CN118501251A - Ferromagnetic component deep defect detection method and device - Google Patents

Abstract

The invention relates to a ferromagnetic member deep defect detection method and a device, belonging to the technical field of electromagnetic nondestructive detection, wherein the ferromagnetic member deep defect detection method comprises the following steps: acquiring a detection signal of a ferromagnetic member to be detected, wherein the detection signal of the ferromagnetic member to be detected is obtained by scanning induced electromotive force generated by a magnetized vortex field on the surface of the ferromagnetic member to be detected by a detection probe; and detecting whether the ferromagnetic member to be detected has a deep defect or not based on whether the detection signal of the ferromagnetic member to be detected has a peak mutation or not. The invention can realize the deep defect detection of the ferromagnetic component without complex operation, thereby reducing the complexity of the deep defect detection of the ferromagnetic component.

Description

A method and device for detecting deep defects of ferromagnetic components

Technical Field

The present invention relates to the technical field of electromagnetic nondestructive testing, and in particular to a method and device for detecting deep defects of ferromagnetic components.

Background Art

Ferromagnetic materials are widely used in engineering fields such as construction, energy, and transportation. When operated for a long time under complex working conditions, the inner wall will produce perforations and bursts, threatening the normal operation of the material. Therefore, it is extremely important to detect and evaluate ferromagnetic materials. For deep defects, ultrasonic testing is considered to be able to accurately detect defects. Conventional ultrasonic testing is limited by coupling agents, and electromagnetic ultrasonic testing is affected by transducer efficiency and magnetic permeability. Eddy current testing is very sensitive to both circumferential and axial defects, but affected by the skin effect, conventional eddy current testing is insufficient in detecting deep defects. The penetration depth of pulsed eddy current testing and low-frequency eddy current testing is greatly reduced in detecting high-permeability carbon steel materials. The detection depth of magnetic flux leakage testing is limited by the applied magnetic field. Due to the limitations of magnetic shielding effect and magnetic compression effect, the magnetic flux leakage caused by internal deep defects is small and difficult to detect. For thicker materials, deeper defects require larger magnetic fields, and larger magnetization devices are required during the detection process.

Therefore, how to accurately detect deep defects in ferromagnetic components without coupling has become an urgent problem to be solved.

Summary of the invention

In view of this, it is necessary to provide a method and device for detecting deep defects in ferromagnetic components to solve the problem of high complexity of current methods for detecting deep defects in ferromagnetic components.

In order to solve the above problems, the present invention provides a method for detecting deep defects of ferromagnetic components, comprising:

Acquire a detection signal of the ferromagnetic component to be detected, wherein the detection signal of the ferromagnetic component to be detected is obtained after the detection probe scans the induced electromotive force generated by the eddy current field on the surface of the magnetized ferromagnetic component to be detected;

Based on whether there is a peak mutation in the detection signal of the ferromagnetic component to be detected, it is detected whether there is a deep defect in the ferromagnetic component to be detected.

In a possible implementation, the magnetized ferromagnetic component to be detected is obtained by magnetizing the ferromagnetic component to be detected to a saturation state or a near-saturation state based on a pulsed magnetic field.

In a possible implementation, the detection signal of the ferromagnetic component to be detected is used to reflect the change in magnetic permeability distribution of the ferromagnetic component to be detected.

In a possible implementation, the detection probe is a differential detection probe including an eddy current excitation coil and two detection coils.

In a possible implementation, center lines of the eddy current excitation coil and the detection coil are arranged along a normal direction on an outer surface of the ferromagnetic component to be detected.

In a possible implementation manner, a sinusoidal voltage signal is applied to the eddy current excitation coil.

In a possible implementation, the step of obtaining a detection signal of the ferromagnetic component to be detected includes:

The ferromagnetic component to be detected is controlled to perform uniform linear motion relative to the detection probe, and the signal collected by the detection probe is used as the detection signal of the ferromagnetic component to be detected.

In a possible implementation, the method further includes:

The signal collected by the detection probe is filtered based on a phase-sensitive detection circuit, and the filtered signal is output to an oscilloscope for display.

In a possible implementation, the method further includes:

The detection position where the detection signal of the ferromagnetic component to be detected has a sudden peak change is determined as the defect position of the ferromagnetic component to be detected.

