적외선 카메라를 이용한 용접부 안전성 평가에 관한 연구

RT and UT are largely used as a non-destructive assessment of welding defects. RT shows difficulty in radioactive exposure and real-time detection. UT shows difficulty in quantitative detection of defects, and examination of a wide area in a short time. In order to settle the aforementioned disadvantages, many researchers try to find solution. In this paper, we apply a new examination method to verify the effectiveness in order to supplement the disadvantages of UT and RT, the existing non-destructive methods. The new method proposed in this paper is to use a difference in heat conductivity. If there is a discontinuous part, that is an internal defect, there is a difference in heat conductivity. Using this fact, it is possible to check the existence of an internal defect due to a temperature difference on the part with a defect and the part without a defect when the welded part is heated. The temperature difference on the surface indicated by the difference in heat conductivity can be checked for a wide area within a short time, by means of a thermal image camera thereby to settle the disadvantage of the conventional non-destructive inspection methods. The thermal image method, however, has a disadvantage in that thermal load must be given to the tested sample and it is difficult to quantify measured data. In order to overcome this disadvantage, we will describe preliminary test and the like for applying thermal load on the tested sample including a welding defect, photographing images by means of a thermal image camera, analyzing thermal images, and analyzing welding defects.