Electrochemical corrosion test device for metal pipeline under stray current

Abstract

The utility model relates to the field of metal pipeline testing devices, and discloses an electrochemical corrosion testing device for a metal pipeline under stray current, the electrochemical corrosion testing device comprises a base, a first supporting column and a second supporting column are symmetrically arranged on the base, and a plurality of bearing frames are fixedly arranged on the side walls of the first supporting column and the second supporting column; a plurality of metal pipelines are placed on the first supporting column and the second supporting column through the bearing frames, a plurality of first wires are fixedly arranged on the side wall of the first supporting column, the first supporting column is fixedly connected with a plurality of conductive clamps through the first wires, a plurality of second wires are fixedly arranged on the side wall of the second supporting column, and the conductive clamps are fixedly connected with the second supporting column through the second wires. The second supporting column is fixedly connected with a plurality of testing rods through a plurality of second wires, so that a closed circuit is formed among the conductive clamp, the testing rods and the electrolyte solution, and the corrosion conditions of the clamping position of the conductive clamp and the outer wall of the metal pipeline and the contact position of the testing rods and the inner wall of the metal pipeline are observed.

Description

Technical Field

[0001] The present application relates to the field of metal pipeline test devices, and in particular, to an electrochemical corrosion test device for metal pipelines under stray current. Background Technique

[0002] Metal pipelines are widely used in modern life and production. During the daily use of metal pipelines, the metal pipelines are corroded due to the influence of stray current. There are many forms of stray current sources, such as electrified railways, DC power supplies in factories, grounding electrodes of high-voltage equipment, and cathodic protection facilities. The objective existence will inevitably generate stray current and cause corrosion of underground pipelines due to stray current. Stray current corrosion has the characteristics of high intensity, great harm, wide range, and strong randomness.

[0003] At present, during the actual use of metal pipelines, they are easily affected by stray current corrosion. However, for the formation of stray current and the influencing factors of the formation of stray current, it is difficult to quickly judge, which leads to difficulties in construction rectification according to the actual situation when there is corrosion in metal pipelines.

[0004] Regarding the above related technologies, the inventor believes that there are defects in the formation factors that are difficult to judge when metal pipelines are corroded by stray current.

[0005] The above information disclosed in this background technique is only used to increase the understanding of the background technique of the present application. Therefore, it may include prior art that is not known to those of ordinary skill in the art. Content of the Utility Model

[0006] In order to solve the problems raised in the background technique, the present application provides an electrochemical corrosion test device for metal pipelines under stray current.

[0007] The electrochemical corrosion test device for metal pipelines under stray current provided by the present application adopts the following technical solutions:

[0008] An electrochemical corrosion test device for metal pipelines under stray current includes a base. On the base, a first support column and a second support column are symmetrically arranged. A plurality of receiving frames are fixedly arranged on the side walls of the first support column and the second support column. A plurality of metal pipelines are placed on the first support column and the second support column through the plurality of receiving frames. A plurality of first wires are fixedly arranged on the side wall of the first support column. The first support column is fixedly connected to a plurality of conductive clips through the plurality of first wires. A plurality of second wires are fixedly arranged on the side wall of the second support column. The second support column is fixedly connected to a plurality of test rods through the plurality of second wires.

[0009] Preferably, a first storage battery is placed on the side of the first support column, and a second storage battery is placed on the side of the second support column. Both between the first support column and the first storage battery and between the second support column and the second storage battery are electrically connected by power transmission lines.

[0010] Preferably, a plurality of control knobs are fixedly arranged on the side walls of the first support column and the second support column.

[0011] Preferably, an insulating sheath is sleeved outside the receiving frame. One end of the receiving frame is fixedly provided with a threaded shaft, and a limiting ring is fixedly arranged on the outer surface of the receiving frame at the side of the threaded shaft.

[0012] Preferably, the second wire and the test rod are fixedly connected by a connecting block, and a plurality of conductive contacts are fixedly arranged on the outer wall of the test rod.

