| 摘要 |
There is provided a method for detecting an abnormal portion (defect, non-adhering portion, and seized portion) lying at a contact region between each part of a pin and each part of a box forming a threaded joint to be used as a joint of pipe or tubes such as OCTG. This invention provides an ultrasonic testing method of a threaded joint of pipes or tubes including a pin having an external thread part, a metal seal part, and a shoulder part on an outer peripheral surface, and a box having an internal thread part, a metal seal part, and a shoulder part corresponding to each part of the pin on an inner peripheral surface and being fastened with the pin by way of a lubricant. The method according to the present invention comprising the steps of: transmitting and receiving ultrasonic waves to and from a plurality of locations along an axial direction of the threaded joint in at least one of the internal thread part, the metal seal part, and the shoulder part of the box; detecting echo intensities and reception times of echoes for the plurality of locations; and detecting an abnormal portion in the threaded joint based on axial directional distribution of the echo intensities and axial directional distribution of reception times of the echoes.
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