Stress corrosion and electrochemical corrosion integrated stray current corrosion experiment system

Abstract

The utility model discloses a stray current corrosion experiment system integrating stress corrosion and electrochemical corrosion. The stray current corrosion experiment system comprises a stray power supply simulation module, an electrochemical test module, a stress loading module and a sample clamp, the sample clamp comprises an upper threaded sleeve, a lower threaded sleeve, two clamping plates and two fixing nuts; the stress loading module comprises a plurality of threaded rods, a plurality of adjusting nuts and a plurality of compression springs; the stray current simulation module is used for generating a stray current signal and loading the stray current signal to the tubular sample; the electrochemical test module is used for completing an electrochemical experiment and obtaining an electrochemical curve of the tubular sample. According to the experimental system, the influence of stray current and stress on the electrochemical corrosion performance of the metal can be researched respectively, and the change of the electrochemical corrosion performance of the metal under the coupling action of the stray current and the stress can be synthesized; the method can be used for researching the influence of stray current on the metal stress corrosion performance and monitoring and recording the change of the voltage of the sample in real time, and can also be applied to the research of a metal stress corrosion mechanism.

Description

TECHNICAL FIELD

[0001] The utility model relates to corrosion experimental device technical field especially relates to a stress corrosion and electrochemistry corrosion integration stray current corrosion experiment system. BACKGROUND

[0002] With the rapid expansion of electrified rail lines such as high-speed rail and subway, the form of stray current and its influence range are increasingly expanding, becoming a problem that cannot be ignored. In particular, the corrosion failure of nearby oil and gas pipelines caused by stray current has caused serious safety problems and attracted much attention in the industry. Among the many corrosion behaviors of buried pipelines, electrochemical corrosion is the most critical one. Although previous studies have shown that external stress has a significant impact on the electrochemical corrosion performance of materials, existing research on the electrochemical corrosion behavior of pipelines generally ignores the important factor of pipeline internal pressure. In particular, when considering the effect of tensile stress, the plate-shaped tensile specimen used has the problem of inconsistent surface conditions, which directly leads to the unreliability of the measurement results. In addition, when studying the impact of stray current on metal corrosion, direct current or alternating current is usually used as the simulation current, but this current mode cannot truly reflect the actual stray current situation around electrified rail lines, further exacerbating the complexity of technical problems. SUMMARY

[0003] The utility model aims at providing a stress corrosion and electrochemistry corrosion integration stray current corrosion experiment system to solve one or more technical problems in the above background technology.

[0004] To achieve this purpose, the utility model adopts the following technical solutions:

[0005] A stress corrosion and electrochemistry corrosion integration stray current corrosion experiment system, comprising a stray power supply simulation module, an electrochemical test module, a stress loading module, and a specimen clamp.

[0006] The specimen clamp comprises an upper threaded sleeve, a lower threaded sleeve, two clamping plates, and two fixed nuts. The two clamping plates are arranged vertically. The upper threaded sleeve and the lower threaded sleeve are respectively used for threaded connection with both ends of the tubular specimen. The ends of the upper threaded sleeve and the lower threaded sleeve respectively pass through the upper and lower clamping plates and extend to the outer side of the clamping plates. The two fixed nuts are respectively threaded with the ends of the upper threaded sleeve and the lower threaded sleeve, and the ends of the fixed nuts are attached to the outer side of the clamping plates.

[0007] The stress loading module comprises a plurality of threaded rods, a plurality of adjusting nuts and a plurality of compression springs, the plurality of threaded rods are distributed on the outer periphery of the upper threaded sleeve, the compression spring sleeve is arranged on the outer side of the threaded rod, the two ends of the compression spring are respectively abutted with the inner sides of the two clamping plates, the two ends of the threaded rod are respectively penetrated through the two clamping plates and extended to the outer side of the clamping plate, the two ends of the threaded rod are respectively threadedly connected with the adjusting nuts, and the end surface of the adjusting nut is attached to the outer side of the clamping plate.

