| 摘要 |
PURPOSE:To perform flaw detection with improved detection precision by feeding two-mode ultrasonic waves including a transverse wave and a longitudinal wave to a metal tube from one focal point type vertical probe. CONSTITUTION:The angle thetai at which ultrasonic waves are fed to a metal tube 1 from a probe 2 is set to the range 0-14.73 deg. so that two-mode ultrasonic waves including a transverse wave and a longitudinal wave can be fed to the tube 1 from the probe 2. The transverse wave fed to the tube 1 from the probe 2 is fed to the inner face at an incident angle thetaF. This transverse wave is reflected on the inner face to be fed to the outer face, and it is mode-converted into a longitudinal wave here and directly fed to the outer face. The longitudinal wave is fed to the outer face at an incident angle thetaL. The longitudinal wave fed to the tube 1 from the probe 2 is directly fed to the outer face, it is mode- converted into a transverse wave here and fed to the inner face, and it is reflected and fed to the outer face at an incident angle theta. The incident angle thetai is selected so that the inner face incident angle thetaF and the outer face incident angle thetaL and/or theta are set in the range 40-50 deg.. |
