FIELD: metallurgy, namely flaw detection of rolled sheets. SUBSTANCE: method comprises steps of exciting in rolled sheet ultrasonic oscillations propagating normally relative to plane of sheet; receiving reflected signal, processing it; feeding compressed air between planes of electromagnetic-acoustic transducers and plane of rolled sheet. Turns of adjacent transducers are oriented in detection plane by angles different from zero at partially or wholly overlapping cross section of detected sheet. Additional pulse normalization of magnetic state of detected sheet is realized. Received ultrasonic signals are subjected to coherence procession. Apparatus for flaw detection of rolled sheets includes set of transducers connected with generator unit and receiving amplifier unit joined with inlet of registration device. Apparatus includes in addition magnetic-pneumatic system for maintaining constant gap between plane of sheet and transducer, unit for accumulating reflected signal connected between outlets of receiving amplifiers and input of registration device. EFFECT: enhanced quality and reliability of flaw detection without lowering efficiency of rolling equipment in manufacturing line. 3 cl, 5 dwg, 1 ex
Authors
Dates
1998-12-20—Published
1998-02-23—Filed