An oxygen-controlled liquid lead-bismuth stress corrosion experiment device and experiment method

Abstract

The present application relates to a kind of oxygen control liquid lead bismuth stress corrosion experimental device, including experimental jar, vacuum system, temperature control system, cooling system, oxygen control system, stress loading system, experimental jar upper cover electric lifting system and stress loading system electric lifting system, experimental jar is equipped with vacuum system, temperature control system, cooling system and oxygen control system respectively, experimental jar upper cover electric lifting system is connected with experimental jar upper cover, experimental jar upper cover electric lifting system can drive experimental jar upper cover to realize rising or falling, stress loading system electric lifting system is connected with stress loading system, stress loading system electric lifting system can drive experimental sample on stress loading system to extend into or extend out the jar body of experimental jar.The present application can carry out liquid lead bismuth corrosion and stress combined research experiment under different oxygen concentration conditions.

Description

Technical Field

[0001] This invention relates to the field of stress corrosion testing technology, specifically to a controlled-oxygen liquid lead-bismuth stress corrosion testing apparatus and method. Background Technology

[0002] Liquid lead-bismuth alloys possess excellent neutronics and physicochemical properties, making them the preferred coolant material for lead-cooled fast reactors. However, structural materials exposed to liquid lead-bismuth and stress may undergo stress corrosion, leading to brittle fracture under low stress. This unpredictable and highly hazardous phenomenon poses a significant threat to the safe operation of lead-cooled fast reactors. Therefore, conducting stress corrosion experiments on structural materials in a liquid lead-bismuth environment and evaluating their stress corrosion performance to provide reliable data support for engineering applications is of great importance to the research and development of lead-cooled fast reactors.

[0003] Currently, there are two main methods for conducting stress corrosion experiments in a liquid lead-bismuth environment. One method involves adding a liquid lead-bismuth corrosion environment to a tensile testing machine to achieve stress corrosion under such an environment. The other method involves conducting a C-ring test within the liquid lead-bismuth corrosion environment. Each method has its advantages and disadvantages. The C-ring test allows for simultaneous stress corrosion experiments on multiple samples, but in the high-temperature corrosion environment, materials are prone to high-temperature creep, making it difficult to determine the stress values ​​during the test. While the tensile testing machine with a liquid lead-bismuth corrosion environment can determine the stress values, only one sample can be used for the stress corrosion test. Furthermore, dissolved oxygen in liquid lead-bismuth affects the wettability of the liquid lead-bismuth to the material, thus impacting the material's stress corrosion performance.

[0004] In summary, existing experimental methods for evaluating the stress corrosion performance of liquid lead-bismuth in structural materials are either inaccurate or inefficient, failing to meet the engineering needs for assessing the stress corrosion performance of materials in this state. Therefore, it is essential to develop novel oxygen-controlled liquid lead-bismuth stress corrosion experimental devices and to improve stress corrosion testing methods while simultaneously enhancing the efficiency and accuracy of material stress corrosion performance assessment.

[0005] Therefore, there is an urgent need for an oxygen-controlled liquid lead-bismuth stress corrosion experimental device. Summary of the Invention

[0006] This invention provides, in one aspect, an oxygen-controlled liquid lead-bismuth stress corrosion experimental apparatus, aiming to solve the problem of low efficiency in evaluating the stress corrosion performance of liquid lead-bismuth in existing technologies. This invention also provides an oxygen-controlled liquid lead-bismuth stress corrosion experimental method.

[0007] To achieve the above objectives, the present invention adopts the following technical solution:

[0008] The first aspect of this invention provides an oxygen-controlled liquid lead-bismuth stress corrosion experimental apparatus, comprising an experimental tank, a vacuum system, a temperature control system, a cooling system, an oxygen control system, a stress loading system, an electric lifting system for the experimental tank lid, and an electric lifting system for the stress loading system. The experimental tank is respectively equipped with the vacuum system, the temperature control system, the cooling system, and the oxygen control system. The electric lifting system for the experimental tank lid is connected to the experimental tank lid and can drive the experimental tank lid to rise or fall. The electric lifting system for the stress loading system is connected to the stress loading system and can drive the experimental sample on the stress loading system to extend into or out of the tank body of the experimental tank.

[0009] Preferably, in the oxygen-controlled liquid lead-bismuth stress corrosion experimental apparatus, the vacuum system includes a vacuum mechanical pump, a vacuum solenoid valve, an extraction pipe, a vacuum measuring element, a vacuum shut-off valve, a vacuum venting valve, and a vacuum display instrument. The experimental vessel is provided with an outlet pipe. One end of the extraction pipe is connected to the outlet pipe, and the other end of the extraction pipe is connected to the vacuum mechanical pump through the vacuum solenoid valve. The outlet pipe is provided with the vacuum shut-off valve, the vacuum measuring element, and the vacuum venting valve in sequence.

[0010] Preferably, in the oxygen-controlled liquid lead-bismuth stress corrosion experimental apparatus, the temperature control system includes a temperature-controlled thermocouple, a heating power supply, a silicon controlled rectifier (SCR), an intelligent temperature controller, an armored heating wire, an insulation shell, and a liftable temperature-measuring thermocouple. The armored heating wire and the insulation shell sequentially cover the exterior of the experimental vessel. The temperature-controlled thermocouple passes through the insulation shell and is in close contact with the outer wall of the experimental vessel. The liftable temperature-measuring thermocouple is connected to the interior of the experimental vessel through a liftable temperature-measuring thermocouple interface provided on the top cover of the experimental vessel. The liftable temperature-measuring thermocouple and the top cover of the experimental vessel are connected by a dynamic seal. The temperature-controlled thermocouple and the liftable temperature-measuring thermocouple are respectively connected to the intelligent temperature controller. The heating power supply is connected to the intelligent temperature controller through the SCR and is connected to the armored heating wire.

