Abstract This paper discusses the possibility of in-situ evaluation of crack propagation using Eddy Current Monitoring (ECM) system in a Boiling Water Reactor (BWR) environment. For the purpose, an ECM experiment was conducted at the System Safety Benchma rk Facility (SSBF). The target for the monitoring was a large-scale pipe specimen made of austenitic stainless steels 304L, 316L, and carbon steel STS410, connected by weld joints of nickel based alloy 182. Slits were prepared at the Heat Affected Zones (...
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In-situ Crack Evaluation using Eddy Current Monitoring in a Boiling Water Reactor Environment

This paper discusses the feasibility of shroud inspections using Eddy Current Testing (ECT). For the purpose, the three steps of simulations were carried out. At first, the propagation of postulated cracks in the H4 weld line of the shroud was estimated. Subsequently, the eddy current signals were numerically simulated based on the reduced vector potential method. At last, the inverse analyses were performed using simulated ECT signals, and crack shapes were reconstructed. The high accuracy of crack reconst...
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Simulation of Shroud Inspection based on Eddy Current Testing

Magnetic Barkhousen Noise, Magnetic Incremental Permeability and Magnetic Flux Leakage methods are non-destructive evaluation methods for ferromagnetic materials. Reduced Activation Ferritic/Martensitic (RAFM) steel is a new kind of ferromagnetic material considered to be an important candidate structural material for thermal nuclear fusion reactors. The feasibility to use magnetic non-destructive evaluation techniques of MBN, MIP and MFL methods to evaluate the plastic strains in RAFM steel is experimental...
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Nondestructive Evaluation for Small Plastic Deformation and Deformation Histories in Reduced-activation Ferritic/Martensitic Steels

During manufacturing and operation, delamination and surface cracks may be initiated in the plasma-facing components (PFCs) of Tokamak devices. To ensure the quality of the PFCs and safety of Tokamak, NDT techniques of different method are needed. This paper introduces recent researches of authors on UT and laser thermography techniques for inspection of PFCs during manufacturing and in-service. For W/Cu mono-block of divertors, the bonding quality was qualified by using the rotating UT with a focus probe. ...
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Some Researches on UT and Laser Thermography for NDT Tokamak Plasma-Facing Components

The authors have proposed a novel probe combining angle beam EMAT (Electro magnetic Acoustic Transducer) and EC (Eddy Current) Probe as a multi-probe with simple structure. In this paper, the structure of the above dual pro be is improved in order to increase sensitivity of the probe as EC probe....
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Proposal of EMAT-EC Dual Probe for Monitoring of Crack Propagation

At present, AE(Acoustic Emission) measurement is positioned as one of nondestructive inspection methods, and is used to monitor, diagnose, and evaluate various mechanical systems, structures, and the like. AE measurement has the advantage of high sensitivity, wide band, and dynamic measurement, but on the other hand, it is susceptible to noise because it is high sensitivity. In addition, since it is easily affected by the measurement system such as the frequency characteristics of the sensor, advanced know-...
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Advanced discrimination of anomalies in AE inspection using system invariant analysis technology (SIAT)

In non-destructive inspection, the probability of abnormality finding in image diagnosis, ECT inspection and so on depends mostly on skills of individuals. Therefore, training of inspectors is an important issue in the maintenance and management of facilities. This study aims at improving accuracy in nondestructive inspection by applying System Invariant Analysis Technology (SIAT) which is one of big data analysis techniques. The feasibility is confirmed by the experiment using ECT this time and it is repor...
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Advanced nondestructive inspection using System Invariant Analysis Technology (SIAT)

Authors previously reported leakage magnetic flux density measured by flux gate (FG) sensor seems to depend on irradiation assisted stress corrosion cracking (IASCC) susceptibility of neutron irradiated austenitic stainless steels. This study aimed to evaluate possibility to develop diagnostic method to detect symptom of IASCC by more practical methods such as Eddy current method and AC magnetization method. Magnetic properties of neutron irradiated specimens and mockup specimens were studied and dep...
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A Study of Correlativity between IASCC Susceptibility and Magnetic Property of Stainless Steel

This paper proposes backpropagation neural network models which are based on artificial intelligence technology to detect the defect signals and to discern the measurements of defects according to the eddy current testing (ECT) results even under the probe lift-off and probe wobble noise effects. In this paper, a stainless plate with three different depth slits is tested by ECT to collect defect signals. And during the scanning process, the noise which is mentioned above is added. All the collected data are...
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Detection and sizing of defects in eddy current testing using artificial neural network

Eddy current testing (ECT) with multi coil probe has been developing for enhancing surface inspection. Defect extraction method based on phase angle of lissajous waveform was effective to identify between defects and noises. This paper describes applicability of crack extraction method for magnetic material. The criteria based on feature of phase angle on magnetic material could extract defects to separate from noises like liftoff using experiment and simulation....
英字タイトル:
Crack Extraction technique for Magnetic Materials by Eddy Current Testing with Multi Coil Probe