The present invention also provides a ferromagnetic component deep defect detection device, comprising:

An acquisition module is used to acquire a detection signal of the ferromagnetic component to be detected, wherein the detection signal of the ferromagnetic component to be detected is obtained after the detection probe scans the induced electromotive force generated by the eddy current field on the surface of the magnetized ferromagnetic component to be detected;

The detection module is used to detect whether the ferromagnetic component to be detected has deep defects based on whether the detection signal of the ferromagnetic component to be detected has a peak mutation.

The beneficial effects of the present invention are as follows: the method and device for detecting deep defects in ferromagnetic components provided by the present invention magnetize the ferromagnetic component to be detected, and then use a detection probe to scan the induced electromotive force generated by the eddy current field on the surface of the magnetized ferromagnetic component to be detected to obtain a detection signal. During the detection, there is no need to directly contact the ferromagnetic component. Then, by analyzing whether there is a peak mutation in the detection signal, it is determined whether there are deep defects in the ferromagnetic component to be detected. The deep defect detection of the ferromagnetic component can be achieved without complicated operations, thereby reducing the complexity of deep defect detection of the ferromagnetic component.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG1 is a schematic flow chart of an embodiment of a method for detecting deep defects in ferromagnetic components provided by the present invention;

FIG2 is a schematic structural diagram of an embodiment of a deep defect detection system for ferromagnetic components provided by the present invention;

FIG3 is a schematic diagram of an embodiment of a ferromagnetic component provided by the present invention being magnetized;

FIG4 is a schematic diagram of an embodiment of a magnetic permeability disturbance caused by a deep defect inside a ferromagnetic component provided by the present invention;

FIG5 is a schematic structural diagram of an embodiment of a differential detection probe provided by the present invention;

FIG6 is a schematic diagram of an embodiment of a principle for detecting deep defects inside a ferromagnetic component provided by the present invention;

FIG. 7 is a schematic structural diagram of an embodiment of a deep defect detection device for ferromagnetic components provided by the present invention.

DETAILED DESCRIPTION

The preferred embodiments of the present invention are described in detail below in conjunction with the accompanying drawings, wherein the accompanying drawings constitute a part of this application and are used together with the embodiments of the present invention to illustrate the principles of the present invention, but are not used to limit the scope of the present invention.

In the description of the present invention, the terms "first" and "second" are used for descriptive purposes only and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In addition, the meaning of "plurality" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

In the description of the present invention, reference to an "embodiment" means that a particular feature, structure, or characteristic described in conjunction with the embodiment may be included in at least one embodiment of the present invention. The appearance of the phrase in various places in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment that is mutually exclusive of other embodiments. It is explicitly and implicitly understood by those skilled in the art that the described embodiments may be combined with other embodiments.

Ferromagnetic materials are widely used in engineering fields such as construction, energy, and transportation. When operated for a long time under complex working conditions, the inner wall will produce perforations and bursts, threatening the normal operation of the material. Therefore, it is extremely important to detect and evaluate ferromagnetic materials. For deep defects, ultrasonic testing is considered to be able to accurately detect defects. Conventional ultrasonic testing is limited by coupling agents, and electromagnetic ultrasonic testing is affected by transducer efficiency and magnetic permeability. Eddy current testing is very sensitive to both circumferential and axial defects, but affected by the skin effect, conventional eddy current testing is insufficient in detecting deep defects. The penetration depth of pulsed eddy current testing and low-frequency eddy current testing is greatly reduced in detecting high-permeability carbon steel materials. The detection depth of magnetic flux leakage testing is limited by the applied magnetic field. Due to the limitations of magnetic shielding effect and magnetic compression effect, the magnetic flux leakage caused by internal deep defects is small and difficult to detect. For thicker materials, deeper defects require larger magnetic fields, and larger magnetization devices are required during the detection process.

In order to solve the above problems, the present invention provides a method for detecting deep defects of ferromagnetic components to reduce the complexity of detecting deep defects of ferromagnetic components.

