CN203287249U - High temperature and high pressure sound emission electrochemical simulation experiment set capable of loading stress - Google Patents

Abstract

The utility model provides a high temperature and high pressure sound emission electrochemical simulation experiment set capable of loading stress. The simulation experiment set comprises a pressure reactor, stretching test systems, a solution cyclic inflation system, sound emission probes, an electrochemical test system and a data collector, wherein the pressure reactor is provided with an inner chamber; a test piece is arranged in the inner chamber; the stretching test systems are mounted at two ends of the test piece, and are used for stretching the test piece and testing and acquiring the pulling force and a strain signal of the test piece; the solution cyclic inflation system is connected with the inner chamber of the pressure reactor, and provides solution required in experiment for the pressure reactor; the sound emission probes are arranged at two ends of the test piece; and are used for testing an acoustical signal of the test piece; the electrochemical test system is connected with the test piece and the pressure reactor, and are used for applying the polarization current on the test piece to polarize and testing and acquiring an electrochemical signal; the data collector is used for collecting the pulling force, the strain signal, the electrochemical signal and the sound emission signal, that are measured at the same time. The set can carry out the controllable supercharging, controllable heating and controllable inflation, and simulates the practical working state of material on sites well.

Description

High temperature and high pressure acoustic emission electrochemical simulation experiment device capable of loading stress

technical field

The utility model relates to the technical field of non-destructive testing, in particular to a high-temperature and high-pressure acoustic emission electrochemical simulation experiment device capable of loading stress.

Background technique

Equipment pipelines in petroleum, petrochemical, nuclear industry, electric power and other industrial fields have been used in high temperature, high pressure, and multi-corrosive medium environments for a long time. Electrochemical corrosion and stress corrosion cracking (SCC) of equipment pipelines are the main causes of damage. Thin, perforated, cracked, ruptured, etc. may cause leakage of toxic, high temperature, flammable, explosive, and radiative media, which in turn may cause fire and explosion, environmental pollution, casualties, property damage, and other accidents, seriously threatening the safe production of enterprises.

As the main means of corrosion research, electrochemical technology has formed a relatively complete system in terms of corrosion, crack formation mechanism, monitoring and detection, control and protection after more than two hundred years of development. Acoustic emission (AE) detection is a non-destructive detection technology for defect location and quantification based on the acoustic emission characteristics of corrosion and cracks. Because it can realize continuous, on-line, in-situ, non-destructive and rapid detection, it has been widely used in equipment and pipeline corrosion in recent years. It has been widely used in crack detection. However, due to the fact that the relationship between the acoustic emission signal and the electrochemical corrosion rate and the relationship between the acoustic emission signal and the electrochemical signal are not thorough in the actual working conditions, and there are many characteristic parameters of the acoustic emission, there is a lack of uniform standards when characterizing the signal characteristics. limits the application of acoustic emission in corrosion and crack monitoring. Studying the corresponding relationship between acoustic emission signals and electrochemical corrosion processes under actual high temperature, high pressure, and stress is the basis for the application of acoustic emission to monitor electrochemical corrosion and stress corrosion cracking processes. However, there is no research on acoustic emission signals under high temperature, high pressure, and stress. Systematic study of the correspondence between emission signals and electrochemical corrosion processes.

Known technologies such as electrode potential testing, electrochemical noise, electrochemical impedance, and polarization curves in electrochemistry are relatively mature in monitoring and explaining corrosion crack phenomena such as uniform corrosion, pitting corrosion, passive film destruction, crack initiation, and crack growth. theory. However, the research on the relationship between the acoustic emission signal and the electrochemical corrosion rate and the relationship between the acoustic emission signal and the electrochemical signal under the actual production conditions (high temperature, high pressure, stress) environment is relatively scarce, which seriously limits the application of acoustic emission in corrosion and corrosion. The reason for the application of crack monitoring is that there is currently a lack of experimental devices that can simulate the high temperature, high pressure, and stress corrosion environments that materials are subjected to under actual working conditions and simultaneously perform acoustic emission testing and electrochemical testing.

Utility model content

The utility model provides a high-temperature and high-pressure acoustic emission electrochemical simulation experiment device capable of loading stress to solve the relationship between the acoustic emission signal and the electrochemical corrosion rate that cannot be obtained under actual production conditions (high temperature, high pressure, and stress). The problem.

