A full-circumference radial excitation electromagnetic ultrasonic transducer

Abstract

The invention discloses a complete cycle radial excitation electromagnetic ultrasonic transducer which is mainly used for electromagnetic ultrasonic detection to a non-ferrous magnetic mental pipe. The complete cycle radial excitation electromagnetic ultrasonic transducer comprises a first bar magnet and a second bar magnet of which the N poles are placed oppositely, and a non-metal filler placed between the first bar magnet and the second bar magnet and used for keeping the distance between the first bar magnet and the second bar magnet, wherein the symmetry axes of the first bar magnet and the second bar magnet coincide, the first bar magnet, the second bar magnet and the non-metal filler are fixed inside a non-metal housing, and the center part of the non-metal housing, in the length direction of the non-metal housing, is circumferentially wrapped with a flexible helicoil array; during the detection, all that is needed is to place the complete cycle radial excitation electromagnetic ultrasonic transducer inside the non-ferrous magnetic mental pipe and axially pull the transducer, namely complete cycle electromagnetic ultrasonic detection to all axial positions of the non-ferrous magnetic mental pipe to be detected can be achieved; the complete cycle radial excitation electromagnetic ultrasonic transducer has the characteristics of simple structure, convenience in use, effectiveness in improving the detection efficiency, the resolution and the accuracy, and the like, and has an important engineering application value.

Description

technical field [0001] The invention belongs to the technical field of non-destructive testing, and relates to a full-circumference radial excitation electromagnetic ultrasonic transducer, which is used for the detection of non-ferromagnetic metal pipe fittings. Background technique [0002] Electromagnetic ultrasonic testing has gradually gained attention and application in the field of nondestructive testing technology due to its advantages that the electromagnetic ultrasonic transducer does not need to be in contact with the metal component to be tested, does not require couplant, and can be used in special conditions such as high temperature and isolation layers. As the core component of the electromagnetic ultrasonic testing system, the electromagnetic ultrasonic transducer is mainly responsible for exciting and picking up ultrasonic signals. [0003] At present, the electromagnetic ultrasonic transducers used in the electromagnetic ultrasonic testing of flat metal stru...

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Problems solved by technology

[0003] At present, the electromagnetic ultrasonic transducers used in the electromagnetic ultrasonic testing of flat metal structures cannot be directly applied to the electromagnetic ultrasonic testing of metal pipes. Electromagnetic ultrasonic detection of metal pipe fittings can only be realized by means of guided waves such as excitation of ultrasonic Lamb waves. However, there are problems such as complex detection system, large signal dispersion, and low signal-to-noise ratio in the electromagnetic ultrasonic detection of metal pipe fittings using guided wave methods.

In order to realize the electromagnetic ultrasonic detection of metal pipe fittings based on ultrasonic shear waves, the traditional method of implementing full-circumferential radial excitation on metal pipe fittings is to arrange a circle of permanent magnets in the circumferential direction inside the pipe fittings. This method is difficult to achieve uniform distribution of the static magnetic field inside the metal pipe fittings. Resulting in low detection efficiency, low resolution and poor accuracy

The structure of traditional metal pipe fittings electromagnetic ultrasonic transducers is relatively complex, and it is difficult to apply to small diameter metal pipe fittings

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