ULTRASONIC FLAW DETECTION METHOD, ULTRASONIC FLAW DETECTION DEVICE, MANUFACTURING EQUIPMENT ROW OF STEEL MATERIAL, MANUFACTURING METHOD OF STEEL MATERIAL, AND QUALITY ASSURANCE OF STEEL MATERIAL

摘要

To provide an ultrasonic flaw detection method and an ultrasonic flaw detection device that can execute ultrasonic flaw detection with high accuracy and resolution at each depth of an inspection material by aperture synthetic processing using a synthetic width determined theoretically without resort to an experimental or empirical determination method.SOLUTION: An ultrasonic flaw detection method according to the present invention includes a receiving step receiving multiple defect signal at an ultrasonic probe while changing a physical relationship between an inspection material and the ultrasonic probe, a determination step that calculates a ratio of a received acoustic pressure of the defect signal to a received acoustic pressure of the defect signal at a reference point for each physical relationship between the inspection material and the ultrasonic probe as a received acoustic pressure ratio, and determines a synthetic width at aperture synthetic processing for each depth location in the inspection materials on the basis of the calculated received acoustic pressure ratio, and an inspection step inspecting inside the inspection material by executing aperture synthetic processing by using multiple defect signals following the determined synthetic width.SELECTED DRAWING: Figure 1