Abstract: An ultrasonic flaw detetor for a wiredrawing apparatus, combined in a compact construction with the drawing die box and guide die box of a wiredrawing machine. The ultrasonic flaw detector comprises a cleaning tank disposed contiguously with and after the drawing box and provided with drain ports, a first partition disk having a hole for passing the drawn wire, an ultrasonic testing tank joined coaxilly to the partition disk and provided with a supply port for receiving an ultrasonic testing medium therein a second partition disk having a hole for passing the drawn wire, and a drain tank having a rear end attached to the second partition disk and a front end attached to the guide die box and provided with drain ports.

Abstract: For the inspection of a square billet, an ultrasonic testing technique using an angle beam is performed using a phased array system. The phased array probe is disposed in a plane perpendicular to the axial direction of a square billet, at a prescribed distance from the surface of the billet and set at a prescribed angle with respect to the billet surface. The billet is inspected both inside and at the surface layer when the ultrasonic beam is electronically scanned. Inspection of the surface layer only is also performed using a surface defect inspection apparatus. Determination of internal defects (including subsurface defects) is performed based on the subtraction of information from the surface defect inspection from the information from the ultrasonic inspection.