Pulse eddy electromagnetism nondestructive detection method based on probe with iron core coil

Abstract

The invention discloses a pulse eddy electromagnetism nondestructive detection method based on a probe with an iron core coil. The probe consists of an iron core bundle, an excitation coil and a detection coil, wherein the iron core bundle is arranged in the center of the excitation coil; the detection coil is arranged outside the excitation coil. When the probe with the iron core coil is adopted to perform pulse eddy detection on a part, a strong pulse magnetic field of a dense space can be generated, an excitation magnetic field is increased, the signal to noise ratio of a signal is increased, and pulse eddy detection on a component with a relatively large wall thickness can be achieved under a relatively high lift-off condition. When a pulse eddy electromagnetism nondestructive detection system based on the probe with the iron core coil is adopted for detection, the influence of the pulse eddy field inside the iron core to the detection signal can be measured according to a probe time constant tau s. When tau s is greatly smaller than a part diffusion time constant tau e, the influence of the pulse eddy field inside the iron core to the detection signal can be ignored, the function of the probe with the iron core coil can be approximated to be linear amplification of the detection signal, and thus the signal processing difficulty is reduced.

Description

Technical field [0001] The present invention relates to the field of electromagnetic nondestructive testing, in particular to a pulsed eddy current electromagnetic nondestructive testing probe capable of generating a pulsed strong magnetic field, and a pulsed eddy current electromagnetic nondestructive testing method based on the probe with an iron core coil. Background technique [0002] In the petroleum, chemical, electric power, metallurgy and other industrial fields, metal pipes and pressure vessels are widely used to transport and store liquid or gaseous media. Most of the conveyed media have the characteristics of high temperature, high pressure, and strong corrosiveness, so the corrosion of pipelines and pressure vessels is very common. Corrosion will cause the wall thickness of the components to be thinned and the pressure-bearing performance to decrease, causing accidents such as leakage and explosion, causing casualties and economic losses. Therefore, it is necessary t...

AI Technical Summary

Problems solved by technology

The pulsed magnetic field generated by this hollow probe method has a large distribution area, and the detection signal obtained by the pulsed eddy current field detection sensor is weak and noisy

When the outer cladding layer of the component is thick or the wall thickness of the component to be inspected is large, the detection capability of the hollow probe method is limited

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