Multi-atmosphere high-temperature stress corrosion tensile test device and method

Abstract

The invention belongs to the technical field of corrosion and protection, and particularly relates to a multi-atmosphere high-temperature stress corrosion tensile test device and method.The multi-atmosphere high-temperature stress corrosion tensile test device comprises a tensile testing machine, a temperature control device, a sample, a telescopic pipe and an air supply device; the tensile testing machine is provided with clamps which are symmetrically arranged up and down and are used for clamping a sample, and the clamps are provided with flange plates which are hermetically connected with the telescopic pipe; the sample is clamped on a tensile testing machine clamp; the temperature control device is used for heating and preserving heat of the test environment; two ends of the telescopic pipe are hermetically connected with an upper clamp and a lower clamp of the tensile testing machine through flanges; the telescopic pipe is sleeved outside the sample to isolate the sample from the outside; and the air supply device is connected with the telescopic pipe and is used for filling air into the telescopic pipe. Influence factors such as corrosive gas flow and temperature can be independently regulated and controlled, high-temperature corrosion tests in complex environments can be realized, and requirements of material performance tests under different working conditions are met; and the manufacturing cost is low.

Description

Technical Field

[0001] The invention belongs to the technical field of corrosion and protection, and in particular relates to a multi-atmosphere high-temperature stress corrosion tensile testing device and method. Background Art

[0002] The corrosion of metal materials has always been a key factor restricting the safe operation of equipment. For example, 316L stainless steel, thanks to its excellent comprehensive mechanical properties and corrosion resistance, is widely used in the thermonuclear industry, petrochemical industry, and other fields. In the oil industry, 316L stainless steel is often used for oilfield pipelines and storage tanks due to its high corrosion resistance to media such as CO2.

[0003] However, when hydrogen sulfide is present in the environment, 316L stainless steel can be poisoned, causing accelerated growth of SCC (stress corrosion cracking), posing a potential risk to related equipment. The combined effects of temperature, corrosive media, and mechanical factors can make equipment highly susceptible to corrosive damage. This corrosion often causes equipment and components to break suddenly and rapidly without any prior signs of deformation.

[0004] Currently, stress corrosion testing equipment for metal materials has many shortcomings. For example, most devices struggle to precisely control the atmosphere of multiple corrosive gases, making them unable to simulate complex, actual operating conditions. Temperature control accuracy is insufficient, affecting the accuracy of test results. Furthermore, the devices are complex in structure, expensive to manufacture, and cumbersome to operate, making them difficult to meet the demands of efficient testing.

[0005] Therefore, there is an urgent need to design a high-temperature stress corrosion tensile testing device and method that can accurately control multiple atmospheres, control temperature with high precision, has a simple structure and low cost, in order to cope with the potential risks faced in practical applications. Summary of the Invention

[0006] The present invention belongs to the field of corrosion and protection technology, and specifically relates to a multi-atmosphere high-temperature stress corrosion tensile testing device and method. The device has the characteristics of being able to individually control influencing factors such as the corrosion gas flow rate and temperature, being able to realize high-temperature corrosion testing in complex environments, having low manufacturing costs, and being able to address the potential risks mentioned in the technical background.

[0007] To achieve the above-mentioned object, the present invention adopts the following specific technical solutions: a multi-atmosphere high-temperature stress corrosion tensile testing device, comprising a tensile testing machine, a temperature control device, a specimen, a telescopic tube, and a gas supply device;

[0008] The tensile testing machine is provided with a fixture symmetrically arranged up and down for clamping the sample, and the fixture is provided with a flange for sealing connection with the telescopic tube;

[0009] The specimen is clamped on the clamp of the tensile testing machine;

[0010] The temperature control device heats and keeps the test environment warm;

[0011] The two ends of the telescopic tube are sealedly connected to the upper and lower clamps of the tensile testing machine through flanges; the telescopic tube is sleeved on the outside of the sample to isolate the sample from the outside;

[0012] The air supply device is connected to the telescopic tube, and the air supply device fills gas into the telescopic tube.