[0008] The stray current simulation module is used for generating a stray current signal and loading the stray current signal on the tubular sample.

[0009] The electrochemical test module is used for completing an electrochemical experiment and obtaining an electrochemical curve of the tubular sample.

[0010] Preferably, the device further comprises an experimental tank, the experimental tank is filled with an experimental solution, and the sample clamp is arranged in the experimental tank.

[0011] Preferably, the device further comprises a connecting wire, one end of the connecting wire is connected to the inner side of the tubular sample through soldering, and the other end of the connecting wire is connected to the output end of the stray current simulation module through the upper threaded sleeve.

[0012] Preferably, the sample clamp further comprises a sealing ring and an outer threaded cap, the top of the upper threaded sleeve is provided with an opening, the sealing ring is arranged on the inner side of the opening, the inner side of the sealing ring is attached to the outer side of the connecting wire, the outer threaded cap is threadedly connected with the opening, the end of the outer threaded cap is attached to the end of the sealing ring, and the connecting wire penetrates through the outer threaded cap.

[0013] Preferably, the upper threaded sleeve and the lower threaded sleeve are both made of polytetrafluoroethylene material.

[0014] Preferably, the stray current simulation module comprises a signal generator, a bipolar direct current power supply and an adjustable resistor, the input end of the bipolar direct current power supply is electrically connected with the output end of the signal generator, the output end of the bipolar direct current power supply is electrically connected with the input end of the adjustable resistor, the output end of the adjustable resistor is electrically connected with the tubular sample, the signal generator is used for generating a stray current signal collected on site, the bipolar direct current power supply is used for converting the stray current signal into a voltage, and the adjustable resistor is used for adjusting the current intensity loaded on the tubular sample.

[0015] Preferably, the stray current simulation module further comprises an auxiliary electrode, the auxiliary electrode is connected with the output end of the bipolar direct current power supply, the auxiliary electrode is a graphite rod, and two graphite rods are distributed on the two sides of the sample clamp.

[0016] Preferably, the electrochemical test module comprises an electrochemical workstation and a display analysis unit, the display analysis unit is electrically connected with the output end of the electrochemical workstation, the counter electrode of the electrochemical workstation is distributed on both sides of the tubular sample, the electrochemical workstation is used for completing electrochemical experiments, and the display analysis unit is used for displaying electrochemical curves in real time.

[0017] Preferably, the counter electrode of the electrochemical workstation is a Pt electrode, and the reference electrode is a saturated calomel solution.

[0018] The utility model discloses the beneficial effect: through the sample fixture to fix the both ends of tubular sample, utilize stress loading module to make the sample fixture produce the outward thrust, can realize to tubular sample to produce the tensile stress, and configure with the stray current simulation module and electrochemical test module, so that the utility model experimental system can respectively study the influence of stray current and stress on metal electrochemical corrosion performance, can comprehensively change metal electrochemical corrosion performance under the coupling action of stray current and stress, can study the influence of stray current on metal stress corrosion performance, and real -time monitoring record sample voltage change, can also be applied to the research of metal stress corrosion mechanism. BRIEF DESCRIPTION OF DRAWINGS

[0019] The drawings further illustrate the utility model, but the contents in the drawings do not constitute any limitation to the utility model.

[0020] Figure 1 It is the overall structure schematic diagram of one embodiment of the utility model;

[0021] Figure 2 It is the structure schematic diagram of sample fixture of one embodiment of the utility model.

[0022] Among them: stray power supply simulation module 1, electrochemical test module 2, stress loading module 3, sample fixture 4, upper threaded sleeve 41, lower threaded sleeve 42, clamping plate 43, fixed nut 44, threaded rod 31, adjusting nut 32, compression spring 33, experimental tank 6, connecting wire 11, external thread cap 45, auxiliary electrode 12, counter electrode 21, tubular sample 5. DETAILED DESCRIPTION

[0023] The technical scheme of the utility model will be further illustrated by specific embodiments in conjunction with the drawings.

