ULTRASONIC FLAW DETECTION FOR DEFECT IN REVERSE BEAD-WELD PART UTILIZING DIAGONAL RELATIVE REFLECTION METHOD

摘要

PURPOSE:To double the flaw detecting efficiency by reducing the misconception and the oversights of defects without changing the position of the probe by the application of diagonal relative reflection method. CONSTITUTION:The defects in a reverse bead-weld part are detected in accordance with diagonal relative reflection method in which defects in a bottom surface are searched simultaneously with two probes from opposite directions along the same line by changing the beam route and the defects are discriminated by the simultaneous indication of the echoes of the same defect of different beam routes. According to the diagonal relative reflection method, the probes are not required to be replaced alternately and the defects are detected simultaneously from both sides of the beads, then the same defect is simultaneously indicated on a CRT in echoes of different beam routes to discriminate defects from beads. Any one of or a combination of a method in which skip distance is changed, a method in which an oscillator and incidence point distance are changed and a method in which the angle of refraction is changed is applicable to the simultaneous indication with different beam routes.