[0013] Furthermore, the middle part of the telescopic tube is a bellows structure, with a through cylinder at each end. The ends of the through cylinder are sealed with flanges, and the flanges on the through cylinders are connected to the flanges on the tensile testing machine fixture; a sealing ring and a pressure ring are arranged between the two flanges; and the two flanges are sealed and connected by hexagonal bolts.

[0014] Furthermore, the temperature control device includes a temperature controller, a heating device and a temperature sensor;

[0015] The temperature controller is connected to the heating device and the temperature sensor via a wire;

[0016] The heating device is a heating rod, one end of which is connected to the temperature controller wire, and the other end extends into the telescopic tube to heat the test environment;

[0017] One end of the temperature sensor is connected to the temperature controller wire, and the other end extends into the interior of the telescopic tube.

[0018] Furthermore, the gas supply device includes a gas cylinder and a flow controller;

[0019] The flow controller has an air inlet and an air outlet, the air inlet is connected to the gas cylinder through an air pipe, and the air outlet is connected to the inside of the telescopic tube through the air pipe;

[0020] The gas cylinder is connected to the gas inlet of the flow controller through a gas pipe, and the gas cylinders are respectively filled with hydrogen sulfide gas, nitrogen and oxygen.

[0021] Furthermore, the air supply device also includes an exhaust device; the exhaust device is a container filled with 10% sodium hydroxide solution, which is connected to the telescopic tube through an air pipe.

[0022] A multi-atmosphere high-temperature stress corrosion tensile test method comprises the following steps:

[0023] S1: Install the specimen and the telescopic tube on the tensile testing machine;

[0024] S2: Connect one end of the heating device and temperature sensor to the temperature controller, and insert the other end into the telescopic tube. Set the program to control the temperature from room temperature to 200℃ and keep it warm.

[0025] S3: Connect the hydrogen sulfide, nitrogen, and oxygen cylinders to the air inlet of the flow controller through the air pipe, and then connect the air pipe of the air outlet to the inside of the telescopic tube;

[0026] S4: Connect the exhaust device to the bottom of the telescopic tube through the air pipe;

[0027] S5: Start the tensile testing machine, apply tensile stress to the sample, and record the temperature, gas flow, stress and displacement data in real time;

[0028] S6: After the test, analyze and test the sample.

[0029] Furthermore, in step S1, installing the sample and the telescopic tube on the tensile testing machine specifically includes: first, sealingly connecting the lower end of the telescopic tube to the clamp on the lower side of the tensile testing machine, compressing the telescopic tube downward to put the telescopic tube into a compressed state, and clamping the sample between the upper and lower clamps of the tensile testing machine; extending the telescopic tube upward, and sealingly connecting the upper end of the telescopic tube to the flange of the upper clamp; at this time, the telescopic tube encloses the sample inside.

[0030] The present invention can achieve the following technical effects:

[0031] The present invention provides a multi-atmosphere high-temperature stress corrosion tensile testing device and method. The device has the characteristics of independently regulating influencing factors such as corrosion gas flow rate and temperature, which can realize high-temperature corrosion testing in complex environments and meet the needs of material performance testing under different working conditions; and has the characteristics of low manufacturing cost.

[0032] The present invention realizes precise control of temperature through the cooperation of the temperature controller, the heating device and the temperature measuring sensor, and the flow controller can control the gas flow to ensure the stability and repeatability of the test conditions. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1 This is a flow chart of the multi-atmosphere high-temperature stress corrosion tensile test method disclosed in the present invention;

[0034] Figure 2 This is a structural diagram of the multi-atmosphere high-temperature stress corrosion tensile testing device disclosed in the present invention.

[0035] In the picture:

[0036] 1. Tensile testing machine, 2. Temperature controller, 3. Heating device, 4. Temperature sensor, 5. Specimen, 6. Telescopic tube, 7. Exhaust device, 8. Flow controller, 9. Gas cylinder. DETAILED DESCRIPTION

[0037] In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, the present invention will be further described in detail below in conjunction with the accompanying drawings and specific embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and do not constitute a limitation of the present invention.

