Lack of Fusion
Undefined lack of fusion occurs when there's no metallurgical fusion between weld metal and base material or between layers. This leads to a lack of mechanical bonding.
Physical-Chemical Working Mechanism
With lack of fusion defects, a clear boundary remains between the weld metal and the base material, or between layers. No metallurgical fusion occurs, so no atomic bond is created.
Metallurgical Relevance & Welding Risks
Lack of fusion leads to a missing mechanical bond between the involved materials. This can cause cracks, separation, or low weld strength. The service life and load-bearing capacity of the whole system are severely impaired.
Workshop Practice & Action Instructions
To avoid lack of fusion, it is crucial to maintain the correct welding temperature. The weld must be cooled slowly and continuously to ensure homogeneous metallurgical fusion. Check the welding parameters regularly and use high-quality materials.