METHOD FOR THE ULTRASONIC FLAW DETECTION OF AN ELECTRIC WELDED PIPE

摘要

An ultrasonic flaw detection method in which cold weld defects in the weld zone of an electric resistance welded steel pipe are detected by projecting an ultrasonic wave (a) having a frequency range of from 25 MHz to 500 MHz and an angle of incidence of from 0.degree. to 12.degree. onto the weld zone of the pipe, and by projecting another ultrasonic wave (b) having a frequency of from 2 MHz to 10 MHz and an angle of incidence of from 15.degree. to 27.degree. onto the same weld zone.