ULTRASONIC FLAW DETECTION METHOD, AND ULTRASONIC FLAW DETECTOR

PROBLEM TO BE SOLVED: To provide an ultrasonic flaw detection method capable of detecting surely a micro internal defect, irrespective of a cross-sectional dimension different in every inspected material, and an ultrasonic flaw detector used therefor. SOLUTION: This ultrasonic flaw detection method uses array probes 2, 10, is applied with a gap method using a vertical flaw detection method in combination with an inclined flaw detection method, for a large cross-sectional dimension of steel material W, out of the steel materials (inspected material) W to detect the internal defect, and is applied with a local submerging method for the small cross-sectional dimension of steel material W. The ultrasonic flaw detection method includes also the ultrasonic flaw detector including a plurality of sets of rollers R for supporting the steel material W to detect the internal defect, the array probes 2 for the gap method arranged on a surface of the steel material W via a water film, and the the array probes 10 for the local submerging method arranged on the surface of the steel material W via a water chamber 14. COPYRIGHT: (C)2007,JPO&INPIT