For this reason, the utility model proposes a high-temperature and high-pressure acoustic emission electrochemical simulation experiment device capable of loading stress, and the high-temperature and high-pressure acoustic emission electrochemical simulation experiment device capable of loading stress includes:

An autoclave, the autoclave has an inner cavity, and a test piece is arranged in the inner cavity;

A tensile testing system installed at both ends of the test piece;

A solution circulation inflation system is connected with the inner chamber of the autoclave;

Acoustic emission probes are arranged at both ends of the test piece;

An electrochemical testing system is connected with the test piece and the autoclave;

The data collector is connected with the tensile test system, the solution circulation gas system, the acoustic emission probe and the electrochemical test system.

Further, the stress-loading high temperature and high pressure acoustic emission electrochemical simulation experiment device further includes: a computer connected to a data collector, and the computer is connected to the tensile testing system.

Further, the autoclave includes: a kettle body and a kettle cover arranged on the kettle body, the kettle cover is provided with an installation hole for installing the test piece, and the installation hole is provided with a sealing The test piece sealing ring of the kettle cover and the gland pressed against the test piece sealing ring, the tensile test system includes: clamping clamps at both ends of the test piece, the clamps are connected to the test piece through the lining The inner lining of the kettle body, the kettle lid, the gland, the test piece sealing ring, and the chuck are all made of glass fiber reinforced plastics.

Further, the acoustic emission probe is in contact with the end surface of the test piece through a coupling agent.

Further, the tensile testing system further includes: a motor connected to the chuck; a servo controller connected to the motor and the computer.

Further, the electrochemical test system includes: a working electrode, an auxiliary electrode and a silver/silver chloride reference electrode connected to the autoclave, and the working electrode is the test piece.

Further, the two ends of the test piece are respectively provided with test piece heads which are threadedly connected with the test piece, and the test piece heads are sleeved on the two ends of the test piece, and the chuck clamps the test piece The piece head holds the test piece.

Further, the acoustic emission probe is sheathed in a plastic threaded ring and installed on the tensile testing system.

Further, the temperature of the solution that the solution circulation aeration system supplies to the autoclave required for the experiment is 20-150° C. and the pressure is 1-16 MPa.

Further, the tensile testing system further includes: a gear pair connected to the motor, and the tensile testing system controls the movement of the gear pair through the motor.

The beneficial effects of the utility model are:

1. The utility model can measure the acoustic emission signal and the electrochemical signal at the same time. When corrosion and cracks appear, the acoustic emission signal and the electrochemical signal collected synchronously can be compared and studied, and the correlation between the acoustic emission signal and the corrosion rate, corrosion rate and corrosion rate can be extracted. Corresponding characteristic parameters such as type and crack growth can promote the research of acoustic emission technology.

2. In the utility model, all parts that may be in contact with the test piece are made of glass fiber reinforced plastics. Under the premise of ensuring the required compressive strength, the good insulation of glass steel is used to avoid the electrical conduction of the test piece and other metal parts from affecting the electrochemical The accuracy of the test data.

3. The utility model can carry out controllable pressurization, controllable heating, and controllable inflation, which better simulates the actual working state of the on-site materials. At the same time, the test piece can be stretched through the drive of the motor to simulate the actual stress conditions of the on-site materials, and The device has the function of anti-explosion and can effectively realize the collection of liquid and the harmless discharge of gas.

4. The design of the test piece and the clamping mechanism is practical. To change the test piece, you only need to loosen the chuck tightening mechanism and lift the upper fixture to replace the sample conveniently. The reproducibility of the experimental results can be guaranteed by processing the standard test piece. At the same time, the two ends of the specimen are in direct contact with the high-temperature acoustic emission probe through the couplant, which avoids the attenuation of the acoustic emission signal through the interface (thread or waveguide rod), and can use the time-difference line positioning technology to locate the location of corrosion and cracks.

5. The utility model can also add stress during the simultaneous measurement of acoustic emission signals and electrochemical signals, and obtain the relationship with stress loading. In addition, the utility model can also perform tests under high temperature and high pressure environment while simultaneously measuring acoustic emission signals and electrochemical signals and loading, and obtain various comprehensive test parameters at the same time, which is very close to the working environment of an oil refinery.

