CN217404104U - Integrated test device for metal corrosion weightlessness test under alternating current-direct current interaction - Google Patents

Abstract

The utility model discloses an integrated test device for metal corrosion weightlessness test under AC-DC interaction, which comprises a circuit testing box, wherein the internal main structure is a circuit board and a medium container groove; the circuit board comprises an alternating current circuit, a direct current circuit and a three-channel data recorder; the alternating current circuit consists of a standard resistor, a slide rheostat, a capacitor, a switch and an interface terminal. An object of the utility model is to provide an integrated test device of metal corrosion weightlessness test under alternating current-direct current interact of simulation on-the-spot actual disturbance operating mode, the device easy operation, convenient to use can automatic recording storage test process data (including diffusion resistance, alternating voltage or current density, direct current potential or current density data) for research oil gas pipeline corrodes the action under different direct current and alternating current parameters, tests its corrosion rate. The labor and time cost investment of the test is reduced, and the accuracy, reliability and convenience of the test are enhanced.

Description

Integrated test device for metal corrosion weightlessness test under alternating current-direct current interaction

Technical Field

The utility model relates to an integrated test device of metal corrosion weightlessness test under alternating current-direct current interaction, specific can be under the circumstances of alternating current and direct current simultaneous action, detect metal corrosion rate, the integrated test device of monitoring diffusion resistance, alternating voltage or current density, direct current potential or current density variation trend that says so.

Background

With the rapid development of the infrastructure construction of energy and transportation industry in China, the phenomenon of parallel intersection between an oil gas pipeline and various alternating current and direct current interference sources is increasingly common, so that the pipeline is subjected to alternating current and direct current interaction superposition, and the stray current interference sources are complex and changeable. In order to clarify the influence and the law of alternating current and direct current interaction on the corrosion of the oil and gas pipeline and provide indexes and bases for evaluation and control of corrosion risk of the oil and gas pipeline, indoor simulation tests based on actual interference working conditions on site are developed in many laboratories, pipeline corrosion behaviors and laws are researched by simulating actual service environments on site, but the test equipment is more, the circuit connection is complex and the interface environment is dynamically changed, and the phenomenon that the disconnection condition is easy to occur at too many connection points and is difficult to discover exists, so that the operation is complicated and time-consuming, and the reliability and the stability of data are difficult to ensure; meanwhile, under the interaction of alternating current and direct current, a metal corrosion mechanism is complex, and when a corrosion weightlessness test is carried out on the metal corrosion mechanism and the corrosion behavior rule of the metal corrosion mechanism is analyzed, the process parameters (including diffusion resistance, alternating voltage or current density, and direct current potential or current density data) related to the test need to be monitored comprehensively in real time. In addition, an integrated test device for simulating metal corrosion behavior and law under alternating current and direct current interaction is not found by searching published patents at home and abroad. To above experimental characteristics, the utility model provides a solution that the device can be fine is the problem that exists in this type test at present.

SUMMERY OF THE UTILITY MODEL

Aiming at the problems in the prior art, the utility model provides an integrated test device for metal corrosion weightlessness test under AC/DC interaction, which has the advantages of being capable of simulating metal corrosion behavior and regular integrated test under AC/DC interaction, solves the metal corrosion weightlessness simulation test under the existing AC/DC interaction, and is characterized in that electronic components are lapped on a test bed, the convenience is not strong, the test bed is in disorder on site, and the integration of the test device is not involved; the objects of interest are mainly the corrosion rate of the pattern, and the lack of test record for other parameters (such as diffusion resistance and direct current density); meanwhile, the process parameters need to be tested and recorded manually in the test process.

The utility model is realized in such a way, the integrated test device for the metal corrosion weightlessness test under the alternating current-direct current interaction comprises a circuit testing box, and the internal main structure is a circuit board and a medium container groove;

the circuit board comprises an alternating current circuit, a direct current circuit and a three-channel data recorder;

the alternating current circuit consists of a standard resistor, a sliding rheostat, a capacitor, a switch and an interface terminal;

the standard resistor, the slide rheostat, the capacitor and the switch are welded on the circuit board in series.