[0011] Preferably, in the oxygen-controlled liquid lead-bismuth stress corrosion experimental apparatus, the cooling system includes a chiller, a cooling water pipe, and a water valve. The experimental tank cover is provided with a cooling water pipe interface. The chiller is connected to the experimental tank cover through the cooling water pipe, and the cooling water pipe is provided with the water valve.

[0012] Preferably, in the oxygen-controlled liquid lead-bismuth stress corrosion experimental apparatus, the oxygen control system includes a gas source, a gas pipeline, an oxygen concentration control device, a liftable oxygen probe, an inlet pipe, an inlet valve, and a check valve. The gas source is connected to the oxygen concentration control device through the gas pipeline. The oxygen concentration control device is connected to the experimental tank through the inlet pipe. The interface between the inlet pipe and the experimental tank is located on the upper part of the tank body. The inlet pipe is equipped with the inlet valve, and the gas outlet of the inlet pipe is located at the bottom of the experimental tank. The outlet pipe is equipped with a check valve. The experimental tank is equipped with a liftable oxygen probe interface. The liftable oxygen probe is mounted on the upper cover of the experimental tank through the liftable oxygen probe interface, and the liftable oxygen probe is connected to the upper cover of the experimental tank through a dynamic seal. The signal output terminal of the liftable oxygen probe is connected to the oxygen concentration control device.

[0013] The oxygen-controlled liquid lead-bismuth stress corrosion experimental apparatus, preferably, includes an oxygen concentration control device comprising a gas regulating valve, a gas flow meter, and an oxygen concentration analyzer. The gas flow meter and the gas regulating valve are respectively installed on the gas pipeline, and the oxygen concentration analyzer is connected to the signal output terminal of the liftable oxygen probe.

[0014] The oxygen-controlled liquid lead-bismuth stress corrosion experimental apparatus, preferably, includes a stress loading system comprising a fixed frame, an experimental sample rack, a tension rod, a pulley counterweight device, a first dynamic seal, and a second dynamic seal. One end of the fixed frame is connected to the electric lifting system of the stress loading system, and the other end of the fixed frame extends into the interior of the experimental tank, forming a semi-sealed chamber between the fixed frame and the top cover of the experimental tank. One end of the tension rod is connected to the pulley counterweight device, and the other end of the tension rod extends into the semi-sealed chamber. The other end of the tension rod is provided with the experimental sample rack, allowing the experimental sample rack to be suspended within the semi-sealed chamber. The upper end of the experimental sample is movably connected to the experimental sample rack, and the lower end of the experimental sample is movably connected to the fixed frame. The connection between the semi-sealed chamber and the tension rod is provided with the first dynamic seal, and the connection between the semi-sealed chamber and the top cover of the experimental tank is provided with the second dynamic seal.

[0015] The oxygen-controlled liquid lead-bismuth stress corrosion experimental apparatus, preferably, includes an electric lifting system for the experimental tank lid comprising a lid lifting motor, a lid transmission screw, a lid guide rod, a lid limiting device, and a lid lifting controller. The lid lifting controller is connected to the lid lifting motor, the lid lifting motor is connected to the lid transmission screw, a slider on the lid transmission screw is connected to the lid, and the lid is fitted onto the lid guide rod. When the lid lifting motor drives the lid to rise or fall via the lid transmission screw, the lid will move along the lid guide rod. The lid guide rod is equipped with the lid limiting device.

[0016] And / or, each of the stress loading system electric lifting systems includes a stress loading system lifting motor, a stress loading system transmission screw, a stress loading system guide rod, a stress loading system limit device, and a stress loading system lifting controller. The stress loading system lifting controller is connected to the stress loading system lifting motor, the stress loading system lifting motor is connected to the stress loading system transmission screw, the slider on the stress loading system transmission screw is connected to the fixed frame, and the fixed frame is sleeved on the stress loading system guide rod. When the stress loading system lifting motor drives the fixed frame to rise or fall through the stress loading system transmission screw, the fixed frame will move along the direction of the stress loading system guide rod. The stress loading system limit device is provided on the stress loading system guide rod.

[0017] A second aspect of the present invention provides a method for experimental testing of oxygen-controlled liquid lead-bismuth stress corrosion, comprising using the aforementioned oxygen-controlled liquid lead-bismuth stress corrosion experimental apparatus, and the specific experimental steps including:

[0018] Start the electric lifting system of the experimental vessel lid to raise the lid of the experimental vessel, put in the lead-bismuth alloy ingot, lower the lid of the experimental vessel to seal the experimental vessel, turn on the vacuum mechanical pump to evacuate the air, and turn on the temperature control system to heat until the lead-bismuth ingot is completely melted into liquid.

[0019] Remove the scum from the surface of the liquid lead-bismuth. When the liquid level of the lead-bismuth alloy reaches the predetermined height, load the experimental sample onto the experimental sample holder and add counterweights to keep the experimental sample in a vertical state.

[0020] Under vacuum conditions in the experimental vessel, the temperature of the liquid lead-bismuth alloy and the oxygen content of the experimental vessel are adjusted by the temperature control system and the oxygen control system respectively, so that the temperature and oxygen content of the liquid lead-bismuth alloy meet the experimental requirements.

[0021] Adjust the counterweights to bring the stress on the experimental sample to the predetermined target, then activate the electric lifting system of the stress loading system to lower the experimental sample rack, so that the liquid lead bismuth can completely immerse the experimental sample.

