Abstract The electromagnetic acoustic resonance (EMAR) method provides accurate and stable evaluation and its capability has been demonstrated through online monitoring using a large-scale corrosion test loop in oper ation at high temperature. This study applies EMAR with the signal processing method of the superposition of n'“ compression to the thickness evaluation of piping in a nuclear power plant during shutdown. Sections of piping evaluated by EMAR include those having long-term service, where thinni...
英字タイトル:
Implementation applicability of piping inspection using electromagneticacoustic resonance

Electromagnetic acoustic resonance (EMAR) method is used for online evaluation of pipe-wall-thinning. In this study, the thickness of the specimens corroded under various conditions is evaluated by EMAR. The thickness is estimated applying the superposition of n th compression (SNC) method to the signals obtained from EMAR. The error of thickness evaluation is investigated in view of thinning shape and the roughness caused by corrosion. As a result, it is suggested that the shape on the order of mm does not...
英字タイトル:
Study of evaluation accuracy of pipe-wall-thinning using electromagnetic acoustic resonance

Electromagnetic acoustic transducer (EMAT) provides non-contacting measurements and is often applied to monitoring in high temperature environment. Electromagnetic acoustic resonance method (EMAR) is transmits an ultrasonic burst wave, and the driving frequency of bust wave is swept. Then signal amplitude of each frequency is computed by the superheterodyne processing at the interval. Pulse-EMAR method is transmits an ultrasonic pulse wave propagating, but the pulse wave is not swept. Then echo waves recei...
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Influence of bottom shape in the pipe wall thinning inspection using an electromagnetic acoustic resonance method

It is well known that alloy 600, one of Ni base alloys, is paramagnetic after solution heat treatment, but as sensitization increases, its magnetic properties change. In this study, fea sibility of nondestructive evaluation of sensitization of alloy 600 is discussed focusing on its magnetic properties. To investigate the relationship between magnetic properties and sen sitization, alloy 600 were heated in different temperatures and duration. Then, the relationship between magnetic properties and sensitizat...
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Evaluation of Sensitization of Ni Base Alloys using Electromagnetic Nondestructive EvaluationMethod

Authors have proposed non-linear eddy current method which is a novel material characterization method foc using on the non-linearity of magnetic properties. This method can be a effective tool to evaluate materia l degradations if the micro-structure changes due to degradations link with change of magnetic properties. In this paper, some examples of its applications are reviewed together with its principle of assessment....
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Nondestructive Evaluation of Material Degradation by Non-linear Eddy Current Method

Abstract: An electromagnetic acoustic transducer (EMAT) design using an air-cored solenoid coil as a pulsed electromagnet is proposed for high-temperature non-contact monitoring, and prototype probe is evaluated through performance test in the range from room temperature to 700°C. The coil generates a biasing magnetic field that enables the device to overcome the Curie temperature limitations of conventional EMATs. Pulsed echo measurements of carbon steel are performed at high temperatures, and verify ...
英字タイトル:
Development and Evaluation of High Temperature EMAT Aiming at Monitoring of High Temperature Components