A welding imperfection characterized by a groove melted into the base metal adjacent to the weld toe and left unfilled by weld metal. This discontinuity weakens the joint and can lead to fatigue failure, particularly under cyclical loading conditions. For example, if a weld is performed on a steel plate and the arc melts away the edge of the plate without depositing sufficient filler metal to compensate, a visible notch or groove forms, indicating this specific type of defect.
The presence of this defect reduces the cross-sectional area of the base metal, consequently diminishing the joint’s overall strength. It acts as a stress concentrator, making the weld more susceptible to cracking, especially in dynamic environments. Mitigation strategies are crucial in welding procedures to ensure structural integrity and longevity of welded components, dating back to the early development of standardized welding practices where quality control measures were not as stringent as today.