallurgical relevance & risks in welding
Birdnest pores weaken the local cross-section of the weld, reducing mechanical strength. They can cause cracks or distortion and are especially dangerous in highly stressed applications. The pores can also promote corrosion.
Workshop practice & instructions
To avoid birdnest pores, keep arc parameters constant and ensure even heat transfer. Optimal travel speed and proper shielding gas flow also help. If birdnest pores are detected, inspect the weld and repair if necessary.