| 摘要 |
PURPOSE: To provide a method and a device capable of discriminating a fire- resistant steel for an architectural structure and another steel product via the utilization of ultrasonic waves nondestructively, easily, and surely and to provide a ultrasonic probe used for the discrimination. CONSTITUTION: This discriminating device is constituted of an ultrasonic probe 2 provided with a longitudinal wave ultrasonic vibrator 5 and two transverse wave ultrasonic vibrators 6, 7 having perpendicular vibrating directions in the bottom face of a unit body 4. The ultrasonic probe 2 is brought into contact with a structure 3 (steel product). The transverse wave ultrasonic beam path WL in the rolling direction of the steel product 3, the transverse wave ultrasonic beam path WC in the direction perpendicular to the rolling direction, and the longitudinal wave ultrasonic beam path Wst are measured. X=Wst/WL and Y=Wst/WC are plotted on the X-Y coordinates, and whether the steel product 3 is an FR steel (fire-resistant steel for architectural structure) or not is discriminated via a discrimination curve (Y=-0.3X+1.297). |
