Lack of side fusion
A lack of fusion at the flank occurs when the weld is not well connected to the base material. This happens due to insufficient heat input and leads to a lack of fusion.
Physical-Chemical Mechanism
The flank of the weld is the boundary between the newly molten metal (weld metal) and the unchanged base material. In a lack of fusion at the flank, there is no complete fusion between these two areas, which is due to insufficient heat input.
Metallurgical Relevance & Risks in Welding
A lack of fusion at the flank can lead to a weak connection between the weld metal and the base material. This increases the risk of cracks, especially under mechanical load. The service life of the weld is reduced and its toughness is impaired.
Workshop Practice & Procedures
To avoid lack of fusion at the flank, it is crucial to ensure sufficient heat input into the weld zone. This can be achieved with higher welding voltage or longer dwell time. Correct preparation of the base material and filler metal, as well as careful selection of the proper welding process, is also essential.