E-2-1

International Strategies by Japan Society of Maintenology (JSM)

Kenzo MIYA (Japan Society of Maintenology)

Abstract
(1) Create fields for activities of experienced engineers
(2) Secure superiority of "Japanese maintenance technology" in the global market
(3) Make clear "contradictions of Japanese nuclear system" based on international comparison
(4) Give hopes and dreams to young engineers

Keywords
Japan Society of Maintenology (JSM), Japanese advanced maintenance technologies, maintenology, maintenance systemization, maintenance optimization, E-journal of Advanced Maintenance (EJAM)

E-2-2

Remote Detection and High Precision Evaluation of Wall Thinning Volume in a Metal Pipe

Linsheng LIU and Yang JU (Nagoya University)

Abstract
We report a nondestructive method to measure the pipe wall-thinning (PWT) remotely using microwaves. A microwave vector network analyzer (VNA) and a self-designed transmitting and receiving (T&R) coaxial-line sensor are employed in the experiment to generate microwave signals propagating in the metal pipe where the frequency was swept from 14.08 to 14.12 GHz. A brass pipe with inner diameter of 17.03 mm, 1.0 mm wall thickness, 2.0 m length, and connected respectively with 9 joints having the lengths of 17.0 mm and PWT volumes from 0 to 550 mm3 were measured. By taking the pipe as a circular waveguide of microwave, after building up a resonance condition and then solving the resonance equations, the remote detection method is achieved. By comparing the experimental results with the evaluated ones using our method, it is found that the evaluated results agree well with the experimental ones, it indicates that a high precision evaluation method is established.

Keywords
Remote detection, Wall thinning, Microwave, Nondestructive measurement, Metal pipe

E-2-3

Introduction of Some Researches on Electromagnetic NDT

Zhenmao CHEN (Xi’an Jiaotong University, Tohoku University) and Toshiyuki TAKAGI (Tohoku University)

Abstract
In this paper, some research activities performed by authors on the Electromagnetic Nondestructive Evaluation (ENDE) for materials and structures of nuclear and other industries are introduced. The major contents includes, theoretical and experimental studies on NDT of ultra-light material and structures, NDT methods for Thermal Barrier Coating (TBC) inspection, improvement on quantitative NDT method of Stress Corrosion Crack (SCC), new inspection method for material degradation etc. Research methods, typical results in addition with objectives are presented.

Keywords
ENDE, Review, Ultra-light Material, Thermal Barrier Coating, SCC, Deep Crack

E-2-4

Experiments of Influencing Factors in the Magneto-mechanical Effect

LiQiang ZHONG and LuMing LI (Tsinghua University)

Abstract
Based on the magneto-mechanical effect, the surface magnetic field of ferromagnetic materials can be used to evaluate their stress status or defects. However, there are several factors which affect the magnetic field distribution. In the last 10 years, we have carefully studied the effect of stress, the environmental field, and the material of the specimens. The experimental results pointed out some relationships between the surface field and the structural safety of ferromagnetic materials:

1. The abnormal change of surface field will be larger in higher carbon content steel as well as the magneto-mechanical effect coincide with magnetic hardness density of ferromagnetic properties.


2. The environmental field is critical to the surface magnetic field distribution. This includes the tendency towards magnetization when the stress increases.


3. In specific environments, the magnetic field change caused by stress concentrations can be approximated by the law of approach by Jiles. DC.

Keywords
Magneto-mechanical effect, stress, environmental field, material

E-2-5

Defects Sizing Using a Pulsed Eddy Current Testing Method for Local Wall-Thinning Evaluation

Shejuan XIE, Toshiyuki TAKAGI and Tetsuya UCHIMOTO (Tohoku University)

