Melt Pool Collapse
Melt pool collapse is a condition where the molten metal in the weld becomes unstable, creating local geometry defects. This can lead to porosity and loss of strength.
Physical-chemical mechanism of action
Melt pool collapse occurs when the liquid metal in the weld builds up excessive stresses. These stresses can arise from uneven cooling or too high fill levels in the melt pool. This causes the metal to suddenly contract and create local geometric defects like porosity.
Metallurgical relevance & welding risks
Melt pool collapse can lead to serious weld defects, such as porosity and loss of strength. This increases the risk of cracking and reduces component life. It can also cause uneven cooling, leading to further metallurgical problems.
Workshop practice & instructions
To avoid melt pool collapse, ensure even cooling of the melt pool. Use a fill level of max. 50% in the melt pool and make sure the metal isn't overloaded beyond critical. If problems occur, check cooling rate and weld temperature closely.