A test device and method for simulating corrosion of small pipes under stress conditions

Abstract

The present invention relates to a test device and method for simulating the corrosion of small pipes under stress conditions. The present invention includes a test model, a stress loading mechanism, a corrosive medium storage container and a circulating pump. The test model includes a main pipeline and a small pipe. The root of the small pipe is welded to the peripheral side of the main pipeline. The connection between the root of the small pipe and the peripheral side of the main pipeline has a weld structure. The stress loading mechanism is arranged on the outer end of the small pipe. The stress loading mechanism includes a weight. Compared with the prior art, the present invention provides a test method for simulating the corrosion state of a small pipe under stress conditions, which can simulate stress conditions of small pipes close to the real ones according to test requirements, thereby providing an effective reference for studying the law of corrosion of small pipes of industrial production equipment under stress conditions.

Description

Technical Field

[0001] The invention belongs to the technical field of small pipe corrosion test equipment, and in particular relates to a test equipment and method for simulating small pipe corrosion under stress conditions. Background Art

[0002] In industrial production equipment, holes are usually directly opened on the equipment body or pipeline, and the half-pipe joints, branch pipe seats, and branch pipe structures of DN50 and below are connected by welding, which are collectively called small pipes. Small pipes are mainly used to install instruments for measuring temperature, pressure, liquid level, etc. and safety relief devices, etc., and are usually located inside the first valve of the equipment or pipeline pipe.

[0003] Since the wall thickness of small pipes is usually much smaller than that of the equipment or pipeline body, and they are in the dead zone of medium flow, when corrosive media are stored or transported in the equipment or pipeline, small pipes are usually more prone to corrosion damage, becoming a weak link in the corrosion management of industrial equipment. In addition, due to the stress of the connected main pipe or mechanical equipment, and the impact of the flowing medium in the pipeline, many small pipes on the production equipment are in service under stress conditions for a long time, resulting in stress corrosion cracking, and even cracks or fractures in the connecting welds between the small pipes and the main pipes or equipment. It can be seen that the corrosion cracking of small pipes under stress conditions has become an important risk point for industrial production equipment. Therefore, it is urgent to carry out research to find out the behavior mechanism and corrosion law of small pipe corrosion under stress conditions. However, there is currently no effective test simulation device and method for the study of small pipe corrosion under stress conditions, which seriously restricts the development of research on small pipe corrosion under stress conditions.

[0004] Therefore, there is an urgent need for a technical solution that can be used to simulate the corrosion of small pipes under stress conditions. Summary of the invention

[0005] One of the purposes of the present invention is to address the deficiencies in the prior art and to provide a test device for simulating corrosion of small pipes under stress conditions, so as to solve the problem in the prior art of lacking a technical solution for simulating corrosion of small pipes under stress conditions.

[0006] In order to achieve the above object, the present invention adopts the following technical solutions:

[0007] A test device for simulating corrosion of small pipes under stress conditions, comprising a test model, a stress loading mechanism, a corrosive medium storage container and a circulating pump, wherein the test model comprises a main pipeline and a small pipe, the root of the small pipe is welded to the peripheral side of the main pipeline, the connection between the root of the small pipe and the peripheral side of the main pipeline has a weld structure, the stress loading mechanism is arranged on the outer end of the small pipe, the stress loading mechanism comprises a weight, the first port of the main pipeline is communicated with the second port of the corrosive medium storage container, the first port of the corrosive medium storage container is communicated with the second port of the circulating pump, and the first port of the circulating pump is communicated with the second port of the main pipeline.

[0008] As a preferred embodiment of the test device for simulating the corrosion of small pipes under stress conditions described in the present invention, it also includes a regulating pipeline, on which a stop valve and a flow detection device are provided; the regulating pipeline is provided at the first port of the main pipeline, and the first port of the main pipeline is connected to the second port of the corrosive medium storage container through the regulating pipeline, or the regulating pipeline is provided at the second port of the main pipeline, and the second port of the main pipeline is connected to the first port of the circulating pump through the regulating pipeline.

[0009] As a preferred solution of the test device for simulating corrosion of small pipes under stress conditions described in the present invention, it includes multiple test models, and the multiple test models are arranged in parallel.

