Being the surface discontinuity appraisal device of the round bar steel by the soaking ultrasonic crack inspect which uses the surface discontinuity appraisal device and its methodological

摘要

PPROBLEM TO BE SOLVED: To provide a surface flaw evaluation device of round bar steel, capable of precisely detecting a gap type surface flaw containing a contact bonding-like flaw with a width of about 0.5 μm or larger in a round bar steel product with a diameter of 15-100 mm. PSOLUTION: The surface flaw evaluation device of the round bar steel is equipped with: at least one array probe unit, which faces the round bar steel and constituted so that a plurality of exciting elements are arranged on the substantially the circumferential surface centered aabout the center axis of the round bar steel of a probe and the surface of the probe and the surface of the round bar steel have a predetermined water distance; and a control part which selects a plurality of the mutually adjacent exciting elements of a predetermined range of a plurality of the exciting elements of the array probe unit, to constitute a simultaneous control element group and performs control for controlling the exciting elements in the simultaneous control element group, at the same time, to form an ultrasonic beam of a predetermined frequency and for applying the ultrasonic beam to the inside of the round bar steel, at a predetermined angle of refraction to detect the surface flaw of the round bar steel. PCOPYRIGHT: (C)2009,JPO&INPIT