Method and device for detecting corrosion of component with permeability magnetic material protective layer

Abstract

The invention provides a method for detecting the corrosion of a component with a permeability magnetic material protective layer. The method comprises the following steps: the permeability magnetic material protective layer is magnetized to be saturated or deeply saturated, a reference area and a area to be detected are selected on the surface of a detected component, pulsed eddy current sensors are arranged on the protective layers of the two areas, the square-wave exciting is applied to exciting coils of the pulsed eddy current sensors, the attenuation curve of the induced voltage in the detecting coils of pulsed eddy current sensors is measured after the level of square waves is reduced to the low level, and the difference between the attenuation curves of the induced voltage in the two areas is compared, thus the corrosion condition of the area to be detected relative to the reference area can be further distinguished. The invention also provides a device for realizing the method, which comprises a pulsed eddy current sensor, a square-wave signal exciting circuit, a signal processing circuit, an A / D conversion circuit and a computer which are connected in sequence, wherein the pulsed eddy current sensor is provided with a magnetization unit. The invention improves the sensitivity of corrosion detection of the component with the permeability magnetic material protective layer and is suitable for detecting the corrosion of the component on-line without dismounting the protective layer and the cladding layer.

Description

technical field [0001] The invention relates to the field of non-destructive testing, in particular to a non-destructive testing method and device based on pulsed eddy current, and is especially suitable for non-stop testing of components with a protective layer of magnetic-permeable material without dismantling the protective layer and cladding layer. Background technique [0002] Ferromagnetic components with a protective layer of magnetic conductive materials, such as steam pipes and pressure vessels, are widely used in oil and gas, chemical industry, water supply and heating and other industries. The insulating material is coated on the outside of the component, and the outside of the coating is usually protected by a metal The protective layer is used to prevent rain, and the commonly used protective layer materials are aluminum, stainless steel or tinplate. At present, the corrosion detection of ferromagnetic components with cladding layers is usually carried out by re...

AI Technical Summary

Problems solved by technology

[0006] The purpose of the present invention is to overcome the deficiencies in the prior art and provide a method for detecting corrosion of components with a protective layer of magnetically permeable material, which overcomes the existing pulsed eddy current technology in detecting ferromagnetic components with a protective layer of magnetically permeable material Disadvantages of low sensitivity

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