CN118329982B - High-flux metal pipe welded joint hydrogen permeation experimental equipment and method - Google Patents

Abstract

The invention relates to the technical field of testing equipment, and in particular to a high-throughput metal pipe welded joint hydrogen permeation test equipment and method, comprising a gas phase system, a liquid phase system, a temperature control system and an electrochemical test system, wherein the gas phase system comprises a pressure autoclave, a nitrogen inlet port 1, a hydrogen inlet port, an exhaust port and a vacuum pump port, the liquid phase system comprises an electrolytic cell device, a platinum electrode and a reference electrode, the temperature control system comprises a tester and a heating device, the electrochemical test system comprises an electrochemical workstation and a computer, the pressure autoclave comprises a total pressure autoclave and a partial pressure autoclave, the total pressure autoclave is connected to a plurality of partial pressure autoclaves through a connecting pipe, a pressure gauge 2 and a gas valve 2 are arranged on the connecting pipe, and the above structure can be used to perform hydrogen permeation tests at different hydrogen partial pressures and ambient temperatures at the same time, and a hydrogen permeation test is performed on a metal pipe welded joint area by an electrochemical test method to evaluate the influence of different hydrogen partial pressures and different temperatures on the hydrogen permeation behavior of the metal pipe.

Description

A high-throughput metal pipe welded joint hydrogen permeation test device and method

Technical Field

The invention relates to the technical field of testing equipment, and in particular to a high-throughput metal pipe welded joint hydrogen permeation test device and method.

Background Art

As a green energy and secondary energy carrier with abundant reserves, zero emissions, high energy density and high conversion efficiency, the development and utilization of hydrogen energy has received great attention from the world. At present, many countries in the world have launched natural gas pipeline hydrogen blending projects. However, when the hydrogen concentration increases during large-scale transportation, it is easy to cause hydrogen embrittlement of steel, resulting in cracking and leakage of the transmission pipeline, and even combustion and explosion, thus causing serious safety problems. Therefore, determining the hydrogen content that can be blended into the natural gas transmission pipeline is an important basis for ensuring its long-term service.

At present, most of the research on hydrogen permeation behavior uses the Devanathan-Stachurski double electrolytic cell device. The experimental device mainly includes two liquid electrolytic cells, platinum electrodes and reference electrodes. The sample is tested between the two electrolytic cells. Electrochemical hydrogen charging has certain limitations. It usually changes the surface state of the metal sample. The measured data cannot truly reflect the hydrogen permeation behavior of the material in the actual service environment. Gas phase hydrogen charging can simulate the actual service environment more realistically and is more suitable for the study of pure hydrogen pipelines and hydrogen-doped natural gas pipelines, so as to accurately explain the influence of various factors such as transmission pressure, temperature and gas doping on hydrogen diffusion. Pipeline steel often uses welding technology for pipeline connection, but due to the influence of factors such as uneven structure and stress concentration in the welding part, the weld area becomes a weak position of pipeline steel in the service process. The weld, heat-affected zone and parent material in the welded joint have different adsorption and diffusion behaviors of hydrogen. Therefore, studying the hydrogen permeation behavior of each area of the welded joint can provide some help for the selection of welding process.

Summary of the invention

The purpose of the present invention is to provide a high-throughput metal pipe welded joint hydrogen permeation test device and method, so as to provide technical support for the determination of hydrogen content in natural gas transmission pipelines.

To achieve the above-mentioned purpose, the present invention provides a high-throughput metal pipe welded joint hydrogen permeation experimental equipment, including a gas phase system, a liquid phase system, a temperature control system and an electrochemical test system, wherein the gas phase system includes a pressure autoclave, a nitrogen inlet port 1, a hydrogen inlet port, an exhaust port and a vacuum pump port, the liquid phase system includes an electrolytic cell device, a platinum electrode, and a reference electrode, the temperature control system includes a tester and a heating device, the electrochemical test system includes an electrochemical workstation and a computer, the pressure autoclave includes a total pressure autoclave and a partial pressure autoclave, the total pressure autoclave includes a autoclave body and an autoclave cover, the total pressure autoclave is connected to a plurality of the partial pressure autoclaves through a connecting pipe, a pressure gauge 2 and a gas valve 2 are provided on the connecting pipe, the partial pressure autoclave includes a lower connecting plate and an upper connecting plate, the upper connecting plate is connected to the electrolytic cell device, and the lower connecting plate and the partial pressure autoclave are integrated;

