Study of Defects of Longitudinal Welded Pipe

Abstract

During the production of longitudinal electric welds by the method of high-frequency welding (HFW), defects of the longitudinal weld were revealed using X-ray inspection. For these defects, metallographic analysis was carried out, which showed that both the base metal and the welded joint met the requirements of regulatory documents. The chemical composition and mechanical properties also comply with the requirements of regulatory documents. Non-metallic inclusions of the liquation strips of the sheet, emerging on the edge and falling into the welding zone, were detected during X-ray inspection and were not correctly identified as a defect. This assumption is based on the coincidence of the position of the "grooves" in the zones of the welded joint with X-ray diffraction patterns, while the defects are not confirmed by other control methods and metallographic studies. Incorrect interpretation of defects during X-ray inspection occurs in the production of pipes [1-4] and requires additional verification or duplicate inspection. © 2022 American Institute of Physics Inc.. All rights reserved.