A method and system for evaluating the health state of galvanized steel based on characteristic frequency

Abstract

The application discloses a kind of based on feature frequency's galvanized steel health state assessment method and system.The galvanized steel health state assessment method of the application includes: the impedance-frequency test system of galvanized steel is constructed, and the impedance-frequency response curve test of galvanized steel is carried out;According to the impedance-frequency response curve of galvanized steel, the feature frequency of the tested galvanized steel is analyzed;Establish the failure feature frequency spectrum diagram of galvanized layer of galvanized steel service failure process;The feature frequency of the galvanized steel to be tested is detected, and the current galvanized steel is judged by using the failure feature frequency spectrum diagram of galvanized layer The health state where it is located.The galvanized steel health state assessment method of the application belongs to nondestructive testing method, without galvanizing treatment on electrode, also without using electrolyte to form impedance test loop, simple operation, accurate result, it is convenient to evaluate the health state of on-site galvanized steel.

Description

Technical Field

[0001] This invention relates to the field of material corrosion and protection technology, specifically to a method and system for assessing the health status of galvanized steel based on characteristic frequencies. Background Technology

[0002] Evaluation of the health status of the galvanized coating on the surface of steel structures is one of the important technologies to prevent corrosion damage to steel structures caused by aging failure of the galvanized coating. The operation of inspecting and evaluating the thickness and / or deterioration status of the galvanized coating of steel structures is a necessary process to check the durability of steel structures and ensure safety.

[0003] Currently, the main methods for evaluating the health status of galvanized steel surface coatings include: manual inspection, ultrasonic thickness testing, thermal imaging systems, and visual inspection. Traditional manual inspection relies on on-site personnel to evaluate the degree of deterioration of galvanized steel according to standard testing procedures. This method requires a high level of experience from the personnel and is difficult to qualitatively describe the health status of galvanized steel, resulting in significant errors. Ultrasonic thickness testing determines the thickness of the galvanized steel by measuring the propagation time of ultrasonic waves. However, its results only characterize the thickness and are insufficient to assess the health status of galvanized steel without substantial thickness loss. The orientation, location, and shape of defects also affect the test results. Thermal imaging and visual inspection rely on artificial intelligence methods to process visual images, thereby visualizing and quantifying the deterioration information of galvanized steel. Their accuracy depends on the intelligence level of the artificial intelligence algorithm, the computing power, and the accumulated amount of various galvanized steel deterioration images.

[0004] The above evaluation methods all have significant drawbacks, as they cannot achieve continuous and accurate monitoring of the deterioration processes of galvanized steel, such as corrosion, delamination, powdering, blistering, cracking, and peeling. Summary of the Invention

[0005] To evaluate the degree of degradation and health status of galvanized steel structures, this invention provides a method and system for assessing the health status of galvanized steel based on characteristic frequencies. This method utilizes the characteristic frequency method to measure the evolution of the impedance characteristic frequency of galvanized steel during service failure in a laboratory setting. Based on the current service failure state of the galvanized steel, the characteristic frequency values ​​and the condition of the galvanized steel are calibrated, thereby evaluating the current degree of degradation of the galvanized steel.

[0006] One technical solution adopted in this invention is: a method for assessing the health status of galvanized steel based on characteristic frequencies, comprising:

[0007] Step 1: Construct an impedance-frequency test system for galvanized steel and conduct impedance-frequency response curve tests on galvanized steel.

[0008] Step 2: Analyze the characteristic frequencies of the tested galvanized steel based on its impedance-frequency response curve.

[0009] Step 3: Establish the frequency spectrum of galvanized layer failure characteristics during the service failure process of galvanized steel;

[0010] Step four: Detect the characteristic frequencies of the galvanized steel to be tested, and use the failure characteristic frequency spectrum of the galvanized layer to determine the current health status of the galvanized steel.

[0011] During the service failure process, corrosion and aging can cause changes in the properties of galvanized steel, such as delamination, cracking, blistering, and peeling. These changes can affect the characteristic frequency of the capacitor. By measuring the characteristic frequency value of the capacitor and comparing it with the failure characteristic frequency spectrum of the galvanized layer, the current health status of the galvanized steel can be determined.

