Material testing equipment and method under coupling action of erosion, cavitation erosion and corrosion

Abstract

The invention discloses equipment and a method for testing a material under the coupling action of erosion, cavitation erosion and corrosion. The equipment comprises a grinding fluid circulating unit, an ultrasonic generation unit, a multi-angle erosion generation unit and a reaction unit, based on the equipment, the abrasive type, concentration and pH value of abrasive liquid are adjusted according to corrosion and erosion test requirements, whether a circulating cooler is started or not is selected according to set reaction liquid temperature requirements, and when the circulating cooler needs to be started, the temperature is set for cooling; setting the amplitude and frequency of the ultrasonic controller according to cavitation erosion test requirements, and setting test duration; the control valve is used for adjusting the rotating speed of the grinding liquid pump according to the erosion test requirement, adjusting the jet velocity and regulating the nozzle with the required jet angle; the sample can be subjected to one or more coupling tests of cavitation erosion, erosion and corrosion. Compared with an existing scheme, the method is more practical, the cavitation erosion process of the material under the actual working condition can be better reflected, and a guarantee is provided for deeper development of hydraulic material test research.

Description

Technical Field

[0001] The invention belongs to the technical field of test equipment, and in particular relates to a material test device under multi-factor coupling, which can perform erosion, cavitation and corrosion tests on materials under different environmental parameters. Background Art

[0002] Hydropower facilities usually face serious problems of cavitation and sediment erosion. On the one hand, the turbines of hydropower stations face problems such as cavitation and sediment wear of flow components, which are mainly manifested in the continuous impact and cutting of solid particles with kinetic energy on the surface of flow components, causing the wear of solid particles on the flow components. At the same time, the cavitation bubbles formed by the fluid at low pressure break in the high pressure area, releasing huge energy and shock waves, causing cavitation damage to the surface of the flow components. When the multiphase flow contains media such as NaCl, cavitation, erosion and corrosion occur almost simultaneously. Under the joint action of cavitation (mechanical action), erosion (mechanical action) and corrosion (electrochemical action), the surface of the engineering components cannot fully resist the external force or environment to which they are exposed, resulting in more serious material degradation.

[0003] The application of coating materials is an effective and economical means to solve the problems of wear, cavitation and corrosion of flow-through parts such as turbines and water pumps in the hydraulic industry. A material cavitation test device under the coupling of multiple environmental factors is disclosed in the Chinese patent with publication number CN 117288664 A. The device consists of an ultrasonic vibrator, an air pump, a sample platform, a mobile platform and a constant temperature system. It can realize the cavitation test of environmental factors such as medium composition, temperature, and gas content during the material test, but can only realize cavitation and cavitation-corrosion experiments. An erosion wear test device disclosed in the Chinese patent with publication number CN 114965127A includes an erosion mechanism, a sample table and a scanning mechanism. The sample table is used to fix the sample to be tested. The erosion mechanism sprays the abrasive slurry used in the test toward the sample through its attached nozzle. The device can realize three-dimensional scanning erosion of the sample. However, this device cannot realize the coupling test of cavitation-erosion, and it is difficult to meet the detection needs of the hydraulic industry.

[0004] At present, the tests of erosion, cavitation and corrosion of coating materials are relatively limited. The cavitation resistance of coatings is tested by ultrasonic cavitation machines, and the erosion resistance of coatings is tested by erosion wear equipment, and cavitation-corrosion and erosion-corrosion tests are carried out by replacing the liquid medium. However, the tests of erosion-cavitation and erosion-cavitation-corrosion are difficult to implement and it is difficult to simulate the actual working conditions of the material structure. Summary of the invention

[0005] The purpose of the present invention is to overcome the shortcomings of the prior art and to seek to design a material testing device under the coupling of multiple environmental factors. By adjusting the medium components or components in the material testing process, one or more coupled tests of erosion, cavitation and corrosion of coating materials can be achieved, especially the simultaneous erosion-cavitation or erosion-cavitation-corrosion tests.

