PROCESS OF ULTRASONIC TEST OF MEDIUM SIZE OF GRAIN IN MATERIAL OF MOVING SHEETS Russian patent published in 2002 - IPC

FIELD: procedure examining internal structure of material with use of ultrasonic waves, metallurgical industry, mechanical engineering. SUBSTANCE: pulses of elastic waves are emitted normally to surface of article placed in immersion fluid, first and second pulses passed through sheet and pulse passed through layer of immersion oil are received. Values of third harmonic of first pulse passed through sheet, of first harmonic of second pulse passed through sheet and of first and third harmonic of pulse passed through immersion oil are measured. Time intervals between sending of pulses and times of arrival of first and second pulses passed through sheet and pulse passed through immersion oil are measured. Medium size of grain in irradiated region of material is found by certain formula. EFFECT: raised accuracy of determination of medium size of grain in material. 3 dwg