[0010] As a preferred embodiment of the test device for simulating the corrosion of small pipes under stress conditions described in the present invention, the stress loading mechanism also includes a loading rod, which is connected to the outer end of the small pipe, and an adjusting slide rail is provided on the loading rod, and a sliding block sliding along the adjusting slide rail is provided on the adjusting slide rail, and the weight is slidably arranged on the loading rod along the adjusting slide rail through the sliding block, and the distance between the weight and the small pipe is adjusted by the adjusting slide rail.

[0011] As a preferred embodiment of the test device for simulating the corrosion of small pipes under stress conditions described in the present invention, it also includes a pressure regulating mechanism, which is used to regulate the internal pressure of the corrosive medium storage container. The corrosive medium storage container is provided with a pressure detection device, which is used to detect the internal pressure of the corrosive medium storage container.

[0012] As a preferred embodiment of the test device for simulating the corrosion of small pipes under stress conditions described in the present invention, the pressure regulating mechanism includes an air pressure container, a regulating air valve, a switching air valve and an air pipeline. The air outlet port of the air pressure container is connected to the air inlet port of the corrosive medium storage container through the air pipeline. The regulating air valve is arranged at the air outlet port of the air pressure container, and the switching air valve is arranged on the air pipeline.

[0013] As a preferred embodiment of the test device for simulating the corrosion of small pipes under stress conditions described in the present invention, it also includes a temperature regulating mechanism, which is used to regulate the temperature of the corrosive medium inside the corrosive medium storage container. The corrosive medium storage container is provided with a temperature detection device, which is used to detect the temperature of the corrosive medium inside the corrosive medium storage container.

[0014] As a preferred solution of the test device for simulating small pipe corrosion under stress conditions described in the present invention, the temperature adjustment mechanism includes a temperature controller and an electric heating tube, the temperature controller is electrically connected to the electric heating tube, and the electric heating tube is arranged inside the corrosive medium storage container.

[0015] One of the purposes of the present invention has the beneficial effect that: the present invention provides a test device for simulating the corrosion state of a small pipe under stress conditions, which can simulate stress conditions of a small pipe close to the real one according to the test requirements, thereby providing an effective reference for studying the law of corrosion of small pipes of industrial production equipment under stress conditions. At the same time, the present invention can also be used to evaluate the applicability of weld structures of different welding methods, different welding qualities, and different pipeline materials under different corrosive media, different operating conditions, and different stress conditions, so as to facilitate the study of the law of corrosion of small pipes.

[0016] The second purpose of the present invention is to address the deficiencies in the prior art and to provide a test method for simulating corrosion of small pipes under stress conditions, so as to solve the problem in the prior art of lacking a technical solution for simulating corrosion of small pipes under stress conditions.

[0017] In order to achieve the above object, the present invention adopts the following technical solutions:

[0018] A test method for simulating corrosion of a small pipe under stress conditions, using a test device for simulating corrosion of a small pipe under stress conditions as described in any one of the purposes of the present invention, comprises the following steps:

[0019] Step S1, configuring a test model with corresponding parameters;

[0020] Step S2, preparing a corrosive medium of corresponding components, and placing the corrosive medium in a corrosive medium storage container;

[0021] Step S3, adjusting the flow rate of the main pipeline in the test model; adjusting the internal pressure of the corrosive medium storage container; adjusting the temperature of the corrosive medium inside the corrosive medium storage container; adjusting the force loading parameters of the force loading mechanism;

[0022] Step S4, setting the test time, starting the circulation pump and the force loading device until the test time ends;

[0023] Step S5, detecting the state of the weld structure in the test model.

[0024] As a preferred embodiment of the test method for simulating stress conditions of small pipe corrosion described in the present invention, the step 5 of detecting the state of the weld structure in the test model also includes: the means of detecting the test model includes penetration testing and / or ultrasonic testing.

