Localized Root Imperfection
Local root defect is a point-like imperfection in the penetration at the root, usually caused by uneven feed. It results in lack of fusion and increases the risk of cracks.
Physical-Chemical Mechanism of Action
A local root defect occurs when the feed rate during the welding process is uneven. This causes certain areas not to be fully closed, leaving a lack of fusion.
Metallurgical Relevance & Welding Risks
A local root defect increases the risk of cracks and reduces the mechanical strength of the weld. It can lead to failure under load, especially if it occurs in highly stressed areas.
Workshop Practice & Action Guidelines
To avoid local root defects, the feed rate during the welding process should always be consistent. A precision of ±0.1 mm per meter of weld is recommended. If defects are suspected, the welds should be carefully inspected and repaired if necessary.