Abstract
In nuclear power plants, because of flow accelerated corrosion and liquid droplet impingement there may happen local wall-thinning in the pipes. Recently, research of pulsed eddy current testing (pulsed ECT) method shows that it has promising capability of detecting and evaluating defects in deep area of specimen due to its rich frequency components and applicability of large electric current. This study discusses the feasibility of detection and evaluation of wall-thinning in thick-walled piping using pulsed ECT method. The content of this study mainly contains two parts. Firstly, capability of thickness evaluation of a stainless steel plate is investigated. Experiments and numerical simulation were carried out using an SUS316 austenitic stainless steel plate, respectively. A novel and more stable feature was extracted from the differential pick-up signal and was discussed for the thickness evaluation of a plate. Numerical and experimental results demonstrate that the thickness of a plate can be obviously sized from characteristics of differential signals. Secondly, capability of depth detection of a slot defect in a stainless steel plate is investigated under condition of small lift-off. In experiments, scanning signals were obtained and through analyzing the magnitude of peak value of differential signal and its spatial distribution, the depth of a slit defect can also be successfully evaluated.

Keywords
Local wall-thinning, Pulsed ECT, Magnetic sensor, Feature extraction, Sizing

E-2-6

Numerical Simulation of Residual Stress Measurement with Acoustic Wave

Cuixiang PEI and Kaziuki DEMACHI (The University of Tokyo)

Abstract
In this work, a FEM (finite element method) simulation program was used in the residual stress measurement with acoustic wave. The possibility of assessing the residual stress, by using an EMAT (electromagnetic acoustic transducer) receiver for precise measurement of the acoustoelstic effect on LCR wave, was investigated by simulation method.

Keywords
Residual stress, Acoustoelastic effect, Ultrasonic NDE, FEM, EMAT

E-2-7

Simulation for the Assessment of Wall Thinning using Eddy Current Method

Weiying CHENG and Ichiro KOMURA (Japan Power Engineering and Inspection Corporation)

Abstract
A pipe with protective lagging and thermal insulation is modeled by a multi-layered structure. Sinusoidal or pulsed eddy current are induced by a circular coil held above the structure to measure the thickness of the pipe wall. Analytical solutions of both sinusoidal and pulsed eddy current measurements are deduced. Parameters affecting the measurement are studied using the analytical solutions. Measurement conditions are discussed based on the analytical results.

Keywords
wall thinning, muti-layered structure, eddy current, pulsed eddy current, analytical solution

E-2-8

Electrochemical response of scratched Alloy 600 in simulated primary water and its influence with hydrogen entry

Fanjiang MENG (Tohoku University, Institute of Metal Research, China), Zhanpeng LU, Tetsuo SHOJI (Tohoku University), Jianqiu WANG and En-Hou HAN (Institute of Metal Research, China)

Abstract
The effect of scratches on oxidation evolution of Alloy 600 was monitored by EIS in 290°C simulated primary water. EIS result indicates that oxide film reached a stable condition until 7 days' immersion. The scratched Alloy 600 possessed almost the same evolution of oxide film with plain specimens. Anodic polarization was performed to study combined effect of scratches and charged hydrogen. The anodic current changes of scratched Alloy 600 after hydrogen charging were not the simple superimposition between that of scratched and charged plain Alloy 600. Alloy 600 after scratching was supposed to trap more hydrogen because of introduction of cold work. The trapped hydrogen could accelerate the oxidation by enhancing dissolution of chromium oxides. Thus, the oxides became less protective and anodic current increased considerably over more noble potential range.

Keywords
SCC; Cathodic charging; Anodic polarization; EIS

E-2-9

Effects of Electrochemical Parameters on SCC of Stainless Steels in Simulated BWR Environments

Zhanpeng LU, Tetsuo SHOJI, Kazuhiko SAKAGUCHI, Fanjiang MENG and Yubing QIU (Tohoku University)

Abstract
The effects of electrochemical parameters in terms of electrochemical potential on stress corrosion cracking growth rates of austenitic stainless steels in high temperature pure water are analyzed based on obtained experimental results and reported data. The effect of decreasing electrochemical potential is more significant in non-hardened sensitized and non-hardened stainless steels than that in strain-hardened stainless steels, which is also supported by the results of Ni-base alloys and weld metals.

Keywords
Stainless steels, Stress corrosion cracking, Boiling water reactors, Electrochemical parameters