[0013] In summary, the present application includes the following beneficial technical effects:

[0014] 1. By fixedly connecting a conductive clip and a test rod to the side walls of the first support column and the second support column respectively, the test rod can be placed inside the metal pipe, and the conductive clip can be clamped on the outer wall of the metal pipe. Secondly, an electrolyte solution is placed inside the metal pipe, so that a closed circuit is formed among the conductive clip, the test rod and the electrolyte solution. Observe the corrosion conditions at the clamping place between the conductive clip and the outer wall of the metal pipe and at the contact place between the test rod and the inner wall of the metal pipe.

[0015] 2. By the first support column and the second wire respectively or simultaneously supplying current to the conductive clip and the test rod, observe the corrosion conditions of the outer wall or the inner wall of the metal pipe when the current is increased, so as to quickly obtain the results, and cooperate with a plurality of metal pipes for comparative tests, so as to quickly judge the corrosion problem of the metal pipe, and the relationship between the current magnitudes of the conductive clip on the outer wall of the metal pipe and the test rod on the inner wall of the metal pipe, or different types of electrolyte solutions placed inside the metal pipe. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 is the overall structural schematic diagram of the metal pipe test device of the application embodiment;

[0017] Figure 2 is the schematic diagram of the storage battery connection structure of the metal pipe test device of the application embodiment;

[0018] Figure 3 is the schematic diagram of the connection structure of the support column of the application embodiment;

[0019] Figure 4 is the schematic diagram of the connection structure of the receiving frame of the application embodiment;

[0020] Figure 5 It is a schematic diagram of the connection structure of the test rod in the application embodiment;

[0021] Figure 6 It is a schematic diagram of the stray current formation structure of the metal pipe in the application embodiment.

[0022] Explanation of reference numerals: 1, base; 2, first support column; 3, metal pipe; 4, first wire; 5, conductive clip; 6, first storage battery; 7, second storage battery; 8, second support column; 9, second wire; 10, test rod; 11, receiving frame; 12, transmission line; 13, insulating sheath; 14, limiting ring; 15, threaded shaft; 16, connection block; 17, conductive contact; 18, control knob. Detailed implementation manners

[0023] The following further describes the present application in detail Figure 1-6 in conjunction with the attached drawings.

[0024] The embodiment of the present application discloses an electrochemical corrosion test device for metal pipes under stray current. Refer to Figure 1 , Figure 2 and Figure 6 , an electrochemical corrosion test device for metal pipes under stray current includes a base 1, and a first support column 2 and a second support column 8 are symmetrically arranged on the base 1, so that the base 1 can fixedly support the first support column 2 and the second support column 8; secondly, a plurality of receiving frames 11 are fixedly arranged on the side walls of the first support column 2 and the second support column 8, so that between the first support column 2 and the second support column 8, a plurality of metal pipes 3 can be placed through the plurality of receiving frames 11, thereby facilitating the electrochemical corrosion test of the plurality of metal pipes 3 under stray current;

[0025] Meanwhile, a plurality of first wires 4 are fixedly arranged on the side wall of the first support column 2, and it is arranged that the first support column 2 is fixedly connected with a plurality of conductive clips 5 through the plurality of first wires 4, so that the conductive clips 5 can be clamped on the outer surface of the plurality of metal pipes 3, and then current is transmitted through the first support column 2 for the test; secondly, a plurality of second wires 9 are fixedly arranged on the side wall of the second support column 8, and it is arranged that the second support column 8 is fixedly connected with a plurality of test rods 10 through the plurality of second wires 9, so that the test rods 10 can be placed inside the metal pipes 3 and be in contact with the inner wall of the metal pipes 3, and then current is transmitted through the second wires 9; secondly, an electrolyte solution such as mixed brine or untreated rainwater is placed inside the metal pipes 3 to replace the solution inside the metal pipes 3 to form a stray current, so that a closed circuit is formed among the conductive clips 5, the test rods 10 and the electrolyte solution, and the corrosion conditions at the clamping positions between the conductive clips 5 and the outer wall of the metal pipes 3 and the contact positions between the test rods 10 and the inner wall of the metal pipes 3 are observed;

