적외선 열화상 기법을 이용한 감육 결함 배관의 결함 검출 최적 계측 조건 평가

Abstract

Non-destruction evaluation(NDE) method with the merits of rapid response, economic efficiency, and manifold applications has been an important role in industries from the safety diagnosis of large infra structure to the reliability evaluation of small products. There are many efficient Non-destruction evaluation(NDE) methods such as Visual Testing(VT), Radio-graphic Testing(RT), Ultrasonic Testing(UT), Magnetic testing(MT), Liquid penetrant Testing(LT), Eddy current Testing(ET), Acoustic Emission(AE), Thermography. Generally, VT, PT, MT, and ET are applied foe the detection of surface defects and UT and RT are done for internal defect. have been used to monitor fatigue damage. This paper aims to describe thermal stress measurement using Lock-in Infrared Thermography as a non-destructive testing method with real time and non-contact technology. NDE methods based on optical metrology such as Thermography, Holography, Electronic Speckle Pattern Interferometry, Shearography etc can provide solution to the problems of previous methods. Infrared Thermography(IRT), application techniques is a two-dimensional non-contact Non-destruction evaluation(NDE) that can detect internal defects from the thermal distribution by the inspection of Infrared light form the object surface. Infrared Thermography thermal imaging of bulk is different form that of a Wall-Thinning defect, In a heated metal with a internal defect, and then location and size of a Wall-Thinning defect can be measured by the analysis of thermal imaging pattern. This study conducted Pulsed Infrared Thermography(IRT) and Lock-in Infrared Thermography(Lock-in IRT) test for 4 inch and small-bore 2.5 inch piping of two type artificial Wall-Thinning defect to find optimal condition for Infrared Thermography(IRT) for Wall-Thinning defect piping components. Pulsed Infrared Thermography thermal imaging is a method to inspect a Wall-Thinning defect by in directly heating treatment, and Lock-in Infrared Thermography thermal imaging is a method to defect by directly heating treatment, respectively. The first, experiment two Halogen Lamps, whose full power capacity are 1 kW, were used th heat pipes, and the esposure distance between pipe and Halogen Lamp and the Halogen Lamp power were considered as experimental parameters. when the exposure distance is 4 inch 1m, 2m, 3m, small-bore 2.5 inch 1m, 1.5m, 2m and the exposure rate is higher than 70% of full power. In the case of 4 inch, IRT and Lock-in IRT thermal image of Wall-Thinning defect was clearer under the conditions of higher exposure rate and exposire distance of 2m than under the conditions of lower exposure rate and exposure distance of 1m and 3m. but image of small-bore 2.5 inch pipe is Wall-Thinning defect was clearer under the conditions of higher exposure rate and exposure distance of 1.5m than under the conditions of lower exposure rate and exposure distance of 1m and 2m. Also, it was recognized that the detect ability of Wall-Thinning defect is similar for both Pulsed Infrared Thermography and Lock-in Infrared Thermography. The second, Infrared Thermography(IRT) test using 4 inch pipe with artificial Wall-Thinning defect to measure on the Wall-Thinned nuclear pipe components. This study conducted for defect detection condition of nuclear small-bore pipe research using deducted condition in the advanced research. Defect process is processed by change for defect length, circumferential direction angle, wall-thinning depth. In the used equipment IR camera and two Halogen Lamps, whose full power capacitany is 1 kW, halogen lamps and Target pipe experiment performed to the distance of the changed 1m, 1.5m, 2m. To analysis of the experimental results ensure for the temperature distribution data, by this data measure for defect length. artificial defect of 4 inch pipe is high reliabillity in the 2m, but small-bore pipe is in the 1.5m from the defect clearly was detected.