INSPECTION METHOD INSIDE WELDED ZONE OF DUMMY WELDING MATERIAL BY ULTRASONIC FLAW DETECTOR

摘要

PROBLEM TO BE SOLVED: To solve the problems of welding detachment or welded zone damage generated at the rolling time of a dummy welding material, by performing before rolling flaw inspection inside a welded zone of the dummy welding material formed by welding a steel product body and a dummy material together.;SOLUTION: In this flaw detection method, the dummy welding material 6 is formed by performing up to the center part gas welding of the dummy material 3 to the tip 2 of the steel product body 1 to be rolled, and an ultrasonic wave 7 is inputted in the vertical direction toward the steel product body 1 from the tip 4 of the dummy material 3, and the height of a bottom face wave inside the welded zone 5 between the steel product body 1 and the dummy material 3 is measured and detected by vertical flaw detection, and it is determined that a flaw does not exist inside the welded zone of the dummy welding material 6 when the measured value is below 150%.;COPYRIGHT: (C)2005,JPO&NCIPI