Preferably, a terminal is respectively led out from one end of the sliding rheostat and one end of the capacitor, is used for connecting an alternating current power supply, and is in a knob type; one end of the standard resistor is connected with the slide rheostat in series, and the other end of the standard resistor leads out a terminal which is used for being connected with the auxiliary electrode in series; one end of the switch is connected with the capacitor, and the other end of the switch is led out of the terminal and used for connecting the sample.

Preferably, the dc circuit of the present invention comprises a standard resistor, a sliding rheostat, an inductor, a switch and an interface terminal, wherein the standard resistor, the sliding rheostat and the inductor switch are serially connected and welded on the circuit board, and one terminal is respectively led out from one end of the sliding rheostat and one end of the inductor for connecting with a potentiostat, and a knob type is selected; one end of the standard resistor is connected with the slide rheostat in series, and the other end of the standard resistor leads out a terminal which is used for being connected with the auxiliary electrode in series; one end of the switch is connected with the inductor, and the other end of the switch and the alternating current circuit switch share one interface terminal for connecting the sample.

As the utility model discloses it is preferred, industrial glue for three channel data record appearance is fixed on the circuit board, and two signal lines of first passageway welded connection respectively to the both ends of standard resistance in the alternating current return circuit, and two signal lines of second passageway welded connection respectively to the both ends of standard resistance in the direct current return circuit, and two terminals are drawn forth respectively to two signal lines of third passageway for connect sample and reference electrode, circuit box one side fluting exposes charging and data derivation interface and switch of data record appearance.

Preferably, the medium container groove is a customized PP polypropylene container and comprises a cover plate and a division plate;

the cover plate is provided with four notches, the caliber of each notch is matched with a test material, and the notches are used for fixing a sample, a reference electrode and two auxiliary electrodes respectively;

the interlayer plate is used for placing and fixing a test circuit box;

the medium container tank is marked with the highest water level line.

Compared with the prior art, the beneficial effects of the utility model are as follows:

1. an object of the utility model is to provide an integrated test device of metal corrosion weightlessness test under alternating current-direct current interact of simulation on-the-spot actual disturbance operating mode, the device easy operation, convenient to use can automatic recording storage test process data (including diffusion resistance, alternating voltage or current density, direct current potential or current density data) for research oil gas pipeline corrodes the action under different direct current and alternating current parameters, tests its corrosion rate. The labor and time cost investment of the test is reduced, and the accuracy, reliability and convenience of the test are enhanced.

2. The utility model has convenient operation, saves manpower and time investment; the integration level is high, the test space is saved, and the test arrangement is convenient; the system has the advantages of automatically recording and collecting data, realizing synchronous collection and storage of multiple data, facilitating analysis of corrosion behavior rules, realizing corrosion behavior simulation of oil and gas pipelines or other buried metal structures under the interaction of alternating current and direct current, and carrying out test analysis according to actual service working conditions on site.

Drawings

Fig. 1 is a schematic view of a media container tank provided in an embodiment of the present invention;

fig. 2 is a schematic diagram of a front side of a circuit box according to an embodiment of the present invention;

fig. 3 is a schematic diagram of a back side of a circuit box according to an embodiment of the present invention;

FIG. 4 is a schematic diagram of the internal structure wiring of the testing device according to the embodiment of the present invention;

fig. 5 is a graph showing corrosion rate distribution under different test parameters provided by the embodiment of the present invention;

fig. 6 is a graph illustrating the influence of ac power on dc current density according to an embodiment of the present invention;

fig. 7 is a graph showing the variation trend of diffusion resistance under the same test parameters.

