ULTRASONIC FLAW DETECTION METHOD

PROBLEM TO BE SOLVED: To accurately measure the defect depth, by performing the image processing and analysis processing of waveform data by reflection waves detected from defects by propagating ultrasonic waves at a surface layer section of the bottom surface side of a specimen. SOLUTION: Electron scanning is performed to a part to be inspected in a welded structure selected from a past operation history by an array-type ultrasonic probe based on flaw detection conditions. Ultrasonic wave waveform data, subjected to flaw detection by reflecting ultrasonic waves, are detected and recorded (steps ST1-ST3). The image processing result of the recorded waveform data is overlapped to the shape of the part to be inspected for color gradation display, corresponding to the level of an echo amplitude value (step ST4). The defect information of the part to be inspected is analyzed, based on the ultrasonic wave waveform data according to the result, obtained by aligning the ultrasonic wave waveform data to positions for each group of transmission oscillators and reception oscillators for computation (step ST5). Then, by determining the presence or absence of defects at the part to be inspected based on the color gradation display result and defect information analysis result, the flaw detection result is displayed (steps ST6, ST7). COPYRIGHT: (C)2009,JPO&INPIT