| 摘要 |
<p>PROBLEM TO BE SOLVED: To distinguish nonmetallic inclusions from voids of an unflat shape, such as approximately spherical shape and voids of flat shape which are not pressed into contact and display them in an easily and visually recognizable way. SOLUTION: In this ultrasonic flaw detection method, ultrasonic converging beams are transmitted to a material to be inspected 1. On the basis of received reflected waves, reflected waves from foreign matter in the material to be inspected are extracted. The amplitudes of the reflected waves are measured to inspect for foreign matter. By measuring the amplitudes of the reflected waves from the foreign matter in the material to be inspected by the plurality of ultrasonic converging beams of different beam diameters at locations in the direction of depth at which the foreign matter is present and obtaining the differences, the type of the foreign matter is determined.</p> |