[0025] The second object of the present invention has the following beneficial effects: the present invention provides a test method for simulating the corrosion state of small pipes under stress conditions, which can simulate stress conditions of small pipes close to the real ones according to the test requirements, thereby providing an effective reference for studying the law of corrosion of small pipes of industrial production equipment under stress conditions. At the same time, the present invention can also be used to evaluate the applicability of weld structures of different welding methods, different welding qualities, and different pipeline materials under different corrosive media, different operating conditions, and different stress conditions, so as to facilitate the study of the law of corrosion of small pipes. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 It is a structural schematic diagram of the present invention.

[0027] Figure 2 for Figure 1 Magnified view of area A.

[0028] Figure 3 for Figure 1 Magnified view of area B.

[0029] Figure 4 It is a cross-sectional view of the test model in the present invention.

[0030] Figure 5 It is a structural schematic diagram of the force loading mechanism in the present invention.

[0031] Figure 6 It is a side sectional view of the loading rod in the present invention.

[0032] In the figure:

[0033] 1-test model; 11-main pipeline; 12-small pipe; 13-weld structure;

[0034] 2-force loading mechanism; 21-weight; 211-weight; 212-carrier plate; 2121-hook; 22-loading rod; 221-adjusting slide rail; 222-sliding carrier block; 2221-hook hole;

[0035] 3-corrosive medium storage container; 31-pressure detection device; 32-temperature detection device; 33-safety valve; 34-feeding port; 35-discharging port;

[0036] 4-Circulation pump;

[0037] 5- regulating pipeline; 51- stop valve; 52- flow detection device;

[0038] 6-pressure regulating mechanism; 61-air pressure container; 62-regulating air valve; 63-switching air valve; 64-air pipeline;

[0039] 7-temperature regulating mechanism; 71-temperature controller; 72-electric heating tube;

[0040] 81 - first pipeline; 82 - second pipeline; 83 - third pipeline. DETAILED DESCRIPTION

[0041] To make the technical solutions and advantages of the present invention more clear, the present invention and its beneficial effects will be described in further detail below in conjunction with specific implementation methods and accompanying drawings, but the implementation methods of the present invention are not limited thereto.

[0042] like Figures 1 to 6 As shown, a test device for simulating corrosion of small pipes under stress conditions includes a test model 1, a stress loading mechanism 2, a corrosive medium storage container 3 and a circulating pump 4. The test model 1 includes a main pipeline 11 and a small pipe 12. The root of the small pipe 12 is welded to the peripheral side of the main pipeline 11. The connection between the root of the small pipe 12 and the peripheral side of the main pipeline 11 has a weld structure 13. The stress loading mechanism 2 is arranged on the outer end of the small pipe 12. The stress loading mechanism 2 includes a weight 21. The first port of the main pipeline 11 is connected to the second port of the corrosive medium storage container 3, the first port of the corrosive medium storage container 3 is connected to the second port of the circulating pump 4, and the first port of the circulating pump 4 is connected to the second port of the main pipeline 11.

[0043] Specifically, the main pipeline 11 is arranged in the vertical direction, the small pipe 12 is arranged in the horizontal direction, and the force loading mechanism 2 applies a vertical downward loading force to the small pipe 12. The test model 1 can be disassembled from the test device, and the test model 1 needs to configure the welding method, welding quality and material of the welding structure according to the test requirements. The corrosive medium needs to be prepared with corresponding components according to the test requirements and placed in the interior of the corrosive medium storage container 3. The force loading mechanism 2 is used to apply force to the small pipe 12 so that the small pipe 12 is in the corresponding force condition. The force loading mechanism 2 can adjust the corresponding loading torque according to the test requirements. The circulating pump 4 is used to circulate the corrosive medium inside the test device. The circulating pump 4 can adjust the flow rate of the circulating pump 4 according to the test requirements to adjust the flow rate of the corrosive medium. The circulating pump 4 is a variable frequency speed regulation vertical pipeline pump with a flow rate of 1.5-340m 3 / h can be adjusted steplessly, and the pump body is made of S31603 stainless steel to prevent the test medium from corroding the pump body. Under the action of the circulating pump 4, the corrosive medium in the corrosive medium storage container 3 circulates in the circulating pump 4, the test model 1 and the corrosive medium storage container 3 in turn, or the corrosive medium in the corrosive medium storage container 3 circulates in the corrosive medium storage container 3, the test model 1 and the circulating pump 4 in turn, to simulate the flow of the corrosive medium in the small pipe 12. The first port of the main pipeline 11 is connected to the second port of the corrosive medium storage container 3 through the first pipeline 81, the first port of the corrosive medium storage container 3 is connected to the second port of the circulating pump 4 through the second pipeline 82, and the first port of the circulating pump 4 is connected to the second port of the main pipeline 11 through the third pipeline 83. The first pipeline 81, the second pipeline 82 and the third pipeline 83 are all made of S31603 stainless steel, taking into account both economy and corrosion resistance.

