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

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

Evaluation of defect and damage for structural materials of energy device was performed by using ectromagnetic techniques. For degradation of thermal aging magnetic characterization of weld specimens HCM12A was performed. Comparing the specimen aged at 550°C for 2000 hours with that aged at D0°C for 600 hours, it was found that the changes in magnetic flux densities was clearly observed near the eld metal and heat affected zone for the specimen aged at 550°C for 2000 hours. Then the degree of egradation fo...
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Evaluation of Defect and Damage for Structural Materials of Energy Device by Using Electromagnetic Techniques

Using Hall and ECT sensors, a non-destructive damage evaluation was performed for the specimen of rail eel with simulated white damage layers. Two types of specimens were used, one with a simulate d white amage layer of 1mm depth and the other that of 100um. First using Hall sensor, distributio n of magnetic ux around the white damage layers was measured by means of magnetic flux leakage tec hnique. Both agnetic flux leakages of B, and B, revealed the presence of the white damage layers. Also from the ag...
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Non-destructive Damage Evaluation of Rail Steel Using Electro-magnetic Techniques

Carbon fiber-reinforced plastics (CFRP), which is expected to reduce the weight or increase the efficiency of transportations and energy products, was cut by an CO2 gas laser (10.6um, 800W, 20kHz, 8us, 1m/min), CW single-m ode fiber laser (1.07um, 300W, 2000W, CW single-mode, 1m/min, 7m/min) and machining with milling. Although the high-power laser cutting processes make it possible to improve cutting rate of CFRP, the laser-cut specimens cl early showed a thermal damage with a heat-affected zone (HAZ) ide...
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(CFRP) using High-power Laser Cutting ProcessStudent Member