Description of drawings

Fig. 1a is a schematic diagram of the front view of the autoclave according to an embodiment of the present invention;

Fig. 1b is a schematic cross-sectional structure diagram of an autoclave according to an embodiment of the present invention, wherein the reference electrode and the pressure gauge are removed;

Fig. 1c is a top view structure schematic diagram of the lid of the autoclave according to the embodiment of the present invention;

Fig. 2 is the front view structure of the test piece according to the utility model embodiment;

Fig. 3a is a front structural schematic diagram of a clamping mechanism according to an embodiment of the present invention;

Fig. 3b is a schematic side view of the clamping mechanism according to an embodiment of the present invention;

Fig. 3c is a schematic top view of the clamping mechanism according to an embodiment of the present invention;

Figure 3d is a schematic diagram of the A-A cross-sectional structure of the clamping mechanism in Figure 3c, wherein, for the convenience of comparison, the test piece and the test piece head are not drawn with section lines;

Fig. 4a is a schematic top view of the connecting plate of the second fixture according to an embodiment of the present invention;

Fig. 4b is the front view structure of the tensile testing system according to the embodiment of the present invention;

Fig. 5 shows the overall structure and working principle of the stress-loaded high temperature and high pressure acoustic emission electrochemical simulation experiment device according to the embodiment of the present invention.

Explanation of reference numbers:

1. Kettle body, 2. Kettle cover, 3. FRP gland, 4. Test piece sealing ring, 5. Test piece, 6. Kettle cover sealing ring, 7. Auxiliary electrode, 8. Ag/AgCl reference electrode, 9 .Pressure gauge, 10. Liquid inlet, 11. Safety valve interface, 12. Liquid outlet, 201. Test piece head, 301. Probe plastic thread ring, 302. Chuck, 303. Chuck lining, 304. Clip Head tightening mechanism, 305. Chuck hanger, 306. First fixture connecting plate, 307. Acoustic emission probe, 401. Second fixture connecting plate, 402. Connecting screw, 403. Displacement indicator, 404. Tension sensor, 405 .Laser displacement sensor, 501. Liquid storage tank, 502. Suction pump, 503. Heater, 504. Thermometer, 505. Booster pump, 506. Cooler, 507. Alkaline cleaning tank, 508. Gear pair, 509. Motor, 510. Servo controller, 511. Data collector, 40 tensile testing system, 408 pull rod, 600 computer

Detailed ways

In order to have a clearer understanding of the technical features, purposes and effects of the utility model, the specific implementation of the utility model is now described with reference to the accompanying drawings.

As shown in Figure 5, the high temperature and high pressure acoustic emission electrochemical simulation experiment device capable of loading stress according to the embodiment of the present utility model includes:

An autoclave, the autoclave has an inner cavity, and a test piece 5 is arranged in the inner cavity. The autoclave uses high-temperature-resistant glass fiber reinforced plastics with high strength, corrosion resistance, light weight, electrical insulation, and low thermal conductivity, and can be heated at 150 ° C. The following long-term use can not only meet the strength requirements of high-voltage resistance, but also realize the electrical insulation between the test piece and the surrounding connectors, and ensure the accuracy of the electrochemical test. The kettle body 1 and the kettle cover 2 are connected by flanges, and are sealed by the kettle cover sealing ring 6, which is convenient for indoor installation and disassembly. The bottom of the kettle and the lid of the kettle have installation holes, and the test specimen 5 is installed in the hole position, and the two ends are equipped with glass fiber reinforced plastic glands 3 and specimen sealing rings 4 to realize sealing, and the two ends of the specimen are tapped with external threads to connect with the specimen head 201 . An auxiliary electrode 7, an Ag/AgCl reference electrode 8, a pressure gauge 9, a safety valve interface 11, and a liquid outlet 12 are installed on the lid 2 of the kettle, and a liquid inlet 10 is installed on the kettle body 1; a liquid inlet pipeline is arranged at the bottom of the kettle. The lid of the kettle has a co-flow pipeline, which can realize pressure;

Tensile testing system 40, as shown in Fig. 4a and 4b, is installed at the two ends of described test piece 5, stretches bar-shaped test piece 5, tests and obtains the tensile force and the strain signal of described test piece, and tensile testing system can comprise Stretch parts for stretching and sensors to reflect tension and strain signals;

