A method for testing metal anti-cavitation ability

Abstract

The present invention relates to a method for testing the cavitation resistance of metals, comprising: S1, using the COMSOL simulation platform to perform acoustic structure boundary modal analysis between the variable-spoke rod and the reaction tank solution of a high-frequency cavitation reaction device under a driving voltage V0, obtaining the distribution of sound waves underwater through pressure acoustic analysis, and then obtaining the parameters and corresponding areas with the greatest cavitation severity; S2, setting the working parameters of the high-frequency cavitation reaction device according to the simulation results of S1, adjusting the sample to the area with the greatest cavitation severity, and performing ultrasonic cavitation treatment on the sample in the high-frequency cavitation reaction device; S3, performing surface morphology detection on the sample, and evaluating its cavitation resistance through the relationship between cavitation rate and roughness. The present invention efficiently realizes the detection of the cavitation resistance of metal samples, and is a new type of green, efficient, and controllable non-contact detection method. To a certain extent, it solves the many disadvantages of traditional in-situ detection, such as long time, limited processing scenarios, and uncontrollable processing effects.

Description

Technical Field

[0001] The invention belongs to the technical field of metal material corrosion resistance evaluation and detection, and particularly relates to a rapid and controllable metal cavitation resistance testing method. Background Art

[0002] Cavitation is primarily a phenomenon in which metal surfaces in contact with fluids undergo cave-like corrosion damage when the fluid is flowing at high speed and undergoing pressure changes. Cavitation primarily damages the protective film on metal materials, accelerating the rate of corrosion. It is characterized by the formation of numerous small pits on the surface of the metal material that then slowly expand into caves. Cavitation is caused by high-frequency elastic stress waves acting on the surface of a metal material immersed in a solution. The stress pulse in the liquid is caused by the pressure wave or high-speed jet generated when the cavitation bubble collapses. The amplitude of the stress pulse varies from several hundred to several thousand. Such a high stress pulse can easily lead to deformation and loss of metal materials used in industry, which can not only directly cause cavitation strength damage to the metal material, but can also cause fatigue damage to the metal material.

[0003] Traditionally, there are two ways to assess the corrosion and cavitation resistance of metal components. One involves conducting in-situ tests on a specific material. However, these tests are time-consuming and uneconomical. Furthermore, due to the complexity of the on-site environment, it is difficult to draw regular evaluation indicators and conclusions. Furthermore, a large magnitude of cyclic loads must be applied to the sample. Because cycles often occur at a relatively low frequency, the test time is too long, and the applied load can easily cause destructive and irreversible damage to the test. After the sample loses its surface integrity, a large amount of debris flakes off, contaminating the test solution and reducing the recyclability of the equipment. Consequently, the cost-effectiveness and timeliness of the test are poor. Summary of the Invention

[0004] The technical problem to be solved by the present invention is to provide a metal cavitation resistance testing method in response to the above-mentioned deficiencies in the prior art, which can qualitatively or quantitatively evaluate the cavitation resistance of metal materials in an efficient, time-saving, labor-saving and controllable manner.

[0005] The technical solution adopted by the present invention to solve the above-mentioned technical problems is:

[0006] A method for testing the cavitation resistance of metals, comprising performing ultrasonic cavitation treatment on a sample using a high-frequency cavitation reaction device, wherein the high-frequency cavitation reaction device comprises a piezoelectric transducer, a horn, a reaction cell, a sample, and an AC signal generator. The reaction cell contains a solution, the sample is placed in the reaction cell, one end of the horn is placed in the solution, and the other end is connected to the piezoelectric transducer. The AC signal generator is connected to the two poles of the piezoelectric transducer.

