Reciprocating type friction galvanic corrosion testing device

Abstract

The utility model belongs to the technical field of metal material corrosion and wear tests, and relates to a galvanic corrosion test device which comprises a friction and wear test system, a galvanic corrosion test system and an in-situ electrochemical test system. The dissimilar metal working electrodes are respectively installed in the electrode holders, the sealing pressing plates are matched with the screws to fix and seal the working electrodes, and the device can be used for testing the corrosive wear rate of dissimilar coupling metal under the corrosive wear working condition. The corrosion current, the corrosion potential, the open circuit potential, the alternating current impedance and the polarization curve of the dissimilar coupling metal under the static and wear conditions can be obtained. And carrying out quantitative analysis on the corrosion-wear interaction of the dissimilar coupling metal according to the in-situ electrochemical information. Through the method, the corrosion performance and the corrosion wear performance of the dissimilar coupling metal material can be evaluated, and data and theoretical reference are provided for material selection, structural design and corrosion and wear protection of key parts of high-end equipment for ocean, nuclear power, petrochemical engineering, traffic and the like.

Description

Technical Field

[0001] The utility model relates to the technical field of friction corrosion electrochemistry testing, and relates to a reciprocating friction galvanic corrosion testing device. Background Art

[0002] High-end equipment in fields such as marine, transportation, petrochemical, aviation, and aerospace contains a large number of moving mechanisms, and the contact or connection of dissimilar metals is inevitable. Under corrosive working conditions, due to the different corrosion potentials of dissimilar metals, there is an electric potential difference between the coupled metals, and thus a galvanic current flowing from the low-potential metal to the high-potential metal is generated, weakening the corrosion of the high-potential metal while accelerating the corrosion of the low-potential metal. Therefore, during the friction and wear process of dissimilar coupled metals, corrosion wear caused by the coupling of galvanic corrosion and mechanical wear will inevitably occur, accelerating the damage of the coupled metals and threatening the reliability and safety of the equipment. At present, most of the tests on metal corrosion wear are for synchronous corrosion and friction wear tests of a single metal, and most of the galvanic corrosion tests are for testing the galvanic voltage and galvanic current of dissimilar coupled metals, while there are few reports on the corrosion wear tests of dissimilar coupled metals. Patent CN106940277A (Chen Jun, Zhang Qing, Zhu Limin, Fu Sanling, Chen Xiaoya, Zhang Shuai, Wang Songbo, Guan Haikun, Corrosion Wear Performance Testing Method and Testing Device for Dissimilar Metal Friction Pairs) mentions a corrosion wear testing device for dissimilar metal pairs. From the perspective of dissimilar coupled metals, the influencing factors of galvanic corrosion mainly include the potential difference, area ratio, and pair spacing of dissimilar coupled metals. During the friction and wear process of the friction pair composed of the coupled metals in this device, the interface of the coupled metals wears, and the changes in the wear morphology of the friction interface, the generation and adhesion of wear debris will all cause changes in the potential, area ratio, and pair spacing of the coupled metals, with uncertainties, and it is impossible to quantitatively study the interaction between galvanic corrosion and friction wear. Content of the Utility Model

[0003] The purpose of the utility model is to provide a reciprocating friction galvanic corrosion testing device, which can realize the in-situ friction galvanic corrosion testing of dissimilar coupled metals, study the corrosion wear behavior of metal materials under the galvanic effect of coupled metals, and quantitatively analyze the interaction between galvanic corrosion and friction wear.

[0004] To achieve the above purpose, the present invention adopts the following technical solutions:

[0005] A reciprocating friction galvanic corrosion testing device includes a galvanic corrosion test system, a friction wear test system, and an in-situ electrochemical test system;

[0006] The galvanic corrosion test system includes an electrolytic cell, in which two working electrode mounting bases are provided. Each working electrode mounting base is respectively installed with a working electrode. The upper surface of the working electrode is tightened by a sealing pressing plate, and the sealing pressing plate is fixed to the bottom of the electrolytic cell by screws. The lower surface of the working electrode contacts and is electrically connected to a copper conductive column embedded in the bottom of the electrolytic cell. A spring is sleeved outside the copper conductive column to keep the copper conductive column in close contact with the lower surface of the working electrode. The bottom of the copper conductive column is connected to a working electrode lead to the outside of the electrolytic cell through a set screw. A lead sealing end is provided at the joint between the working electrode lead and the electrolytic cell.