The lower connecting plate and the upper connecting plate are each provided with a sunken groove on one side thereof, an upper sealing block and a lower sealing block are respectively bonded to the inner side of the groove, an opening for the test material to pass through is provided at the center position of the top end of the upper sealing block and the lower sealing block, a test sample is provided between the upper sealing block and the lower sealing block, and the test sample is connected to the electrochemical workstation through a wire, and a connection structure for sealing and clamping the test sample is provided between the lower connecting plate and the upper connecting plate.

In the above technical solution, further, the connection structure includes a screw rod, a pair of the screw rods are provided, a pair of L-shaped cavities are diagonally opened inside the upper connection plate, the inner sides of the L-shaped cavities are slidably connected with L-shaped plates, and the screw rods are respectively threadedly connected to the front and rear sides of the upper connection plate, and the side walls of the screw rods are rotatably connected to the side walls of the L-shaped plates;

Four locking frames are fixedly connected to the top of the lower connecting plate, and locking grooves are provided on the side walls of the four locking frames, and the tops of the locking grooves are inclined. Lower right-angle blocks are provided next to the locking grooves, and a connecting plate is fixedly connected between the bottom end of the transverse end of the L-shaped plate and two of the lower right-angle blocks and passes through the bottom of the upper connecting plate, and the side walls of the longitudinal ends of the L-shaped plate are fixedly connected to the upper right-angle blocks, and the tops of the other two lower right-angle blocks are fixedly connected to oblique blocks through the bottom of the L-shaped cavity.

In the above technical solution, further, the inclined surface of the lower right angle block fits with the inclined surface of the top of the locking groove, the inclined surface of the upper right angle block fits with the inclined surface of the inclined block, a spring is fixedly connected between the inclined block and the inner wall of the L-shaped cavity, and a pair of guide rods are diagonally fixedly connected to the top of the lower connecting plate and are arranged through the top of the upper connecting plate.

In the above technical solution, further, a pair of liquid accumulation grooves are opened on the inner side of the opening on the upper sealing block, and floats are provided inside the liquid accumulation grooves. The top of the float is fixedly connected with a positioning rod and is arranged through the top of the upper connecting plate. The top of the L-shaped plate is fixedly connected with a positioning plate and is arranged through the top of the upper connecting plate. Positioning holes are opened on the top of the positioning plate, and the bottom of the liquid accumulation grooves are tilted toward the side that is close to each other.

In the above technical solution, further, the test sample has a nickel-plated side placed toward the upper sealing block, and a side of the test sample without a nickel layer is placed toward the lower sealing block, and the exposed surface area of the test sample is between 0.30-1.53 ^cm2 .

In the above technical solution, further, the upper connecting plate is made of ceramic material, and the upper sealing block and the lower sealing block are both made of polytetrafluoroethylene material.

In the above technical solution, further, the kettle cover is sealed and connected to the kettle body by an embedded connection method, a tee is provided on one side of the upper end of the total pressure kettle, the tee is connected with a nitrogen inlet and a vacuum pump port, a hydrogen inlet is provided on one side of the upper end of the total pressure kettle away from the tee, and a pressure gauge and an exhaust port are also provided on the total pressure kettle.

In the above technical solution, further, the electrolytic cell device is made of organic glass material, the electrolytic cell is filled with anode hydrogen permeation liquid, the platinum electrode and the reference electrode are both inserted into the anode hydrogen permeation liquid, the platinum electrode and the reference electrode are connected to an electrochemical workstation, the electrochemical workstation is connected to a computer, and the electrolytic cell device is provided with a second nitrogen inlet.

In the above technical solution, further, the tester is arranged on the outer wall of the pressure-partitioning kettle and connected to the heating device, and an exhaust port 1 is arranged on the side of the pressure-partitioning kettle, and an air valve 1 is arranged on the exhaust port 1.

