Interval of Observation Plane in Visualization of Region near Defects in Billets Using Ultrasonic Computerized Tomography Method

We performed defect detection simulation considering billets with a deep-hole or spherical defect. We conducted defect detection in a billet of duralumin with a deep-hole defect and found no discrepancy between our previous and present research results because the images obtained are similar. We also conducted defect detection in a billet of steel with a spherical defect. We obtained visualization images in multiple measurement planes. We also obtained three-dimensional visualization images by binarizing the pseudo sound velocity. From the images, we found that the three-dimensional visualization of spherical defects is possible and that the scanning pitch in the longitudinal direction is about 10 mm at maximum.