[0007] The friction and wear test system includes a grinding head that contacts the upper surface of any one of the working electrodes, and the grinding head is connected to a friction and wear testing machine.

[0008] The in-situ electrochemical testing system includes an electrochemical workstation and a working electrode, a reference electrode, and an auxiliary electrode connected to the electrochemical workstation. The reference electrode and the auxiliary electrode are respectively fixed to the electrolytic cell by electrode clamps.

[0009] To prevent the electrolyte from seeping into the working electrode mounting base and corroding the copper conductive column, an O-ring seal is embedded at the bottom of the working electrode mounting base, and the lower surface of the working electrode contacts the O-ring seal to achieve sealing.

[0010] To achieve quantitative and controllable galvanic corrosion, a round hole for exposing the working electrode is opened in the middle of the sealing pressing plate, and the area of the round hole is 0.1 to 0.9 times the upper surface area of the working electrode. Round holes of different sizes can adjust the exposed area of the working electrode, thereby playing a role in controlling the galvanic corrosion effect.

[0011] To avoid electric leakage, the electrolytic cell, screws, electrode clamps, grinding heads, lead sealing ends, O-ring seals, and sealing pressing plates are all made of insulating materials.

[0012] During testing, the electrolytic cell is filled with a test solution, and the working electrode, reference electrode, and auxiliary electrode all need to be immersed in the test solution.

[0013] Compared with the prior art, the present invention has the following beneficial effects:

[0014] Based on the principle of galvanic corrosion and in-situ tribo-electrochemical testing, this device reasonably arranges the positions and exposed areas of dissimilar-coupled metals, tribological pairs, and electrochemical test electrodes. It can conduct reciprocating tribogalvanic corrosion tests on dissimilar-coupled metals, realizing in-situ tribo-electrochemical testing of dissimilar-coupled metals, synchronously obtaining tribological properties (friction coefficient, wear rate) and galvanic corrosion properties (galvanic voltage, galvanic current), and quantitatively studying the interaction between galvanic corrosion and tribological wear. At the same time, this device has diverse functions and can simultaneously achieve corrosion-wear tests under multiple service conditions. In addition to static galvanic corrosion tests and tribogalvanic corrosion tests, this device can also conduct static electrochemical corrosion tests and in-situ tribo-electrochemical tests. Moreover, in this device, the specimens do not need to be sealed with epoxy resin or paint, the exposed area is controllable, there is no stray current, the specimen treatment is simple, and the tribogalvanic corrosion rate of metal materials can be quickly evaluated by combining in-situ electrochemical testing and the weight loss method. The test accuracy is high, and the disassembly and assembly are simple and reliable. Description of the Drawings

[0015] Figure 1 This is a top view of the structure of a reciprocating tribogalvanic corrosion test device of the present utility model.

[0016] Figure 2 is Figure 1 A-A sectional view of the structure of

[0017] Figure 3 is Figure 2 An enlarged view of the structure of part B of

[0018] Figure 4 This is a three-dimensional structure diagram of a reciprocating tribogalvanic corrosion test device of the present utility model.

[0019] In the figure: 1 - electrolytic cell, 2 - screw, 3 - reference electrode, 4 - electrode clamp A, 5 - working electrode lead A, 6 - lead sealing end A, 7 - electrode clamp B, 8 - auxiliary electrode, 9 - grinding head, 10 - working electrode A, 11 - working electrode B, 12 - working electrode lead B, 13 - lead sealing end B, 14 - sealing pressing plate, 15 - electrolyte, 16 - set screw, 17 - copper conducting column, 18 - O-ring, 19 - spring. Detailed Embodiments

[0020] The following further explains and illustrates the present invention in conjunction with the drawings and detailed embodiments.

[0021] As Figures 1-4 shown, a reciprocating tribogalvanic corrosion test device includes a galvanic corrosion test system, a tribological wear test system, and an in-situ electrochemical test system.