[0007] The metal anti-cavitation ability testing method comprises the following steps:

[0008] S1. Use the COMSOL simulation platform to perform acoustic-structural boundary modal analysis between the variable-spoke rod and the reaction tank solution of the high-frequency cavitation reaction device at a driving voltage V0. Through pressure acoustic analysis, the distribution of the sound wave underwater is obtained, and then the parameters and corresponding areas with the greatest cavitation severity are obtained;

[0009] S2. Setting the working parameters of the high-frequency cavitation reaction device according to the simulation results of S1, adjusting the sample to the area where the cavitation intensity is the greatest, and performing ultrasonic cavitation treatment on the sample in the high-frequency cavitation reaction device;

[0010] S3. Surface morphology of the sample is tested and its anti-cavitation ability is evaluated through the relationship between cavitation power and roughness.

[0011] In the above solution, step S1 specifically includes the following steps:

[0012] S1.1. Build the model of piezoelectric transducer, amplitude transformer, and reaction cell, and import them into COMSOL simulation platform; set the driving voltage V0 of the piezoelectric transducer as a single parameter, set the minimum operating frequency f0min and the maximum operating frequency f0max of the piezoelectric transducer, the scanning frequency θ∈f0min~f0max, the frequency step f0step, and the number of times the characteristic frequency is scanned. Perform pressure acoustic analysis at Nth eigenfrequency;

[0013] S1.2. Analyze the simulation results of the Nth acoustic field characteristic value to obtain the underwater acoustic field distribution cloud map of the maximum sound pressure level under the driving voltage V0 input. The corresponding piezoelectric transducer acoustic vibration frequency is f and the sound pressure level is p.

[0014] S1.3. Calculate the hard point coordinates P (X, Y, Z) of the sound pressure center of the reaction zone using simulation software.

[0015] In the above solution, step S2 specifically includes the following steps:

[0016] S2.1. Build a high-frequency cavitation reaction device, set the AC signal generator's drive voltage to V0, the AC wave frequency to F, and the processing time to t; where the AC wave frequency F is derived from the acoustic vibration frequency f;

[0017] S2.2. Adjust the coordinate position of the specimen to be roughly consistent with the hard point coordinates P (X, Y, Z) of the sound pressure center simulated in step S1;

[0018] S2.3. Turn on the AC signal generator to perform ultrasonic cavitation treatment on the sample.

[0019] In the above solution, step S2 specifically includes the following steps:

[0020] S3.1. Define the instantaneous cavitation power Pc based on the sound pressure level p and acoustic frequency f obtained in S1 and the processing time t in step S2;

[0021] S3.2. Obtain the 3D profile of the sample surface and obtain the surface integrity roughness coefficient Ra by observing the difference between the peak Rp and the valley Rv of the roughness. Compare it with the surface integrity roughness coefficient of the initial material to obtain the surface integrity factor σ n ;

[0022] S3.3, with A c =σ n / P c As a control and judgment index of the sample's anti-cavitation ability, the smaller the Ac value, the more corrosion-resistant the metal is under a certain degree of cavitation and the better its anti-cavitation ability is.

[0023] In the above solution, in step S2.2, the AC wave frequency F is calculated based on the acoustic vibration frequency f, which is specifically determined by the characteristic equations of the two elastic materials, the isotropic piezoelectric ceramic and the horn:

[0024]

[0025] Where ρ is the material density of the piezoelectric ceramic, ω is the angular frequency, f is the acoustic frequency, u is the structural displacement, and P is the bolt preload force. is the driving force of the piezoelectric ceramic to the horn, and F is the frequency of the AC wave.

[0026] In the above scheme, in step S3.1, the instantaneous cavitation power Pc is:

[0027]

[0028] Where p is the sound pressure level, f is the acoustic frequency, t is the processing time, and θ is the correction coefficient.

