Corrosion rate in-situ monitoring device and method

Abstract

The invention relates to the technical field of corrosion resistance testing, and discloses a corrosion rate in-situ monitoring device and method. The corrosion rate in-situ monitoring device comprises a reaction container, a first connecting line body and a measuring system. The reaction container comprises a containing cavity capable of storing a corrosion medium. The reaction vessel is provided with a counter electrode assembly and a reference electrode. The first connecting line body penetrates through the reaction container; the first connecting line body comprises a first end and a second end. The first end of the first connecting line body is used for being connected with a metal sample located in the containing cavity. The metal sample can be used as a working electrode. The measuring system is respectively connected with the second end of the first connecting wire body, the counter electrode assembly and the reference electrode, and the measuring system is used for measuring the potential and the current of the metal sample. The accuracy of measuring the potential and the current can be improved, and the accuracy of analyzing the corrosion rate can be improved.

Description

Technical Field

[0001] The present application belongs to the technical field of corrosion resistance testing, and specifically relates to an in-situ corrosion rate monitoring device and method. Background Art

[0002] Among reactors, water-cooled reactors are the mainstream type of reactors for large international nuclear power plants, in which the primary water is used to cool the core and take away the heat from the core. The primary water is a high-temperature, high-pressure weakly alkaline aqueous solution containing B, Li and other aqueous media. The interior of the reactor fuel element cladding material (for example, zirconium alloy) contains the fuel exothermic core blocks and has a high service temperature in the primary circuit. The outside of the cladding material is directly exposed to the primary water quality, and reacts in the high-temperature water to form a film structure. For example, zirconium alloy undergoes a significant zirconium-water reaction in high-temperature water to form an insulating zirconium oxide film structure. The corrosion resistance of the cladding material, such as the uniform corrosion behavior and corrosion rate at the service operating temperature and high pressure, is the key performance that restricts the service performance, life and safety of the entire core.

[0003] In the related art, the high temperature electrochemical analysis of the cladding material studies the corrosion rate of the metal by the AC impedance spectroscopy method. In practical applications, a single Pt electrode is used as a counter electrode and a quasi-reference electrode, which affects the accuracy of the potential measurement and thus affects the accuracy of the corrosion rate analysis. Summary of the invention

[0004] The present application aims to solve at least one of the technical problems existing in the related art.

[0005] Therefore, a first aspect of the present application provides an in-situ corrosion rate monitoring device.

[0006] A second aspect of the present application provides a method for in-situ monitoring of corrosion rate.

[0007] In view of this, according to the first aspect of an embodiment of the present application, a corrosion rate in-situ monitoring device is proposed, including: a reaction container, the reaction container including a containing cavity capable of storing a corrosive medium, the reaction container being provided with a counter electrode assembly and a reference electrode; a first connecting wire body, passed through the reaction container, the first connecting wire body including a first end and a second end, the first end being used to connect to a metal sample located in the containing cavity, the metal sample being able to serve as a working electrode; a measuring system, respectively connected to the second end of the first connecting wire body, the counter electrode assembly and the reference electrode, for measuring the potential and current of the metal sample.

[0008] Optionally, the electrode assembly includes: a second connecting wire body, which is inserted into the reaction container and one end of which is connected to a measuring system; an auxiliary electrode, which is disposed in the accommodating cavity and connected to one end of the second connecting wire body away from the measuring system.

[0009] Optionally, the corrosion rate in-situ monitoring device further includes: an insulating portion, which is arranged outside the first connecting wire body and the second connecting wire body.

[0010] Optionally, the corrosion rate in-situ monitoring device further includes: a control device electrically connected to the measurement system, wherein the control device is used to obtain the corrosion rate of the metal sample according to the potential and the current measured by the measurement system.

[0011] According to the second aspect of an embodiment of the present application, a method for in-situ monitoring of corrosion rate is proposed, which is applied to an in-situ monitoring device for corrosion rate as in any of the previous embodiments. The method for in-situ monitoring of corrosion rate includes the following steps: in response to a monitoring request, obtaining corrosion characteristic data, the corrosion characteristic data including multiple standard electrode potentials and multiple current densities; determining the open circuit potential and the Tafel line based on the corrosion characteristic data; and obtaining the corrosion rate based on the open circuit potential and the Tafel line.

[0012] Optionally, the step of determining the open circuit potential according to the corrosion characteristic data includes: obtaining a minimum value among a plurality of the current densities to obtain a minimum current density; and obtaining a standard electrode potential corresponding to the minimum current density to obtain an open circuit potential.

