Abstract
Several nondestructive methods, for example, measurements of thickness, repulsive hardness, surface roughness, electrical characteristics, ultrasonic test, were tried on the debased test specimens to estimate the degradation of epoxy lining (0.6-1.2mm) on steel plates. It was found that the measurements of capacitance, tanδ, and intensity of reflected ultrasonic on the boundary between steel and epoxy were useful for estimating the degradation of epoxy lining. Especially, the value of tanδ was most useful, and also it was not dependent on thickness of lining.
