| 摘要 |
A measuring-point setting unit 51 sets an arbitrary measuring point near a weld portion inside of steel material and assumes a virtual reflecting surface that includes the measuring point and is parallel to a weld line direction. An array-control calculating unit 52 transmits ultrasonic waves of a shear wave mode satisfying an arbitrary expression and focusing onto the measuring point via a coupling medium at a predetermined incident angle with respect to the virtual reflecting surface. An echo-height extracting unit 53 detects reflected waves of the transmitted ultrasonic waves at a boundary between a base metal portion and the weld portion. A controller 5 evaluates the shape of the weld portion based on the reflected waves. |