[0044] The beneficial effects of this embodiment are as follows: this embodiment provides a test device for simulating the corrosion state of a small pipe 12 under stress conditions, which can simulate stress conditions of the small pipe 12 close to the real ones according to the test requirements, thereby providing an effective reference for studying the corrosion law of the small pipe 12 of industrial production equipment under stress conditions. At the same time, this embodiment can also be used to evaluate the applicability of weld structures 13 of different welding methods, different welding qualities, and different pipeline materials under different corrosive media, different operating conditions, and different stress conditions, so as to facilitate the study of the law of corrosion of the small pipe 12.

[0045] Preferably, it also includes a regulating pipeline 5, on which a stop valve 51 and a flow detection device 52 are provided; the regulating pipeline 5 is provided at the first port of the main pipeline 11, and the first port of the main pipeline 11 is connected to the second port of the corrosive medium storage container 3 through the regulating pipeline 5, or the regulating pipeline 5 is provided at the second port of the main pipeline 11, and the second port of the main pipeline 11 is connected to the first port of the circulation pump 4 through the regulating pipeline 5. Through the above settings, this embodiment can adjust the flow rate of the corrosive medium through the stop valve 51; this embodiment can detect the flow rate of the corrosive medium through the flow detection device 52, and further calculate the flow rate of the corrosive medium in the main pipeline 11 through the pipeline flow area of ​​the main pipeline 11; wherein, the instantaneous flow rate detected by the flow detection device 52 is divided by the pipeline flow area of ​​the main pipeline 11 to obtain the flow rate of the corrosive medium in the main pipeline 11. Specifically, the stop valve 51 is a J41H-25 stop valve 51 with a valve body material of CF3M and a nominal diameter of DN80; the flow detection device 52 is a LWGY-80A turbine flowmeter of Shanghai Automation Instrument Co., Ltd., and is equipped with a TBS display that can display instantaneous flow and cumulative total flow in real time.

[0046] Preferably, multiple test models 1 are included, and the multiple test models 1 are arranged in parallel. Through the above arrangement, this embodiment can simultaneously study the corrosion of the small pipe 12 under different test models 1 or different stress conditions under the same corrosive medium, the same temperature and the same pressure according to the test requirements.

[0047] Preferably, the force loading mechanism 2 also includes a loading rod 22, which is connected to the outer end of the small pipe 12, and an adjusting rail 221 is provided on the loading rod 22, and a sliding block 222 is provided on the adjusting rail 221 to slide along the adjusting rail 221, and the weight 21 is slidably set on the loading rod 22 along the adjusting rail 221 through the sliding block 222, and the distance between the weight 21 and the small pipe 12 is adjusted by the adjusting rail 221. Through the above arrangement, the force loading mechanism 2 can adjust the distance between the weight 21 and the small pipe 12 by adjusting the rail 221 according to the test requirements, so as to adjust the loading torque of the force loading mechanism 2 and improve the application range of the test device. Specifically, the loading rod 22 is arranged in the horizontal direction, and the weight 21 naturally hangs down in the vertical direction, that is, the weight 21 naturally hangs down in the direction of gravity.

[0048] Preferably, it further comprises a pressure regulating mechanism 6, which is used to regulate the internal pressure of the corrosive medium storage container 3. The corrosive medium storage container 3 is provided with a pressure detection device 31, which is used to detect the internal pressure of the corrosive medium storage container 3. Through the above arrangement, this embodiment can regulate the pressure of the corrosive medium in the test device through the pressure regulating mechanism 6, and detect the internal pressure of the corrosive medium storage container 3 through the pressure detection device 31, thereby improving the application range of the test device.