[0012] Furthermore, in step one,

[0013] The impedance-frequency test system for galvanized steel uses a dual-electrode galvanized steel test system, with the galvanized steel as the anode and the metal substrate as the cathode;

[0014] When testing the impedance-frequency response curve of galvanized steel, the test frequency range for galvanized steel is 100kHz-0.01Hz, and the frequency test range is determined according to the type and condition of the galvanized steel.

[0015] Furthermore, the preparation process of the dual-electrode galvanized steel test system is as follows: the galvanized steel is regarded as the parallel plate capacitor to be monitored. Using a dual-electrode system, one end of the electrode is connected to the metal substrate with galvanized steel, and the other end is attached to the surface of the galvanized steel. The area attached to the galvanized steel is regarded as the working area of ​​the parallel plate capacitor to be monitored.

[0016] Furthermore, the test procedure for the impedance-frequency response curve of galvanized steel is as follows:

[0017] Connect the two-electrode system to an impedance meter. Use an LCR meter, network analyzer, or electrochemical workstation to test the frequency impedance curve of the capacitor. Set the test frequency and step size, start testing the impedance-frequency response curve of the galvanized steel, and plot the impedance-frequency response curve of the galvanized steel based on the obtained data.

[0018] Furthermore, in step two, the impedance-frequency response curve of galvanized steel is analyzed using a series RLC circuit, where R is the equivalent series resistance, L is the equivalent series inductance, and C is an ideal capacitor.

[0019] Complex impedance is expressed as:

[0020]

[0021] In the formula, Z is the complex impedance of the series RLC circuit, R is the resistance, L is the inductance, C is the capacitance, ω is the angular frequency, and j is the complex unit.

[0022] The magnitude of the impedance is expressed as:

[0023]

[0024] Based on the above formula, the impedance-frequency response curve of galvanized steel is obtained.

[0025] Furthermore, when the RLC circuit in the galvanized steel is in a resonant state, the overall impedance modulus is at its minimum. The frequency at which the impedance modulus is at its minimum can be analyzed from the impedance-frequency response curve of the galvanized steel. This frequency is the characteristic frequency of the galvanized steel in its current state. The characteristic frequency and the impedance value at the characteristic frequency are recorded.

[0026] Furthermore, in step three,

[0027] Based on the analysis of various failure states of galvanized steel, the relationship between the failure types of galvanized steel and the range of characteristic frequency changes and the change of impedance modulus is analyzed.

[0028] The characteristic frequencies of galvanized steel in its initial state and the impedance modulus at those characteristic frequencies were tested. The evolution of characteristic frequencies of galvanized steel under corrosion, aging, cracking, peeling, blistering, powdering, and color changes throughout its service life was tested, and a failure characteristic frequency spectrum of the galvanized layer was established.

[0029] Another technical solution adopted in this invention is: a health status assessment system for galvanized steel based on characteristic frequencies, comprising:

[0030] Impedance-frequency test system construction unit: Construct an impedance-frequency test system for galvanized steel and conduct impedance-frequency response curve tests on galvanized steel;

[0031] Characteristic frequency analysis unit: Analyzes the characteristic frequencies of the tested galvanized steel based on the impedance-frequency response curve of the galvanized steel;

[0032] Unit for establishing frequency spectrum diagram of galvanized layer failure characteristics: Establishing frequency spectrum diagram of galvanized layer failure characteristics during the service failure process of galvanized steel;

[0033] Health status assessment unit: Detects the characteristic frequencies of the galvanized steel to be tested, and uses the frequency spectrum of galvanized layer failure characteristics to determine the current health status of the galvanized steel.

[0034] The beneficial effects of this invention are as follows: The method for detecting the health status of galvanized steel is a non-destructive testing method. It does not require brushing the galvanizing solution onto the designated electrode, nor does it require forming an impedance test circuit with an electrolyte. It is simple to operate, produces accurate results, and facilitates the on-site assessment of the health status of galvanized steel. Attached Figure Description

[0035] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0036] Figure 1 This is a flowchart of the method for assessing the health status of galvanized steel according to the present invention;

[0037] Figure 2 This is a structural block diagram of the galvanized steel health status system of the present invention;

[0038] Figure 3 These are images of the four surface conditions of galvanized steel corresponding to 0h, 56h, 80h and 120h salt spray corrosion tests of the present invention.

