A welding defect characterized by a groove or channel melted into the base metal adjacent to the weld toe or weld root and left unfilled by weld metal. This discontinuity weakens the joint and can lead to premature failure due to stress concentration. As an example, if a weld bead does not fully fuse with the base material along its edge, it leaves a recessed area, which is considered a instance of this flaw.
The formation of this flaw significantly reduces the structural integrity and fatigue strength of the welded component. Its presence can necessitate costly repairs and rework, and in critical applications, can lead to catastrophic failures. Understanding its causes and preventative measures has been a concern since the early days of fusion welding processes, leading to ongoing research and refinement of welding techniques and parameters.