[0013] Optionally, according to the corrosion characteristic data, the step of determining the Tafel line includes: drawing a polarization curve according to multiple standard electrode potentials and multiple current densities; obtaining a cathode strong polarization zone, which corresponds to a portion of the polarization curve; taking the logarithm of the absolute value of each current density located in the cathode strong polarization zone to obtain multiple logarithmic current densities; performing linear fitting on the multiple standard electrode potentials and the corresponding multiple logarithmic current densities in the cathode strong polarization zone to obtain the Tafel line; wherein, the step of obtaining the cathode strong polarization zone includes: obtaining the equipotential line where the open circuit potential is located to obtain a reference line; on the polarization curve side of the reference line, determining a preset potential range to obtain the cathode strong polarization zone.

[0014] Optionally, in response to a monitoring request, the step of obtaining corrosion characteristic data includes: in response to the monitoring request, controlling the measurement system to measure the potential and current of the metal sample to obtain multiple measurement potentials and multiple measurement currents; obtaining the surface area of ​​the metal sample; performing potential standardization on the multiple measurement potentials to obtain multiple standard electrode potentials; and obtaining multiple current densities based on the multiple measurement currents and the surface area of ​​the metal sample.

[0015] Optionally, the step of obtaining the corrosion rate according to the open circuit potential and the Tafel line includes: determining the current density corresponding to the open circuit potential on the Tafel line to obtain the corrosion current density; and calculating the corrosion rate according to the corrosion current density.

[0016] The corrosion rate in-situ monitoring device and method provided in this application can at least achieve the following technical effects:

[0017] In the present application, the reaction vessel includes a holding cavity capable of storing a corrosive medium for an electrochemical reaction. The reaction vessel is provided with an electrode assembly and a reference electrode. The metal sample in the holding cavity can be used as a working electrode to form a three-electrode system, which can reduce interference with potential and current measurement and improve the accuracy of measuring potential and current. The measuring system is respectively connected to the second end of the first connecting wire body, the electrode assembly and the reference electrode, and can measure the potential and current of the metal sample. The present application improves the accuracy of measuring potential and current, and when used to analyze the corrosion rate of a metal sample, it can improve the accuracy of analyzing the corrosion rate.

[0018] The above general description and the following description are exemplary and explanatory only and are not intended to limit the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] One or more embodiments are exemplarily described by corresponding drawings, which do not limit the embodiments. Elements with the same reference numerals in the drawings are shown as similar elements, and the drawings do not constitute a scale limitation, and wherein:

[0020] Figure 1 A schematic diagram of the structure of an in-situ corrosion rate monitoring device provided in an embodiment of the present disclosure;

[0021] Figure 2 A schematic diagram of the structure of a first connecting wire body and a metal sample provided in an embodiment of the present disclosure;

[0022] Figure 3 A schematic diagram of the structure of an electrode assembly provided in an embodiment of the present disclosure;

[0023] Figure 4 A flow chart of a method for in-situ monitoring of corrosion rate provided by one embodiment of the present disclosure;

[0024] Figure 5 A flow chart of a method for determining open circuit potential based on corrosion characteristic data provided by one embodiment of the present disclosure;

[0025] Figure 6 A flow chart of a method for determining a Tafel line based on corrosion characteristic data provided by one embodiment of the present disclosure;

[0026] Figure 7 A flowchart of a method for obtaining corrosion characteristic data provided by an embodiment of the present disclosure;

[0027] Figure 8 A flowchart of a method for in-situ monitoring of corrosion rate provided by another embodiment of the present disclosure;

[0028] Fig. 9 A schematic coordinate diagram of standard electrode potential and current density provided for embodiments of the present disclosure;

[0029] Fig.10 A schematic diagram of the monitoring results of the corrosion rates of 6 metal samples in an example of the present disclosure;

[0030] Fig.11 A schematic diagram of the structure of a control device provided in an embodiment of the present disclosure.

[0031] The reference numerals are as follows:

[0032] 1: In-situ corrosion rate monitoring device;

[0033] 100: reaction container; 101: containing chamber; 102: kettle body; 103: kettle cover; 104: liquid inlet interface; 105: liquid outlet interface; 106: welding sealing point; 107: electrical penetration;

[0034] 200: counter electrode assembly; 201: second connecting wire body; 202: auxiliary electrode;

[0035] 300: reference electrode; 400: first connecting wire body; 500: metal sample; 600: measurement system;

[0036] 700: insulating part; 701: first insulating tube; 702: second insulating tube;

[0037] 800: control device; 802: processor; 804: memory; 806: communication interface; 808: bus. DETAILED DESCRIPTION

[0038] In order to be able to understand the features and technical contents of the embodiments of the present disclosure in more detail, the implementation of the embodiments of the present disclosure is described in detail below in conjunction with the accompanying drawings. The attached drawings are for reference only and are not used to limit the embodiments of the present disclosure. In the following technical description, for the convenience of explanation, a full understanding of the disclosed embodiments is provided through multiple details. However, one or more embodiments can still be implemented without these details. In other cases, to simplify the drawings, well-known structures and devices can be simplified for display.

