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How can lack of fusion defects be detected and remedied?


Frequently Asked Questions

If the imperfections are surface breaking, they can be detected using a penetrant or magnetic particle inspection technique. For sub-surface imperfections, detection is by radiography or ultrasonic inspection. Ultrasonic inspection is normally more effective than radiography in detecting lack of inter-run fusion imperfections, but the effectiveness of the inspection technique will be affected by the material of construction.

Remedial action will normally require their removal by localised gouging, or grinding, followed by re-welding as specified in the agreed procedure.

If lack of fusion is a persistent problem, and is not caused by magnetic arc blow, the welding procedures should be amended and/or the welders retrained.

For more extensive information on lack of fusion defects, see Job Knowledge for Welders 41 - Weld defects/imperfections in welds - lack of sidewall and inter-run fusion.

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