[0038] refer to Figure 1-2 , a multi-atmosphere high-temperature stress corrosion tensile testing device, comprising a tensile testing machine 1, a temperature control device, a specimen 5, a telescopic tube 6 and an air supply device;

[0039] The tensile testing machine 1 is the main structure of the device. The tensile testing machine 1 is a frame-type main structure with upper and lower symmetrically arranged clamps for clamping the sample 5. The clamps are provided with flanges for sealing connection with the telescopic tube 6. The tensile testing machine 1 provides mechanical support and tensile stress for the test. The upper and lower clamps clamp the sample 5, applying tensile stress to the sample 5 to simulate the mechanical loads to which the material is subjected in actual working conditions.

[0040] Specimen 5 is cylindrical with a length of 10 cm and a diameter of 1 cm. Both ends of specimen 5 are notched according to ASTM G49 standard and clamped in the fixture of tensile testing machine 1 as the stress corrosion test object.

[0041] The temperature control device controls the heating device 3 to heat and keep the test environment warm through the temperature controller 2, and monitors the temperature of the test environment in real time through the temperature sensor 4;

[0042] The two ends of the telescopic tube 6 are sealedly connected to the upper and lower clamps of the tensile testing machine 1 through flanges; the telescopic tube 6 is sleeved on the outside of the sample 5 to isolate the sample 5 from the outside;

[0043] The gas supply device is connected to the telescopic tube 6, and the gas supply device fills the telescopic tube 6 with gas to perform the experiment.

[0044] Furthermore, the telescopic tube 6 is a hollow tube with a bellows structure in the middle. The bellows structure in the middle is elastic and can expand and contract along with the deformation of the sample 5 when the sample 5 is stretched, without affecting the tensile test of the sample 5, while maintaining the sealing of the test space.

[0045] Each end of the telescopic tube 6 has a hollow cylinder with a height of 3 cm and a diameter of 5 cm. The ends of the hollow cylinder are sealed with flanges, which are connected to the flanges on the fixture of the tensile testing machine 1; a sealing ring and a pressure ring are provided between the two flanges; the two flanges are sealed and connected by hexagonal bolts to form a closed test space and accommodate the tensile deformation of the specimen 5.

[0046] Furthermore, the temperature control device includes a temperature controller 2, a heating device 3 and a temperature sensor 4;

[0047] The temperature controller 2 is connected to the heating device 3 and the temperature sensor 4 through wires, and is used to set the heating program, control the operation of the heating device 3 and monitor the test temperature;

[0048] The heating device 3 is a heating rod, one end of which is connected to the wire of the temperature controller 2, and the other end of which extends into the interior of the telescopic tube 6, for heating the test environment;

[0049] The temperature sensor 4 is a slender rod-shaped thermocouple, one end of which is connected to the wire of the temperature controller 2 and the other end extends into the interior of the telescopic tube 6, and is used to measure the test temperature in real time and transmit signals to the temperature controller 2.

[0050] Furthermore, the gas supply device includes a gas cylinder 9 and a flow controller 8;

[0051] The flow controller 8 has an air inlet and an air outlet. The air inlet is connected to the gas cylinder 9 through an air pipe, and the air outlet is connected to the inside of the telescopic tube 6 through an air pipe. The flow controller 8 controls the gas flow from the gas cylinder 9 into the telescopic tube 6. The flow ratio of different gases is adjusted according to the test requirements to achieve accurate simulation of multiple atmosphere environments.

[0052] It should be noted that the heating device 3, temperature sensor 4, flow controller 8 and exhaust device, which extend into the telescopic tube or are connected to the telescopic tube, need to be sealed with Maitu TSE382 high-temperature sealant to prevent air leakage.

[0053] The gas cylinder 9 is a cylindrical container, which is connected to the gas inlet of the flow controller 8 through a gas pipe and is used to store the gas required for the test. The gas cylinder 9 has three gas cylinders respectively filled with hydrogen sulfide gas, nitrogen and oxygen.

[0054] Furthermore, the gas supply device also includes an exhaust device 7; the exhaust device 7 is a container filled with 10% sodium hydroxide solution, which is connected to the telescopic tube 6 through an air pipe and is used to treat test waste gas, such as corrosive gases such as hydrogen sulfide, by chemically reacting the sodium hydroxide solution with the waste gas to absorb it and prevent the waste gas from being discharged into the environment and causing pollution.