[0024] The stress corrosion and electrochemical corrosion integrated stray current corrosion experimental system of the embodiment, reference is made to the drawings of the utility model Figure 1 And 2 , including stray power supply simulation module 1, electrochemical test module 2, stress loading module 3 and sample fixture 4;

[0025] The sample clamp 4 comprises an upper threaded sleeve 41, a lower threaded sleeve 42, two clamping plates 43 arranged in an upper and lower manner, the upper threaded sleeve 41 and the lower threaded sleeve 42 are respectively used for threaded connection with two ends of the tubular sample 5, the end portions of the upper threaded sleeve 41 and the lower threaded sleeve 42 respectively pass through the upper and lower clamping plates 43 and extend to the outer side of the clamping plates 43, and two fixing nuts 44 are respectively threaded connected with the end portions of the upper threaded sleeve 41 and the lower threaded sleeve 42, and the end portions of the fixing nuts 44 are attached to the outer side of the clamping plates 43;

[0026] The stress loading module 3 comprises a plurality of threaded rods 31, a plurality of adjusting nuts 32 and a plurality of compression springs 33, the plurality of threaded rods 31 are distributed on the outer periphery of the upper threaded sleeve 41, the compression springs 33 are sleeved on the outer side of the threaded rods 31, the two ends of the compression springs 33 respectively abut against the inner sides of the two clamping plates 43, the two ends of the threaded rods 31 respectively pass through the two clamping plates 43 and extend to the outer side of the clamping plates 43, the two ends of the threaded rods 31 are respectively threaded matched with the adjusting nuts 32, and the end faces of the adjusting nuts 32 are attached to the outer side of the clamping plates 43;

[0027] The stray current simulation module 1 is used for generating a stray current signal and loading the stray current signal on the tubular sample 5;

[0028] The electrochemical test module 2 is used for completing an electrochemical experiment and obtaining an electrochemical curve of the tubular sample 5.

[0029] The upper threaded sleeve 41 and the lower threaded sleeve 42 are both connected with the two ends of the tubular sample 5 through threads to realize loading of an axial stress. In order to study the influence of stress on the electrochemical corrosion performance of the pipeline, the spring compression amount is adjusted by loading the adjusting nuts 32 in the embodiment, so that the tensile stress is simply and accurately controlled. Since the upper threaded sleeve 41, the lower threaded sleeve 42 and the sample clamp 4 are connected through threads, after the adjusting nuts 32 are loosened and unloaded, the outward pushing force of the compression springs 33 on the clamping plates 43 is transmitted to the upper threaded sleeve 41 and the lower threaded sleeve 42 through the upper and lower clamping plates 43, and then the tensile stress on the tubular sample 5 is realized. In order to truly reflect the influence of the stray current on the electrochemical corrosion performance of the pipeline, the stray current simulation module 1 and the electrochemical test module 2 are applied in the embodiment.

[0030] Therefore, the two ends of the tubular sample 5 are fixed by the sample clamp 4, the outward pushing force of the sample clamp 4 is generated by the stress loading module 3, the tensile stress on the tubular sample 5 is realized, and the stray current simulation module 1 and the electrochemical test module 2 are configured, so that the experimental system can respectively study the influences of the stray current and the stress on the electrochemical corrosion performance of the metal, can comprehensively study the change of the electrochemical corrosion performance of the metal under the coupling action of the stray current and the stress, can study the influence of the stray current on the stress corrosion performance of the metal and can real-time monitor and record the change of the sample voltage, and can be applied to the study of the stress corrosion mechanism of the metal.

[0031] Preferably, the experimental tank 6 is further included, and the experimental tank 6 is filled with experimental solution, and the sample holder 4 is placed in the experimental tank 6. By placing the sample holder 4 together with the tubular sample 5 in the experimental tank 6, and the experimental tank 6 is filled with experimental solution, the simulation of the corrosion environment is realized. The experimental solution is simulated soil solution, and 4g / L NaCl solution.

