Device and method for determining material defects in rotationally symmetrical test specimens by means of ultrasound

摘要

A method for non-destructive testing of a test body, in particular a rotationally symmetrical test body, by means of ultrasound using a phased array probe with a control and processing unit, comprising the steps: a) placing the phased array on the test body in a first angular position so that a large number of insonification directions Phased array is directed into the test body, b) operation of the phased array with the control and processing unit, so that a multitude of corresponding A-images is recorded and stored from a backscattered signal for the multitude of insonification directions; c) generation and storage of a B-image the plurality of A-images per angular position; d) placing the phased array along a circumferential direction in a new angular position; e) repeating steps b, c, d until the new angular position essentially corresponds to a complete rotation of the test body; f) generating a s median B-image from the generated B-images; g) generating difference images by calculating the amount of a difference between B-image and median B-image for each B-image; h) determining a maximum value of the reflected signal in each differential image for each insonification direction and entering the determined maximum values in a first C-image; i) averaging the first C-image over all angles resulting from the corresponding angular positions and storing the averaged first C-image as a data series; k) subtracting the data series obtained by averaging from each angle-related data series, forming the amount and entering the data series obtained in a geometry-corrected second C-image.