[0022] Monitor the stress corrosion state of the experimental sample, and end the stress corrosion experiment when the experimental sample breaks or reaches the predetermined corrosion time.

[0023] Preferably, in the oxygen-controlled liquid lead-bismuth stress corrosion test method, when the liquid level of the lead-bismuth alloy has not reached the predetermined height, the temperature control system is turned off. After the temperature of the lead-bismuth alloy in the test vessel drops to room temperature, the steps of "starting the electric lifting system of the test vessel cover to raise the test vessel cover, placing the lead-bismuth alloy ingot in it, lowering the test vessel cover to seal the test vessel, turning on the vacuum mechanical pump to evacuate the air, and turning on the temperature control system to heat the vessel until the lead-bismuth ingot is completely melted into a liquid state" and "removing the scum from the surface of the liquid lead-bismuth alloy" are repeated until the liquid level of the lead-bismuth alloy reaches the predetermined height.

[0024] The present invention has the following advantages due to the adoption of the above technical solutions:

[0025] The oxygen-controlled liquid lead-bismuth stress corrosion experimental device described in this invention can conduct research experiments on the combination of liquid lead-bismuth corrosion and stress under different oxygen concentration conditions.

[0026] The stress loading system described in this invention can simultaneously provide different loads to multiple experimental samples, enabling multiple experimental samples under different stress states to undergo liquid lead-bismuth corrosion experiments at the same time.

[0027] This invention uses counterweights to apply loads to experimental samples. By adjusting the counterweights, quasi-continuous load conditions with intervals of 0.01 kgf can be provided within the range of 1-100 kgf. Attached Figure Description

[0028] Figure 1 A front sectional view of the oxygen-controlled liquid lead-bismuth stress corrosion experimental setup;

[0029] Figure 2 This is a front sectional view of the stress loading system;

[0030] Figure 3 This is a schematic diagram of the electrical control cabinet.

[0031] Figure 4 This is a magnified view of a portion of point A.

[0032] 1. Experimental container; 1-1. Container body; 1-2. Top cover of experimental container; 1-3. Sealing ring; 1-4. Cooling water chamber; 2. Vacuum system; 2-1. Vacuum mechanical pump; 2-2. Vacuum solenoid valve; 2-3. Vacuum extraction pipe;

[0033] 2-4. Vacuum measuring elements; 2-5. Vacuum shut-off valve; 2-6. Vacuum venting valve; 2-7. Vacuum display instrument;

[0034] 3-1. Temperature-controlled thermocouple; 3-2. Heating power supply; 3-3. Silicon control unit (SCR); 3-4. Intelligent temperature controller;

[0035] 3-5. Armored heating wire; 3-6. Insulation shell; 3-7. Adjustable temperature measuring thermocouple;

[0036] 4. Cooling system; 4-1. Chiller; 4-2. Cooling water pipes; 4-3. Water valves;

[0037] 5. Oxygen control system; 5-1. Gas source; 5-2. Gas pipeline; 5-3. Oxygen concentration control equipment; 5-4. Adjustable oxygen probe;

[0038] 5-5. Inlet pipe; 5-6. Outlet pipe; 5-7. Inlet valve; 5-8. Check valve; 5-9. Gas regulating valve;

[0039] 5-10. Gas flow meter; 5-11. Oxygen concentration analyzer;

[0040] 6. Stress loading system; 6-1. Semi-sealed chamber; 6-2. Experimental sample holder; 6-3. Tension bar; 6-4. Steel wire rope;

[0041] 6-5. Pulley block; 6-6. Counterweight; 6-7. First dynamic seal; 6-8. Second dynamic seal;

[0042] 6-9. Pulley block support; 6-10. Stress loading system support; 6-11. Fixing frame;

[0043] 7-1. Electric lifting system for the top cover of the experimental tank; 7-2. Lifting motor for the top cover of the experimental tank; 7-3. Drive screw for the top cover of the experimental tank; 7-4. Guide rod for the top cover of the experimental tank; 7-5. Limiting device for the top cover of the experimental tank; 7-6. Lifting controller for the top cover of the experimental tank;

[0044] 8. Electrical control cabinet;

[0045] 9-1. Electric lifting system for stress loading system; 9-2. Lifting motor for stress loading system; 9-3. Drive screw for stress loading system; 9-4. Guide rod for stress loading system; 9-5. Limit device for stress loading system; 9-6. Lifting controller for stress loading system;

[0046] 10-1, First pin; 10-2, Second pin;

[0047] 11. Experimental samples. Detailed Implementation

[0048] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this invention. All other embodiments obtained by those skilled in the art based on the embodiments of this invention without creative effort are within the scope of protection of this invention.

[0049] In the description of this invention, it should be noted that the terms "lower end", "upper end", "one end", "other end", "above", "below", "first" and "second", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the system or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limiting this invention.

[0050] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "set up" and "equipped with" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0051] This invention provides an oxygen-controlled liquid lead-bismuth stress corrosion experimental apparatus, comprising an experimental vessel, a vacuum system, a temperature control system, a cooling system, an oxygen control system, a stress loading system, an electric lifting system for the vessel lid, and an electric lifting system for the stress loading system. The experimental vessel is equipped with the vacuum system, the temperature control system, the cooling system, and the oxygen control system. The electric lifting system for the vessel lid is connected to the vessel lid and can raise or lower the lid. The electric lifting system for the stress loading system is connected to the stress loading system and can move the experimental sample on the stress loading system into or out of the vessel. This invention can simultaneously provide different loads to multiple experimental samples, allowing multiple samples under different stress states to undergo liquid lead-bismuth corrosion experiments simultaneously.

