Challenges in improving the performance of eddy current testing: Review

Eddy current testing plays an important role in numerous industries, particularly in material coating, nuclear and oil and gas. However, the eddy current testing technique still needs to focus on the details of probe structure and its application. This paper presents an overview of eddy current testing technique and the probe structure design factors that affect the accuracy of crack detection. The first part focuses on the development of different types of eddy current testing probes and their advantages and disadvantages. A review of previous studies that examined testing samples, eddy current testing probe structures and a review of factors contributing to eddy current signals is also presented. The second part mainly comprised an in-depth discussion of the lift-off effect with particular consideration of ensuring that defects are correctly measured, and the eddy current testing probes are optimized. Finally, a comprehensive review of previous studies on the application of intelligent eddy current testing crack detection in non destructive eddy current testing is presented

Development of Non-Destructive Testing by Eddy Currents for Highly Demanding Engineering Applications

Defect detection with Non-Destructive Testing (NDT) is essential in accidents prevention, requiring R&TD to generate new scientific and procedural knowledge for new products with high safety requirements. A current challenge lies in the detection of surface and sub-surface micro defects with NDT by Eddy Currents (EC). The main objective of this work was the development of applied research, technological innovation and experimental validation of EC customized systems for three highly demanding inspection scenarios: micro defects in tubular geometries; brazed joints for the automotive industry; and high-speed moving composite materials. This objective implied starting from the scientific fundamentals of NDT by EC to design and simulate EC probes and the prototypes developed were tested in industrial environment, reaching a TRL ≈ 5. Another objective, of a more scientific and disruptive nature, was to test a new technique for the creation of EC in the materials to be inspect, named Magnetic Permeability Pattern Substrate (MPPS). This technique consists on the development of substrates/films with patterns of different magnetic permeabilities rather than the use of excitation bobbin coils or filaments of complex geometry. The experimental results demonstrated that the prototypes developed for the three industrial applications studied outperformed the state of the art, allowing the detection of target defects with a very good signal-to-noise ratio: in tubular geometries defects with depth of 0.5 mm and thickness of 0.2 mm in any scanning position; in the laser brazed weld beads pores with 0.13 mm diameter and internal artificial defects 1 mm from the weld surface; in composite materials defects under 1 mm at speeds up to 4 m/s and 3 mm lift-off. The numerical simulations assisted the probe design, allowing to describe and characterize electrical and magnetic phenomena. The new MPPS concept for the introduction of EC was validated numerically and experimentally

Proceedings of the 10th International Conference on NDE in Relation to Structural Integrity for Nuclear and Pressurized Components

This conference, the tenth in a series on NDE in relation to structural integrity for nuclear and pressurized components, was held from 1st October to 3 October 2013, in Cannes, France. The scientific programme was co-produced by the European Commission’s Joint Research Centre, Institute for Energy and Transport (EC-JRC/IET). The Conference has been coordinated by the Confédération Française pour les Essais Non Destructifs (COFREND). The first conference, under the sole responsibility of EC-JRC was held in Amsterdam, 20-22 October 1998. The second conference was locally organized by the EPRI NDE Center in New Orleans, 24-26 May 2000, the third one by Tecnatom in Seville, 14-16 November 2001, the fourth one by the British Institute of Non-Destructive Testing in London, 6-8 December 2004, the fifth by EPRI in San Diego, 10-12 May 2006, the sixth by Marovisz in Budapest, 8-10 October 2007, the seventh by the University of Tokyo and JAPEIC in Yokohama, the eight by DGZfP, 29 September to 1st October 2010, the ninth by Epri NDE Center, 22-24 May 2012 in Seattle. The theme of this conference series is to provide the link between the information originated by NDE and the use made of this information in assessing structural integrity. In this context, there is often a need to determine NDE performance against structural integrity requirements through a process of qualification or performance demonstration. There is also a need to develop NDE to address shortcomings revealed by such performance demonstration or otherwise. Finally, the links between NDE and structural integrity require strengthening in many areas so that NDE is focussed on the components at greatest risk and provides the precise information required for assessment of integrity. These were the issues addressed by the papers selected for the conference.JRC.F.5-Nuclear Reactor Safety Assessmen