[0006] In order to achieve the above object, the technical solution adopted by the present invention is as follows:

[0007] A material testing device under the coupled action of erosion, cavitation and corrosion, comprising: a grinding liquid circulation unit, an ultrasonic generating unit, a multi-angle erosion generating unit and a reaction unit;

[0008] The reaction unit comprises a closed reaction chamber having a liquid inlet and a liquid outlet, wherein the liquid outlet is provided with a filter screen;

[0009] The ultrasonic generating unit is connected to the reaction chamber through a flange, and comprises an ultrasonic controller, an ultrasonic transducer, and an ultrasonic tool head which are connected in sequence. The ultrasonic controller and the ultrasonic transducer are arranged outside the reaction chamber, the ultrasonic tool head extends into the reaction chamber, and a sample to be tested is fixedly installed at the end of the ultrasonic tool head;

[0010] The grinding liquid circulation unit includes a grinding liquid tank, a circulation cooler, and an abrasive pump. The grinding liquid tank contains slurry abrasive or replaces the liquid medium according to the corrosion research needs. The grinding liquid tank, the circulation cooler, the abrasive pump, and the liquid inlet and outlet of the reaction chamber are connected through pipelines to form a grinding liquid circulation.

[0011] The multi-angle erosion generating unit comprises a multi-channel nozzle mounting platform for mounting a plurality of detachable Venturi nozzles, each Venturi nozzle forms a different angle with the sample to be tested, and each channel can be independently controlled.

[0012] Furthermore, the multi-channel nozzle mounting platform is fixedly installed at the liquid inlet end of the reaction chamber, and has multiple independent flow channels therein, each flow channel is connected to the grinding liquid circulation unit through an external pipeline, and a control device corresponding to the flow channel is provided on the external pipeline; the multi-channel nozzle mounting platform has multiple angle surfaces, each angle surface corresponds to an independent flow channel, and a detachable Venturi nozzle is installed at the end of the independent flow channel on each of the surfaces.

[0013] Furthermore, the control device includes a flow meter and a nozzle control valve installed on the external pipeline of the corresponding flow channel.

[0014] Furthermore, different venturi nozzles form different angles with the test sample, and at least three angles are formed, including 30°, 60°, and 90°.

[0015] Furthermore, a grinding liquid agitator and a baffle are provided in the grinding liquid tank. The grinding liquid agitator has blades, which move to prevent the slurry abrasive from depositing. The baffle is fixed to the bottom of the grinding liquid tank.

[0016] Furthermore, the abrasive pump includes a grinding liquid delivery pump and a grinding liquid reflux pump. The grinding liquid tank outlet is connected to the cooling inlet of the circulating cooler through a pipeline. The cooling outlet of the circulating cooler is connected to the inlet of the grinding liquid delivery pump. The grinding liquid delivery pump outlet is connected to the liquid inlet end of the reaction chamber through a pipeline. A flow meter is provided on the pipeline. The liquid outlet of the reaction chamber is connected to the grinding liquid tank inlet through the reflux grinding liquid pump.

[0017] Furthermore, the ultrasonic controller is connected to the ultrasonic transducer via a signal line, the ultrasonic tool head is connected to the ultrasonic transducer via a thread, and the sample to be tested is connected to the end of the ultrasonic tool head via a thread.

[0018] A material testing method under the coupled effects of erosion, cavitation and corrosion is implemented based on the equipment as described in any of the above items. Abrasive liquid is added, and the abrasive type, concentration and pH of the abrasive liquid are adjusted according to the requirements of corrosion and erosion tests. Whether to turn on the circulating cooler is selected according to the set reaction liquid temperature requirements. When it needs to be turned on, the temperature is set for cooling; the amplitude and frequency of the ultrasonic controller are set according to the requirements of the cavitation test, and the test duration is set; the speed of the abrasive liquid pump is adjusted to adjust the jet speed according to the requirements of the erosion test, and the control valve of the nozzle of the required injection angle is adjusted; one or more coupled tests of cavitation, erosion and corrosion can be performed on the sample.

[0019] Compared with the cavitation and erosion test device under the action of a single factor in the prior art, the main test part of the present invention includes a grinding fluid circulation unit, an ultrasonic generating unit, a multi-angle erosion generating unit and a reaction unit. The cooperation of multiple units can realize different tests of materials under different erosion, cavitation, erosion-corrosion, erosion-cavitation, cavitation-corrosion and erosion-cavitation-corrosion. The simulated multi-factor coupling environment is more in line with the actual working conditions and can better reflect the cavitation process of the material under actual working conditions, providing a guarantee for more in-depth hydraulic material test research and solving the problem of single variables in conventional equipment.