[0026] And it can supply current to the conductive clamp 5 and the test rod 10 respectively or simultaneously through the first support column 2 and the second wire 9, observe the corrosion condition of the outer wall or the inner wall of the metal pipe 3 when the current is increased, so as to quickly obtain the result, and cooperate with several metal pipes 3 for comparative tests, so as to quickly judge the corrosion problem of the metal pipe 3, and the relationship between the current magnitude of the conductive clamp 5 on the outer wall of the metal pipe 3 and the test rod 10 on the inner wall of the metal pipe 3, or different types of electrolyte solutions placed inside the metal pipe 3;

[0027] In addition, the corrosion caused by stray current is called stray current corrosion, also known as lost current corrosion or interference corrosion; in engineering practice, there are many forms of stray current sources, such as the objective existence of electrified railways, DC power supplies in factories, grounding electrodes of high-voltage equipment, cathodic protection facilities, etc., which will inevitably generate stray current and cause corrosion of underground metal pipes 3 due to stray current; stray current corrosion has the characteristics of high intensity, great harm, wide range and strong randomness; due to external factors, there is stray current between the basement walls, and the metal pipe 3 directly passes through the wall or contacts the wall through pipe clamps, brackets, etc. that are not fully insulated, forming a closed loop and causing stray current corrosion;

[0028] When cutting steel pipes, metal particles on the grinding wheel splash into the inside of the metal pipe 3 and are likely to stay at the lower part of the metal pipe 3 after installation. When stray current passes through the metal pipe 3, a part of the current flows through the grinding wheel particles and then flows into the metal pipe 3. At the parts where the stray current leaves the metal pipe 3, the metal pipe 3 will be corroded due to discharging;

[0029] Since the severity of stray current corrosion follows Faraday's law and is proportional to the amount of stray current flowing out and proportional to the electrochemical equivalent of the metal material of the metal pipe 3,

[0030] That is: ΔW =

[0031] In the formula, ΔW: the corrosion amount of the metal pipe 3 caused by stray current, in grams; N: the atomic weight of the metal pipe 3; I: the stray current intensity, in amperes; T: the acting time of the stray current on the metal pipe 3, in seconds; n: the valence of the metal pipe 3; F: Faraday constant.

[0032] The corrosion rate of stray current on the metal pipe 3 per unit area can be expressed as

[0033] Vsc == I

[0034] When stray current causes pipeline corrosion, the anodic reaction at the place where the stray current flows out of the metal pipe 3 is:

[0035] Fe Fe+2+2e-

[0036] Given N = 55.84 grams, n = 2, and F = 26.8 ampere-hours, we assume that the intensity of the stray current is 1 mA (10^-3 amperes), and at the location where the stray current flows out, the damaged area of the anti-corrosion layer on the pipeline surface is 1 cm². Thus,

[0037] VSC == 10.4 grams per square meter per hour

[0038] Taking the density of the pipe body as 7.80 grams per cubic centimeter, thus, the corrosion rate of the pipeline caused by the stray current under the above assumed conditions is

[0039] VSC == 11.68 millimeters per year ≈ 1 millimeter per month

[0040] That is to say, when there is a 1 cm² damaged anti-corrosion layer on the metal pipeline 3 and a 1 mA stray current flows out on the metal pipeline 3 in this area, then such a small stray current causes a corrosion rate of 11.7 millimeters per year for the metal pipeline 3, which is equivalent to 1 millimeter per month. If the intensity of the stray current is greater than 1 mA and the outflow area is smaller than 1 cm², the corrosion rate it causes will be higher. If a 1 A current passes through the surface of the metal pipeline 3 and flows into the ground, then 9 kg of steel will be dissolved in one year. In fact, the intensity of the stray current occurring in the soil is very large, the potential between the pipeline and the ground can be as high as 8 - 9 V, and the maximum current passing through can reach several hundred amperes. For a metal pipeline 3 with a wall thickness of 7 - 8 mm, under the action of the stray current, corrosion perforation can occur within a few months.