[0055] Working principle of a multi-atmosphere high-temperature stress corrosion tensile testing device

[0056] First, the sample 5 is clamped on the fixture of the tensile testing machine 1, and sealed to the fixture through the telescopic tube 6 to form a closed test space. The temperature controller 2 heats the test space by controlling the heating device 3, and uses the temperature sensor 4 to monitor the temperature in real time to achieve the temperature conditions required for the test. The gas in the gas cylinder 9 enters the test space after the flow is adjusted by the flow controller 8, providing the required multi-atmosphere environment for the test. During the test, the tensile testing machine 1 applies tensile stress to the sample 5 to simulate the mechanical effects that the material is subjected to in actual use. The exhaust gas generated by the test is treated through the exhaust device 7 to prevent environmental pollution. By separately regulating factors such as temperature, gas flow, and stress, high-temperature corrosion tests in complex environments can be achieved, thereby studying the stress corrosion behavior of materials under different conditions.

[0057] The present invention also discloses a multi-atmosphere high-temperature stress corrosion tensile test method, comprising the following steps:

[0058] S1: Install the sample 5 and the telescopic tube 6 on the tensile testing machine 1;

[0059] S2: Connect one end of the heating device 3 and the temperature sensor 4 to the temperature controller 2, and extend the other end into the telescopic tube 6. Set the program to control the temperature from room temperature to 200°C and keep it warm; and monitor the temperature of the test environment in real time through the temperature sensor 4 to ensure that the temperature is stable within the set range.

[0060] S3: After the temperature stabilizes, open the hydrogen sulfide, nitrogen, and oxygen cylinders 9. According to the test requirements, set the flow rate of each gas through the flow controller 8 so that the gas enters the experimental space at the set flow rate to form the required multi-atmosphere environment.

[0061] S4: Connect the exhaust device 7 to the bottom of the telescopic tube 6 through the air pipe, and use 10% sodium hydroxide solution to treat the exhaust gas;

[0062] S5: Start the tensile testing machine 1 and start the multi-atmosphere high-temperature stress corrosion tensile test. During the test, the temperature, gas flow, stress and other parameters are monitored in real time and the test data are recorded.

[0063] S6: After the test, sample 5 was analyzed and tested to study the stress corrosion behavior of the material in a multi-atmosphere high-temperature environment.

[0064] Furthermore, in step S1, installing the specimen 5 and the telescopic tube 6 on the tensile testing machine 1 specifically includes: first, sealingly connecting the lower end of the telescopic tube 6 to the clamp on the lower side of the tensile testing machine 1, compressing the telescopic tube 6 downward to put the telescopic tube 6 into a compressed state. In this state, the telescopic tube 6 will not interfere with the installation of the specimen 5 on the clamp. According to the ASTM G49 standard, a notched tensile specimen 5 is used, and a cylindrical specimen 5 with a length of 10 cm and a diameter of 1 cm is clamped between the upper and lower clamps of the tensile testing machine 1, ensuring that the axis of the specimen 5 coincides with the axis of the tensile machine; when both ends of the specimen 5 are tightened on the clamps, the telescopic tube 6 is extended upward, and the upper end of the telescopic tube 6 is sealed to the flange of the upper clamp; at this time, the telescopic tube 6 encloses the specimen 5 inside, and the experiment can be carried out.

[0065] In the description of this specification, the reference terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" mean that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art can combine and combine different embodiments or examples described in this specification and features of different embodiments or examples without contradiction.

[0066] Although the embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those skilled in the art may make changes, modifications, substitutions, and variations to the above embodiments within the scope of the present invention.

[0067] The above specific embodiments of the present invention do not constitute a limitation on the scope of protection of the present invention. Any other corresponding changes and modifications made based on the technical concept of the present invention should be included in the scope of protection of the claims of the present invention.