[0029] In the above scheme, the piezoelectric transducer includes a mass block, a pre-tightening bolt, and a piezoelectric ceramic. The piezoelectric ceramic is composed of several positive and negative stacked ceramic sheets. The pre-tightening bolt connects the mass block with the positive and negative stacked ceramic sheets from top to bottom, and finally the piezoelectric ceramic is fixedly contacted with the big end of the amplitude transformer; the mass block is used to seal the piezoelectric transducer, and the pre-tightening bolt is used to provide a pre-tightening force for the piezoelectric ceramic. The two poles of the piezoelectric ceramic are correspondingly connected to the positive and negative poles of the AC signal generator to convert the electrical signal into an ultrasonic vibration signal.

[0030] In the above solution, the piezoelectric ceramic is made of lead zirconium carbonate, and the mass block and the pre-tightening bolt are both made of steel.

[0031] In the above scheme, the high-frequency cavitation reaction device also includes a tray, which is suspended in the reaction tank by steel wires on both sides, and the Z-position of the sample is adjusted by pulling up or lowering the steel wires; the surface of the tray is covered with a 1×1 cm grid, and the position of the sample in the XY plane is adjusted according to the grid.

[0032] In the above scheme, the high-frequency cavitation reaction device also includes a mounting bracket, which includes a base, a vertical rod installed on the base, and a horizontal bracket installed on the vertical rod; a slide groove with a scale is provided on the base along the X direction, and a movable stud is provided in the slide groove. The bottom of the reaction pool is provided with a threaded hole adapted to the stud, and the reaction pool is fixed to a suitable position of the base through the threaded stud; the horizontal bracket is used to install the piezoelectric transducer and the amplitude rod above the reaction pool, one end of the horizontal bracket is mounted on the vertical rod and can move along the vertical rod, and the other end of the horizontal bracket is connected to the large end of the radiator of the amplitude rod.

[0033] The beneficial effects of the present invention are:

[0034] The method of the present invention efficiently detects the cavitation resistance of metal samples. For different metal materials, the input and output operating parameters, such as driving voltage, acoustic vibration frequency, and reaction time, can be controlled through a combination of simulation and experimentation to achieve personalized adjustment of the reaction rate and intensity of the cavitation reaction on the sample surface. The cavitation resistance is then determined by detecting the microscopic surface morphology. This invention is a new, green, efficient, and controllable non-contact detection method that, to a certain extent, addresses the many drawbacks of traditional in-situ detection, such as long time consumption, limited processing scenarios, and uncontrollable processing effects.

[0035] The method uses the vibration of the end of the horn as the sound source. Simulating the sound pressure center obtained under a single-factor input, the spatial position of the reaction sample is designed to reflect the sound waves from the bottom and side walls of the reaction tank, creating different vibration modes in the sound field within the liquid. This ensures that the point where the ultrasonic wave has the highest energy in the water is consistent with the simulation results, ensuring that the end face with the strongest sound pressure covers the vicinity of the metal surface to be treated. By utilizing the acoustic resonance of the reaction tank, a low-power sound source is used to generate a concentrated sound field in a localized area of the water, thereby improving the efficiency of cavitation erosion of the sample surface. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] The present invention will be further described below with reference to the accompanying drawings and embodiments, in which:

[0037] Figure 1 is a flow chart of a method for testing metal anti-cavitation capability according to the present invention;

[0038] Figure 2 It is a structural diagram of the high-frequency cavitation reaction device used in the method of the present invention;

[0039] Figure 3 is the underwater sound field distribution cloud map of the maximum two groups of sound pressure levels at the driving voltage V0=350V in step S1 of the embodiment of the present invention;

[0040] Figure 4 is the surface morphology observation result of the four groups of samples in step S3 of the embodiment of the present invention;

[0041] Figure 5 It is a 3D contour diagram of the four groups of samples in step S3 of the embodiment of the present invention.

[0042] In the figure: 10, piezoelectric transducer; 11, mass block; 12, pre-tightening bolt; 13, piezoelectric ceramic;

[0043] 20. Horn;

[0044] 30. Reaction tank; 31. Solution;

[0045] 40. Test specimen;

[0046] 50. AC signal generator;

[0047] 60. Pallet;

[0048] 70. Fixed bracket; 71. Base; 72. Vertical rod; 73. Horizontal bracket. DETAILED DESCRIPTION

[0049] In order to have a clearer understanding of the technical features, purposes and effects of the present invention, specific embodiments of the present invention are now described in detail with reference to the accompanying drawings.