[0052] The following is a detailed description of an oxygen-controlled liquid lead-bismuth stress corrosion experimental apparatus provided by an embodiment of the present invention, with reference to the accompanying drawings.

[0053] Example 1

[0054] Reference Figure 1 and Figure 2The apparatus shown is an oxygen-controlled liquid lead-bismuth stress corrosion test device, comprising an experimental tank 1, a vacuum system 2, a temperature control system, a cooling system 4, an oxygen control system 5, a stress loading system 6, and an electric lifting system. The experimental tank 1 is equipped with the vacuum system 2, the temperature control system, the cooling system 4, and the oxygen control system 5. The electric lifting system is connected to the stress loading system 6 and the experimental tank cover 1-2. The electric lifting system can drive the experimental sample on the stress loading system 6 to extend into or out of the tank body 1-1 of the experimental tank, and the electric lifting system can also drive the experimental tank cover 1-2 to rise or fall.

[0055] Among them, experimental container 1 is a cylindrical vacuum sealed container. Experimental container 1 consists of container body 1-1, upper cover 1-2 and sealing ring 1-3. The upper cover 1-2 is provided with interfaces that are connected to vacuum system 2, temperature control system, cooling system 4, oxygen control system 5, stress loading system 6 and electric lifting system respectively. The upper cover 1-2 is also provided with cooling water chamber 1-4 for cooling the upper cover 1-2. Cooling water chamber 1-4 is connected to cooling system 4.

[0056] Continue to refer to Figure 1 As shown, the vacuum system 2 includes a vacuum mechanical pump 2-1, a vacuum solenoid valve 2-2, an evacuation pipe 2-3, a vacuum measuring element 2-4, a vacuum shut-off valve 2-5, a vacuum venting valve 2-6, and a vacuum display instrument 2-7. The experimental vessel body 1-1 is provided with an outlet pipe 5-6. One end of the evacuation pipe 2-3 is connected to the outlet pipe 5-6, and the other end of the evacuation pipe 2-3 is connected to the vacuum mechanical pump 2-1 through the vacuum solenoid valve 2-2. The outlet pipe 5-6 is provided with the vacuum shut-off valve 2-5, the vacuum measuring element 2-4, and the vacuum venting valve 2-6 in sequence.

[0057] Among them, vacuum system 2 can achieve a vacuum level of 1.0 × 10⁻⁶ inside the experimental container. -1 Pa.

[0058] Continue to refer to Figure 1As shown, the temperature control system includes a temperature-controlled thermocouple 3-1, a heating power supply 3-2, a silicon controlled rectifier (SCR) 3-3, an intelligent temperature controller 3-4, an armored heating wire 3-5, an insulation shell 3-6, and a liftable temperature-measuring thermocouple 3-7. The armored heating wire 3-5 and the insulation shell 3-6 sequentially cover the exterior of the experimental container 1-1. The temperature-controlled thermocouple 3-1 passes through the insulation shell 3-6 and is in close contact with the outer wall of the experimental container 1-1. The liftable temperature-measuring thermocouple 3-7 is connected to the interior of the experimental container 1 through a liftable temperature-measuring thermocouple 3-7 interface provided on the experimental container cover 1-2. The liftable temperature-measuring thermocouple 3-7 and the experimental container cover 1-2 are connected by a dynamic seal. The liftable temperature-measuring thermocouple 3-7 is used to measure the temperature of the liquid lead-bismuth alloy inside the experimental container 1. The dynamic seal includes two fluororubber O-rings and a metal sealing spacer sandwiched between the O-rings. When the fluororubber O-ring is compressed, it fills the gap in the metal sealing spacer to form a seal. At the same time, because fluororubber is elastic, the thermocouple can be raised and lowered by sliding inside the O-ring.

[0059] Among them, the temperature-controlling thermocouple 3-1 and the adjustable temperature-measuring thermocouple 3-7 are respectively connected to the intelligent temperature controller 3-4, the heating power supply 3-2 is connected to the intelligent temperature controller 3-4 through the silicon controlled rectifier 3-3, and the heating power supply 3-2 is connected to the armored heating wire 3-5.

[0060] The intelligent temperature controller 3-4 can set the required temperature of the experimental tank 1, and by comparing the difference between the set temperature and the feedback temperature of the temperature control thermocouple 3-1, it controls the conduction angle of the thyristor 3-3 to adjust the power of the heating power supply, so that the experimental tank 1 reaches the set temperature and maintains it. The temperature control system can control the temperature of the lead-bismuth alloy at RT-650℃.

[0061] Continue to refer to Figure 1 As shown, the cooling system 4 includes a chiller 4-1, a cooling water pipe 4-2, and a water valve 4-3. The experimental tank cover 1-2 is equipped with a cooling water pipe 4-2 interface. The chiller 4-1 is connected to the experimental tank cover 1-2 via the cooling water pipe 4-2. The cooling water pipe 4-2 is equipped with a water valve 4-3 and is connected to the cooling water chamber 1-4. The cooling water circulates sequentially through the chiller 4-1, cooling water pipe 4-2, cooling water chamber 1-4, cooling water pipe 4-2, and back to the chiller 4-1.

[0062] The cooling system 4 can keep the temperature of the experimental tank cover 1-2 below 50℃.