[0039] Figure 4 This is an impedance-frequency response curve of galvanized steel corresponding to four surface conditions according to the present invention. Detailed Implementation

[0040] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0041] Example 1

[0042] This embodiment provides a method for assessing the health status of galvanized steel based on characteristic frequencies, which includes the following steps:

[0043] Step 1: Construct an impedance-frequency test system for galvanized steel and conduct impedance-frequency response curve tests on galvanized steel.

[0044] 1) Preparation of the dual-electrode galvanized steel test system

[0045] The galvanized steel system is regarded as the parallel plate capacitor to be monitored. A two-electrode system is used, with the galvanized steel as the anode and the metal substrate as the cathode. One end of the electrode is connected to the metal substrate with galvanized steel, and the other end is attached to the surface of the galvanized steel. The area of ​​the electrode attached to the galvanized steel is regarded as the working area of ​​the parallel plate capacitor to be monitored.

[0046] 2) Impedance-frequency response curve test of galvanized steel

[0047] Connect the two electrodes to an impedance meter. The impedance-frequency response curve of the capacitor can be obtained using an LCR meter, network analyzer, or electrochemical workstation. Set the test frequency and step size to begin testing the impedance-frequency response curve of the galvanized steel. Typically, the frequency should be selected within a wide range to ensure coverage of the capacitor's characteristic frequencies. The test frequency for galvanized steel ranges from 100 kHz to 0.01 Hz, with the frequency selection range depending on the type and condition of the galvanized steel. Plot the impedance-frequency response curve of the galvanized steel based on the obtained data.

[0048] Step 2: Analyze the characteristic frequencies of the tested galvanized steel based on its impedance-frequency response curve.

[0049] In step two, the impedance-frequency response curve of galvanized steel is analyzed using a series RLC circuit. Galvanized steel can be regarded as a non-ideal capacitor, which can be represented by a simplified equivalent circuit model, namely a series RLC circuit, where R is the equivalent series resistance, L is the equivalent series inductance, and C is an ideal capacitor.

[0050] Based on the above model, the complex impedance of a capacitor can be expressed as:

[0051]

[0052] In the formula, Z is the complex impedance of the series RLC circuit, R is the resistance, L is the inductance, C is the capacitance, ω is the angular frequency, and j is the complex unit.

[0053] The magnitude of the impedance is expressed as:

[0054]

[0055] Based on the above formula, the impedance-frequency response curve of galvanized steel is obtained.

[0056] When the RLC circuit in the galvanized steel is in a resonant state, the overall impedance modulus is at its minimum. The frequency at which the impedance modulus is at its minimum can be analyzed from the impedance-frequency response curve of the galvanized steel. This frequency is the characteristic frequency of the galvanized steel in its current state. Record this characteristic frequency and the impedance value at the characteristic frequency.

[0057] The characteristic frequency of galvanized steel is related to the RLC property of galvanized steel capacitors. When galvanized steel is corroded, aged, blistered, cracked, or has a change in gloss during service, its RLC property will change, that is, the capacitance property of the capacitor will change. By measuring the characteristic frequency of galvanized steel under different states, the changes in the properties of galvanized steel relative to its original state can be known.

[0058] Step 3: Establish the frequency spectrum of galvanized layer failure characteristics during the service failure process of galvanized steel.

[0059] In step three, the relationship between the failure types of galvanized steel and the range of characteristic frequency changes and impedance modulus changes is analyzed based on various failure states of galvanized steel.

[0060] The characteristic frequencies of galvanized steel in its initial state and the impedance modulus at those characteristic frequencies were tested. The evolution of characteristic frequencies of galvanized steel under corrosion, aging, cracking, peeling, blistering, powdering, and color changes throughout its service life was tested, and a failure characteristic frequency spectrum of the galvanized layer was established.

[0061] Typically, the characteristic frequency spectrum corresponding to the condition of galvanized steel is a range. The relationship between the type of galvanized steel, the failure mode, and the characteristic frequency attenuation is different. Therefore, this invention only provides the spectrum establishment method, as shown in Table 1. Among them, various failure states of galvanized steel correspond to certain characteristic frequency ranges, and the corresponding impedance modulus values ​​are obtained. Through corresponding failure tests, the characteristic frequency spectrum of galvanized layer failure can be obtained.

[0062] Table 1. Relationship between failure types of galvanized steel, characteristic frequency variation range, and impedance modulus variation.