A solution circulation inflation system, connected to the inner cavity of the autoclave, provides the autoclave with the solution required for the experiment to simulate various on-site environments, such as simulating the corrosive environment of an oil refinery;

Acoustic emission probes 307, as shown in Figures 3a, 3b, 3c and 3d, also known as acoustic emission sensors, are arranged at both ends of the test piece 5 to test the acoustic signal of the test piece;

The electrochemical test system is connected to the pressure vessel, applies a polarization current to the test piece to polarize and test and obtain electrochemical signals, and can carry out tests such as electrode potential, electrochemical noise, electrochemical impedance, and polarization curves , to detect electrochemical signals of corrosion crack phenomena such as uniform corrosion, pitting corrosion, passivation film destruction, crack initiation, and crack growth;

The data collector 511 is connected with the tensile test system, the acoustic emission probe 307 and the electrochemical test system, and collects simultaneously measured tensile force and strain signals, electrochemical signals and acoustic emission signals.

The utility model can measure acoustic emission signals and electrochemical signals at the same time. When corrosion and cracks occur, the acoustic emission signals and electrochemical signals collected synchronously can be compared and studied, and the acoustic emission signals related to corrosion speed, corrosion type, Corresponding characteristic parameters such as crack growth can promote the research of acoustic emission technology. In addition, in the process of simultaneously measuring the acoustic emission signal and the electrochemical signal, stress can be added to obtain a relationship with stress loading.

Further, as shown in Figure 5, the high temperature and high pressure acoustic emission electrochemical simulation experiment device capable of loading stress also includes: a computer 600 connected to the data collector 511, and the computer 600 is connected to the tensile testing system, so The computer 600 controls the tensile test system to stretch the specimen according to the tension and strain signals obtained by the data collector 511 . In addition to the acoustic emission test and electrochemical test, the test piece can be flexibly loaded according to the site environment to obtain more test parameters.

Further, as shown in Fig. 1a, Fig. 1b and Fig. 1c, the pressure kettle includes: a kettle body 1 and a kettle cover 2 arranged on the kettle body 1, the kettle body 1 has an open cavity, and the kettle body Cover 2 is covered on the opening, and kettle cover 2 is provided with the installation hole (not shown) that described test piece is installed on, and described installation hole is provided with the test piece sealing ring 4 that seals described kettle cover, and resists Press the gland 3 on the test piece sealing ring 4 so that after the test piece 5 is installed, the autoclave can keep sealed. The tensile testing system includes: chucks 302 clamping the two ends of the test piece, the chucks are in contact with the test piece 5 through the lining 303, the kettle body 1, the kettle cover 2, the The gland 3, the test piece sealing ring 4, and the lining of the chuck 302 are all made of glass fiber reinforced plastics. Under the premise of ensuring the required compressive strength, the good insulation of FRP is used to avoid the electrical conduction of the test piece and other metal parts from affecting the accuracy of the electrochemical test data.

Further, the acoustic emission probe is in contact with the end face of the test piece through a coupling agent, such as vaseline paste, which avoids the attenuation of the acoustic emission signal through the interface (thread or waveguide rod), and can use time-difference positioning technology to locate corrosion and crack occurrence sites.

Further, as shown in FIG. 5 , the tensile testing system also includes: a motor 509 connected to the chuck through a transmission device; a servo controller 510 connected to the motor 509 and the computer 600, and the computer obtains the The tension and strain signals are used to control the servo controller 510, thereby controlling the start-stop and rotation speed of the motor 509, and controlling the stretching or loading of the test piece, which can realize flexible and convenient loading.

Further, as shown in Fig. 1a, Fig. 1b and Fig. 1c, the electrochemical test system includes: a working electrode connected to the lid 2 of the autoclave, an auxiliary electrode 7 and a silver/silver chloride reference electrode 8 (Ag/AgCl reference electrode, suitable for high temperature and high pressure), the working electrode is the test piece 5. In this way, tests such as electrode potential, electrochemical noise, electrochemical impedance, and polarization curve can be carried out effectively, and electrochemical signals of corrosion crack phenomena such as uniform corrosion, pitting corrosion, passive film destruction, crack initiation, and crack growth can be detected.