[0063] Continue to refer to Figure 1As shown, the oxygen control system 5 includes a gas source 5-1, a gas pipeline 5-2, an oxygen concentration control device 5-3, a liftable oxygen probe 5-4, an inlet pipe 5-5, an inlet valve 5-7, and a check valve 5-8. The gas source 5-1 is connected to the oxygen concentration control device 5-3 through the gas pipeline 5-2. The oxygen concentration control device 5-3 is connected to the experimental tank through the inlet pipe 5-5. The interface between the inlet pipe 5-5 and the experimental tank 1 is located at the upper part of the tank body 1-1. The inlet pipe 5-5 is equipped with an inlet valve 5-7. The gas outlet of the inlet pipe 5-5 is located at the bottom of the experimental tank 1, so that the gas enters the experimental tank 1 through the oxygen concentration control device 5-3 and is ejected from the bottom of the experimental tank 1. After the gas reacts with the lead-bismuth alloy, it is discharged from the outlet pipe 5-6. The outlet pipe 5-6 is equipped with a check valve 5-8, so that the gas can only flow unidirectionally from the experimental tank 1 outward. The experimental tank 1 is equipped with a liftable oxygen probe 5-4 interface. The liftable oxygen probe 5-4 is installed on the upper cover 1-2 of the experimental tank through the liftable oxygen probe 5-4 interface, and the liftable oxygen probe 5-4 and the upper cover 1-2 of the experimental tank are connected by a dynamic seal. The signal output terminal of the liftable oxygen probe 5-4 is connected to the oxygen concentration control device 5-3.

[0064] The dynamic seal consists of two fluororubber O-rings and a metal sealing spacer sandwiched between them. When the fluororubber O-rings are compressed, they fill the gaps in the metal sealing spacer to form a seal. At the same time, due to the elasticity of fluororubber, the liftable oxygen probe can be raised and lowered by sliding within the O-rings.

[0065] The oxygen concentration control device 5-3 includes a gas regulating valve 5-9, a gas flow meter 5-10, and an oxygen concentration analyzer 5-11. The gas flow meter 5-10 and the gas regulating valve 5-9 are respectively installed on the gas pipeline 5-2. The oxygen concentration analyzer 5-11 is connected to the signal output terminal of the liftable oxygen probe 5-4. The measured oxygen concentration is finally displayed on the oxygen concentration analyzer 5-11 and can be collected and recorded by a computer.

[0066] Continue to refer to Figure 1 and Figure 2As shown, the stress loading system 6 includes a fixed frame 6-11, an experimental sample rack 6-2, a tension rod 6-3, a pulley counterweight device, a first dynamic seal 6-7, and a second dynamic seal 6-8. One end of the fixed frame 6-11 is connected to the electric lifting system of the stress loading system, and the other end of the fixed frame 6-11 extends into the interior of the experimental tank 1. A semi-sealed chamber 6-1 is formed between the fixed frame 6-11 and the upper cover 1-2 of the experimental tank. One end of the tension rod 6-3 is connected to the pulley counterweight device, and the other end of the tension rod... Extending into the semi-sealed chamber 6-1, the other end of the tension rod 6-3 is provided with an experimental sample holder 6-2, so that the experimental sample holder 6-2 can be suspended in the semi-sealed chamber 6-1. The connection between the semi-sealed chamber 6-1 and the tension rod 6-3 is provided with a first dynamic seal 6-7, so that the tension rod 6-3 will not affect the sealing environment inside the experimental tank 1 when it moves up and down. A second dynamic seal 6-8 is provided between the semi-sealed chamber 6-1 and the upper cover 1-2 of the experimental tank, so that the experimental tank 1 can be kept sealed when the stress loading system 6 is raised and lowered.

[0067] The pulley counterweight device includes a pulley block bracket 6-9, a wire rope 6-4, a pulley block 6-5, and a counterweight 6-6. The pulley block 6-9 is equipped with the pulley block 6-5. The upper end of the tension rod 6-3 passes through the semi-sealed chamber 6-1 and is connected to the counterweight 6-6 outside the experimental tank 1 through the wire rope 6-4 and the pulley block 6-5. One end of the fixing frame 6-11 is fixed on the pulley block bracket 6-9.

[0068] The stress loading system 6 also includes a stress loading system bracket 6-10, a pulley block bracket 6-9 positioned above the stress loading system bracket 6-10, the stress loading system bracket 6-10 passing through the experimental tank cover 1-2, a fixing frame 6-11 inside the stress loading system bracket 6-10, the other end of the fixing frame 6-11 extending sequentially into the stress loading system bracket 6-10 and the experimental tank 1, and forming a semi-sealed chamber 6-1 between the other end of the fixing frame 6-11 and the stress loading system bracket 6-10 and the experimental tank cover 1-2.

[0069] Reference Figure 4 As shown, the experimental sample 11 has holes at both the top and bottom. The experimental sample 11 is hung on the lower end of the experimental sample holder 6-2. The upper and lower ends of the experimental sample 11 have connecting holes, the diameter of which is larger than the diameter of the first pin 10-1 and the second pin 10-2, respectively. This allows the experimental sample 11 to be movably fixed to the experimental sample holder 6-2 via the first pin 10-1 and to the fixing frame 6-11 via the second pin 10-2. When a weight is added, under the action of the tension, the axial direction of the experimental sample 11 will remain parallel to the load direction, ensuring that the load on the experimental sample 11 is perpendicular to the cross-section of the experimental sample 11.

[0070] Continue to refer to Figure 2 As shown, multiple experimental sample holders 6-2 can be provided. The stress loading system 6 can be equipped with even more experimental sample holders 6-2, enabling simultaneous stress corrosion experiments on multiple experimental samples 11 under different stress conditions.