[0041] Refer to Figure 1 and Figure 2 , on the side of the first support column - 2 and the side of the second support column 8, a first storage battery 6 and a second storage battery 7 are respectively placed, and both the first storage battery 6 and the second storage battery 7 are respectively connected to the first support column 2 and the second support column 8 through transmission lines 12, so that the current used by the conductive clip 5 during the test can be transmitted to the transmission line 12 through the first storage battery 6 and then transmitted to the first support column 2, and then transmitted to the conductive clip 5 through the wire 4 on the side wall of the first support column 2; while the current used by the test rod 10 during the test can be transmitted to the transmission line 12 through the second storage battery 7 and then transmitted to the second support column 8, and then transmitted to the test rod 10 through the wire 9 on the side wall of the second support column 8; in this way, it is convenient for the conductive clip 5 and the test rod 10 to have current to test the influence on the corrosion situation of the metal pipeline 3 by adjusting the current magnitude.

[0042] Refer to Figure 2 and Figure 3 , on the side walls of the first support column 2 and the second support column 8, a number of control knobs 18 are fixedly arranged, so that the number of control knobs 18 can control the current transmitted by the number of wires 4 and wires 9, in this way, it is convenient for the conductive clip 5 and the test rod 10 to conduct a current control comparison test.

[0043] Refer to Figure 4 , an insulating sheath 13 is sleeved outside the receiving frame 11, so that the insulating sheath 13 is convenient for increasing the insulation of the outer surface of the receiving frame 11 and preventing the metal pipe 3 from being affected by the receiving frame 11 when placed inside the receiving frame 11;

[0044] At the same time, a threaded shaft 15 is fixedly arranged at one end of the receiving frame 11, and a limiting ring 14 is fixedly connected to the outer wall of the receiving frame 11, so that when the receiving frame 11 is installed and used, it is convenient to install through the threaded shaft 15 and limit through the limiting ring 14.

[0045] Refer to Figure 5 , a connecting block 16 is fixedly connected between the second wire 9 and the test rod 10, so that the round shaft-shaped connecting block 16 is convenient for the test rod 10 to be placed inside the metal pipe 3 for testing; at the same time, a plurality of conductive contacts 17 are arranged on the outer surface of the test rod 10, so that the plurality of conductive contacts 17 are convenient for imitating metal debris to form current-conducting contacts.

[0046] The implementation principle of an electrochemical corrosion test device for metal pipelines under stray current in an embodiment of the present application is as follows: By setting a base 1, and symmetrically arranging a first support column 2 and a second support column 8 on the base 1, the base 1 can fixedly support the first support column 2 and the second support column 8; Secondly, a number of receiving frames 11 are fixedly arranged on the side walls of the first support column 2 and the second support column 8, so that between the first support column 2 and the second support column 8, a number of metal pipelines 3 can be placed through the number of receiving frames 11, thereby facilitating the electrochemical corrosion test of the number of metal pipelines 3 under stray current. At the same time, a number of first wires 4 are fixedly arranged on the side wall of the first support column 2, and it is set that the first support column 2 is fixedly connected with a number of conductive clips 5 through the number of first wires 4, so that the conductive clips 5 can be clamped on the outer surface of the number of metal pipelines 3, and then current is transmitted through the first support column 2 for the test; Secondly, a number of second wires 9 are fixedly arranged on the side wall of the second support column 8, and it is set that the second support column 8 is fixedly connected with a number of test rods 10 through the number of second wires 9, so that the test rods 10 can be placed inside the metal pipeline 3 and fit against the inner wall of the metal pipeline 3, and then current is transmitted through the second wires 9; Secondly, an electrolyte solution such as mixed salt water or untreated rainwater is placed inside the metal pipeline 3 to replace the solution inside the metal pipeline 3 to form a stray current, so that a closed circuit is formed among the conductive clips 5, the test rods 10 and the electrolyte solution. Observe the corrosion conditions at the clamping positions between the conductive clips 5 and the outer wall of the metal pipeline 3, and the contact positions between the test rods 10 and the inner wall of the metal pipeline 3. And current can be transmitted to the conductive clips 5 and the test rods 10 respectively or simultaneously through the first support column 2 and the second wires 9. Observe the corrosion conditions of the outer wall or the inner wall of the metal pipeline 3 when the current is increased, so as to quickly obtain the results, and cooperate with a number of metal pipelines 3 for a comparative test, thereby facilitating the quick judgment of the corrosion problem of the metal pipeline 3, the relationship between the current magnitudes of the conductive clips 5 on the outer wall of the metal pipeline 3 and the test rods 10 on the inner wall of the metal pipeline 3, or different types of electrolyte solutions placed inside the metal pipeline 3.

