| 摘要 |
PURPOSE:To non-destructively obtain the depth of a corrosion part by measuring the reflection time of reflection wave of ultrasonic wave and performing calculation from the relationship among the difference in reflection time between the cases when there is the corrosion part and there is no corrosion part, corrosion depth, and sound speed. CONSTITUTION:A single-pulse ultrasonic wave is applied to an ultrasonic oscillator 10 on the surface of tungsten carbide sintered body 1 consisting of all integrity parts (a) and a reflection time T from the bottom is measured. Then, using a sintered body 1a located at a corrosion part (b), a reflection time T1 is similarly measured. When the sound speed of the sound parts (a), that of the corrosion part (b), the thickness of the sintered body 1, and the corrosion depth are set to V, V1, H, and H1, respectively, H1 {(1/V1)- (1/V)}=-T1-T results. Also, the sound speed V1 decreases from the sound speed V proportionally with the depth H1 and V1=6380--315H1 results. The corrosion depth H1 can be obtained from both expressions. |