[0050] like Figure 1 As shown in FIG, it is a flow chart of a method for testing the metal anti-cavitation ability provided by the present invention, wherein the method uses a high-frequency cavitation reaction device to perform ultrasonic cavitation treatment on the sample. Figure 2 As shown, the high-frequency cavitation reaction device includes a piezoelectric transducer, a horn, a reaction cell, a sample, and an AC signal generator. The reaction cell contains a solution, and the sample is placed in the reaction cell. One end of the horn is placed in the solution, and the other end is connected to the piezoelectric transducer. The AC signal generator is connected to the two poles of the piezoelectric transducer. The AC signal generator is used to generate an AC signal with a certain frequency and waveform. The piezoelectric transducer is used to convert the input AC into mechanical vibration (i.e., ultrasonic waves of a certain frequency). The horn is used to amplify the vibration displacement of the ultrasonic waves, increasing the intensity of the ultrasonic waves, and finally outputting them into the solution in the reaction cell, thereby generating an acoustic field and a cavitation bubble field in the reaction cell. The horn facilitates stress concentration in specific reaction areas, causing accelerated damage and failure of the material surface. The solution is configured as an acidic or alkaline solution with different physical and chemical properties according to the different service environments of the metal material.

[0051] Specifically, the piezoelectric transducer includes a mass block, a pre-tightening bolt, and a piezoelectric ceramic. The piezoelectric ceramic is composed of several positive and negative stacked ceramic sheets. The pre-tightening bolts connect the mass block to the positive and negative stacked ceramic sheets from top to bottom, respectively, and finally the piezoelectric ceramic is fixedly contacted with the large end of the amplitude transformer. The mass block is used to seal the piezoelectric transducer, and the pre-tightening bolts are used to provide pre-tightening force for the piezoelectric ceramic. The two poles of the piezoelectric ceramic are connected to the positive and negative poles of the AC signal generator respectively, converting the electrical signal into an ultrasonic vibration signal. The piezoelectric ceramic is made of lead zirconium carbonate, and the mass block and pre-tightening bolts are both made of steel.

[0052] The high-frequency cavitation reaction device also includes a tray and a mounting bracket. The tray is suspended in the reaction tank by steel wires on both sides, and the Z-position of the sample is adjusted by pulling or lowering the steel wires. The surface of the tray is covered with a 1×1 cm grid, and the position of the sample in the XY plane is adjusted according to the grid. The mounting bracket includes a base, a vertical rod mounted on the base, and a horizontal bracket mounted on the vertical rod. A slide with a scale is provided on the base along the X direction, and a movable stud is provided in the slide. The bottom of the reaction tank is provided with a threaded hole adapted to the stud, and the reaction tank is fixed to the appropriate position of the base via the threaded stud. The horizontal bracket is used to install the piezoelectric transducer and amplitude transformer above the reaction tank. One end of the horizontal bracket is mounted on the vertical rod and can move along the vertical rod. The other end of the horizontal bracket is connected to the large end of the radiator of the amplitude transformer. The reaction tank is made of a transparent material.

