ULTRASONIC FLAW DETECTING METHOD FOR STEEL TUBE WELD SEAM PART

摘要

PURPOSE:To cover a target flaw detection range by selecting vibrators to be used for linear scanning corresponding to variation in distance between an array type probe and a weld seam. CONSTITUTION:When the positions of the array type probe 6 which performs flaw detection in the target flaw detection range 9 by vibrators 56-523 and the weld seam 81 are set as shown in figure (a), 59-526 are selected as vibrators used for linear scanning at the time of the short distance between the probe 6 and seam 81 as shown in figure (b), so that a flaw detection range 10 is the same as the target flaw detection range 9. Further, when the distance between the probe 6 and seam 81 becomes long as shown in figure (c), vibrators 53-520 are used for the linear scanning and then a flaw detection range 11 is the same as the target flaw detection range 9. Thus, an ultrasonic wave beam can be made follow up variation in the distance between the probe 6 and seam 81 with the position of the weld seam 81 at a high speed, so the flaw detection is performed accurately in the target flaw detection range all the time.