[0071] Continue to refer to Figure 2 As shown, the counterweights 6-6 are set as follows: one 0.01kg, two 0.02kg, one 0.05kg, one 0.1kg, two 0.2kg, one 0.5kg, one 1kg, two 2kg, one 5kg, one 10kg, two 20kg, and one 50kg, so as to achieve quasi-continuous counterweight loading with an interval of 0.01kg in the range of 1kg-100kg.

[0072] Reference Figure 1 and Figure 3 As shown, the electric lifting system includes an electric lifting system 7-1 for the experimental tank cover and an electric lifting system 9-1 for the stress loading system. The electric lifting system 7-1 for the experimental tank cover is connected to the experimental tank cover 1-2, and the electric lifting system 9-1 for the stress loading system is connected to the semi-sealed chamber 6-1. The electric lifting system 9-1 for the stress loading system can control the experimental sample 11 on the experimental sample rack 6-2 to be above or below the liquid lead-bismuth liquid surface.

[0073] The electric lifting system 7-1 for the experimental tank lid includes an experimental tank lid lifting motor 7-2, an experimental tank lid transmission screw 7-3, an experimental tank lid guide rod 7-4, an experimental tank lid limiting device 7-5, and an experimental tank lid lifting controller 7-6. The experimental tank lid lifting controller 7-6 is connected to the experimental tank lid lifting motor 7-2, and the experimental tank lid lifting motor 7-2 is connected to the experimental tank lid transmission screw 7-3. The slider on the experimental tank lid transmission screw 7-3 is connected to the experimental tank lid 1-2, and the experimental tank lid 1-2 is fitted onto the experimental tank lid guide rod 7-4. When the experimental tank lid lifting motor 7-2 drives the experimental tank lid 1-2 to rise or fall via the experimental tank lid transmission screw 7-3, the experimental tank lid 1-2 will move along the direction of the guide rod. The experimental tank lid limiting device 7-5 is provided on the experimental tank lid guide rod 7-4 or the experimental tank lid transmission screw 7-3.

[0074] The electric lifting system 9-1 of the stress loading system includes a stress loading system lifting motor 9-2, a stress loading system transmission screw 9-3, a stress loading system guide rod 9-4, a stress loading system limit device 9-5, and a stress loading system lifting controller 9-6. The stress loading system lifting controller 9-6 is connected to the stress loading system lifting motor 9-2, and the stress loading system lifting motor 9-2 is connected to the stress loading system transmission screw 9-3. The slider on the stress loading system transmission screw 9-3 is connected to the fixed frame 6-11, and the fixed frame 6-11 is fitted onto the stress loading system guide rod 9-4. When the stress loading system lifting motor 9-2 drives the fixed frame 6-11 to rise or fall via the stress loading system transmission screw 9-3, the fixed frame 6-11 will move along the direction of the guide rod. The stress loading system limit device 9-5 is provided on the stress loading system guide rod 9-4 or the stress loading system transmission screw 9-3.

[0075] Both the experimental tank cover limiting device 7-5 and the stress loading system limiting device 9-5 include a limit sensor and a limit switch. The limit sensor is set at the position where the limit is required, and the limit switch is connected to the lifting controller.

[0076] When the electric lifting system 7-1 for the experimental tank cover and the electric lifting system 9-1 for the stress loading system move to the position of the limit sensor, the limit sensor will trigger the limit switch, which will transmit a signal to the experimental tank cover lifting controller 7-6 to shut down the experimental tank cover lifting motor 7-2 or to the stress loading system lifting controller 9-6 to shut down the stress loading system lifting motor 9-2, so that the electric lifting system 7-1 for the experimental tank cover or the electric lifting system 9-1 for the stress loading system stops moving.

[0077] Continue to refer to Figure 3 As shown, the electrical control cabinet 8 integrates a vacuum display instrument 2-7, a heating power supply 3-2, a silicon controlled rectifier 3-3, an intelligent temperature controller 3-4, a lifting controller for the experimental tank lid 7-6, and a lifting controller for the stress loading system 9-6, which facilitates the control of the experimental device and the observation of the experimental device's operating data during the experiment.

[0078] Example 2

[0079] An oxygen-controlled liquid lead-bismuth stress corrosion test method includes using the oxygen-controlled liquid lead-bismuth stress corrosion test apparatus described in Example 1, and the specific experimental steps include:

[0080] S1: Start the electric lifting system of the experimental vessel lid 7-1 to lift the experimental vessel lid, put in the lead-bismuth alloy ingot and then lower the experimental vessel lid 1-2 to seal the experimental vessel, turn on the vacuum mechanical pump 2-1 to evacuate air, and turn on the temperature control system to heat until the lead-bismuth ingot is completely melted into a liquid state.

[0081] The vacuum degree is less than 5 Pa, and the heating temperature is 200-300℃.

[0082] S2: Remove the scum from the surface of the liquid lead-bismuth. When the liquid level of the lead-bismuth alloy reaches the predetermined height, load the experimental sample 11 onto the experimental sample holder 6-2 and add a counterweight 6-6 to keep the experimental sample 11 in a vertical state.

[0083] The specific method for removing the scum from the surface of lead-bismuth is as follows: after opening the vacuum venting valve 2-6 to balance the pressure in the experimental container 1 with the atmospheric pressure, start the electric lifting system 7-1 of the experimental container to lift the upper cover 1-2 of the experimental container and remove the scum from the surface of the liquid lead-bismuth.

[0084] The process involves measuring and recording the height of the lead-bismuth alloy liquid level. Specifically, after raising the lid of the experimental vessel, the distance from the surface of the lead-bismuth alloy liquid to the top surface of the vessel is measured using a ruler. The depth of the experimental vessel minus this distance gives the liquid level.