[0020] The ultrasound in the ultrasonic generating unit of the present invention is indirectly introduced. Compared with the direct introduction of the existing cavitation equipment, it avoids the wear of the sample due to direct contact and reduces the damage to the sample. At the same time, compared with direct ultrasound, it has a more uniform energy distribution, and the distribution of the cavitation area on the surface of the sample is more uniform, which is more in line with the situation of cavitation on the surface of the material in the actual cavitation environment. In addition, the erosion generating unit of the present invention is provided with multiple angle nozzles, which can realize the simultaneous action of multi-angle jets on the surface of the material, and can more comprehensively simulate the erosion scene of the surface of the material in a complex jet environment. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 It is a schematic diagram of the main structure of a specific example of the test equipment of the present invention. DETAILED DESCRIPTION

[0022] The technical solution of the present invention is further described in detail below through implementation examples and in conjunction with the accompanying drawings.

[0023] Embodiment 1:

[0024] The main structure of the material testing equipment under the coupled action of erosion, cavitation and corrosion involved in this embodiment includes a grinding fluid circulation unit, an ultrasonic generating unit, a multi-angle erosion generating unit and a reaction unit; wherein the ultrasonic generating unit is mainly used as a cavitation mechanism, and is a device for simulating cavitation on the surface of the sample, and mainly includes an ultrasonic controller, an ultrasonic transducer and a tool head. The multi-angle erosion generating unit is a device for eroding and wearing the surface of the sample, which needs to work together with the grinding fluid circulation unit. The grinding fluid impacts the sample surface through the nozzle through the circulation pipeline. The nozzle is a Venturi structure and is installed in the reaction chamber through a multi-channel nozzle mounting table. The nozzle corresponding to each channel forms a different angle with the sample surface and has an independent control valve. Cavitation, erosion and cavitation-erosion coupling tests can be realized by switching the ultrasonic controller and the control valve. The liquid medium in the grinding fluid circulation unit can be adjusted according to the needs of the corrosion test, so as to realize the introduction of corrosion phenomena.

[0025] According to a specific example of the present invention, Figure 1 As shown, the test equipment includes: an ultrasonic transducer 1, an ultrasonic controller 2, an ultrasonic tool head 3, a sample 4, a 60° Venturi nozzle 5, a 90° Venturi nozzle 6, a 30° Venturi nozzle 7, a 60° nozzle control valve 8, a 90° nozzle control valve 9, a first flow meter 10, a second flow meter 11, a 30° nozzle control valve 12, a third flow meter 13, a grinding liquid delivery pump 14, a circulating cooler 15, a fourth flow meter 16, a baffle 17, a grinding liquid agitator 18, a filter 19, a stirring motor 20, a reflux grinding liquid pump 21, and a reaction chamber 22.

