| Title |
Challenges in ultrasonic NDT/NDE of small-scale structural defects in metal pipelines of the energy sector |
| Authors |
Raišutis, Renaldas ; Samaitis, Vykintas ; Stravinskas, Audrius ; Žukauskas, Egidijus ; Cicėnas, Vaidotas |
| DOI |
10.58286/32985 |
| Full Text |
|
| Is Part of |
e-Journal of nondestructive testing: 14th European conference on non-destructive testing (ECNDT 2026), 15-19 June 2026, Verona, Italy.. Mayen : NDT.net. 2026, vol. 31, spec. iss. 7, p. 1-2.. ISSN 1435-4934 |
| Keywords [eng] |
ultrasonic NDT / NDE ; detection and characterization ; structural defects ; creep damage ; hydrogen-induced cracking (HIC) |
| Abstract [eng] |
This research investigates the ultrasonic detection of small-scale structural defects in pipelines, pressure vessels and heat exchangers used in thermal and nuclear power plants, petrochemical facilities, refineries and hydrogen infrastructure. These components operate under harsh conditions (high temperatures, pressures and hydrogen-rich environments), that promote the formation of defects such as creep damage and hydrogen-induced cracking (HIC). Creep typically initiates in welds and heat-affected zones (HAZ) due to residual stresses and microstructural changes, while HIC results from hydrogen diffusion into the material. Although early-stage inhomogeneities are initially harmless, they can evolve into critical cracks, leading to failures, costly downtime and environmental risk. Detecting such early-stage defects remains a major challenge for nondestructive testing (NDT). Conventional X-ray and ultrasonic techniques often fail to detect features smaller than the ultrasonic wavelength or obscured by structural noise or low density variation. This study evaluates higher frequency ultrasonic transducers and arrays for earlystage creep and HIC detection. Structural noise analysis, amplitude ratio and artificial intelligence (AI) techniques proved effective in identifying microstructural degradation in the HAZ. Cracks smaller than 0.2 mm became detectable as they progressed. The findings demonstrate an enhanced approach for characterizing small-scale defects and overcoming current NDT limitations in critical energy infrastructure. |
| Published |
Mayen : NDT.net |
| Type |
Conference paper |
| Language |
English |
| Publication date |
2026 |
| CC license |
|