[0085] The counterweight 6-6 weighs 1 kg.

[0086] S21: When the liquid level of the lead-bismuth alloy does not reach the predetermined height, activate the electric lifting mechanism 7-1 of the experimental tank cover to lower the experimental tank cover 1-2 to seal the experimental tank 1, turn off the temperature control system, and repeat step S1 after the temperature of the lead-bismuth alloy in the experimental tank drops to room temperature until the liquid level of the lead-bismuth alloy reaches the predetermined height.

[0087] S3: Under the vacuum conditions of the experimental vessel, the temperature of the liquid lead-bismuth alloy and the oxygen content of the experimental vessel 1 are adjusted by the temperature control system and the oxygen control system 5 respectively, so that the temperature and oxygen content of the liquid lead-bismuth alloy meet the experimental requirements.

[0088] The vacuum condition is a vacuum degree of less than 5 Pa. Specifically, the experimental tank lid 1-2 is lowered by activating the electric lifting system 7-1 to seal the experimental tank 1, and the vacuum mechanical pump 2-1 is turned on to evacuate the air to achieve a vacuum degree of less than 5 Pa.

[0089] The temperature control system is adjusted to raise the temperature of the liquid lead-bismuth alloy, so that the temperature of the liquid lead-bismuth alloy reaches the experimental temperature.

[0090] In this process, the air inlet valves 5-7 are opened to continuously introduce Ar-H2 mixed gas or compressed air into the experimental tank 1, thereby reducing or increasing the oxygen content in the liquid lead-bismuth alloy to achieve the expected oxygen content control target.

[0091] The oxygen content in the liquid lead bismuth was measured using the liftable oxygen probe 5-4 arranged in experimental vessel 1.

[0092] S4: Adjust the counterweight 6-6 to make the stress on the experimental sample 11 reach the predetermined target, start the stress loading system electric lifting system 7-2 to lower the experimental sample rack 6-2, so that the liquid lead bismuth completely immerses the experimental sample 11;

[0093] S5: Monitor the stress corrosion state of experimental sample 11. When experimental sample 11 breaks or reaches the predetermined corrosion time, end the stress corrosion experiment.

[0094] The stress corrosion state of the experimental sample 11 is monitored by setting a camera in front of the counterweight. That is, when the experimental sample 11 breaks, the counterweight will undergo a large displacement.

[0095] S51: When the experimental sample 11 breaks or reaches the predetermined corrosion time, start the electric lifting system 9-1 of the stress loading system to raise the experimental sample rack 6-2, close the air inlet valve 5-7, and turn off the temperature control system. When the temperature of the liquid lead-bismuth alloy is lower than 200℃, open the experimental tank cover 1-2 to take out the experimental sample 11 and end the stress corrosion experiment.

[0096] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A controlled-oxygen liquid lead-bismuth stress corrosion experimental apparatus, characterized in that, The system includes an experimental container, a vacuum system, a temperature control system, a cooling system, an oxygen control system, a stress loading system, an electric lifting system for the experimental container lid, and an electric lifting system for the stress loading system. The experimental container is equipped with the vacuum system, the temperature control system, the cooling system, and the oxygen control system. The electric lifting system for the experimental container lid is connected to the experimental container lid and can raise or lower the experimental container lid. The electric lifting system for the stress loading system is connected to the stress loading system and can cause the experimental sample on the stress loading system to extend into or out of the experimental container. The temperature control system includes a temperature-controlled thermocouple, a heating power supply, a silicon controlled rectifier (SCR), an intelligent temperature controller, an armored heating wire, an insulation shell, and a liftable temperature-measuring thermocouple. The armored heating wire and the insulation shell sequentially cover the exterior of the experimental container. The temperature-controlled thermocouple passes through the insulation shell and is in close contact with the outer wall of the experimental container. The liftable temperature-measuring thermocouple is connected to the interior of the experimental container through a liftable temperature-measuring thermocouple interface provided on the top cover of the experimental container. The liftable temperature-measuring thermocouple and the top cover of the experimental container are connected by a dynamic seal. The temperature-controlled thermocouple and the liftable temperature-measuring thermocouple are respectively connected to the intelligent temperature controller. The heating power supply is connected to the intelligent temperature controller through the SCR and is also connected to the armored heating wire. The oxygen control system includes a gas source, a gas pipeline, an oxygen concentration control device, a liftable oxygen probe, an inlet pipe, an inlet valve, and a check valve. The gas source is connected to the oxygen concentration control device through the gas pipeline. The oxygen concentration control device is connected to the experimental tank through the inlet pipe. The interface between the inlet pipe and the experimental tank is located on the upper part of the tank body. The inlet pipe is equipped with the inlet valve. The gas outlet of the inlet pipe is located at the bottom of the experimental tank. The outlet pipe is equipped with a check valve. The experimental tank is equipped with a liftable oxygen probe interface. The liftable oxygen probe is mounted on the upper cover of the experimental tank through the liftable oxygen probe interface, and the liftable oxygen probe and the upper cover of the experimental tank are connected by a dynamic seal. The signal output terminal of the liftable oxygen probe is connected to the oxygen concentration control device. The oxygen concentration control device includes a gas regulating valve, a gas flow meter, and an oxygen concentration analyzer. The gas flow meter and the gas regulating valve are respectively installed on the gas pipeline, and the oxygen concentration analyzer is connected to the signal output terminal of the liftable oxygen probe. The stress loading system includes a fixed frame, a sample holder, a tension rod, a pulley counterweight device, a first dynamic seal, and a second dynamic seal. One end of the fixed frame is connected to the electric lifting system of the stress loading system, and the other end of the fixed frame extends into the interior of the experimental container, forming a semi-sealed chamber between the fixed frame and the top cover of the experimental container. One end of the tension rod is connected to the pulley counterweight device, and the other end of the tension rod extends into the semi-sealed chamber. The other end of the tension rod is equipped with the sample holder, allowing the sample holder to be suspended within the semi-sealed chamber. The upper end of the experimental sample is movably connected to the sample holder, and the lower end of the experimental sample is movably connected to the fixed frame. The connection between the semi-sealed chamber and the tension rod is provided with the first dynamic seal, and the connection between the semi-sealed chamber and the top cover of the experimental container is provided with the second dynamic seal.