[0026] The top of the reaction chamber 22 is connected to the flange of the ultrasonic generating device, and the right end is connected to the filter 19. The filter outlet is connected to the return liquid pipe. A 30° Venturi nozzle 7, a 60° Venturi nozzle 5 and a 90° Venturi nozzle 6 are provided at the lower end of the reaction chamber. Each nozzle is fixedly installed at the liquid inlet end of the reaction chamber through a multi-channel nozzle mounting platform. The multi-channel nozzle mounting platform has multiple independent flow channels, each of which is connected to the grinding liquid circulation unit through an external pipeline. The external pipeline is provided with a control device corresponding to the flow channel, namely a flow meter and a nozzle control valve; the multi-channel nozzle mounting platform has a plurality of angle surfaces, each of which corresponds to an independent flow channel, and a detachable Venturi nozzle is installed at the end of the independent flow channel on each of the surfaces. In this example, there are three independent flow channels, corresponding to the 30° Venturi nozzle 7, the 60° Venturi nozzle 5 and the 90° Venturi nozzle 6, respectively. The inner nozzle 5 and the 90° Venturi nozzle 6, further, the 30° Venturi nozzle 7 is provided with a control valve 12 and a third flowmeter 13 at the liquid inlet section, the 60° Venturi nozzle 5 is provided with a control valve 8 and a first flowmeter 10 at the front end, and the 90° Venturi nozzle 6 is provided with a control valve 9 and a second flowmeter 11 at the front end; the grinding liquid circulation unit is composed of a grinding liquid tank, a circulating cooler, a grinding liquid delivery pump and a reflux grinding liquid pump, the side of the circulating cooler 15 is provided with a coolant outlet and a coolant inlet, the grinding liquid tank outlet is connected to the coolant inlet, and the coolant outlet is connected to the inlet of the grinding liquid delivery pump 14; the grinding liquid delivery pump 14 outlet is connected to the liquid inlet section of each flow channel nozzle, and a fourth flowmeter 16 is provided at the outlet of the grinding liquid delivery pump; the reaction chamber is connected to the grinding liquid tank through an external reflux pipe, and the grinding liquid is recycled to avoid waste and environmental pollution. This device adopts slurry abrasives and a grinding liquid pump as the output power. By adjusting the rotation speed, a wide range of jet velocity can be controlled, which is conducive to the simulation and detection of specific service conditions. Furthermore, the grinding liquid tank prevents abrasive deposition by the movement of the blades of the grinding liquid agitator, and the slurry circulated by the grinding liquid pump is cooled by the circulating cooler to achieve precise control of the temperature. The grinding liquid tank is also provided with a baffle fixed to the bottom of the grinding liquid tank. The high-speed rotation of the blades causes the liquid to produce vortices of varying degrees. The placement of the baffle will reduce the high-speed flow of the liquid caused by the rotation of the blades, and can effectively prevent the generation of vortices. The baffle produces local losses through boundary mutations, which makes it play a role. The huge velocity gradient of the interface produces strong turbulence, so that the effective energy of the mainstream part is continuously dissipated through momentum exchange. Furthermore, the grinding liquid tank and the nozzle are both externally connected to a pressure gauge to display the slurry flow rate, and the slurry flow rate can be controlled by adjusting the grinding liquid pump power. The ultrasonic controller 2 is connected to the ultrasonic transducer 1 through a signal line, and the ultrasonic tool head 3 is connected to the ultrasonic transducer 1 through a thread. The tool head extends into the reaction chamber, and the sample 4 is connected to the bottom of the ultrasonic tool head 3 through a thread.

[0027] The specific process steps of using the material cavitation test device under the coupling of multiple environmental factors involved in this embodiment can be as follows:

[0028] First, clean the sample, polish the oxide layer on the surface of the sample, and perform ultrasonic cleaning;

[0029] Laying out the specimen, and connecting the ultrasonically cleaned specimen to the ultrasonic tool head;

[0030] The ultrasonic controller 2 is connected to the ultrasonic transducer 1 through a signal line, the ultrasonic tool head 3 is connected to the ultrasonic transducer 1 through a thread, the sample 4 is connected to the bottom of the ultrasonic tool head 3 through a thread, and the assembled ultrasonic device is fixed to the reaction chamber 22 through a nut, and its sealing is checked at the same time;

[0031] Then, add the abrasive liquid, and adjust the abrasive type, concentration and pH of the abrasive liquid according to the relevant test requirements. Pour the required test liquid into the abrasive supply mechanism, turn on the stirring motor 20 at the same time, and choose whether to turn on the circulating cooler 15 according to the set reaction liquid temperature requirements. If it needs to be turned on, turn on the power and set the temperature for cooling;

[0032] Finally, the test is carried out, the driving power is turned on, the amplitude and frequency of the ultrasonic controller 2 are set according to the cavitation intensity required by the test, the test duration is set, the speed of the grinding liquid pump 14 is adjusted to adjust the jet speed, the control valve of the nozzle corresponding to the injection angle is opened, and the sample test is started.