[0049] Preferably, the pressure regulating mechanism 6 comprises a pressure vessel 61, a regulating gas valve 62, a switch gas valve 63 and a gas pipeline 64. The gas outlet port of the pressure vessel 61 is connected to the gas inlet port of the corrosive medium storage container 3 through the gas pipeline 64. The regulating gas valve 62 is provided at the gas outlet port of the pressure vessel 61, and the switch gas valve 63 is provided on the gas pipeline 64. The pressure vessel 61 stores pressurized gas inside. The regulating gas valve 62 is used to adjust the flow rate of the pressurized gas to adjust the applied pressure of the pressure regulating mechanism 6, and the switch gas valve 63 is used to control the opening and closing of the pressure regulating mechanism 6. Specifically, the pressure vessel 61 is a high-pressure nitrogen gas cylinder, the regulating gas valve 62 is a pressure reducing valve, and the switch gas valve 63 is a gas circuit ball valve.

[0050] Preferably, the test device further comprises a temperature regulating mechanism 7, which is used to regulate the temperature of the corrosive medium in the corrosive medium storage container 3. The corrosive medium storage container 3 is provided with a temperature detection device 32, which is used to detect the temperature of the corrosive medium in the corrosive medium storage container 3. Through the above arrangement, the present embodiment can regulate the temperature of the corrosive medium in the test device through the temperature regulating mechanism 7, and detect the temperature of the corrosive medium in the corrosive medium storage container 3 through the temperature detection device 32, thereby improving the application range of the test device.

[0051] Preferably, the temperature regulating mechanism 7 includes a temperature controller 71 and an electric heating tube 72. The temperature controller 71 is electrically connected to the electric heating tube 72. The electric heating tube 72 is arranged inside the corrosive medium storage container 3. The electric heating tube 72 is used to heat and regulate the temperature of the corrosive medium inside the corrosive medium storage container 3. The temperature controller 71 is used to control the heating power and switching state of the electric heating tube 72.

[0052] Preferably, the weight 21 includes a weight 211 and a carrier plate 212, one or more weights 211 are placed on the carrier plate 212, and the carrier plate 212 is hung on the sliding carrier block 222. Through the above configuration, according to the test requirements, the number of weights 211 on the carrier plate 212 is increased or decreased to adjust the weight of the weight 21. More preferably, the carrier plate 212 is provided with a hook 2121, and the sliding carrier block 222 is provided with a hook hole 2221 that cooperates with the hook 2121, and the carrier plate 212 is hung on the sliding carrier block 222 through the hook 2121 and the hook hole 2221.

[0053] Preferably, a safety valve 33 is provided on the corrosive medium storage container 3, and the safety valve 33 is used for emergency pressure relief to improve the safety of the test device.

[0054] Preferably, the corrosive medium storage container 3 is provided with a feed port 34 and a discharge port 35 , and the corrosive medium is placed into the corrosive medium storage container 3 through the feed port 34 , and the corrosive medium in the corrosive medium storage container 3 is discharged to the outside of the test device through the discharge port 35 .

[0055] Example 2

[0056] A test method for simulating corrosion of a small pipe under stress conditions, using the test device for simulating corrosion of a small pipe under stress conditions of any one of Embodiment 1, comprising the following steps:

[0057] Step S1, according to the test requirements, configure the test model 1 with corresponding parameters. Specifically, the parameters of the test model 1 include: the material, outer diameter, wall thickness and / or length of the main pipe 11, and the material, outer diameter, wall thickness and / or length of the small pipe 12; the welding method and / or welding quality between the main pipe 11 and the small pipe 12.

[0058] Step S2: prepare a corrosive medium of corresponding components according to the test requirements, and place the corrosive medium in the corrosive medium storage container 3. Specifically, add corresponding chemical agents according to the test requirements to prepare the corrosive medium of corresponding components.