[0053] To improve the efficiency of the cavitation sample surface, the method of the present invention first obtains the sound pressure center through simulation, thereby designing the spatial position of the sample in the high-frequency cavitation reaction device, so as to achieve the purpose of generating a concentrated sound field in a local area of water by a low-power sound source. Finally, the morphology of the sample after cavitation treatment is tested to further evaluate its cavitation resistance. Specifically, the method of testing the cavitation resistance of metals of the present invention includes the following steps:

[0054] S1. Using the COMSOL simulation platform, we conducted an acoustic-structural boundary modal analysis of the high-frequency cavitation reaction device between the variable-spoke rod and the reaction tank solution under a single parameter (i.e., driving voltage V0). The underwater distribution of the acoustic waves was obtained through pressure acoustic analysis. Specifically, this includes:

[0055] S1.1. Create a 1:1 model of the electric transducer, horn, and reaction tank in CATIA and import it into the COMSOL simulation platform. The solver used is eigenfrequency analysis. The coupled physical fields include solid mechanics, pressure acoustics, and piezoelectric effect. Set the driving voltage V0 of the piezoelectric transducer as a single parameter, set the minimum operating frequency f0min and maximum operating frequency f0max of the piezoelectric transducer, scan frequency θ∈f0min~f0max, and frequency step f0step. Then, scan the number of times to obtain the eigenfrequency. Perform pressure acoustic analysis at the Nth eigenfrequency. The purpose of this step is to find the optimal resonant frequency between the piezoelectric transducer and the horn under a certain driving voltage.

[0056] S1.2. Analyze the simulation results of the N-th sound field characteristic value to obtain the underwater sound field distribution cloud map of the maximum sound pressure level under the input of the driving voltage V0. The corresponding piezoelectric transducer acoustic vibration frequency is f and the sound pressure level is p.

[0057] S1.3. Calculate the hard point coordinates P (X, Y, Z) of the sound pressure center of the reaction zone using simulation software.

[0058] S2. According to the simulation results of S1, the working parameters of the high-frequency cavitation reaction device are set, and the sample is subjected to ultrasonic cavitation treatment in the high-frequency cavitation reaction device. Specifically including:

[0059] S2.1. Build a high-frequency cavitation reaction device, set the AC signal generator's drive voltage to V0, the AC wave frequency to F, and the processing time to t. The AC wave frequency F is calculated based on the acoustic vibration frequency f, which is specifically determined by the characteristic equations of the two elastic materials, the isotropic piezoelectric ceramic and the horn:

[0060]

[0061] Where ρ is the material density of the piezoelectric ceramic, ω is the angular frequency, f is the acoustic frequency, u is the structural displacement, and P is the bolt preload force. is the driving force of the piezoelectric ceramic to the horn, and F is the frequency of the AC wave.

[0062] S2.2. Adjust the coordinate position of the sample to be roughly consistent with the hard point coordinate P (X, Y, Z) of the sound pressure center simulated in step S1.

[0063] S2.3. Turn on the AC signal generator to perform ultrasonic cavitation treatment on the sample.

[0064] S3. Surface morphology test of the sample and evaluation of its cavitation resistance. Specifically including:

[0065] S3.1. Define the instantaneous cavitation power Pc based on the sound pressure level p and acoustic frequency f obtained in S1 and the processing time t in step S2. Define the instantaneous cavitation power Pc as:

[0066]

[0067] Where p is the sound pressure level, f is the acoustic frequency, t is the processing time, and θ is the correction coefficient.

[0068] S3.2. Obtain the 3D profile of the sample surface and obtain the surface integrity roughness coefficient Ra by observing the difference between the peak Rp and the valley Rv of the roughness. Compare it with the surface integrity roughness coefficient of the initial material to obtain the surface integrity factor σ n .

[0069] S3.3, with A c =σ n / P c As a control and judgment index of the sample's anti-cavitation ability, the smaller the Ac value, the more corrosion-resistant the metal is under a certain degree of cavitation and the better its anti-cavitation ability is.

[0070] The following describes the method for testing the metal anti-cavitation ability of the present invention through specific examples.

[0071] S1.1. Create a 1:1 model of the piezoelectric transducer, horn, and reaction tank in CATIA and import it into the COMSOL simulation platform. Figure 3 Set the driving voltage V0 of the piezoelectric transducer to 350V, set the minimum operating frequency f0min to 19kHz and the maximum operating frequency f0max to 21kHz, the scanning frequency θ∈19~21kHz, the frequency step f0step to 50Hz, and then scan the number of times to obtain the characteristic frequency times, and performed pressure acoustic analysis at 40 characteristic frequencies.