[0022] The galvanic corrosion test system includes an electrolytic cell 1. Inside the electrolytic cell 1, there are two working electrode mounting bases, and working electrodes (working electrode A and working electrode B) are respectively installed in each working electrode mounting base; the upper surface of the working electrode is tightened by a sealing pressing plate 14, and the sealing pressing plate 14 is fixed to the bottom of the electrolytic cell 1 by screws; the lower surface of the working electrode is in contact with and electrically conducts with a copper conductive column 17 embedded in the bottom of the electrolytic cell 1. A spring 19 is sleeved outside the copper conductive column 17 to keep the copper conductive column 17 in close contact with the lower surface of the working electrode. The bottom of the copper conductive column 17 is crimped with a working electrode lead wire by a set screw 16. The other end of the working electrode lead wire extends outside the electrolytic cell 1, and a lead wire sealing end is provided at the joint of the working electrode lead wire and the electrolytic cell 1.

[0023] The friction and wear test system includes a grinding head 9 in contact with the upper surface of any working electrode. The grinding head 9 is connected to a friction and wear testing machine; the mating contact mode of the friction and wear testing machine is ball - disk or pin - disk, and the friction mode is reciprocating.

[0024] The in - situ electrochemical testing system includes an electrochemical workstation and a working electrode, a reference electrode 3, and an auxiliary electrode 8 connected to the electrochemical workstation. The reference electrode 3 and the auxiliary electrode 8 are respectively fixed to the electrolytic cell 1 with electrode clamps.

[0025] To prevent the electrolyte from seeping into the working electrode mounting base and corroding the copper conductive column, an O - ring 18 is embedded at the bottom of the working electrode mounting base, and the lower surface of the working electrode is in contact with the O - ring 18 to achieve sealing.

[0026] To achieve quantitative and controllable galvanic corrosion, a round hole for exposing the working electrode is opened in the middle of the sealing pressing plate 14. The size of the round hole is guaranteed by machining according to experimental requirements to adjust the exposed area of the working electrode, thereby playing a role in controlling the galvanic corrosion effect.

[0027] In addition, to avoid electric leakage, the electrolytic cell, screws, electrode clamps, grinding heads, lead wire sealing ends, O - rings, and sealing pressing plates are all made of insulating materials.

[0028] During the test, the electrolytic cell is filled with the test solution, and the working electrode, reference electrode, and auxiliary electrode all need to be immersed in the test solution.

[0029] According to the test requirements, the device of the present invention can perform the following three tests:

[0030] 1. Static galvanic corrosion test

[0031] The working electrode lead A 5 is connected to the working electrode (WE) port of the electrochemical workstation, the working electrode lead B 12 is connected to the ground (GND) port of the electrochemical workstation, and the reference electrode 3 is connected to the reference electrode (RE) port of the electrochemical workstation. The galvanic current and galvanic voltage of the working electrode A 10 and the working electrode B 11 are respectively tested by the electrochemical workstation to determine the galvanic corrosion characteristics of the two working electrodes.

[0032] 2. Frictional galvanic corrosion test + Static electrochemical test

[0033] The working electrode lead A 5 is connected to the working electrode (WE) port of the electrochemical workstation, the working electrode lead B 12 is connected to the ground (GND) port of the electrochemical workstation, and the reference electrode 3 is connected to the reference electrode (RE) port of the electrochemical workstation. The friction and wear testing machine and the electrochemical workstation are turned on, and one of the working electrode A 10 or the working electrode B 11 is subjected to friction and wear, and the galvanic corrosion (current, voltage) and the friction coefficient are synchronously tested to determine the interaction between galvanic corrosion and friction and wear.

[0034] The working electrode lead A 5 and the working electrode lead B 12 are successively and respectively connected to the working electrode (WE) port of the electrochemical workstation, the reference electrode 3 is connected to the reference electrode (RE) port of the electrochemical workstation, and the auxiliary electrode 8 is connected to the auxiliary electrode (CE) port of the electrochemical workstation. The open circuit potential, alternating current impedance, and polarization curve of the working electrode A 10 and the working electrode B 11 are respectively tested by the electrochemical workstation to determine the electrochemical corrosion characteristics of the two working electrodes after the frictional galvanic corrosion test.