A high-throughput metal pipe welded joint hydrogen permeation test method is used using the above-mentioned high-throughput metal pipe welded joint hydrogen permeation test equipment, and the method steps are as follows:

Step 1: Grind both sides of the test specimen and nickel plate the anode side of the test specimen;

Step 2: Place the test sample on the lower seal, then insert the upper connecting plate on the lower connecting plate, and insert the guide rod into the corresponding hole at the same time, and then rotate the screws at both ends to move inward, thereby pushing the L-shaped plate to move, and then driving two of the lower right-angle blocks to insert into the locking groove through the connecting plate, and squeezing the lower right-angle block downward through the inclined surface at the top of the locking groove. At the same time, when the L-shaped plate moves, it will drive the upper right-angle block to move, and then squeeze the inclined surface of the inclined block to push the inclined block to slide and compress the spring, thereby driving the other two upper right-angle blocks to insert into the locking groove, thereby driving the upper connecting plate downward to squeeze the lower connecting plate to tightly squeeze the test sample between the upper sealing block and the lower sealing block;

Step 3: Fill the total pressure kettle and the partial pressure kettle with nitrogen through the nitrogen inlet port 1 for purging, and check the air tightness of the device. After the inspection is completed, discharge the nitrogen in the total pressure kettle from the exhaust port, and open the gas valve 1 to discharge the nitrogen in the partial pressure kettle from the exhaust port 1;

Step 4: Add 0.2 mol/L sodium hydroxide solution to the electrolytic cell device, turn on the electrochemical workstation to connect the test sample, platinum electrode, and reference electrode, turn on the heating device to heat the ambient temperature to the set experimental temperature, and reduce the background current to the experimental requirements;

Step 5: Use gas valve 2 and pressure gauge 2 to introduce hydrogen and nitrogen of the specified pressure from the total pressure reactor into the partial pressure reactor and monitor the current;

Step 6: After the hydrogen permeation current test is completed, open the exhaust port to treat the exhaust gas.

Compared with the prior art, the present invention has the following beneficial effects:

1. The present invention designs a high-throughput metal pipe welded joint hydrogen permeation experimental device, which is close to the actual working environment and can realize hydrogen permeation tests at different partial pressures and different temperatures at the same time, thereby improving the experimental efficiency.

2. The present invention can achieve sealing by replacing sealing blocks with openings of different sizes, while performing hydrogen permeation experimental tests on different micro areas of the welded joint.

3. Through the setting of the connection structure, not only can the test sample be quickly disassembled and assembled without using tools to remove multiple bolts, but it also has the function of preventing accidental disassembly. When the sodium hydroxide solution in the electrolytic cell device is not extracted after the experiment, it is impossible to remove the connection structure to take out the test sample. This can effectively prevent the experimenter from mistakenly taking out the test sample in advance, causing the sodium hydroxide solution to flow out, thereby improving the safety performance of the experiment.

BRIEF DESCRIPTION OF THE DRAWINGS

In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art are briefly introduced below.

FIG1 is a schematic diagram of the overall appearance structure of the experimental equipment of the present invention;

Fig. 2 is a schematic diagram of the principle structure of the experimental equipment of the present invention;

FIG3 is a schematic diagram of the overall appearance structure of the pressure reactor of the present invention;

FIG4 is a schematic diagram of a three-dimensional structure of a pressure reactor according to the present invention, viewed from above and in full section;

FIG5 is a schematic diagram of a partially enlarged structure of point A in FIG4 of the present invention;

FIG6 is a schematic diagram of the front full cross-section of the upper connection plate and the lower connection plate of the present invention;

7 is a schematic diagram of a top view of the three-dimensional structure of the lower connecting plate of the present invention;

FIG. 8 is a bottom-up perspective structural diagram of the upper connecting plate of the present invention.

Description of the numbers in the figure:

1. Total pressure kettle; 2. Kettle body; 3. Kettle cover; 4. Vacuum pump port; 5. Tee; 6. Nitrogen inlet port 1; 7. Pressure gauge 1; 8. Hydrogen inlet port; 9. Lower connecting plate; 10. Upper connecting plate; 11. Electrolytic cell device; 12. Platinum electrode; 13. Reference electrode; 14. Nitrogen inlet port 2; 15. Upper sealing block; 16. Guide rod; 17. Test sample; 18. Lower sealing block; 19. Pressure kettle; 20. Gas Valve 1; 21. Exhaust port 1; 22. Connecting pipe; 23. Pressure gauge 2; 24. Air valve 2; 25. Screw; 26. Opening; 27. L-shaped cavity; 28. L-shaped plate; 29. Locking frame; 30. Locking groove; 31. Lower right-angle block; 32. Connecting plate; 33. Upper right-angle block; 34. Oblique block; 35. Spring; 36. Liquid accumulation groove; 37. Float; 38. Positioning rod; 39. Positioning plate; 40. Positioning hole.