[0072] S1.2. Analyze the simulation results of 40 acoustic field characteristic values and obtain the underwater acoustic field distribution cloud map of the maximum two groups of sound pressure levels under the driving voltage V0 = 350V input, as shown in Figure 3 As shown in (a) and (b), the corresponding piezoelectric transducer acoustic vibration frequencies are f1 = 20 kHz, f2 = 19.85 kHz, and the sound pressure levels are p1 = 8.1 × 10 3 MPa, p2=8.4×10 3 The maximum sound pressure areas (i.e., the areas with the maximum cavitation intensity) under the two sets of acoustic vibration frequencies are distributed on the left and right wings of the central axis of the reaction tank.

[0073] S1.3. Calculate the hard point coordinates P1 (X1, Y1, Z1) and P2 (X2, Y2, Z2) of the sound pressure center of the reaction area using simulation software and output specific values.

[0074] S2. To better illustrate the method of the present invention, this embodiment processes three groups of samples of the same metal material. A high-frequency cavitation reaction device is built as required, and the operating parameters of the AC signal generator are set to:

[0075] For the first set of samples, the driving voltage V0 = 350 V, the AC wave frequency F1 = 50 Hz (corresponding to the acoustic vibration frequency f1 = 20 kHz), and the processing time t1 = 1 min were used. The sample was adjusted to P1 (X1, Y1, Z1) and the AC signal generator was activated.

[0076] The second set of samples: driving voltage V0 = 350V, AC wave frequency F2 = 100Hz (corresponding to acoustic vibration frequency f2 = 19.85kHz), processing time t2 = 1min; adjust the sample to P2 (X2, Y2, Z2) and start the AC signal generator;

[0077] The third group of samples: driving voltage V0 = 350 V, AC wave frequency F2 = 100 Hz (corresponding acoustic vibration frequency f2 = 19.85 kHz), processing time t3 = 5 min; adjust the sample to P2 (X2, Y2, Z2) and start the AC signal generator.

[0078] S3, Figure 4 In the figure, (a) is the original surface morphology observation result of the metal material, (b), (c), and (d) are the surface morphology observation results of the first, second, and third groups of samples after ultrasonic cavitation treatment, respectively. Figure 5 (a)-(d) correspond to the 3D profiles of the surfaces of the four groups of samples after ultrasonic cavitation treatment. The surface integrity factor σ after cavitation can be evaluated by observing the difference between the peak and valley of the roughness. The larger the σ, the better the sample is after a certain intensity of ultrasonic cavitation treatment. Figure 5 In (a), the more significant the decrease in the original surface roughness of the base material, the higher the degree of deterioration, and thus the more severe the cavitation degree of the metal.

[0079] In this embodiment, by Figure 5 (a) The surface integrity roughness coefficient of the initial material is obtained as Ra1 = Rp1 - Rv1 = 0.705609, and its surface integrity factor σ1 = 1; the other three groups of surface integrity factors are:

[0080]

[0081] In the above formula, Ran represents the surface integrity roughness coefficient, Ran = Rpn-Rvn, Rpn is the peak value, Rvn is the valley value, and n = 2, 3, 4.

[0082] Please continue to see Figure 3Under a certain driving voltage and acoustic vibration frequency, the sound field is distributed symmetrically around the axis of the horn. The sound pressure value in the water area along the axis is larger than that in other water areas. The sound pressure at the end of the horn is the largest relative to the surrounding sound pressure, and the sound pressure gradually decreases with the increase of the distance from the end face of the horn. The locations with large positive and negative phase sound pressure are mainly concentrated directly below the end of the horn, while in the water area outside the axis of the horn, the sound pressure value is greatly reduced, and the distribution of the sound field is uneven. Therefore, it is necessary to establish a generalized instantaneous cavitation power P c The transient equation is:

[0083]

[0084] Where p is the sound pressure level, f is the acoustic frequency, t is the processing time, and θ is the correction coefficient.

