| 摘要 |
PURPOSE:To accurately detect a defect by adjusting the focal length of a focus type vertical probe to a segregation zone in a cast and forged material and measuring the length of the defect, and arranging two focus type oblique probes on the right and left sides of the defect and detecting the height of the defect. CONSTITUTION:A continuously cast and forged material 1 is easy to have a defect 3 such as cracking in its internal segregation zone 2. For the purpose, the focal length 6 of the focus type probe 4 is set to the segregation zone 2 and the probe 4 is scanned to find the movement distance 5 of the probe from the appearance of a cracking echo to the disappearance, thereby detecting the length of the defect 3. Further, the two focus type oblique probes 7 and 8 are arranged at right and left symmetrical positions across the cracking 3 and an ultrasonic wave beam is sent. Then the interference composite effect of an overlap between the echoes of the probes 7 and 8 is utilized to add or subtract an end part echo 9 from the tip of the cracking 3 and an end part echo b10, thereby detecting the defect height. Thus, the defect length and height of the continuously cast and forged material in a complicate shape can be detected with high accuracy. |
