Reliability of the Ultrasonic Technique Applied to Detection of Pipe Weld Defects

摘要

The objective of this work is to evaluate the reliability of the ultrasonic nondestructive test technique (NDT), for specific test conditions, using POD (probability of detection) curves developed by experimental procedures. Two classes of defects, lack of penetration (LP) and lack of fusion (LF) were intentionally inserted in 24 weld beads belonging to 4 API X70 steel pipeline specimens with an outer diameter of 254mm and wall thickness of 19.05mm. These specimens were inspected using manual and automatic ultrasonic techniques. The results, besides producing real POD curves, showed the superiority of the automatic techniques over the manual test in the probability of detection of these two classes of defects.