Patent ID: 7779694

Claim:
An ultrasonic testing system for a pipe member, comprising: a transmitting/receiving unit including a transmitting unit, which transmits an ultrasonic wave to a welded surface of a welded portion in a pipe axis direction of a pipe member and to an inside surface of the pipe member so that the ultrasonic wave is incident at an angle within a range from 33.2° to 56.8°, and a receiving unit, which partly or entirely receives an echo reflected in a direction within a range from −12° to 16° to a mirror reflecting direction in the welded surface, wherein the transmitting unit and the receiving unit are composed of different groups of transducer elements on at least one array probe disposed in a pipe member peripheral direction; and a controller for scanning the pipe member in a thickness direction by carrying out control to change the groups of transducer elements corresponding to the transmitting unit and the receiving unit on said at least one array probe or to change an angle of said at least one array probe, and controlling the angle of incidence of the ultrasonic wave to the pipe member in the respective transmitted wave and received wave so that the angles of incidence to the welded surface and the inside surface and the angle of the echo on the welded surface are kept within the ranges defined as to the transmitted wave and the received wave, respectively.