[0035] 3. Frictional galvanic corrosion test + Frictional electrochemistry test

[0036] The working electrode lead A 5 is connected to the working electrode (WE) port of the electrochemical workstation, the working electrode lead B 12 is connected to the ground (GND) port of the electrochemical workstation, and the reference electrode 3 is connected to the reference electrode (RE) port of the electrochemical workstation. The friction and wear testing machine and the electrochemical workstation are turned on, and one of the working electrode A 10 or the working electrode B 11 is subjected to friction and wear, and the galvanic corrosion (current, voltage) and the friction coefficient are synchronously tested to determine the interaction between galvanic corrosion and friction and wear.

[0037] The working electrode lead A 5 and the working electrode lead B 12 are successively connected to the working electrode (WE) port of the electrochemical workstation. The reference electrode 3 is connected to the reference electrode (RE) port of the electrochemical workstation, and the auxiliary electrode 8 is connected to the auxiliary electrode (CE) port of the electrochemical workstation. Turn on the friction and wear testing machine and the electrochemical workstation, measure the friction coefficient, and simultaneously measure the in-situ open circuit potential, AC impedance, and polarization curve during the friction between the working electrode A 10 and the working electrode B 11 to determine the corrosion and wear characteristics of the two working electrodes after the tribocorrosion test.

[0038] After the test, unload and shut down the friction and wear test system, turn off the electrochemical workstation, and disconnect the connections between the working electrode, reference electrode, and auxiliary electrode and the electrochemical workstation. Unscrew the screws, open the sealing pressing plate, take out the working electrode, rinse the surface of the sample with deionized water, dry it, and place it in a desiccator for further testing.

[0039] During the above test process, the working electrodes are two metal materials to be tested, and the reference electrode and the auxiliary electrode are selected from the prior art according to the test requirements, which are not limited here.

[0040] The above is the preferred embodiment of the present invention. It should be noted that for those of ordinary skill in the art, any improvements and modifications made without departing from the principles and design concepts shown in the present invention shall be considered as within the protection scope of the present invention.

Claims

1. A reciprocating tribo-galvanic corrosion test device, characterized in that, It includes a galvanic corrosion test system, a friction and wear test system, and an in-situ electrochemical test system; The galvanic corrosion test system includes an electrolytic cell (1). There are two working electrode mounting bases arranged in the electrolytic cell (1). Working electrodes are respectively installed in each working electrode mounting base. The upper surface of the working electrode is tightened by a sealing pressing plate (14), and the sealing pressing plate (14) is fixed to the bottom of the electrolytic cell (1) by screws. The lower surface of the working electrode contacts and is electrically connected to a copper conductive column (17) embedded in the bottom of the electrolytic cell (1). A spring (19) is sleeved on the outer periphery of the copper conductive column (17) to keep the copper conductive column (17) in close contact with the lower surface of the working electrode. The bottom of the copper conductive column (17) is connected to a working electrode lead outside the electrolytic cell (1) by a set screw (16). A lead sealing end is provided at the joint of the working electrode lead and the electrolytic cell (1); The friction and wear test system includes a grinding head (9) that contacts the upper surface of the working electrode, and the grinding head (9) is connected to a friction and wear testing machine; The in-situ electrochemical test system includes an electrochemical workstation and a working electrode, a reference electrode (3), and an auxiliary electrode (8) connected to the electrochemical workstation. The reference electrode (3) and the auxiliary electrode (8) are respectively fixed to the electrolytic cell (1) by electrode clamps.

2. The reciprocating tribo-galvanic corrosion testing device according to claim 1, characterized in that, An O-ring (18) is embedded at the bottom of the working electrode mounting base, and the lower surface of the working electrode contacts the O-ring (18) to achieve sealing.

3. The reciprocating tribo-galvanic corrosion test device according to claim 1, wherein, A circular hole for exposing the working electrode is opened in the middle of the sealing pressing plate (14), and the area of the circular hole is 0.1 to 0.9 times the upper surface area of the working electrode.

4. The reciprocating tribo-galvanic corrosion test device according to claim 1, wherein The electrolytic cell (1), screws, electrode clamps, grinding head (9), lead sealing end, O-ring (18), and sealing pressing plate (14) are all made of insulating materials.

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