| 摘要 |
PROBLEM TO BE SOLVED: To easily and inexpensively carry out non-destructive evaluation with high precision even in a thin metal plate by transmitting ultrasonic waves and detecting total output strength of a plurality of transverse waves in the different vibrating directions. SOLUTION: An ultrasonic sensor 11 in a water-immersed condition is set opposedly to a steel plate 1, and ultrasonic longitudinal waves 2a are emitted to the steel plate 1. When the longitudinal wave 2a is reflected on a bottom face 1a, transverse wave 2b is generated and received by the sensor 11. From an output waveform of a bottom face reflected transverse wave 2b provided via a pulser and receiver 14, its output strength is detected. On the basis of this strength, a computing device 13 computes a Lankford value. Finally, this value is outputted to a display device 16, so that deep-drawing performance of the steel plate 1 can be grasped easily. In this way, in-line measurement can be carried out, and ascertainment can be performed timely and quantitatively for handling. On the other hand, deep-drawing performance in a desired point in the metal plate can be automatically evaluated continuously. |
