Instead of using the array probe, the study of 3D image reconstruction using the single probe was done. EMAT single probe has large diameter and large aperture and so the ultrasonic wave propagates not only toward direction z but also x-y directions. An d so the time series of data received by EMAT probe include the information of the flaws not only in z direction but also in x-y direction and it means the image has higher resolution than that can be expected from the sampling space in x-y direction ca n b...
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The study of 3D image reconstruction using EMAT

Magnetic flux leakage measurements were performed by using a fluxgate sensor. For an artificial defect of 0.3mm width of SS400 steel, changes in p erpendicular magnetic flux leakage B, could be measured at a lift off height of 5mm, and changes in longitudinal magnetic flux leakage B, could be measured at a lift off height of 10mm. For artificial surface defects, magnetic flux density distribution of By was well correlated to the shape o f the defects. In-situ magnetic flux density measurement By for permal...
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High Accuracy Damage Evaluation Technique Using FG Sensor

Fatigue damage evaluation for austenitic stainless steel SUS304 was performed by electromagnetic non-destructive testings using magnetoresista nce(MR) and eddy current technique(ECT) sensors. The fatigue damage and fatigue crack could be detected by MR and ECT sensors. Especially, by M R sensors, changes in fatigue crack of notched specimens were measured, and by ECT sensors fatigue damage of martensitic transformation of pla in specimens was evaluated. These results were explained by the difference of mar...
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Fatigue Damage Evaluation of Austenitic Stainless Steel by MR and ECT sensors

Creep tests for energy structural materials of austenitic stainless steel SUS316FR were performed. And degradation mechanism of welded specimen was investigated by using microcharacterization technique of magnetic force microscopy. In as-received specimen, magnetic phases of S-ferrite were interconnected at weld metal region. While in crept specimen, the magnetic phases at weld metal region were isolated, and the amount of magnetic phases decreased. It was found that creep da mage of welded specimen could ...
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Microcharacterization of damage degradation for energy structural materialsof advanced fast breeder reactor

Magnetic characterization of creep-fatigue damage for welded specimens of austenitic stainless steel (SUS316FR) and high-chronium steel (Mod.9Cr-1Mo) steel was performed using magnetic force microscope an d Hall sensor. In SUS316FR volume fraction of d-ferrite at weld metal region decreased by creep or creep-fatigue and the remanent magnetic flux density at weld metal region also decreased. In Mod.9Cr-1Mo steel magnetic characteristics at weld metal region were different from those at base metal initially,...
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Magnetic Characterization of Creep-fatigue Damagefor Energy Structural Materials

1 緒言カラー セラミックス部材はその剛性と耐熱性において金 属材料くらべ有利である. しかし,その破壊過程は 脆性的であり金属材料のそれと比べ急峻である. 破壊が始まってからではその進行を止めたり遅らせ たりすることはできない. そのため製造直後の欠 陥検査が重要である。部材中の欠陥存在確率はその 体積に比例するので、フリーの大型部材を作成する」 ことは非常に困難である。また、大きな部材の欠陥 検査を行うことも容易ではない。この対策として欠 陥の少ないことが確認された小型部材を接着組み合 わせることで欠......
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Study of non-destructive evaluation for ceramics materials

Defect in S45C cylindrical component was evaluated by using fluxgate (FG) magnetic sensor, which could measur e the order of 10 T magnetic flux density. Changes in magnetic flux densities were measured around a defect i n a plain cylinder component. In order to analyze defect shape and size quantitatively, the relationship betwe en magnetic flux densities and magnetic dipole moment of the defect plane in cylindrical component was formul ated. And the inverse analysis of Tikhonov regularization technique wa...
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Evaluation of Cross-section Shape of Defect in Cylindrical Component byUsing Fluxgate Magnetic Sensor

Recently, ceramics materials have become used in many industrial fields because of their thermally stability and stiffness. But they have not been employed to manufacture structure parts larger than one meter. The fracture pattern of ceramics materials is usually more instantaneous than that of ordinary materials, such as steel. Conventionally, inspections for improving the qualities of ceramics parts were often do ne with sampled products, not all products, by optical microscope and/or SEM. In this study,...
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Study of inspection for ceramics materials using X-CT

Creep-fatigue (Creep fatigue and fatigue) tests of Mod. 9Cr-1Mo steel have been performed by varying stress holding time at 550℃. Creep-fatigue properties are affected by stress holding, and strain rate increases with increasing stress holding time．In Vickers hardness measurements Vickers hardness of creep fatigue damaged specimen is larger than that of fatigue damaged specimen. In magnetic characterization the saturated magnetic flux density and permeability of creep fatigue damaged specimens are larg...
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Creep-fatigue evaluation and damage characterization for structural materials of advanced fast breeder reactor

In this paper, an improvement technique for non-destructive evaluation using magnetic flux leakage is presented. It is indicated that the magnetic flux density varies steeply around defects. The response function which associates magnetic dipole and magnetic flux density in terms of geometrical coordinate is improved in order to catch the average value of magnetic flux along sensor length instead of locally-restricted value. The effect of that improvement is verified in the scheme of numerical simulat...
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Evaluation of Defect Shape Based on Inverse Analysis Considering the Resolution of Magnetic Sensor