Ultrasonic detecting and positioning method and device based on TOFD (time of flight diffraction) and phased array

Abstract

The invention relates to an ultrasonic detecting and positioning method and device based on TOFD (time of flight diffraction) and a phased array. The device comprises a TOFD detection unit and a phased array detection unit, wherein the TOFD detection unit is used for scanning weld joints with a TOFD-based ultrasonic detection method to determine positions of defects; the phased array detection unit is used for scanning weld joints nearby the determined defect positions with a phased-array-based ultrasonic detection method, identifying defects with sizes exceeding a preset size threshold and positioning the identified defects. Position information of the defects in horizontal and depth directions can be determined accurately through phased-array-based ultrasonic detection, during positioning in cooperation with TOFD detection, the defects of the weld joints are accurately positioned with TOFD scanning serving as a main method and phased array scanning serving as an auxiliary method, and problems that the positioning accuracy of TOFD scanning is poor and transverse defects cannot be detected during non-parallel scanning are solved.

Description

technical field [0001] The invention relates to the technical field of ultrasonic flaw detection, in particular to an ultrasonic detection and positioning method and device based on TOFD and phased array. Background technique [0002] TOFD (Time Of Flight Diffraction, Ultrasonic Diffraction Time-of-Flight Diffraction) is a method to detect defects by relying on the diffraction energy obtained from the "end angle" and "end point" of the internal structure of the test piece (mainly referring to defects). Applied to the detection, quantification and localization of defects. As a newly developed and applied detection technology in recent years, TOFD technology has a good detection effect on some harmful defects (such as cracks), and has positive significance for improving product quality. But on the other hand, it also has the problems of insufficient positioning accuracy (horizontal position and longitudinal depth) and difficulty in detecting transverse defects during non-para...

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Problems solved by technology

[0005] The purpose of the present invention is to propose an ultrasonic detection and positioning method and device based on TOFD and phased array, which uses TOFD scanning as the main method and phased array scanning as the auxiliary method to accurately locate weld defects, and overcomes TOFD scanning and positioning. Poor accuracy and difficulty in detecting transverse defects during non-parallel scanning

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