Wherein: 1. a media container tank; 2. a media container slot cover plate; 3. a division plate for erecting the circuit box; 4. a highest water line; 5. the auxiliary electrode of the alternating current circuit fixes the notch; 6. a reference electrode fixing notch; 7. a pattern fixing notch; 8. a direct current circuit auxiliary electrode fixing notch; 9. an integrated circuit box; 10. a power interface terminal; 11. potentiostat interface terminal (+); 12. a potentiostat interface terminal (-); 13. potentiostat interface terminals (reference electrodes); 14. an alternating current circuit sliding rheostat knob; 15. a DC circuit sliding rheostat knob; 16. an alternating current circuit switch; 17. a direct current circuit switch; 18. data recorder interface terminals (reference electrodes); 19. a sample interface terminal (a common terminal for an alternating current circuit, a direct current circuit and a data recorder); 20. an interface terminal (auxiliary electrode); 21. an interface terminal (auxiliary electrode); 22. a back side of the integrated circuit box; 23. a data logger charging and data export interface; 24. and (6) switching on and off of the data recorder.

Detailed Description

For further understanding the contents, features and functions of the present invention, the following embodiments will be illustrated in detail with reference to the accompanying drawings.

The structure of the present invention will be described in detail with reference to the accompanying drawings.

As shown in fig. 1 to 7, an integrated test device for a metal corrosion weightlessness test under ac/dc interaction provided by the embodiment of the present invention includes a circuit testing box, and an internal main structure includes a circuit board and a medium container tank;

the circuit board comprises an alternating current circuit, a direct current circuit and a three-channel data recorder;

the alternating current circuit consists of a standard resistor, a sliding rheostat, a capacitor, a switch and an interface terminal, wherein the standard resistor is 10 omega, the range of the sliding rheostat is 0-1000 omega, and the capacitance value is 450V/1000 muF;

the standard resistor, the slide rheostat, the capacitor and the switch are welded on the circuit board in series.

One end of the sliding rheostat and one end of the capacitor are respectively led out to form a terminal which is used for being connected with an alternating current power supply and is in a knob type; one end of the standard resistor is connected with the slide rheostat in series, and the other end of the standard resistor leads out a terminal which is used for being connected with the auxiliary electrode in series; one end of the switch is connected with the capacitor, and the other end of the switch is led out of the terminal and used for connecting the sample.

The direct current circuit consists of a standard resistor, a sliding rheostat, an inductor, a switch and an interface terminal, wherein the standard resistor is 10 omega, the range of the sliding rheostat is 0-1000 omega, and the inductance value is 10H; one end of the standard resistor is connected with the slide rheostat in series, and the other end of the standard resistor leads out a terminal which is used for being connected with the auxiliary electrode in series; one end of the switch is connected with the inductor, and the other end of the switch and the alternating current circuit switch share one interface terminal for connecting the sample.

The three-channel data recorder is fixed on a circuit board by industrial glue, two signal wires of a first channel are respectively welded and connected to two ends of a standard resistor in an alternating current circuit and used for monitoring the change of alternating current density in the test process, two signal wires of a second channel are respectively welded and connected to two ends of the standard resistor in a direct current circuit and used for monitoring the change of direct current density in the test process, two terminals are respectively led out of two signal wires of a third channel and used for connecting a sample and a reference electrode and monitoring the change of polarization potential and alternating current interference voltage in the test process, a groove is formed in one side of a circuit box, and a charging and data leading-out interface and a switch of the data recorder are exposed.

The medium container groove is a customized PP polypropylene container and comprises a cover plate and a division plate;

the cover plate is provided with four notches, the caliber of each notch is matched with a test material, and the notches are used for fixing a sample, a reference electrode and two auxiliary electrodes respectively;

the interlayer plate is used for placing and fixing a test circuit box;

the medium container tank is marked with the highest water level line, and when the solution is injected, the line cannot be exceeded.