[0059] Step S3, adjusting the flow rate of the main pipeline 11 in the test model 1; adjusting the internal pressure of the corrosive medium storage container 3; adjusting the temperature of the corrosive medium in the corrosive medium storage container 3; adjusting the force loading parameters of the force loading mechanism 2. Specifically, the flow rate of the main pipeline 11 is adjusted by the stop valve 51 and / or the circulation pump 4; the internal pressure of the corrosive medium storage container 3 is adjusted by adjusting the air valve 62 to adjust the internal pressure of the main pipeline 11; the temperature of the corrosive medium in the corrosive medium storage container 3 is adjusted by the temperature adjustment mechanism 7; and the loading torque of the small connecting pipe 12 is adjusted by the force loading mechanism 2.

[0060] Step S4, setting the test time according to the test requirements, starting the circulation pump 4 and the force loading device until the test time is over. Specifically, setting a fixed test cycle time, detecting the state of the weld structure 13 in units of cycle time; or conducting the test until a visible crack position appears in the weld structure 13.

[0061] Step S5, detecting the state of the weld structure 13 in the test model 1. Specifically, the test device is turned off, and after cooling down, the test model 1 is disassembled and tested, so as to conduct research on the corrosion of the small pipe 12.

[0062] The beneficial effects of this embodiment are as follows: this embodiment provides a test method for simulating the corrosion state of a small pipe 12 under stress conditions, and can simulate stress conditions of the small pipe 12 close to the real ones according to the test requirements, thereby providing an effective reference for studying the corrosion law of the small pipe 12 of industrial production equipment under stress conditions. At the same time, this embodiment can also be used to evaluate the applicability of weld structures 13 of different welding methods, different welding qualities, and different pipeline materials under different corrosive media, different operating conditions, and different stress conditions, so as to facilitate the study of the law of corrosion of the small pipe 12.

[0063] Preferably, step 5, detecting the state of the weld structure 13 in the test model 1, further includes: the means for detecting the test model 1 includes penetration testing and / or ultrasonic testing. Through the above settings, this embodiment detects whether there are surface cracks on the surface of the test model 1 and the surface of the weld structure 13 by penetration testing means, and detects whether there are internal cracks inside the test model 1 and the inside of the weld structure 13 by ultrasonic testing means.

[0064] It should be noted that:

[0065] Penetrant testing is a non-destructive testing technology based on the principle of capillary action. It is mainly used to detect surface opening defects of non-porous metal or non-metal parts. During the test, a penetrant containing fluorescent dye or coloring dye is applied to the surface of the part. Due to the capillary action, the penetrant penetrates into the tiny surface opening defects. The excess penetrant attached to the surface of the workpiece is removed, and the developer is applied after drying. The penetrant in the defect is re-adsorbed onto the surface of the part under the action of capillary phenomenon, forming an enlarged defect display, and the morphology and distribution of the defect can be detected.

[0066] Ultrasonic testing is a non-destructive testing method that uses ultrasonic waves to inspect internal defects of metal components. Ultrasonic waves are emitted to the surface of the component through a coupling agent using a transmitting probe. When the ultrasonic waves propagate inside the component, they will produce different reflected signals (echoes) when they encounter different interfaces. The time difference between different reflected signals transmitted to the probe can be used to detect defects inside the component.

[0067] According to the disclosure and teaching of the above description, those skilled in the art to which the present invention belongs can also change and modify the above embodiment. Therefore, the present invention is not limited to the above specific embodiment, and any obvious improvement, replacement or modification made by those skilled in the art on the basis of the present invention belongs to the protection scope of the present invention. In addition, although some specific terms are used in this specification, these terms are only for the convenience of description and do not constitute any limitation to the present invention.

Claims

1. A test device for simulating corrosion of small pipes under stress conditions, characterized in that: The invention comprises a test model (1), a force loading mechanism (2), a corrosive medium storage container (3) and a circulation pump (4), wherein the test model (1) comprises a main pipeline (11) and a small pipe (12), the root of the small pipe (12) is welded to the peripheral side of the main pipeline (11), the connection between the root of the small pipe (12) and the peripheral side of the main pipeline (11) has a weld structure (13), the force loading mechanism (2) is arranged on the outer end of the small pipe (12), the force loading mechanism (2) comprises a weight (21), the first port of the main pipeline (11) is communicated with the second port of the corrosive medium storage container (3), the first port of the corrosive medium storage container (3) is communicated with the second port of the circulation pump (4), and the first port of the circulation pump (4) is communicated with the second port of the main pipeline (11); It also includes a regulating pipeline (5), on which a stop valve (51) and a flow detection device (52) are provided; A pressure regulating mechanism (6), the pressure regulating mechanism (6) being used to regulate the internal pressure of the corrosive medium storage container (3); A temperature regulating mechanism (7), the temperature regulating mechanism (7) comprising a temperature controller (71) and an electric heating tube (72), the temperature controller (71) being electrically connected to the electric heating tube (72), and the electric heating tube (72) being arranged inside the corrosive medium storage container (3); The force loading mechanism (2) also includes a loading rod (22).

