| 摘要 |
PURPOSE:To make it possible to detect a crack which is formed on the inner surface of a furnace wall pipe at the outside of a furnace from the inner side of the furnace by vertically sending an ultrasonic wave from the outer surface of the pipe at the opposite side of a part to be inspected from an ultrasonic wave probe, and detecting the flaw of the crack based on the attenuating amount of the ultrasonic wave. CONSTITUTION:A furnace wall pipe 2 is filled with, e.g. water 5, as a medium for transmitting an ultrasonic wave. A crack which is formed on the inner wall surface of the pipe at the outside of a furnace is detected. For this purpose, a vertical ultrasonic-wave probe 6 is brought into contact with the opposite side of a part to be inspected, i.e. the outer surface of the pipe on the inner side of the furnace. When the ultrasonic wave is inputted from the probe 6, the ultrasonic wave is propagated from the inner side of the furnace wall pipe 2 with respect to the furnace to the pipe wall on the outside of the furnace through the water 5 filled in the furnace wall pipe 2. Thus the ultrasonic wave reaches the part to be inspected. Then the ultrasonic wave which has reached the part to be inspected is reflected from the part to be inspected, propagated through the part in the reverse direction and returned to the probe 6. The crack is detected based on the attenuated amount of the returned ultrasonic wave. |