[0032] Preferably, the connecting wire 11 is further included, one end of the connecting wire 11 is connected to the inner side of the tubular sample 5 by soldering, and the other end of the connecting wire 11 is connected to the output end of the stray current simulation module 1 through the upper threaded sleeve 41. In this way, the stray current simulation module 1 and the tubular sample 5 are electrically connected through the connecting wire 11, so that the stray current signal generated by the stray current simulation can be transmitted to the tubular sample 5 through the connecting wire 11.

[0033] Further, the sample holder 4 further includes a sealing ring and an outer threaded cap 45, the top of the upper threaded sleeve 41 is provided with an opening, the sealing ring is arranged on the inner side of the opening, the inner side of the sealing ring is in contact with the outer side of the connecting wire 11, the outer threaded cap 45 is threadedly connected to the opening, the end of the outer threaded cap 45 is in contact with the end of the sealing ring, and the connecting wire 11 passes through the outer threaded cap 45. In this way, by arranging the sealing ring, the tubular sample 5 is sealed, avoiding the deviation of the experimental results caused by the contact of the solder joint of the connecting wire 11 with the tubular sample 5.

[0034] Preferably, the upper threaded sleeve 41 and the lower threaded sleeve 42 are made of polytetrafluoroethylene material. In this way, the upper threaded sleeve 41 and the lower threaded sleeve 42 in direct contact with the tubular sample 5 are made of insulating material, avoiding affecting the experimental results.

[0035] Preferably, the stray current simulation module 1 includes a signal generator, a bipolar direct current power supply and an adjustable resistor, the input end of the bipolar direct current power supply is electrically connected to the output end of the signal generator, the output end of the bipolar direct current power supply is electrically connected to the input end of the adjustable resistor, and the output end of the adjustable resistor is electrically connected to the tubular sample 5. The signal generator is used to generate the stray current signal collected on site, the bipolar direct current power supply is used to convert the stray current signal into voltage, and the adjustable resistor is used to adjust the current intensity loaded on the tubular sample 5.

[0036] Preferably, the electrochemical test module 2 includes an electrochemical workstation and a display analysis unit, the display analysis unit is electrically connected to the output end of the electrochemical workstation, the counter electrode 21 of the electrochemical workstation is distributed on both sides of the tubular sample 5, the electrochemical workstation is used to complete the electrochemical experiment, and the display analysis unit is used to display the electrochemical curve in real time. The counter electrode 21 of the electrochemical workstation is a Pt electrode, and the reference electrode is a saturated calomel solution.

[0037] The experimental process of the experimental system of the embodiment is as follows:

[0038] 1. Process the tubular sample 5 to form external threads on both ends of the tubular sample 5; connect the wire 11 to the steel tubular sample 5 by soldering;

[0039] 2. Pass the connecting wire 11 through the upper end threaded sleeve and tighten the upper end threaded sleeve to the sample until the upper end threads of the sample are completely covered. Put a sealing ring on the opening at the top of the upper end threaded sleeve, then screw on the external threaded cap 45. If there is a gap between the sealing ring or the external threaded cap 45 and the connecting wire 11, remove the threaded cap, wrap a suitable amount of polytetrafluoroethylene tape on the copper wire, and then install the external threaded cap 45.

[0040] 3. Pass the upper threaded sleeve 41 through the clamping plate 43, then lock the upper threaded sleeve 41 by the fixing nut 44, pass the four threaded rods 31 through the lower clamping plate 43, and then pass the four threaded rods 31 into the compression springs 33 respectively, and then fix the four threaded rods 31 relative to the upper and lower clamping plates 43 by screwing the adjusting nuts 32.