2. The oxygen-controlled liquid lead-bismuth stress corrosion experimental apparatus according to claim 1, characterized in that, The vacuum system includes a vacuum mechanical pump, a vacuum solenoid valve, a suction pipe, a vacuum measuring element, a vacuum shut-off valve, a vacuum venting valve, and a vacuum display instrument. The experimental vessel is equipped with an outlet pipe. One end of the suction pipe is connected to the outlet pipe, and the other end of the suction pipe is connected to the vacuum mechanical pump through the vacuum solenoid valve. The outlet pipe is equipped with the vacuum shut-off valve, the vacuum measuring element, and the vacuum venting valve in sequence.

3. The oxygen-controlled liquid lead-bismuth stress corrosion experimental apparatus according to claim 2, characterized in that, The cooling system includes a chiller, cooling water pipes, and a water valve. The top cover of the experimental tank is equipped with a cooling water pipe interface. The chiller is connected to the top cover of the experimental tank through the cooling water pipes, and the water valve is installed on the cooling water pipes.

4. The oxygen-controlled liquid lead-bismuth stress corrosion experimental apparatus according to claim 3, characterized in that, The electric lifting system for the experimental tank lid includes a lifting motor for the experimental tank lid, a transmission screw for the experimental tank lid, a guide rod for the experimental tank lid, a limiting device for the experimental tank lid, and a lifting controller for the experimental tank lid. The lifting controller for the experimental tank lid is connected to the lifting motor for the experimental tank lid, and the lifting motor for the experimental tank lid is connected to the transmission screw for the experimental tank lid. The slider on the transmission screw for the experimental tank lid is connected to the experimental tank lid, and the experimental tank lid is fitted onto the guide rod for the experimental tank lid. When the lifting motor for the experimental tank lid drives the experimental tank lid to rise or fall through the transmission screw for the experimental tank lid, the experimental tank lid will move along the direction of the guide rod for the experimental tank lid. The guide rod for the experimental tank lid is equipped with the limiting device for the experimental tank lid. And / or the electric lifting system of the stress loading system includes a stress loading system lifting motor, a stress loading system transmission screw, a stress loading system guide rod, a stress loading system limit device, and a stress loading system lifting controller. The stress loading system lifting controller is connected to the stress loading system lifting motor, the stress loading system lifting motor is connected to the stress loading system transmission screw, the slider on the stress loading system transmission screw is connected to the fixed frame, and the fixed frame is sleeved on the stress loading system guide rod. When the stress loading system lifting motor drives the fixed frame to rise or fall through the stress loading system transmission screw, the fixed frame will move along the direction of the stress loading system guide rod. The stress loading system limit device is provided on the stress loading system guide rod.

5. A controlled-oxygen liquid lead-bismuth stress corrosion test method, characterized in that, The experimental apparatus includes the oxygen-controlled liquid lead-bismuth stress corrosion test apparatus as described in any one of claims 1 to 4, and the specific experimental steps include: Start the electric lifting system of the experimental vessel lid to raise the lid of the experimental vessel, put in the lead-bismuth alloy ingot, lower the lid of the experimental vessel to seal the experimental vessel, turn on the vacuum mechanical pump to evacuate the air, and turn on the temperature control system to heat until the lead-bismuth ingot is completely melted into liquid. Remove the scum from the surface of the liquid lead-bismuth. When the liquid level of the lead-bismuth alloy reaches the predetermined height, load the experimental sample onto the experimental sample holder and add counterweights to keep the experimental sample in a vertical state. Under vacuum conditions in the experimental vessel, the temperature of the liquid lead-bismuth alloy and the oxygen content of the experimental vessel are adjusted by the temperature control system and the oxygen control system respectively, so that the temperature and oxygen content of the liquid lead-bismuth alloy meet the experimental requirements. Adjust the counterweights to bring the stress on the experimental sample to the predetermined target, then activate the electric lifting system of the stress loading system to lower the experimental sample rack, so that the liquid lead bismuth can completely immerse the experimental sample. Monitor the stress corrosion state of the experimental sample, and end the stress corrosion experiment when the experimental sample breaks or reaches the predetermined corrosion time.

6. The oxygen-controlled liquid lead-bismuth stress corrosion test method according to claim 5, characterized in that, When the lead-bismuth alloy liquid level does not reach the predetermined height, turn off the temperature control system. After the temperature of the lead-bismuth alloy in the experimental vessel drops to room temperature, repeat the steps "start the electric lifting system of the experimental vessel cover to raise the experimental vessel cover, put in the lead-bismuth alloy ingot and then lower the experimental vessel cover to seal the experimental vessel, turn on the vacuum mechanical pump to evacuate air, and turn on the temperature control system to heat until the lead-bismuth ingot is completely melted into a liquid state" and "remove the scum on the surface of the liquid lead-bismuth" until the lead-bismuth alloy liquid level reaches the predetermined height.

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