[0047] Finally, several points should be noted: First, in the description of the present application, it should be noted that unless otherwise specified and limited, the terms "installation", "connection", and "coupling" should be understood in a broad sense, which can be a mechanical connection or an electrical connection, or the communication inside two components. It can be directly connected. "Up", "down", "left", "right", etc. are only used to represent relative position relationships. When the absolute position of the object being described changes, the relative position relationship may change;

[0048] Secondly: In the drawings of the disclosed embodiments of the present utility model, only the structures related to the disclosed embodiments are involved. For other structures, reference can be made to the general design. Without conflict, the same embodiment and different embodiments of the present utility model can be combined with each other;

[0049] Finally: The above are only the preferred embodiments of the present utility model and are not used to limit the present utility model. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present utility model shall be included within the protection scope of the present utility model.

[0050] The above are all the preferred embodiments of this application, and do not limit the protection scope of this application accordingly. Therefore, any equivalent changes made according to the structure, shape, and principle of this application shall be covered within the protection scope of this application.

Claims

1. An electrochemical corrosion test device for metal pipelines under stray current, comprising a base (1), characterized in that: The base (1) is symmetrically provided with a support column 1 (2) and a support column 2 (8); the side walls of the support column 1 (2) and the support column 2 (8) are fixedly provided with a plurality of receiving frames (11); and the support column 1 (2) and the support column 2 (8) are provided with a plurality of metal pipes (3) via the plurality of receiving frames (11); The side wall of the support column one (2) is fixedly provided with a plurality of conductive wires one (4), and the support column one (2) is fixedly connected to a plurality of conductive clips (5) via the plurality of conductive wires one (4); the side wall of the support column two (8) is fixedly provided with a plurality of conductive wires two (9), and the support column two (8) is fixedly connected to a plurality of test rods (10) via the plurality of conductive wires two (9).

2. The electrochemical corrosion test device for metal pipelines under stray current according to claim 1, characterized in that: A No. 1 storage battery (6) is placed on the side of the support column 1 (2), and a No. 2 storage battery (7) is placed on the side of the support column 2 (8). The support column 1 (2) and the No. 1 storage battery (6) as well as the support column 2 (8) and the No. 2 storage battery (7) are electrically connected via a transmission line (12).

3. The electrochemical corrosion test device for metal pipelines under stray current according to claim 1, characterized in that: The side walls of the support column 1 (2) and the support column 2 (8) are both fixedly provided with a plurality of control knobs (18).

4. The electrochemical corrosion test device for metal pipelines under stray current according to claim 1, characterized in that: The outside of the receiving frame (11) is sleeved with an insulating sheath (13), one end of the receiving frame (11) is fixedly provided with a threaded shaft (15), and the outer surface of the receiving frame (11) is fixedly provided with a limiting ring (14) at the side of the threaded shaft (15).

5. The electrochemical corrosion test device for metal pipelines under stray current according to claim 1, characterized in that: The second conductor (9) and the test rod (10) are fixedly connected via a connecting block (16), and a plurality of conductive contacts (17) are fixedly arranged on the outer wall of the test rod (10).

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