[0063]

[0064]

[0065] Step four: Detect the characteristic frequencies of the galvanized steel to be tested, and use the failure characteristic frequency spectrum of the galvanized layer to determine the current health status of the galvanized steel.

[0066] During the service failure process, corrosion and aging can cause changes in the properties of galvanized steel, such as delamination, cracking, blistering, and peeling. These changes can affect the characteristic frequency of the capacitor. By measuring the characteristic frequency value of the capacitor and comparing it with the failure characteristic frequency spectrum of the galvanized layer, the current health status of the galvanized steel can be determined.

[0067] This embodiment combines four surface states of galvanized steel corresponding to salt spray corrosion tests at 0h, 56h, 80h, and 120h, as follows: Figure 3 As shown, the impedance-frequency response curves of galvanized steel corresponding to four surface conditions were tested as follows: Figure 4 As shown, the corresponding characteristic frequencies are 0h, 13073Hz; 56h, 8024Hz; 80h, 6551Hz; and 120h, 6247Hz. The results indicate that as the corrosion state of the galvanized steel deteriorates, its characteristic frequency gradually decreases. Therefore, by testing the impedance-frequency response curve of the current galvanized steel and comparing it with the state values ​​in this embodiment, the health status of the galvanized steel can be determined.

[0068] Application examples

[0069] This application example uses the method described in Example 1 to evaluate galvanized steel with an unknown service life.

[0070] (1) The galvanized steel is hot-dip galvanized. First, the workpiece is pickled to remove the oxide layer on the surface, providing conditions for the firm adhesion of the coating. Then, it is cleaned with ammonium chloride or zinc chloride flux to further remove impurities from the surface. Finally, it is immersed in the zinc bath of the hot-dip galvanizing tank to make the zinc liquid adhere evenly and densely to the workpiece, forming a coating. According to the cross-sectional thickness test, the thickness of the galvanized layer in this application example is 120±5μm.

[0071] (2) The impedance-frequency response curve of the galvanized steel was tested using the testing methods in step two. The frequency test range was set to 100kHz-0.01Hz, the disturbance voltage was set to 10mV, and the scan step size was set to 10PTs / Dec. The characteristic frequency of the galvanized steel and the impedance value at the characteristic frequency were analyzed using step three.

[0072] (3) Place the galvanized steel in a neutral salt spray corrosion test chamber for accelerated corrosion test. Take out the impedance-frequency response curve of the galvanized steel at regular intervals every day to test it, and record the characteristic frequency and the impedance value at the characteristic frequency. At the same time, record the current galvanized layer damage and corrosion state of the galvanized steel.

[0073] (4) Draw the frequency spectrum of the failure characteristics of the zinc coating.

[0074] (5) Test the galvanized steel with unknown service time, and combine the characteristic frequency of galvanized steel with the failure characteristic frequency spectrum of galvanized layer to determine the current health status of galvanized steel.

[0075] Example 2

[0076] This embodiment is a health status assessment system for galvanized steel based on characteristic frequencies, which includes:

[0077] Impedance-frequency test system construction unit: Construct an impedance-frequency test system for galvanized steel and conduct impedance-frequency response curve tests on galvanized steel;

[0078] Characteristic frequency analysis unit: Analyzes the characteristic frequencies of the tested galvanized steel based on the impedance-frequency response curve of the galvanized steel;

[0079] Unit for establishing frequency spectrum diagram of galvanized layer failure characteristics: Establishing frequency spectrum diagram of galvanized layer failure characteristics during the service failure process of galvanized steel;

[0080] Health status assessment unit: Detects the characteristic frequencies of the galvanized steel to be tested, and uses the frequency spectrum of galvanized layer failure characteristics to determine the current health status of the galvanized steel.

[0081] In the impedance-frequency test system construction unit, the impedance-frequency test system for galvanized steel uses a dual-electrode galvanized steel test system, with galvanized steel as the anode to be tested and the metal substrate as the cathode; when testing the impedance-frequency response curve of galvanized steel, the test frequency of galvanized steel is from 100KHz to 0.01Hz, and the frequency test range is determined according to the type and condition of galvanized steel.

[0082] The preparation process of the dual-electrode galvanized steel test system is as follows: the galvanized steel is regarded as the parallel plate capacitor to be monitored. Using the dual-electrode system, one end of the electrode is connected to the metal substrate with galvanized steel, and the other end is attached to the surface of the galvanized steel. The area attached to the galvanized steel is regarded as the working area of ​​the parallel plate capacitor to be monitored.