[0085] Finally, the control and judgment index A of the sample's anti-cavitation ability can be obtained c =σ n / P c , if A c The smaller the value, the more corrosion-resistant the metal is under a certain degree of cavitation and the better its cavitation resistance is.

[0086] In this embodiment, the surface integrity factor of the second group of samples is σ2=270%, and the instantaneous cavitation power P c =2.7Amm 2 / s, its A c =100%;

[0087] The surface integrity factor of the third group of samples is σ3 = 333%, and the instantaneous cavitation power P c =2.49Amm 2 / s, its A c =133.74%;

[0088] The surface integrity factor of the fourth group of samples is σ4 = 725%, and the instantaneous cavitation power P c =2.49Amm 2 / s, its A c =291.17%;

[0089] By comparison, it can be seen that the anti-cavitation ability of the three groups of samples is: the second group of samples > the third group of samples > the fourth group of samples.

[0090] The embodiments of the present invention are described above in conjunction with the accompanying drawings, but the present invention is not limited to the above-mentioned specific implementation methods. The above-mentioned specific implementation methods are merely illustrative and not restrictive. Under the guidance of the present invention, ordinary technicians in this field can also make many forms without departing from the scope of protection of the present invention and the claims, all of which are protected by the present invention.

Claims

1. A method for testing the cavitation resistance of metals, characterized in that: The sample is subjected to ultrasonic cavitation treatment using a high-frequency cavitation reaction device, which includes a piezoelectric transducer, a horn, a reaction cell, a sample, and an AC signal generator. The reaction cell is filled with a solution, the sample is placed in the reaction cell, one end of the horn is placed in the solution, and the other end is connected to the piezoelectric transducer. The AC signal generator is connected to the two poles of the piezoelectric transducer. The metal anti-cavitation ability testing method comprises the following steps: S1. Use the COMSOL simulation platform to perform acoustic-structural boundary modal analysis between the variable-spoke rod and the reaction tank solution of the high-frequency cavitation reaction device at a driving voltage V0. Through pressure acoustic analysis, the distribution of the sound wave underwater is obtained, and then the parameters and corresponding areas with the greatest cavitation severity are obtained; S2. Setting the working parameters of the high-frequency cavitation reaction device according to the simulation results of S1, adjusting the sample to the area where the cavitation intensity is the greatest, and performing ultrasonic cavitation treatment on the sample in the high-frequency cavitation reaction device; S3. Surface morphology test of the sample is performed, and the cavitation resistance is evaluated based on the relationship between cavitation power and roughness, including: S3.

1. Define the instantaneous cavitation power Pc based on the sound pressure level p and acoustic frequency f obtained in S1 and the processing time t in step S2; S3.

2. Obtain the 3D profile of the sample surface and obtain the surface integrity roughness coefficient Ra by observing the difference between the peak Rp and the valley Rv of the roughness. Compare it with the surface integrity roughness coefficient of the initial material to obtain the surface integrity factor σ n ; S3.3, with A c =σ n / P c As a control and judgment indicator of the sample's cavitation resistance, the smaller the Ac value, the more corrosion-resistant the metal is under a certain cavitation degree and the better its cavitation resistance is.

2. The method for testing the metal anti-cavitation ability according to claim 1, characterized in that: Step S1 specifically includes the following steps: S1.

1. Build the model of piezoelectric transducer, amplitude transformer, and reaction cell, and import them into COMSOL simulation platform; set the driving voltage V0 of the piezoelectric transducer as a single parameter, set the minimum operating frequency f0min and the maximum operating frequency f0max of the piezoelectric transducer, the scanning frequency θ∈f0min~f0max, the frequency step f0step, and the number of times the characteristic frequency is scanned. Perform pressure acoustic analysis at Nth eigenfrequency; S1.

