Abstract
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.
Highlights
Pipelines are regarded as a preferable way of transporting oil, refined oil products or natural gas in large quantities over land
Two linear arrays of giant magneto resistive (GMR) sensors are located above and below the orthogonal coils. This technique allows the distribution of the distorted EM field around outside diameter stress corrosion cracking to be imaged without the need of a rotating apparatus The acquired experimental results showed a great sensing capability of the designed probe in the 10–800 kHz frequency range The magnetic flux density is closely correlated with the crack’s depths where maximum amplitude disturbance depends on the crack depth All of the results show that the array is not just sensitive to micro cracks, able to crack length size The efficiency of the suggested bobbin coil is effective to inspect the small diameter tube Experimental results present that the probe can detect flaws regardless of their orientation
eddy current testing (ECT) is strongly affected by the amount of lift-off which can be defined as the separation distance between the excitation coil surface and the conducting material surface
Summary
Pipelines are regarded as a preferable way of transporting oil, refined oil products or natural gas in large quantities over land. Designs of GMR array probes in identical elements had been studied to detect subsurface cracks.[44] Highdensity GMR arrays were especially promising for rapid scanning of a large area as well as high-resolution imaging.[7,45] Another type of GMR array sensors that use two-directional elements was investigated in the EC testing to detect surface cracks of unknown orientation They measure both X-component and Y-component of the MF at the same point.[5] A fast Fourier transformation to enhance the ECT probe based on the GMR array sensors for pipe inspection was utilized by Du et al.[46].
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