[0083] The test procedure for the impedance-frequency response curve of galvanized steel is as follows:

[0084] Connect the two-electrode system to an impedance meter. Use an LCR meter, network analyzer, or electrochemical workstation to test the frequency impedance curve of the capacitor. Set the test frequency and step size, start testing the impedance-frequency response curve of the galvanized steel, and plot the impedance-frequency response curve of the galvanized steel based on the obtained data.

[0085] In the characteristic frequency analysis unit, the impedance-frequency response curve of galvanized steel is analyzed using a series RLC circuit, where R is the equivalent series resistance, L is the equivalent series inductance, and C is an ideal capacitor.

[0086] Complex impedance is expressed as:

[0087]

[0088] In the formula, Z is the complex impedance of the series RLC circuit, R is the resistance, L is the inductance, C is the capacitance, ω is the angular frequency, and j is the complex unit.

[0089] The magnitude of the impedance is expressed as:

[0090]

[0091] Based on the above formula, the impedance-frequency response curve of galvanized steel is obtained.

[0092] When the RLC circuit in the galvanized steel is in a resonant state, the overall impedance modulus is at its minimum. The frequency at which the impedance modulus is at its minimum can be analyzed from the impedance-frequency response curve of the galvanized steel. This frequency is the characteristic frequency of the galvanized steel in its current state. Record this characteristic frequency and the impedance value at the characteristic frequency.

[0093] In the aforementioned unit for establishing the characteristic frequency spectrum of galvanized layer failure, the relationship between the failure type of galvanized steel and the range of characteristic frequency changes and the change of impedance modulus is analyzed based on various failure states of galvanized steel; the characteristic frequency of galvanized steel in its initial state and the impedance modulus at the characteristic frequency are tested; the evolution law of characteristic frequency under the states of corrosion, aging, cracking, peeling, blistering, powdering, and color change of galvanized layer during the entire service cycle of galvanized steel is tested, and the characteristic frequency spectrum of galvanized layer failure is established.

[0094] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any person skilled in the art can easily conceive of various equivalent modifications or substitutions within the technical scope disclosed in the present invention, and such modifications or substitutions should all be covered within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. A method for assessing the health status of galvanized steel based on characteristic frequencies, characterized in that, include: Step 1: Construct an impedance-frequency test system for galvanized steel and conduct impedance-frequency response curve tests on galvanized steel. Step 2: Analyze the characteristic frequencies of the tested galvanized steel based on its impedance-frequency response curve. Step 3: Establish the frequency spectrum of galvanized layer failure characteristics during the service failure process of galvanized steel; Step 4: Detect the characteristic frequencies of the galvanized steel to be tested, and use the failure characteristic frequency spectrum of the galvanized layer to determine the current health status of the galvanized steel. In step one, the impedance-frequency test system for galvanized steel uses a dual-electrode galvanized steel test system, with the galvanized steel as the anode and the metal substrate as the cathode. When testing the impedance-frequency response curve of galvanized steel, the test frequency ranges from 0.01Hz to 100KHz, and the frequency test range is determined according to the type and condition of the galvanized steel.

2. The method for assessing the health status of galvanized steel based on characteristic frequencies according to claim 1, characterized in that, The preparation process of the dual-electrode galvanized steel test system is as follows: the galvanized steel is regarded as the parallel plate capacitor to be monitored. Using the dual-electrode system, one end of the electrode is connected to the metal substrate with galvanized steel, and the other end is attached to the surface of the galvanized steel. The area attached to the galvanized steel is regarded as the working area of ​​the parallel plate capacitor to be monitored.

3. The method for assessing the health status of galvanized steel based on characteristic frequencies according to claim 1, characterized in that, The test procedure for the impedance-frequency response curve of galvanized steel is as follows: Connect the two-electrode system to an impedance meter. Use an LCR meter, network analyzer, or electrochemical workstation to test the frequency impedance curve of the capacitor. Set the test frequency and step size, start testing the impedance-frequency response curve of the galvanized steel, and plot the impedance-frequency response curve of the galvanized steel based on the obtained data.