Selecting X80 steel as a sample material, polishing the sample material step by using water abrasive paper, connecting a lead on one surface of the sample by using conductive adhesive to ensure good current connection, and sealing the working surface of the sample by using insulating adhesive; sealing the rest surfaces of the pattern by using paraffin, taking out the working surface insulating glue after solidification, scrubbing the working surface insulating glue by using alcohol, washing the working surface insulating glue by using deionized water, drying the working surface insulating glue by using cold air, and manufacturing the pattern by using a noble metal oxide anode (MMO anode) as an auxiliary anode; adopting a saturated calomel reference electrode, placing the reference electrode in a Lujin capillary tube, fixing and electrically connecting a sample, an auxiliary anode and the reference electrode on corresponding terminals of a circuit box (shown as 9 in figure 2) placed on a interlayer plate (shown as 3 in figure 1) through corresponding notches (shown as 5, 6, 7 and 8 in figure 1) of a medium container groove, adopting typical soil on site or adopting a soil simulation solution prepared by chemically analyzing pure reagents and deionized water according to typical soil components and physical and chemical properties on site, pouring the soil simulation solution into the medium container groove (shown as 1 in figure 1) without exceeding the highest water level line (shown as 4 in figure 1), wherein the environment temperature is room temperature, an alternating current power supply is electrically connected to an interface terminal (shown as 10 in figure 2) of the circuit box, and a potentiostat anode, a cathode and the reference electrode are respectively connected to interface terminals (11, 11 in figure 2) of the circuit box, 12 and 13), after the test circuit is connected, the potentiostat adopts a constant potential output mode to ensure that the polarization potential of the test piece is kept at a set value; adjusting a sliding rheostat knob of an alternating current circuit to ensure that an alternating current power supply outputs constant current according to a set value, turning on switches of the alternating current power supply, the potentiostat and the data recorder, starting a test, wherein the test period is six days, after the test is finished, turning off the alternating current power supply and the potentiostat, immediately taking out a sample, and exporting stored data of the data recorder; firstly, observing and recording the corrosion condition of a sample, describing and recording the distribution (uniform and non-uniform), thickness, color, structure (layered, powdery or porous), compactness (loose, compact and hard) of a corrosion product, and photographing and archiving the corrosion condition by using a color camera; secondly, according to GB/T16545-2015 "removal of Corrosion products from Corrosion samples of metals and alloys", ASTM G4-01 Standard guide for reducing Corrosion tests in field applications, NACE SP 0775:2018Preparation, Analysis and Interpretation of correction coupling in Oilfield Operation standards, weight loss inspection piece cleaning, weighing and Corrosion rate calculation were carried out, weighing was carried out using an electronic balance (precision 0.01mg), and Corrosion rate was calculated using the following formula (1); the ac interference voltage of the sample monitored by the data recorder was averaged, and the diffusion resistance was calculated by the following equation (2).

Wherein: w-sample weight loss, g; a-area of sample, mm 2; t-test time, days; d-sample density, g/cm 3.

Wherein: r is _s -diffusion resistance, Ω · m 2; u shape _AC -an alternating interference voltage average value, V; i.e. i _AC Alternating current density, A/m 2.

Selecting test parameters (by adjusting a potentiostat, an alternating current power supply and a sliding rheostat, obtaining various set test parameters): the AC current density (ratio of current to sample area) was 5 sizes (preliminary set: 0, 30A/m2, 100A/m2, 200A/m2, 300A/m2), the DC polarization potential (potential relative to copper sulfate reference electrode) was 3 sizes (-0.50VCSE, -0.95VCSE, and-1.00 VCSE), the weight loss test time was set to 6 days, and 3 parallel samples were set for each set of tests.