DETAILED DESCRIPTION

In order to more clearly understand the above-mentioned objects, features and advantages of the present invention, the present invention is further described in detail below with reference to the accompanying drawings and specific embodiments.

A high-throughput metal pipe welding joint hydrogen permeation experimental equipment as shown in Figures 1 to 8 includes a gas phase system, a liquid phase system, a temperature control system and an electrochemical test system, the gas phase system includes a pressure autoclave, a nitrogen inlet 6, a hydrogen inlet 8, an exhaust port and a vacuum pump port 4, the liquid phase system includes an electrolytic cell device 11, a platinum electrode 12, and a reference electrode 13, the temperature control system includes a tester and a heating device, the electrochemical test system includes an electrochemical workstation and a computer, the pressure autoclave includes a total pressure autoclave 1 and a pressure autoclave 19, the total pressure autoclave 1 includes a autoclave body 2 and an autoclave cover 3, the total pressure autoclave 1 is connected to a plurality of pressure autoclaves 19 through a connecting pipe 22, a pressure gauge 23 and a gas valve 24 are provided on the connecting pipe 22, the pressure autoclave 19 includes a lower connecting plate 9 and an upper connecting plate 10, the upper connecting plate 10 is connected to the electrolytic cell device 11, and the lower connecting plate 9 and the pressure autoclave 19 are integrally arranged;

A sunken groove is provided on one side of the lower connecting plate 9 and the upper connecting plate 10, and an upper sealing block 15 and a lower sealing block 18 are respectively bonded to the inner side of the groove. An opening 26 for the test material to pass through is provided at the center position of the top of the upper sealing block 15 and the lower sealing block 18. A test sample 17 is provided between the upper sealing block 15 and the lower sealing block 18, and the test sample 17 is connected to the electrochemical workstation through a wire. A connecting structure for sealing and clamping the test sample 17 is provided between the lower connecting plate 9 and the upper connecting plate 10.

In order to quickly fix the test specimen 17, the connection structure includes a screw rod 25, a pair of screw rods 25 are provided, a pair of L-shaped cavities 27 are diagonally opened inside the upper connection plate 10, and L-shaped plates 28 are slidably connected inside the L-shaped cavities 27, and the screw rods 25 are respectively threadedly connected to the front and rear sides of the upper connection plate 10, and the side walls of the screw rods 25 are rotatably connected to the side walls of the L-shaped plates 28;

Four locking frames 29 are fixedly connected to the top of the lower connecting plate 9, and locking grooves 30 are provided on the side walls of the four locking frames 29, and the tops of the locking grooves 30 are inclined. Lower right-angle blocks 31 are provided beside the locking grooves 30. A connecting plate 32 is fixedly connected between the bottom end of the lateral end of the L-shaped plate 28 and two of the lower right-angle blocks 31 and is arranged through the bottom of the upper connecting plate 10. The side walls of the longitudinal end of the L-shaped plate 28 are fixedly connected to upper right-angle blocks 33, and the tops of the other two lower right-angle blocks 31 are fixedly connected to inclined blocks 34 through the bottom of the L-shaped cavity 27.

The inclined surface of the lower right-angle block 31 fits with the inclined surface of the top of the locking groove 30, and the inclined surface of the upper right-angle block 33 fits with the inclined surface of the inclined block 34. A spring 35 is fixedly connected between the inclined block 34 and the inner wall of the L-shaped cavity 27. The setting of the spring 35 facilitates the rapid reset of the inclined block 34. A pair of guide rods 16 are fixedly connected to the top of the lower connecting plate 9 diagonally and penetrate the top of the upper connecting plate 10. The setting of the guide rods 16 facilitates the insertion of the upper connecting plate 10 when docking with the lower connecting plate 9, thereby quickly aligning the upper right-angle block 33 with the locking groove 30, thereby improving the installation efficiency of the device.