2. Analyze the simulation results of the Nth acoustic field characteristic value to obtain the underwater acoustic field distribution cloud map of the maximum sound pressure level under the driving voltage V0 input. The corresponding piezoelectric transducer acoustic vibration frequency is f and the sound pressure level is p. S1.

3. Calculate the hard point coordinates P(X, Y, Z) of the sound pressure center of the reaction zone using simulation software.

3. The method for testing the metal anti-cavitation ability according to claim 2, characterized in that: Step S2 specifically includes the following steps: S2.

1. Build a high-frequency cavitation reaction device, set the AC signal generator's drive voltage to V0, the AC wave frequency to F, and the processing time to t; where the AC wave frequency F is derived from the acoustic vibration frequency f; S2.

2. Adjust the coordinate position of the specimen to be roughly consistent with the hard point coordinates P (X, Y, Z) of the sound pressure center simulated in step S1; S2.

3. Turn on the AC signal generator to perform ultrasonic cavitation treatment on the sample.

4. The method for testing the metal anti-cavitation ability according to claim 2, characterized in that: In step S2.2, the AC wave frequency F is calculated based on the acoustic vibration frequency f, which is specifically determined by the characteristic equations of the two elastic materials, the isotropic piezoelectric ceramic and the horn: Where ρ is the material density of the piezoelectric ceramic, ω is the angular frequency, f is the acoustic frequency, u is the structural displacement, and P is the bolt preload force. is the driving force of the piezoelectric ceramic to the horn, and F is the frequency of the AC wave.

5. The method for testing the metal anti-cavitation ability according to claim 3, characterized in that: In step S3.1, the instantaneous cavitation power Pc is: Where p is the sound pressure level, f is the acoustic frequency, t is the processing time, and θ is the correction coefficient.

6. The method for testing the metal anti-cavitation ability according to claim 1, characterized in that: The piezoelectric transducer includes a mass block, a pre-tightening bolt, and a piezoelectric ceramic. The piezoelectric ceramic is composed of several positive and negative stacked ceramic sheets. The pre-tightening bolt connects the mass block to the positive and negative stacked ceramic sheets from top to bottom, and finally the piezoelectric ceramic is fixedly contacted with the large end of the amplitude transformer. The mass block is used to seal the piezoelectric transducer, and the pre-tightening bolt is used to provide a pre-tightening force for the piezoelectric ceramic. The two poles of the piezoelectric ceramic are correspondingly connected to the positive and negative poles of the AC signal generator to convert the electrical signal into an ultrasonic vibration signal.

7. The method for testing the metal anti-cavitation ability according to claim 6, characterized in that: The piezoelectric ceramic is made of lead zirconium carbonate, and the mass block and the pre-tightening bolt are both made of steel.

8. The method for testing the metal anti-cavitation ability according to claim 1, characterized in that: The high-frequency cavitation reaction device also includes a tray, which is suspended in the reaction tank by steel wires on both sides, and the Z-direction position of the sample is adjusted by pulling up or lowering the steel wires; the surface of the tray is covered with a 1×1 cm grid, and the position of the sample in the XY plane is adjusted according to the grid.

9. The method for testing the metal anti-cavitation ability according to claim 8, characterized in that: The high-frequency cavitation reaction device also includes a mounting bracket, which includes a base, a vertical rod installed on the base, and a horizontal bracket installed on the vertical rod; a slide groove with a scale is provided on the base along the X direction, and a movable stud is provided in the slide groove. The bottom of the reaction pool is provided with a threaded hole adapted to the stud, and the reaction pool is fixed to a suitable position of the base through the threaded stud; the horizontal bracket is used to install the piezoelectric transducer and the amplitude rod above the reaction pool, one end of the horizontal bracket is sleeved on the vertical rod and can move along the vertical rod, and the other end of the horizontal bracket is connected to the large end of the radiator of the amplitude rod.

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