The specific embodiments are described in detail below:

A specific embodiment of the present invention discloses a method for detecting deep defects of ferromagnetic components. In conjunction with FIG. 1 , FIG. 1 is a schematic flow chart of an embodiment of a method for detecting deep defects of ferromagnetic components provided by the present invention, including step S101 and step S102, wherein:

In step S101, a detection signal of the ferromagnetic component to be detected is obtained, wherein the detection signal of the ferromagnetic component to be detected is obtained after the detection probe scans the induced electromotive force generated by the eddy current field on the surface of the magnetized ferromagnetic component to be detected;

In step S102, based on whether there is a peak mutation in the detection signal of the ferromagnetic component to be detected, it is detected whether there is a deep defect in the ferromagnetic component to be detected.

During implementation, the ferromagnetic component to be detected can be magnetized first, and then the induced electromotive force generated by the eddy current field on the surface of the magnetized ferromagnetic component to be detected can be scanned by the detection probe, so as to obtain the detection signal of the ferromagnetic component to be detected. Subsequently, it can be detected whether the ferromagnetic component to be detected has deep defects based on whether there is a peak mutation in the detection signal of the ferromagnetic component to be detected. If there is a peak mutation in the detection signal of the ferromagnetic component to be detected, it can be determined that the ferromagnetic component to be detected has deep defects; if there is no peak mutation in the detection signal of the ferromagnetic component to be detected, it can be determined that the ferromagnetic component to be detected does not have deep defects.

The deep defect detection method for ferromagnetic components provided by the present invention can be applied to defect detection of steel pipes, and can also be applied to defect detection of other ferromagnetic components, and the present invention does not make specific limitations on this.

Compared with the prior art, the method for detecting deep defects in ferromagnetic components provided in this embodiment magnetizes the ferromagnetic component to be detected, and then uses a detection probe to scan the induced electromotive force generated by the eddy current field on the surface of the magnetized ferromagnetic component to be detected to obtain a detection signal. During detection, there is no need to directly contact the ferromagnetic component. Then, by analyzing whether there is a peak mutation in the detection signal, it is determined whether there are deep defects in the ferromagnetic component to be detected. Deep defect detection of ferromagnetic components can be achieved without complicated operations, thereby reducing the complexity of deep defect detection of ferromagnetic components.

Exemplarily, the magnetized ferromagnetic component to be detected is obtained by magnetizing the ferromagnetic component to be detected to a saturation state or a near-saturation state based on a pulsed magnetic field.

Specifically, when the ferromagnetic component to be detected is magnetized, a pulsed magnetic field can be used to magnetize the ferromagnetic component to be detected to a saturated state or a near-saturated state. In addition, the magnetizer used during magnetization can be a yoke magnetizer or other types of magnetizers, and the present invention does not specifically limit this.

Exemplarily, the detection signal of the ferromagnetic component to be detected is used to reflect the change in the magnetic permeability distribution of the ferromagnetic component to be detected.

Specifically, the detection signal of the ferromagnetic component to be detected can be used to reflect the change in the magnetic permeability distribution of the ferromagnetic component to be detected. If there is a defect in the ferromagnetic component to be detected, the magnetic permeability distribution at the defect will change, which will be reflected in the detection signal.

Exemplarily, the detection probe is a differential detection probe, including an eddy current excitation coil and two detection coils.

Specifically, the detection probe used to obtain the detection signal can be set as a differential detection probe, so as to more intuitively reflect the sudden change of the detection signal. The differential detection probe can include an eddy current excitation coil and two detection coils.

Exemplarily, the center lines of the eddy current excitation coil and the detection coil are arranged along the normal direction on the outer surface of the ferromagnetic component to be detected.

Specifically, when the ferromagnetic component to be detected is detected, the center lines of the eddy current excitation coil and the detection coil of the detection probe can be arranged along the normal direction on the outer surface of the ferromagnetic component to be detected.

Exemplarily, a sinusoidal voltage signal is applied to the eddy current excitation coil.

Specifically, when the ferromagnetic component to be detected is detected, the excitation signal applied to the eddy current excitation coil of the detection probe may be a sinusoidal voltage signal.

Exemplarily, the step of acquiring a detection signal of a ferromagnetic component to be detected includes:

The ferromagnetic component to be detected is controlled to perform uniform linear motion relative to the detection probe, and the signal collected by the detection probe is used as the detection signal of the ferromagnetic component to be detected.