When installing the test sample 17, place the test sample 17 on the lower sealing block 18, then insert the upper connecting plate 10 on the lower connecting plate 9, and insert the guide rod 16 into the corresponding hole, and then rotate the screw rods 25 at both ends to move inward, thereby pushing the L-shaped plate 28 to move, and then drive two of the lower right-angle blocks 31 to insert into the locking groove 30 through the connecting plate 32, and squeeze the lower right-angle block 31 to move downward through the inclined surface at the top of the locking groove 30. At the same time, when the L-shaped plate 28 moves, it will drive the upper right-angle block 3 3 is moved, and the inclined surface of the inclined block 34 is pressed to push the inclined block 34 to slide and compress the spring 35, thereby driving the other two upper right-angle blocks 33 to insert into the locking groove 30, thereby simultaneously pulling the four corners of the upper connecting plate 10 downward to press the lower connecting plate 9 to tightly squeeze the test sample 17 between the upper sealing block 15 and the lower sealing block 18, so as to achieve the sealing and fixing of the test sample 17, and the four corners can be quickly fixed by rotating the two screws 25, without using tools to rotate multiple bolts for fixing, thereby improving the installation efficiency of the experimental equipment.

In order to improve the safety performance of the device during use, a pair of liquid accumulation grooves 36 are provided inside the opening 26 on the upper sealing block 15, and a floating ball 37 is provided inside the liquid accumulation grooves 36. A positioning rod 38 is fixedly connected to the top of the floating ball 37 and is arranged through the top of the upper connecting plate 10. A positioning plate 39 is fixedly connected to the top of the L-shaped plate 28 and is arranged through the top of the upper connecting plate 10. A positioning hole 40 is provided on the top of the positioning plate 39, and the bottom of the liquid accumulation grooves 36 is tilted toward the adjacent side, so that the liquid flowing into the liquid accumulation grooves 36 can be quickly discharged;

During the experiment, when the hydrogen permeation liquid is injected into the electrolytic cell device 11 and flows into the opening 26 on the upper sealing block 15, a part of the hydrogen permeation liquid will flow into the liquid accumulation groove 36, and then the float 37 will float on the liquid due to its own buoyancy, thereby driving the positioning rod 38 to slide downward and slide out of the upper surface of the upper connecting plate 10. Before this, when the rotating screw 25 locks the test sample 17, the sliding of the L-shaped plate 28 will drive the positioning plate 39 to move, thereby moving the positioning hole 40 to above the positioning rod 38 to tightly fix the test sample 17, and then during the experiment, the positioning rod 38 will be inserted into the positioning hole 40, thereby preventing the experimenter from mistakenly removing the test sample 17 in advance, causing the sodium hydroxide solution to flow out, thereby improving the safety performance of the experiment.

The test sample 17 has a nickel-plated side placed toward the upper sealing block 15 and in contact with the hydrogen permeation liquid in the electrolytic cell device 11, and a side of the test sample 17 without a nickel layer is placed toward the lower sealing block 18 and in contact with the hydrogen and nitrogen in the pressure-dividing kettle 19. The exposed surface area of the test sample 17 is between 0.30 and 1.53 ^cm2 .

In order to improve the service life of the equipment, the upper connecting plate 10 is made of ceramic material, which has good insulation properties. The upper sealing block 15 and the lower sealing block 18 are both made of polytetrafluoroethylene material, which has the characteristics of high temperature resistance, acid and alkali resistance.

Among them, the kettle cover 3 is sealed and connected to the kettle body 2 by an embedded connection method. A tee 5 is provided on one side of the upper end of the total pressure kettle 1. The tee 5 is connected to a nitrogen inlet 6 and a vacuum pump port 4. A hydrogen inlet 8 is provided on the side of the upper end of the total pressure kettle 1 away from the tee 5. The total pressure kettle 1 is also provided with a pressure gauge 7 and an exhaust port.

