ULTRASONIC FLAW INSPECTION METHOD AND APPARATUS

PROBLEM TO BE SOLVED: To provide an ultrasonic flaw inspection method and an apparatus for understandably displaying an internal defect even if a laminated structure is inspected under the condition that there are many noise echoes. SOLUTION: In the ultrasonic flaw inspection method of the invention, the echoes from an internal gate and a bottom gate are detected, and a strength (a height) of the echo from the bottom gate is subtracted from a strength (a height) of the echo from the internal gate so as to be displayed. The echo appearing in the internal gate remains in an internal defect region. The echo disappears in sound portions on a surface and at the bottom. The echo due to the laminated structure member is canceled and reduced. The internal defect and an adhesion failure between layers can be vividly displayed. COPYRIGHT: (C)2009,JPO&INPIT