Claims

1. A multi-atmosphere high-temperature stress corrosion tensile testing device, characterized in that: It comprises a tensile testing machine (1), a temperature control device, a specimen (5), a telescopic tube (6) and an air supply device; The tensile testing machine (1) has a clamp symmetrically arranged up and down for clamping the sample (5), and the clamp is provided with a flange for sealing connection with the telescopic tube (6); The sample (5) is clamped on the clamp of the tensile testing machine (1); The temperature control device heats and keeps the test environment warm; The two ends of the telescopic tube (6) are sealedly connected to the upper and lower clamps of the tensile testing machine (1) through flanges; the telescopic tube (6) is sleeved on the outside of the sample (5) to isolate the sample (5) from the outside; The gas supply device is connected to the telescopic tube (6), and the gas supply device fills gas into the telescopic tube (6).

2. The multi-atmosphere high-temperature stress corrosion tensile testing device according to claim 1, characterized in that: The middle part of the telescopic tube (6) is a bellows structure, with a through cylinder at each end. The ends of the through cylinder are sealed with flanges, and the flanges on the through cylinders are connected to the flanges on the clamp of the tensile testing machine (1); a sealing ring and a pressure ring are provided between the two flanges; and the two flanges are sealed and connected by hexagonal bolts.

3. The multi-atmosphere high-temperature stress corrosion tensile testing device according to claim 1, characterized in that: The temperature control device comprises a temperature controller (2), a heating device (3) and a temperature sensor (4); The temperature controller (2) is connected to the heating device (3) and the temperature sensor (4) via wires; The heating device (3) is a heating rod, one end of which is connected to the wire of the temperature controller (2), and the other end of which extends into the interior of the telescopic tube (6) for heating the test environment; One end of the temperature sensor (4) is connected to the wire of the temperature controller (2), and the other end extends into the interior of the telescopic tube (6).

4. The multi-atmosphere high-temperature stress corrosion tensile testing device according to claim 1, characterized in that: The gas supply device comprises a gas cylinder (9) and a flow controller (8); The flow controller (8) has an air inlet and an air outlet, the air inlet is connected to the gas cylinder (9) through an air pipe, and the air outlet is connected to the inside of the telescopic tube (6) through the air pipe; The gas cylinder (9) is connected to the gas inlet of the flow controller (8) through an air pipe. The gas cylinder (9) has three gas cylinders respectively filled with hydrogen sulfide gas, nitrogen gas and oxygen gas.

5. The multi-atmosphere high-temperature stress corrosion tensile testing device according to claim 4, characterized in that: The air supply device further comprises an exhaust device (7); the exhaust device (7) is a container filled with 10% sodium hydroxide solution and is connected to the telescopic tube (6) through an air pipe.

6. A multi-atmosphere high-temperature stress corrosion tensile test method, characterized in that: The following steps are involved: S1: Install the sample (5) and the telescopic tube (6) on the tensile testing machine (1); S2: Connect one end of the heating device (3) and the temperature sensor (4) to the temperature controller (2), and extend the other end into the interior of the telescopic tube (6), set the program to control the temperature and keep it warm; S3: Connect the gas cylinder (9) to the gas inlet of the flow controller (8) through the gas pipe, and then connect the gas pipe of the gas outlet to the inside of the telescopic tube (6); S4: Connect the exhaust device (7) to the bottom of the telescopic tube (6) through the air pipe; S5: starting the tensile testing machine (1), applying tensile stress to the sample (5), and recording temperature, gas flow, stress and displacement data in real time; S6: After the test, the sample (5) is analyzed and tested.

7. The multi-atmosphere high-temperature stress corrosion tensile testing method according to claim 6, characterized in that: In step S1, the sample (5) and the telescopic tube (6) are mounted on the tensile testing machine (1), specifically comprising: first, sealingly connecting the lower end of the telescopic tube (6) to the clamp on the lower side of the tensile testing machine (1), compressing the telescopic tube (6) downward to put the telescopic tube (6) in a compressed state, and clamping the sample (5) between the upper and lower clamps of the tensile testing machine (1); extending the telescopic tube (6) upward, and sealingly connecting the upper end of the telescopic tube (6) to the flange of the upper clamp; at this time, the telescopic tube (6) encloses the sample (5) inside.

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