Among them, the electrolytic cell device 11 is made of organic glass material, the electrolytic cell is filled with anode hydrogen permeation liquid, the platinum electrode 12 and the reference electrode 13 are both inserted into the anode hydrogen permeation liquid, the platinum electrode 12 and the reference electrode 13 are connected to the electrochemical workstation, the electrochemical workstation is connected to the computer, and the electrolytic cell device 11 is provided with a nitrogen inlet port 14.

The tester is arranged on the outer wall of the pressure-dividing kettle 19 and connected to a heating device, through which the test sample 17 can be subjected to hydrogen permeation tests at different temperatures.

The side of the pressure reactor 19 is provided with an exhaust port 21, and the exhaust port 21 is provided with an air valve 20.

A high-throughput metal pipe welded joint hydrogen permeation test method is used using the above-mentioned high-throughput metal pipe welded joint hydrogen permeation test equipment, and the method steps are as follows:

Step 1: Grind both sides of the test sample 17 and perform nickel plating on the anode side of the test sample 17.

Step 2: Place the test sample 17 on the lower sealing block 18, then insert the upper connecting plate 10 on the lower connecting plate 9, and insert the guide rod 16 into the corresponding hole at the same time, and then rotate the screw rods 25 at both ends to move inward, thereby pushing the L-shaped plate 28 to move, and then drive two of the lower right-angle blocks 31 to insert into the locking groove 30 through the connecting plate 32, and squeeze the lower right-angle block 31 downward through the inclined surface at the top of the locking groove 30. At the same time, when the L-shaped plate 28 moves, it will drive the upper right-angle block 33 to move, and then squeeze the inclined surface of the inclined block 34 to push the inclined block 34 to slide and compress the spring 35, and then drive the other two upper right-angle blocks 33 to insert into the locking groove 30, thereby driving the upper connecting plate 10 to squeeze the lower connecting plate 9 downward to squeeze the test sample 17 tightly between the upper sealing block 15 and the lower sealing block 18;

Step 3: Fill the total pressure vessel 1 and the pressure vessel 19 with nitrogen through the nitrogen inlet 6 for purging, and check the air tightness of the device. After the inspection, discharge the nitrogen in the total pressure vessel 1 from the exhaust port, and open the gas valve 20 to discharge the nitrogen in the pressure vessel 19 from the exhaust port 21.

Step 4: Add 0.2 mol/L sodium hydroxide solution to the electrolytic cell device 11, turn on the electrochemical workstation to connect the test sample 17, the platinum electrode 12, and the reference electrode 13, turn on the heating device to heat the ambient temperature to the set experimental temperature, and reduce the background current to the experimental requirements.

Step 5: With the help of the gas valve 24 and the pressure gauge 23, hydrogen and nitrogen of the specified pressure are introduced from the total pressure vessel 1 into the partial pressure vessel 19 and the current is monitored.

Step 6: After the hydrogen permeation current test is completed, open the exhaust port to treat the exhaust gas.

According to the experimental conditions, different hydrogen partial pressures and ambient temperatures are set, and the test sample 17 is clamped between the upper sealing block 15 and the lower sealing block 18 through the connecting structure to ensure that the pressure-dividing kettle 19 is completely sealed. According to the conditions simulated by the experimental working conditions, the gas valve is controlled, the hydrogen partial pressure and ambient temperature are changed, and the hydrogen permeation behavior of the metal pipe welding joint under different conditions is obtained.

What is disclosed above is only one or more preferred embodiments of the present application, and cannot be used to limit the scope of rights of the present application. Ordinary technicians in this field can understand that all or part of the processes of implementing the above embodiments and equivalent changes made according to the claims of the present application are still within the scope covered by the present application.

In the description of the present invention, it is also necessary to explain that, unless otherwise clearly specified and limited, the terms "set", "install", "connect", and "connect" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be directly connected, or indirectly connected through an intermediate medium, or it can be the internal connection of two components. For ordinary technicians in this field, it can be understood that the specific meanings of the above terms in the present invention are only the preferred embodiments of the present invention, and are not other forms of limitations on the present invention. Any technician familiar with this profession may use the technical content disclosed above to change or modify it into an equivalent embodiment with equivalent changes for application in other fields. However, any simple modification, equivalent change and modification made to the above embodiments based on the technical essence of the present invention without departing from the content of the technical solution of the present invention still belongs to the protection scope of the technical solution of the present invention.