4. The method for assessing the health status of galvanized steel based on characteristic frequencies according to claim 1, characterized in that, In step two, the impedance-frequency response curve of galvanized steel is analyzed using a series RLC circuit, where R is the equivalent series resistance, L is the equivalent series inductance, and C is an ideal capacitor. Complex impedance is expressed as: In the formula, Z is the complex impedance of the series RLC circuit, R is the resistance, L is the inductance, and C is the capacitance. Angular frequency, j For complex units; The magnitude of the impedance is expressed as: Based on the above formula, the impedance-frequency response curve of galvanized steel is obtained.

5. The method for assessing the health status of galvanized steel based on characteristic frequencies according to claim 4, characterized in that, When the RLC circuit in the galvanized steel is in a resonant state, the overall impedance modulus is at its minimum. The frequency at which the impedance modulus is at its minimum can be analyzed from the impedance-frequency response curve of the galvanized steel. This frequency is the characteristic frequency of the galvanized steel in its current state. Record this characteristic frequency and the impedance value at the characteristic frequency.

6. The method for assessing the health status of galvanized steel based on characteristic frequencies according to claim 4, characterized in that, In step three, Based on the analysis of various failure states of galvanized steel, the relationship between the failure types of galvanized steel and the range of characteristic frequency changes and the change of impedance modulus is analyzed. The characteristic frequencies of galvanized steel in its initial state and the impedance modulus at those characteristic frequencies were tested. The evolution of characteristic frequencies of galvanized steel under corrosion, aging, cracking, peeling, blistering, powdering, and color changes throughout its service life was tested, and a failure characteristic frequency spectrum of the galvanized layer was established.

7. A health status assessment system for galvanized steel based on characteristic frequencies, characterized in that, include: Impedance-frequency test system construction unit: Construct an impedance-frequency test system for galvanized steel and conduct impedance-frequency response curve tests on galvanized steel; Characteristic frequency analysis unit: Analyzes the characteristic frequencies of the tested galvanized steel based on the impedance-frequency response curve of the galvanized steel; Unit for establishing frequency spectrum diagram of galvanized layer failure characteristics: Establishing frequency spectrum diagram of galvanized layer failure characteristics during the service failure process of galvanized steel; Health status assessment unit: Detects the characteristic frequencies of the galvanized steel under test, and uses the failure characteristic frequency spectrum of the galvanized layer to determine the current health status of the galvanized steel; In the impedance-frequency test system construction unit, the impedance-frequency test system for galvanized steel uses a dual-electrode galvanized steel test system, with galvanized steel as the anode to be tested and the metal substrate as the cathode; when testing the impedance-frequency response curve of galvanized steel, the test frequency of galvanized steel is from 0.01Hz to 100KHz, and the frequency test range is determined according to the type and condition of galvanized steel.

8. The galvanized steel health status assessment system based on characteristic frequencies according to claim 7, characterized in that, In the characteristic frequency analysis unit, the impedance-frequency response curve of galvanized steel is analyzed using a series RLC circuit, where R is the equivalent series resistance, L is the equivalent series inductance, and C is an ideal capacitor. Complex impedance is expressed as: In the formula, Z is the complex impedance of the series RLC circuit, R is the resistance, L is the inductance, and C is the capacitance. Angular frequency, j For complex units; The magnitude of the impedance is expressed as: Based on the above formula, the impedance-frequency response curve of galvanized steel is obtained; When the RLC circuit in the galvanized steel is in a resonant state, the overall impedance modulus is at its minimum. The frequency at which the impedance modulus is at its minimum can be analyzed from the impedance-frequency response curve of the galvanized steel. This frequency is the characteristic frequency of the galvanized steel in its current state. Record this characteristic frequency and the impedance value at the characteristic frequency.

9. The galvanized steel health status assessment system based on characteristic frequencies according to claim 7, characterized in that, In the aforementioned unit for establishing the frequency spectrum of zinc plating failure characteristics, Based on the analysis of various failure states of galvanized steel, the relationship between the failure types of galvanized steel and the range of characteristic frequency changes and the change of impedance modulus is analyzed. The characteristic frequencies of galvanized steel in its initial state and the impedance modulus at those characteristic frequencies were tested. The evolution of characteristic frequencies of galvanized steel under corrosion, aging, cracking, peeling, blistering, powdering, and color changes throughout its service life was tested, and a failure characteristic frequency spectrum of the galvanized layer was established.

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