[0033] The above description is only part of the preferred embodiments of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A material testing device under the coupled action of erosion, cavitation and corrosion, characterized in that: include: Grinding liquid circulation unit, ultrasonic generating unit, multi-angle erosion generating unit and reaction unit; The reaction unit comprises a closed reaction chamber having a liquid inlet and a liquid outlet, wherein the liquid outlet is provided with a filter screen; The ultrasonic generating unit is connected to the reaction chamber through a flange, and comprises an ultrasonic controller, an ultrasonic transducer, and an ultrasonic tool head which are connected in sequence. The ultrasonic controller and the ultrasonic transducer are arranged outside the reaction chamber, the ultrasonic tool head extends into the reaction chamber, and a sample to be tested is fixedly installed at the end of the ultrasonic tool head; The grinding liquid circulation unit includes a grinding liquid tank, a circulation cooler, and an abrasive pump. The grinding liquid tank contains slurry abrasive or replaces the liquid medium according to the corrosion research needs. The grinding liquid tank, the circulation cooler, the abrasive pump, and the liquid inlet and outlet of the reaction chamber are connected through pipelines to form a grinding liquid circulation. The multi-angle erosion generating unit comprises a multi-channel nozzle mounting platform for mounting a plurality of detachable Venturi nozzles, each Venturi nozzle forms a different angle with the sample to be tested, and each channel can be independently controlled.

2. The material testing equipment under the coupled action of erosion, cavitation and corrosion according to claim 1, characterized in that: The multi-channel nozzle mounting platform is fixedly installed at the liquid inlet end of the reaction chamber, and has multiple independent flow channels therein. Each flow channel is connected to the grinding liquid circulation unit through an external pipeline, and a control device corresponding to the flow channel is provided on the external pipeline; the multi-channel nozzle mounting platform has multiple angle surfaces, each angle surface corresponds to an independent flow channel, and a detachable Venturi nozzle is installed at the end of the independent flow channel on each of the surfaces.

3. The material testing equipment under the coupled action of erosion, cavitation and corrosion according to claim 2, characterized in that: The control device comprises a flow meter and a nozzle control valve which are installed on the external pipeline of the corresponding flow channel.

4. The material testing equipment under the coupled effects of erosion, cavitation and corrosion according to claim 2, characterized in that: Different venturi nozzles form different angles with the test sample, and at least three angles are formed, including 30°, 60°, and 90°.

5. The material testing equipment under the coupled effects of erosion, cavitation and corrosion according to claim 1, characterized in that: The grinding liquid tank is provided with a grinding liquid agitator and a baffle. The grinding liquid agitator has blades, which move to prevent the slurry abrasive from depositing. The baffle is fixed to the bottom of the grinding liquid tank.

6. The material testing equipment under the coupled action of erosion, cavitation and corrosion according to claim 1, characterized in that: The abrasive pump comprises a grinding liquid delivery pump and a grinding liquid reflux pump. The grinding liquid tank outlet is connected to the cooling inlet of the circulating cooler through a pipeline. The cooling outlet of the circulating cooler is connected to the inlet of the grinding liquid delivery pump. The grinding liquid delivery pump outlet is connected to the liquid inlet end of the reaction chamber through a pipeline. A flow meter is provided on the pipeline. The liquid outlet of the reaction chamber is connected to the grinding liquid tank inlet through the reflux grinding liquid pump.

7. The material testing equipment under the coupled effects of erosion, cavitation and corrosion according to claim 1, characterized in that: The ultrasonic controller is connected to the ultrasonic transducer via a signal line, the ultrasonic tool head is connected to the ultrasonic transducer via a thread, and the sample to be tested is connected to the end of the ultrasonic tool head via a thread.

8. A material testing method under the coupled effects of erosion, cavitation and corrosion, characterized in that: Based on the equipment as described in any one of claims 1 to 7, by adding abrasive liquid, adjusting the abrasive type, concentration and pH of the abrasive liquid according to the requirements of corrosion and erosion tests, choosing whether to turn on the circulating cooler according to the set reaction liquid temperature requirements, and setting the temperature for cooling when it needs to be turned on; setting the amplitude and frequency of the ultrasonic controller according to the requirements of the cavitation test, and setting the test duration; adjusting the speed of the abrasive liquid pump to adjust the jet speed and regulating the control valve of the nozzle of the required injection angle according to the requirements of the erosion test; and performing one or more coupled tests of cavitation, erosion and corrosion on the sample.

Images