Claims (8)

1. The high-flux metal pipe welding joint hydrogen permeation experimental equipment is characterized by comprising a gas phase system, a liquid phase system, a temperature control system and an electrochemical test system, wherein the gas phase system comprises a pressure kettle, a first nitrogen gas inlet (6), a first hydrogen gas inlet (8), an exhaust port and a vacuum pump port (4), the liquid phase system comprises an electrolytic cell device (11), a platinum electrode (12) and a reference electrode (13), the temperature control system comprises a tester and a heating device, the electrochemical test system comprises an electrochemical workstation and a computer, the pressure kettle comprises a total pressure kettle (1) and a pressure dividing kettle (19), the total pressure kettle (1) comprises a kettle body (2) and a kettle cover (3), the total pressure kettle (1) is connected with a plurality of pressure dividing kettles (19) through a communication pipeline (22), a second pressure gauge (23) and a second air valve (24) are arranged on the communication pipeline (22), the pressure dividing kettle (19) comprises a lower connecting disc (9) and an upper connecting disc (10), the upper connecting disc (10) is connected with the electrolytic cell device (11), and the pressure dividing kettle (9) and the pressure dividing kettle (19) are integrally arranged;

An inward sinking groove is formed in one side, close to the upper connecting disc (10), of the lower connecting disc (9), an upper sealing block (15) and a lower sealing block (18) are respectively bonded to the inner side of the sinking groove, an opening (26) for a test material to pass through is formed in the center of the top ends of the upper sealing block (15) and the center of the top ends of the lower sealing block (18), a test sample (17) is arranged between the upper sealing block (15) and the lower sealing block (18), the test sample (17) is connected with an electrochemical workstation through a wire, and a connecting structure for sealing and clamping the test sample (17) is arranged between the lower connecting disc (9) and the upper connecting disc (10); the connecting structure comprises a screw rod (25), the screw rod (25) is provided with a pair, a pair of L-shaped cavities (27) are formed in the upper connecting disc (10) in opposite angles, the inner sides of the L-shaped cavities (27) are respectively and slidably connected with an L-shaped plate (28), the screw rod (25) penetrates through the front side and the rear side of the upper connecting disc (10) in a threaded connection mode respectively, and the side walls of the screw rod (25) are respectively and rotatably connected to the side walls of the L-shaped plate (28);

Four locking frames (29) are fixedly connected to the top of the lower connecting disc (9), locking grooves (30) are formed in the side walls of the four locking frames (29), the top ends of the locking grooves (30) are obliquely arranged, lower right-angle blocks (31) are arranged beside the locking grooves (30), a connecting plate (32) is fixedly connected between the bottom end of the transverse end of the L-shaped plate (28) and two lower right-angle blocks (31) and penetrates through the bottom of the upper connecting disc (10), upper right-angle blocks (33) are fixedly connected to the side walls of the longitudinal end of the L-shaped plate (28), and oblique blocks (34) are fixedly connected to the tops of the other two lower right-angle blocks (31) through the bottom of the L-shaped cavity (27); the inclined plane of lower right angle piece (31) is laminated with the inclined plane on locking groove (30) top mutually, the inclined plane of going up right angle piece (33) is laminated with the inclined plane of sloping piece (34) mutually, fixedly connected with spring (35) between sloping piece (34) and L die cavity (27) inside wall, lower connection pad (9) top diagonal angle fixedly connected with a pair of guide bar (16) just runs through last connection pad (10) top setting.

2. The high-flux metal pipe welding joint hydrogen permeation experimental equipment according to claim 1, wherein a pair of liquid accumulation tanks (36) are formed inside the holes (26) in the upper sealing block (15), floating balls (37) are arranged inside the liquid accumulation tanks (36), positioning rods (38) are fixedly connected to the tops of the floating balls (37) and penetrate through the top ends of the upper connecting plates (10), positioning plates (39) are fixedly connected to the tops of the L-shaped plates (28) and penetrate through the top ends of the upper connecting plates (10), positioning holes (40) are formed in the tops of the positioning plates (39), and the bottoms of the liquid accumulation tanks (36) are obliquely arranged towards the side close to each other.

