3210 ステップ加熱時の温度変動解析による減肉欠陥検出(OS13 貯槽の防災と設計IV)

Abstract

Thermographic NDT techniques based on transient temperature distribution after active heating have been developed by many researchers as one of effective quantitative nondestructive testing techniques. The interest of the researchers has been focused on how to process transient temperature data after active heating i.e., pulse heating or step heating, to conduct successful identification of defect parameters such as its depth, shape and size. In this paper, a data processing technique based on the Fourier analysis is proposed. When a step heat flux is applied to the surface of material containing a defect inside, characteristic temperature change is observed on the surface due to the heat insulation effect of the defect. Especially defect depth influences the time profile of the transient temperature change after active heating. In this study, experimental investigations were carried out to demonstrate the feasibility of the proposed technique for identification of material loss corrosion defect in steel plates.