Specifically, when the ferromagnetic component to be detected is detected, the ferromagnetic component to be detected can be controlled to move linearly at a uniform speed relative to the detection probe, and the signal collected by the detection probe is used as the detection signal of the ferromagnetic component to be detected.

Exemplarily, the method further includes:

The signal collected by the detection probe is filtered based on a phase-sensitive detection circuit, and the filtered signal is output to an oscilloscope for display.

Specifically, after obtaining the detection signal of the ferromagnetic component to be detected, the signal collected by the detection probe can be filtered by a phase-sensitive detection circuit, and then the filtered signal is output to an oscilloscope for display, so as to observe the detection signal more intuitively.

Exemplarily, the method further includes:

The detection position where the detection signal of the ferromagnetic component to be detected has a sudden peak change is determined as the defect position of the ferromagnetic component to be detected.

Specifically, when detecting whether the ferromagnetic component to be detected has deep defects based on the detection signal of the ferromagnetic component to be detected, the detection position where the peak value of the detection signal of the ferromagnetic component to be detected suddenly changes can also be determined as the defect position of the ferromagnetic component to be detected.

The following is a specific application scenario to better illustrate the technical solution of the present invention:

In conjunction with Figure 2, Figure 2 is a structural schematic diagram of an embodiment of a deep defect detection system for ferromagnetic components provided by the present invention, the system comprising: 1: a ferromagnetic component to be tested, 2: a deep defect, 3: a detection probe, 4: a yoke magnetizer, 5: a coil, 6: a pulse signal, 7: a signal generator, 8: a filter circuit, and 9: an oscilloscope.

In conjunction with Figure 3, Figure 3 is a schematic diagram of an embodiment of the magnetization of a ferromagnetic component provided by the present invention. First, a pulse signal can be output by a magnetization power supply to energize the excitation coil, and the magnetizer magnetizes the inspected steel pipe to a saturation state. The magnetic saturation state refers to the maximum magnetic permeability distortion around the internal defects of the steel pipe. This magnetic permeability disturbance phenomenon will spread to the surface of the steel pipe, thereby causing the defective area of the steel pipe to present different magnetic permeability characteristics from other areas far away from the defects. In conjunction with Figure 4, Figure 4 is a schematic diagram of an embodiment of the magnetic permeability disturbance caused by deep defects inside a ferromagnetic component provided by the present invention.

The detection probe adopts differential probe detection, including an eddy current excitation coil and two detection coils. The signal generator applies sinusoidal excitation to the excitation coil, and the center lines of the eddy current excitation coil and the two detection coils are arranged on the outer surface of the steel pipe along the normal direction. The eddy current excitation coil generates eddy currents on the surface of the steel pipe. The two detection coils are spatially staggered along the direction of the magnetization field and adopt differential output to detect the differential change of the magnetic permeability of the surface of the steel pipe parallel to the magnetization direction. Combined with Figure 5, Figure 5 is a structural schematic diagram of an embodiment of the differential detection probe provided by the present invention.

The steel pipe makes a uniform linear motion relative to the probe and the magnetizer, and the output signal changes when it passes through the area above the defect. The signal collected by the probe is filtered by the filter circuit and then transmitted to the oscilloscope for display. The internal defect condition is judged by analyzing the output signal characteristics. In conjunction with Figure 6, Figure 6 is a schematic diagram of an embodiment of the deep defect detection principle inside the ferromagnetic component provided by the present invention. A sinusoidal voltage is applied to both ends of the eddy current excitation coil, and the eddy current receiving coil is used to detect the magnetic permeability distortion transmitted from the deep defect inside the steel pipe to the surface of the steel pipe, and the defect signal is differentially output. The signal is filtered by the phase-sensitive detection circuit, and the phase-sensitive detection board is connected to the oscilloscope. The final processed signal will be displayed in the oscilloscope, and the peak value of the signal is used to identify whether there is a defect inside the steel pipe.

The embodiment of the present invention further provides a ferromagnetic component deep defect detection device. In conjunction with FIG. 7 , FIG. 7 is a schematic structural diagram of an embodiment of the ferromagnetic component deep defect detection device provided by the present invention. The ferromagnetic component deep defect detection device 700 includes:

An acquisition module 701 is used to acquire a detection signal of the ferromagnetic component to be detected, wherein the detection signal of the ferromagnetic component to be detected is obtained after a detection probe scans the induced electromotive force generated by the eddy current field on the surface of the magnetized ferromagnetic component to be detected;

The detection module 702 is used to detect whether the ferromagnetic component to be detected has deep defects based on whether the detection signal of the ferromagnetic component to be detected has a peak mutation.