The corrosion rate distribution result is shown in the following figure 5, and it can be known from the figure that the corrosion rate of the sample is obviously accelerated by the alternating current, under the same polarization potential, the corrosion rate increases along with the increase of the alternating current density, and the increase tends to be gradually slowed down; under the same alternating current density, the corrosion rate is obviously reduced when the polarization potential is-0.95 VCSE and-1.00 VCSE, but when the alternating current density is more than 100A/m2, the corrosion rate of the sample is still more than 0.1mm/y, and a direct current density change trend chart is respectively shown in the following figure 6; when the anode is polarized, the alternating current can reduce the direct current, the coefficient of variation amplitude shows an increasing trend along with the negative shift of the polarization potential, the variation trend graph of the diffusion resistance is respectively shown in the following figure 7, the diffusion resistance is positioned in the interval of 0.032 omega-m 2-0.063 omega-m 2, the diffusion resistance shows a decreasing trend along with the negative shift of the polarization potential, and the reduced proportionality coefficient is about 1/3.

It is noted that, herein, relational terms such as first and second, and the like may be used solely to distinguish one entity or action from another entity or action without necessarily requiring or implying any actual such relationship or order between such entities or actions. Also, the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus.

Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and alterations can be made in these embodiments without departing from the principles and spirit of the invention, the scope of which is defined in the appended claims and their equivalents.

Claims (5)

1. The utility model provides an integrated test device of metal corrosion weightlessness test under alternating current-direct current interact which characterized in that: the integrated test device comprises a circuit testing box, wherein the internal main structure of the circuit testing box is a circuit board and a medium container groove;

the circuit board comprises an alternating current circuit, a direct current circuit and a three-channel data recorder;

the alternating current circuit consists of a standard resistor, a sliding rheostat, a capacitor, a switch and an interface terminal;

the standard resistor, the slide rheostat, the capacitor and the switch are welded on the circuit board in series.

2. The integrated test device for the metal corrosion weight loss test under the alternating current-direct current interaction of claim 1, which is characterized in that: one end of the sliding rheostat and one end of the capacitor are respectively led out of a terminal which is used for connecting an alternating current power supply and is in a knob type; one end of the standard resistor is connected with the slide rheostat in series, and the other end of the standard resistor leads out a terminal which is used for being connected with the auxiliary electrode in series; one end of the switch is connected with the capacitor, and the other end of the switch is led out of the terminal and used for connecting the sample.

3. The integrated test device for the metal corrosion weight loss test under the alternating current-direct current interaction according to claim 2, characterized in that: the direct current circuit consists of a standard resistor, a sliding rheostat, an inductor, a switch and an interface terminal, wherein the standard resistor, the sliding rheostat and the inductor switch are welded on a circuit board in series, and one terminal is respectively led out from one end of the sliding rheostat and one end of the inductor and used for connecting a potentiostat and selecting a knob type; one end of the standard resistor is connected with the slide rheostat in series, and the other end of the standard resistor leads out a terminal which is used for being connected with the auxiliary electrode in series; one end of the switch is connected with the inductor, and the other end of the switch and the alternating current circuit switch share one interface terminal for connecting the sample.

4. The integrated test device for the metal corrosion weight loss test under the alternating current-direct current interaction of claim 3, wherein: the three-channel data recorder is fixed on a circuit board by using industrial glue, two signal wires of a first channel are respectively welded and connected to two ends of a standard resistor in an alternating current circuit, two signal wires of a second channel are respectively welded and connected to two ends of the standard resistor in a direct current circuit, two terminals are respectively led out from two signal wires of a third channel and used for connecting a sample and a reference electrode, a groove is formed in one side of a circuit box, and a charging and data leading-out interface and a switch of the data recorder are exposed.

5. The integrated test device for the metal corrosion weight loss test under the alternating current-direct current interaction of claim 4, wherein: the medium container groove is a customized PP polypropylene container and comprises a cover plate and a division plate;

the cover plate is provided with four notches, the caliber of each notch is matched with a test material, and the notches are used for fixing a sample, a reference electrode and two auxiliary electrodes respectively;

the interlayer plate is used for placing and fixing a test circuit box;

the medium container tank is marked with the highest water level line.

Images