Periodic Reporting for period 2 - CreepUT (An ultrasonic non-destructive testing system for detection and quantification of early stage subsurface creep damage in the thermal power generation industry)
Reporting period: 2018-04-01 to 2019-03-31
CreepUT is an ultrasonic scanner designed for early detection of creep damage in power plant piping. It is designed specifically for scanning of critical welds susceptible to creep damage. Conventionally, these welds have been tested with metallographic replication, with detection limited to surface damage. The system provides complementary volumetric coverage, enabling early stage, subsurface creep damage to be detected for the first time. This is achieved using a high frequency ultrasonic transducer powered by bespoke electronics. The system is controlled by dedicated software and driven by stepper motors which provide high-precision, automatic scanning. The CreepUT scanner is designed to be used by NDT personnel who have previous experience with ultrasonic testing and an understanding of ultrasonic signal interpretation.
The CreepUT mechanical scanning manipulator was designed to can carry the ultrasonic testing inspection head, that consists of an ultrasound probe and wedge assembly. The scanner was designed to be ergonomic, taking extra care to adapt it to actual power plants working conditions and various component geometries to be tested, allowing operators to easily manipulate it during any kind of planned inspections.
Regarding the TRL rating, the CreepUT scanner in the current form is TRL7. The scanner was used for demonstration in multiple occasions and it was operational in two occasions in the harsh working environment of Kardia and Agios DImitrios power plants in Greece.
The electronics and battery are encased in aluminum enclosures. The enclosures have thick walls and sealed covers with O-rings. Almost all connectors, switches and LED’s that are used have IP67 rating.
Two parts of the software package have been developed. The first one is designed for debugging, adjustment and verification of the electronic unit. This part enables to set any of the parameters for the signal excitation, complete control of gain and data acquisition. The second one is the general software of working inspection tools which control both the electronic unit and the scanner, and there is also a part for the signal processing.
The CreepUT system was deployed on its industrial trial at S.E.S. Agios Dimitrios in Greece. The system successfully scanned 10 welds, 26 scans were made in total. This trial of the system was successful and the system was able to detect creep damage on several welds.
The CreepUT system is able to fulfill the tasks for which it has been designed: to find creep damage on site in the pipelines of a power plant.