2. A test device for simulating corrosion of small pipes under stress conditions according to claim 1, characterized in that: The regulating pipe (5) is arranged at the first port of the main pipe (11), and the first port of the main pipe (11) is connected to the second port of the corrosive medium storage container (3) through the regulating pipe (5), or the regulating pipe (5) is arranged at the second port of the main pipe (11), and the second port of the main pipe (11) is connected to the first port of the circulation pump (4) through the regulating pipe (5).

3. A test device for simulating corrosion of small pipes under stress conditions according to claim 1 or 2, characterized in that: It comprises a plurality of the test models (1), wherein the plurality of the test models (1) are arranged in parallel.

4. A test device for simulating corrosion of small pipes under stress conditions according to claim 1, characterized in that: The loading rod (22) is connected to the outer end of the small connecting pipe (12); an adjusting slide rail (221) is provided on the loading rod (22); a sliding block (222) is provided on the adjusting slide rail (221) for sliding along the adjusting slide rail; the weight (21) is slidably arranged on the loading rod (22) along the adjusting slide rail (221) via the sliding block (222); the distance between the weight (21) and the small connecting pipe (12) is adjusted via the adjusting slide rail (221).

5. The test device for simulating corrosion of small pipes under stress conditions according to claim 1, characterized in that: The corrosive medium storage container (3) is provided with a pressure detection device (31), and the pressure detection device (31) is used to detect the internal pressure of the corrosive medium storage container (3).

6. A test device for simulating corrosion of small pipes under stress conditions according to claim 5, characterized in that: The pressure regulating mechanism (6) comprises a pressure vessel (61), a regulating gas valve (62), a switch gas valve (63) and a gas pipeline (64); the gas outlet port of the pressure vessel (61) is connected to the gas inlet port of the corrosive medium storage container (3) via the gas pipeline (64); the regulating gas valve (62) is arranged at the gas outlet port of the pressure vessel (61); and the switch gas valve (63) is arranged on the gas pipeline (64).

7. The test device for simulating corrosion of small pipes under stress conditions according to claim 1, characterized in that: The temperature regulating mechanism (7) is used to regulate the temperature of the corrosive medium inside the corrosive medium storage container (3). The corrosive medium storage container (3) is provided with a temperature detection device (32). The temperature detection device (32) is used to detect the temperature of the corrosive medium inside the corrosive medium storage container (3).

8. A test method for simulating corrosion of small pipes under stress conditions, characterized in that: The test device for simulating corrosion of small pipes under stress conditions according to any one of claims 1 to 7 comprises the following steps: Step S1, configuring a test model with corresponding parameters (1); Step S2, preparing a corrosive medium of corresponding components, and placing the corrosive medium in a corrosive medium storage container (3); Step S3, using the regulating pipe (5) to regulate the flow rate of the main pipe (11) in the test model (1); using the pressure regulating mechanism (6) to regulate the internal pressure of the corrosive medium storage container (3); using the temperature regulating mechanism (7) to regulate the temperature of the corrosive medium in the corrosive medium storage container (3); and using the loading rod (22) to regulate the force loading parameters of the force loading mechanism (2); Step S4, setting the test time, starting the circulation pump (4) and the force loading device until the test time ends; Step S5, detecting the state of the weld structure (13) in the test model (1).

9. A test method for simulating corrosion of small pipes under stress conditions according to claim 8, characterized in that: The step S5, detecting the state of the weld structure (13) in the test model (1), also includes: the means of detecting the test model (1) includes penetration testing and / or ultrasonic testing.

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