Further, as shown in Figure 2, the two ends of the test piece 5 are respectively provided with a test piece head 201 which is threadedly connected with the said test piece, the test piece head 201 is a nut for example, and the said test piece head 201 is sleeved on the At both ends of the test piece, as shown in FIG. 3 d , the chuck 302 clamps the test piece by clamping the test piece head 201 . The test piece 5 can be a standard piece, which can ensure the reproducibility of the experimental results. To replace the test piece, you only need to loosen the chuck tightening mechanism, and lift the upper fixture to replace it conveniently.

Further, as shown in Figure 3d, the acoustic emission probe 307 (acoustic emission sensor) is sleeved in a plastic threaded ring 301 and installed on the tensile testing system, for example, as shown in Figures 3a and 3b, the plastic threaded ring 301 Installed on the first clamp connection plate 306 . The acoustic emission probe 307 can test the acoustic signal of corrosion cracks to extract characteristic parameters, and can use time-difference line positioning technology to locate corrosion and crack occurrence sites. The first clamp connecting plate 306 is connected to the clamp 302 through the clamp hanger 305, and the clamp hanger 305 can be a bolt, which plays the role of connecting.

Further, the temperature of the solution circulation and aeration system to provide the solution required for the experiment to the autoclave is from normal temperature to 150° C., and the pressure is from normal pressure to 16 MPa. The solution circulation inflation system pumps the liquid in the liquid storage tank 501 to the autoclave or pressure kettle 1 by the pump 502, and heats it through the heater 503 with a thermometer 504 for temperature measurement and temperature control to simulate the actual working condition medium temperature. When the pressure kettle 1 is full of liquid, it can flow to the liquid storage tank 501 through the co-flow pipeline, close the valve of the liquid storage tank and the co-flow valve, pressurize it by the booster pump 505, and control the pressure in the pressure kettle according to the pressure gauge 9 When the required pressure is reached, the booster pump will be automatically stopped to obtain the required temperature and pressure conditions. The experimental solution (solution required for the experiment) is cooled by the cooler 506, and flows to the liquid storage tank 501 to realize the liquid collection. The gas (such as: nitrogen, oxygen, hydrogen sulfide, carbon dioxide, etc.) is decompressed by the self-operated pressure regulating valve under the pressure of the steel cylinder, and after the solution in the liquid storage tank 501 is deoxygenated or inflated, it is washed by the alkali cleaning tank 507 to remove sulfide. The hydrogen and carbon dioxide are directly vented. The liquid storage tank, autoclave and alkali washing tank in the solution circulation and inflation system are equipped with safety valves to realize overpressure protection. A thermometer is set in the solution circulation inflation system to automatically measure and control the heating temperature of the heater to ensure the accuracy of the experiment temperature. A pressure gauge is installed in the autoclave to automatically measure the pressure and control the start and stop of the booster pump to ensure the accuracy of the experiment pressure.

Further, as shown in FIG. 5 , the tensile testing system also includes: a gear pair 508 (also referred to as a gear set) connected to the motor 509, and the tensile testing system controls the gear pair 508 through the motor 509. movement to realize constant load, constant strain or dynamic load loading on the test piece, so as to obtain the stress conditions required for the experiment.

The tensile testing system clamps the test piece 5 through the upper and lower chucks 302 . There is a chuck liner (glass fiber reinforced plastic material) 303 inside the chuck 302 to realize insulation from the test piece and other metals. After the bolt is tightened and the spring sleeved on the bolt is locked, the chuck 302 is connected to the first clamp connecting plate 306 through the chuck hanger 305 . The acoustic emission sensor 307 equipped with a plastic threaded ring 301 is screwed into the first fixture connecting plate 306 and contacts both ends of the specimen through a coupling agent, the second fixture connecting plate 401 is connected to the first fixture connecting plate 306 through a connecting screw 402, Forms a quick-change jig. The second clamp connection plate 401 and the first clamp connection plate 306 may be connected to a tensile testing machine or a tension rod 408 .

A tension sensor 404 and a displacement indicator 403 (such as a pointer or other indicators) are installed on the upper part of the second fixture connecting plate 401 . The tension sensor 404 is arranged on the second fixture connecting plate 401 to measure the tensile force of the test piece. The laser displacement sensor 405 and the displacement target 403 can simultaneously measure the strain of the test piece, and through the data collector 511 and Computer connection for recording. The tensile test can be performed through the specimen clamping mechanism, and to replace the specimen, it is only necessary to loosen the chuck tightening mechanism 304 and remove the specimen head 201 to conveniently replace the specimen.