The specific implementation methods of each module of the deep defect detection device for ferromagnetic components can refer to the description of the above-mentioned deep defect detection method for ferromagnetic components, and have similar beneficial effects, which will not be repeated here.

It should be noted that the deep defect detection device for ferromagnetic components can be set in an indoor steel pipe defect detection device or an outdoor steel pipe defect detection device, and the present invention does not make specific limitations on this.

The present invention discloses a method and device for detecting deep defects of ferromagnetic components. The method magnetizes the ferromagnetic component to be detected, and then uses a detection probe to scan the induced electromotive force generated by the eddy current field on the surface of the magnetized ferromagnetic component to be detected to obtain a detection signal. During the detection, there is no need to directly contact the ferromagnetic component. Then, by analyzing whether there is a peak mutation in the detection signal, it is determined whether there is a deep defect in the ferromagnetic component to be detected. The deep defect detection of the ferromagnetic component can be achieved without complicated operations, thereby reducing the complexity of the deep defect detection of the ferromagnetic component.

The above description is only a preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any changes or substitutions that can be easily conceived by any technician familiar with the technical field within the technical scope disclosed by the present invention should be covered within the protection scope of the present invention.

Claims (10)

1. A method for detecting deep defects of ferromagnetic components, comprising: Acquire a detection signal of the ferromagnetic component to be detected, wherein the detection signal of the ferromagnetic component to be detected is obtained after the detection probe scans the induced electromotive force generated by the eddy current field on the surface of the magnetized ferromagnetic component to be detected; Based on whether there is a peak mutation in the detection signal of the ferromagnetic component to be detected, it is detected whether there is a deep defect in the ferromagnetic component to be detected. 2. The method for deep defect detection of ferromagnetic components according to claim 1 is characterized in that the magnetized ferromagnetic component to be detected is obtained by magnetizing the ferromagnetic component to be detected to a saturation state or a near-saturation state based on a pulsed magnetic field. 3. The method for deep defect detection of ferromagnetic components according to claim 1 is characterized in that the detection signal of the ferromagnetic component to be detected is used to reflect the change in magnetic permeability distribution of the ferromagnetic component to be detected. 4. The method for detecting deep defects of ferromagnetic components according to claim 1 is characterized in that the detection probe is a differential detection probe, including an eddy current excitation coil and two detection coils. 5. The method for deep defect detection of ferromagnetic components according to claim 4 is characterized in that the center lines of the eddy current excitation coil and the detection coil are arranged along the normal direction on the outer surface of the ferromagnetic component to be detected. 6 . The method for detecting deep defects of ferromagnetic components according to claim 4 , wherein a sinusoidal voltage signal is applied to the eddy current excitation coil. 7. The method for detecting deep defects of ferromagnetic components according to claim 1, characterized in that the step of obtaining the detection signal of the ferromagnetic component to be detected comprises: The ferromagnetic component to be detected is controlled to perform uniform linear motion relative to the detection probe, and the signal collected by the detection probe is used as the detection signal of the ferromagnetic component to be detected. 8. The method for detecting deep defects of ferromagnetic components according to claim 7, characterized in that the method further comprises: The signal collected by the detection probe is filtered based on a phase-sensitive detection circuit, and the filtered signal is output to an oscilloscope for display. 9. The method for detecting deep defects of ferromagnetic components according to any one of claims 1 to 8, characterized in that the method further comprises: The detection position where the detection signal of the ferromagnetic component to be detected has a sudden peak change is determined as the defect position of the ferromagnetic component to be detected. 10. A deep defect detection device for ferromagnetic components, comprising: An acquisition module is used to acquire a detection signal of the ferromagnetic component to be detected, wherein the detection signal of the ferromagnetic component to be detected is obtained after the detection probe scans the induced electromotive force generated by the eddy current field on the surface of the magnetized ferromagnetic component to be detected; The detection module is used to detect whether the ferromagnetic component to be detected has deep defects based on whether the detection signal of the ferromagnetic component to be detected has a peak mutation.