| 摘要 |
PROBLEM TO BE SOLVED: To easily and securely determine anisotropy of a crystal grain by utilizing an ultrasonic wave.SOLUTION: An ultrasonic probe 2 oscillates an ultrasonic wave into a round bar material 1, and a signal processing device 3 takes a reflected wave in a predetermined time range out of a received reflected wave, and makes a frequency analysis of the taken-out reflected wave so as to be determined whether a crystal grain of the round bar material 1 has anisotropy upon the basis of the rate of a total value of reflected wave power of predetermined frequency or higher to a total value of reflected wave power of all frequencies. |