[0041] 4. Measure and record the distance L0 between the upper and lower clamping plates 43. According to Hooke's law and the required loading stress, calculate the spring compression amount l. According to the calculation result, adjust the adjusting nuts 32 on the threaded rods 31 and ensure that the compression amount of each spring is consistent until the spring compression amount reaches the calculated value.

[0042] 5. Adjust the upper end threaded sleeve by screwing the fixing nut 44 to make the sample as much as possible in the middle of the upper and lower clamping plates 43, and then lock the lower threaded sleeve 42 by the fixing nut 44.

[0043] 6. Put the sample clamp 4 together with the tubular sample 5 into the experimental tank 6 containing the experimental solution, and vertically cross the two auxiliary electrodes 12 of the stray signal simulation system and the two counter electrodes 21 of the electrochemical test system around the sample.

[0044] 7. Start the experiment. When only the effect of stress on the electrochemical corrosion performance of the metal is studied, open the switch S1 (stray signal simulation module 1 switch) and close the electrochemical workstation switch. When the electrochemical corrosion performance under the coupling effect of stress and stray current is studied, close the switches S1 and S2.

[0045] The technical principles of the present application are described above in combination with specific embodiments. These descriptions are only for the purpose of explaining the principles of the present application, and cannot be interpreted in any way as a limitation on the scope of protection of the present application. Based on the explanations here, those skilled in the art can easily think of other specific embodiments of the present application without any creative effort, and these embodiments will all fall within the scope of protection of the present application.

Claims

1. A stress corrosion and electrochemical corrosion integrated stray current corrosion experiment system, characterized in that, The stress loading module, the stray current simulation module, the electrochemical test module and the sample clamp are included. The sample clamp includes an upper threaded sleeve, a lower threaded sleeve, two clamping plates and two fixing nuts. The stress loading module includes a plurality of threaded rods, a plurality of adjusting nuts and a plurality of compression springs. The stray current simulation module is used to generate a stray current signal and load the signal on the tubular sample. The electrochemical test module is used to complete an electrochemical experiment and obtain an electrochemical curve of the tubular sample.

2. The stress corrosion and electrochemical corrosion integrated stray current corrosion experimental system according to claim 1 is characterized in that: The experiment tank is further included, and the experiment tank is filled with an experimental solution.

3. The stress corrosion and electrochemical corrosion integrated stray current corrosion experimental system according to claim 1, characterized in that, The connecting wire is further included, one end of the connecting wire is connected to the inner side of the tubular sample through soldering, and the other end of the connecting wire is connected to the output end of the stray current simulation module through the upper threaded sleeve.

4. The stress corrosion and electrochemical corrosion integrated stray current corrosion experimental system according to claim 3, characterized in that, The sample clamp further includes a sealing ring and an outer threaded cap.

5. The stress corrosion and electrochemical corrosion integrated stray current corrosion experimental system according to claim 1, characterized in that, The upper threaded sleeve and the lower threaded sleeve are made of polytetrafluoroethylene material.

6. The stress corrosion and electrochemical corrosion integrated stray current corrosion experimental system according to claim 1, characterized in that, The stray current simulation module includes a signal generator, a bipolar DC power supply and an adjustable resistor.

7. The stress corrosion and electrochemical corrosion integrated stray current corrosion experimental system according to claim 6, characterized in that, The stray current simulation module further includes an auxiliary electrode.

8. The stress corrosion and electrochemical corrosion integrated stray current corrosion experimental system according to claim 1, characterized in that, The electrochemical test module comprises an electrochemical workstation and a display analysis unit, the display analysis unit is electrically connected with an output end of the electrochemical workstation, a counter electrode of the electrochemical workstation is distributed on both sides of a tubular sample, the electrochemical workstation is used for completing an electrochemical experiment, and the display analysis unit is used for displaying an electrochemical curve in real time.

9. The stress corrosion and electrochemical corrosion integrated stray current corrosion experimental system according to claim 8, characterized in that, The counter electrode of the electrochemical workstation is a Pt electrode, and the reference electrode is a saturated calomel solution.

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