| 摘要 |
Dispersed penetraters in which oxide particles of several micrometers are dispersed widely and in a thin region can be detected. Specifically, an ultrasonic test device comprises a transmitting/receiving unit which has a transmitting section (6) for transmitting an ultrasonic wave toward the welded surface of the welded part (2) of a tubular object (1) in the axial direction in such a way that a transmitted beam (8) has a beam width lying in the range from 0.5 mm to 2.5 mm and a receiving section (7) for receiving a part or the whole (received wave beam (9)) of the reflected wave at the welded surface, and in which the transmitting section (6) and the receiving section (7) are composed of different vibrator groups on one or more array probes (5) arranged in the circumferential direction of the tubular object. |