3. A high throughput metal tubing welded joint hydrogen permeation testing apparatus according to claim 1, wherein said test specimen (17) has a nickel plated side placed toward an upper sealing block (15), said test specimen (17) side without a nickel layer placed toward a lower sealing block (18), and said test specimen (17) has an exposed surface area between 0.30-1.53 cm ².

4. The high-flux metal pipe welded joint hydrogen permeation test equipment according to claim 1, wherein the upper connecting disc (10) is made of ceramic materials, and the upper sealing block (15) and the lower sealing block (18) are made of polytetrafluoroethylene materials.

5. The high-flux metal pipe welding joint hydrogen permeation experimental equipment according to claim 1, wherein the kettle cover (3) is in sealing connection with the kettle body (2) in an embedded connection mode, a tee joint (5) is arranged on one side of the upper end of the total autoclave (1), the tee joint (5) is connected with a nitrogen gas inlet (6) and a vacuum pump port (4), a hydrogen gas inlet (8) is arranged on one side, far away from the tee joint (5), of the upper end of the total autoclave (1), and a pressure meter (7) and an exhaust port are further arranged on the total autoclave (1).

6. The high-flux metal pipe welded joint hydrogen permeation experimental equipment according to claim 1, wherein the electrolytic cell device (11) is made of organic glass materials, anode hydrogen permeation liquid is filled in the electrolytic cell, the platinum electrode (12) and the reference electrode (13) both extend into the anode hydrogen permeation liquid, the platinum electrode (12) and the reference electrode (13) are connected with an electrochemical workstation, the electrochemical workstation is connected with a computer, and a nitrogen gas inlet II (14) is arranged on the electrolytic cell device (11).

7. The high-flux metal pipe welded joint hydrogen permeation experimental equipment according to claim 1, wherein the tester is arranged on the outer wall of the pressure dividing kettle (19) and connected with the heating device, an exhaust port I (21) is arranged on the side surface of the pressure dividing kettle (19), and an air valve I (20) is arranged on the exhaust port I (21).

8. A hydrogen permeation experimental method for a high-flux metal pipe welding joint, which is used by adopting the hydrogen permeation experimental equipment for the high-flux metal pipe welding joint according to any one of claims 1 to 7, and comprises the following steps:

Step one: polishing two sides of a test sample (17), and plating nickel on the anode side of the test sample (17);

Step two: placing a test sample (17) on a lower seal (15), inserting an upper connecting disc (10) on a lower connecting disc (9), inserting a guide rod (16) into a corresponding hole, then moving a screw (25) at two rotating ends in a spiral manner, pushing an L-shaped plate (28) to move, driving two lower right angle blocks (31) to be inserted into a locking groove (30) through a connecting plate (32), and pressing the lower right angle blocks (31) to move downwards through the inclined surface at the top end of the locking groove (30), wherein at the same time, the L-shaped plate (28) can drive an upper right angle block (33) to move when moving, and then the inclined surface of an inclined block (34) is pressed to push an inclined block (34) to slide a compression spring (35), so as to drive other two upper right angle blocks (33) to be inserted into the locking groove (30), and driving the upper connecting disc (10) to downwards press the lower connecting disc (17) to be tightly pressed between the upper seal block (15) and the lower seal block (18);

Step three: filling nitrogen into the total autoclave (1) and the partial pressure autoclave (19) through a nitrogen inlet I (6) for purging, checking the air tightness of the device, discharging the nitrogen in the total autoclave (1) from an exhaust port after checking, and opening a gas valve I (20) to discharge the nitrogen in the partial pressure autoclave (19) from an exhaust port I (21);

Step four: adding 0.2mol/L sodium hydroxide solution into the electrolytic cell device (11), opening an electrochemical workstation to connect a test sample (17), a platinum electrode (12) and a reference electrode (13), starting a heating device to heat the environment temperature to a set experimental temperature, and reducing background current to the experimental requirement;

Step five: the second air valve (24) and the second pressure gauge (23) are matched, hydrogen and nitrogen with specified experimental pressure are introduced into the pressure dividing kettle (19) from the total pressure kettle (1), and current monitoring is carried out;

step six: and after the hydrogen permeation current test is finished, opening an exhaust port to treat tail gas.