Volume 7, Issue 4 (July 1979)
Acoustic Emission Monitoring of Weldments
Weld tests were performed on low-carbon and high-strength, low-alloy steel weldments. The weldments were monitored with an acoustic emission detector during both the “in-process” and the “in-cooling” phases of the welding operation. Artificial defects were induced in several of the welds to promote cracking. Some high-strength weldments were designed to produce welds subject to high restraint. Nondestructive and destructive evaluation of the completed weldments revealed that high acoustic emission activity during in-cooling could be correlated with embedded defects and cold-cracking. Copious emission activity was also detected from unflawed weldments. Acoustic emissions were detected in high-strength steel weldments for periods up to 265 h. However, there was no clear relation between the duration of acoustic emission activity and cracking. On a per-electrode-deposited basis, high-stressed welds produced more emissions than low-stressed welds.