The utility model can realize the simulation of the working environment and stress conditions of materials, and is convenient for synchronous observation of various acoustic emission signals and electrochemical signals, and meets the requirements of indoor experimental teaching and controllable and repeatable experiments. Electrochemical detection theory and method research provides an experimental platform.

The above descriptions are only illustrative specific implementations of the present utility model, and are not intended to limit the scope of the present utility model. Because the components of this utility model can be combined with each other under the condition of no conflict, any equivalent changes and modifications made by any person skilled in the art without departing from the concept and principles of this utility model shall belong to this utility model. The scope of utility model protection.

Claims (10)

1. A high-temperature and high-pressure acoustic emission electrochemical simulation experiment device capable of loading stress, characterized in that, the high-temperature and high-pressure acoustic emission electrochemical simulation experiment device capable of loading stress comprises: An autoclave, the autoclave has an inner cavity, and a test piece is arranged in the inner cavity; A tensile testing system installed at both ends of the test piece; Solution circulation inflation system, connected with the inner cavity of the pressure kettle; Acoustic emission probes are arranged at both ends of the test piece; An electrochemical test system, connected with the test piece and the autoclave; A data collector is connected with the tensile testing system, the solution circulation and gas charging system, the acoustic emission probe and the electrochemical testing system. the 2. The high temperature and high pressure acoustic emission electrochemical simulation experiment device capable of loading stress as claimed in claim 1, characterized in that, the high temperature and high pressure acoustic emission electrochemical simulation experiment device capable of loading stress also includes: computer, and data acquisition connected to the computer, and the computer is connected to the tensile testing system. the 3. the high temperature and high pressure acoustic emission electrochemical simulation experiment device capable of loading stress as claimed in claim 2, is characterized in that, described autoclave comprises: still body and the still cover that is arranged on described still body, described The lid of the kettle is provided with an installation hole for installing the test piece, and the installation hole is provided with a sealing ring of the test piece sealing the lid of the kettle and a gland pressed against the sealing ring of the test piece. The tensile test system It includes: chucks clamping the two ends of the test piece, the chuck is in contact with the test piece through the lining, the kettle body, the kettle cover, the gland, the test piece sealing ring, and The inner lining of the chuck is all made of glass fiber reinforced plastics. the 4. The high-temperature and high-pressure acoustic emission electrochemical simulation experiment device capable of loading stress according to claim 1, wherein the acoustic emission probe is in contact with the end surface of the test piece through a coupling agent. the 5. The high-temperature and high-pressure acoustic emission electrochemical simulation experiment device capable of loading stress as claimed in claim 3, wherein the tensile testing system further comprises: a motor connected with the chuck; a servo controller connected with the motor and the computer. the 6. The high-temperature and high-pressure acoustic emission electrochemical simulation experiment device capable of loading stress as claimed in claim 1, wherein the electrochemical test system comprises: a working electrode, an auxiliary electrode and a silver electrode connected to the autoclave. /silver chloride reference electrode, and the working electrode is the test piece. the 7. the high temperature and high pressure acoustic emission electrochemical simulation experiment device capable of loading stress as claimed in claim 3, is characterized in that, the two ends of described test piece are respectively provided with the test piece head that is threadedly connected with described test piece, so The test piece head is set on both ends of the test piece, and the chuck clamps the test piece by clamping the test piece head. the 8. The high-temperature and high-pressure acoustic emission electrochemical simulation experiment device capable of loading stress according to claim 1, wherein the acoustic emission probe is sleeved in a plastic threaded ring and installed on the tensile testing system. the 9. The high-temperature and high-pressure acoustic emission electrochemical simulation experiment device capable of loading stress as claimed in claim 1, wherein the temperature of the solution that the solution circulation and inflation system provides to the autoclave for the experiment is 20 to 150 °C. ℃, the pressure is 1~16MPa. the 10. The high-temperature and high-pressure acoustic emission electrochemical simulation experiment device capable of loading stress as claimed in claim 5, wherein the tensile test system further comprises: a gear pair connected with the motor, and the tensile test system The system controls the motion of the gear pair through the motor. the

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