The defective type form discrimination modulo null due to electronic scanning-type

摘要

PURPOSE:To discriminate a kind and a shape of a defect in a short time and with high reliability by deriving plural discrimination characteristic values for featuring a difference of reflection behaviors of each reflected wave from a defect obtained by an electronic scanning type ultrasonic flaw detection. CONSTITUTION:A pair of array probes 7A, 7B formed by placing linearly plural pieces of vibrators in positions of almost the same distance on a cross-cut are placed relatively by inserting and holding a defect 6 of a seam welded part 5 of a body to be inspected. In such a state, with respect to these probes 7A, 7B, a linear scanning is executed by switching the transmission and reception by a flaw detection refractive angle existing in one side each. That is, first of all, a reflected wave of the defect 6 obtained by following up transmission of an ultrasonic beam 8A is received by the probe 7A, and by a variation of the reflection behavior, a beam path of the reflected wave, a peak crest value and a sharpness evaluation of a waveform and a reflection directional pattern are extracted as discrimination characteristic values. Subsequently, the same scanning is performed by the other probe 7B, as well. By evaluating synthetically these discrimination characteristic values, the kind and a shape of the defect 6 can be decided easily.