Effect of Auto-UT Tandem Detection Technology on Detection Results of Welding Seam of Double-side Submerged-arc Welding Steel Pipes

According to the requirements in DEP 31.40.20.37:2013, auto-UT detection was down to the welding seam of φ610 mm×15 mm double-side submerged-arc welding steel pipes by two probes of which the refraction angle was 45°. The defects in the welding seam center were tested from the two sides of the welding seam through the tandem detection. During the tandem detection process, it was found that: not only the echo wave signal from artificial reference reflectors was weak and instable, but also there was a large deviation between the actual position of detection probes and theoretical position calculated according to the center of the main beam. Through the theoretical analysis and experimental verification, it was proved that the welding reinforcement had big effect on the detection results. Finally, the detection technology was adjusted according to the cause of the problems, and the problems existing in the tandem detection were effectively solved.