[0039] The terms "first", "second", etc. in the specification and claims of the embodiments of the present disclosure and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the terms used in this way can be interchanged where appropriate, so as to describe the embodiments of the embodiments of the present disclosure described herein. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions.

[0040] In the embodiments of the present disclosure, the terms "upper", "lower", "inside", "middle", "outside", "front", "back" and the like indicate directions or positional relationships based on the directions or positional relationships shown in the accompanying drawings. These terms are mainly intended to better describe the embodiments of the present disclosure and their embodiments, and are not intended to limit the indicated devices, elements or components to have a specific direction, or to be constructed and operated in a specific direction. Moreover, in addition to being used to indicate directions or positional relationships, some of the above terms may also be used to indicate other meanings. For example, the term "upper" may also be used to indicate a certain dependency or connection relationship in certain circumstances. For those of ordinary skill in the art, the specific meanings of these terms in the embodiments of the present disclosure can be understood according to specific circumstances.

[0041] In addition, the terms "disposed", "connected", and "fixed" should be understood in a broad sense. For example, "connected" can be a fixed connection, a detachable connection, or an integral structure; it can be a mechanical connection, or an electrical connection; it can be a direct connection, or an indirect connection through an intermediate medium, or it can be an internal connection between two devices, elements, or components. For those of ordinary skill in the art, the specific meanings of the above terms in the embodiments of the present disclosure can be understood according to specific circumstances.

[0042] Unless otherwise stated, the term "plurality" means two or more.

[0043] In the embodiment of the present disclosure, the character " / " indicates that the preceding and following objects are in an "or" relationship. For example, A / B indicates: A or B.

[0044] The term "and / or" is a description of the association relationship between objects, indicating that three relationships can exist. For example, A and / or B means: A or B, or, A and B.

[0045] It should be noted that, in the absence of conflict, the embodiments and features in the embodiments of the present disclosure may be combined with each other.

[0046] like Figures 1 to 3 As shown, an embodiment of the present disclosure provides an in-situ monitoring device 1 for corrosion rate. The in-situ monitoring device 1 for corrosion rate includes a reaction vessel 100, a first connecting wire body 400 and a measuring system 600. The reaction vessel 100 includes a containing cavity 101 capable of storing a corrosive medium. The reaction vessel 100 is provided with a counter electrode assembly 200 and a reference electrode 300. The first connecting wire body 400 is passed through the reaction vessel 100. The first connecting wire body 400 includes a first end and a second end. The first end of the first connecting wire body 400 is used to connect to a metal sample 500 located in the containing cavity 101. The metal sample 500 can be used as a working electrode. The measuring system 600 is respectively connected to the second end of the first connecting wire body 400, the counter electrode assembly 200 and the reference electrode 300, and the measuring system 600 is used to measure the potential and current of the metal sample 500.

[0047] In this embodiment, the reaction vessel 100 includes a housing chamber 101, which can store a corrosive medium for electrochemical reaction. Exemplarily, the corrosive medium can be a primary circuit water of a water-cooled reactor. The corrosive medium can also be a high-temperature and high-pressure aqueous solution. The corrosive medium can also be a low-alkaline aqueous solution containing boron (B), lithium (Li) and other aqueous media at high temperature and high pressure.

[0048] In this embodiment, the reaction container 100 is provided with an electrode assembly 200 and a reference electrode 300, and the metal sample 500 located in the containing cavity 101 can be used as a working electrode to form a stable three-electrode system, reduce interference with potential and current measurement, and improve the accuracy of measuring potential and current.

[0049] In this embodiment, the first connecting wire body 400 is inserted into the reaction container 100, and the first end of the first connecting wire body 400 is used to connect with the metal sample 500, so that the metal sample 500 is stably located in the corrosive medium in the containing cavity 101 to generate an electrochemical reaction.

[0050] In this embodiment, the measurement system 600 is connected to the second end of the first connecting wire body 400, the electrode assembly 200 and the reference electrode 300, respectively, and is used to measure the potential and current of the metal sample 500. This embodiment improves the accuracy of measuring the potential and current, and when used to analyze the corrosion rate of the metal sample 500, it can improve the accuracy of analyzing the corrosion rate.

[0051] It is understood that the metal sample 500 can be selected from the reactor fuel element cladding material. The material of the metal sample 500 includes but is not limited to stainless steel, nickel-based alloy, zirconium alloy, etc. The shape of the metal sample 500 is not limited, for example, tubular, sheet, etc.

[0052] Optionally, reaction vessel 100 comprises an autoclave.

[0053] Alternatively, if Figure 1 As shown, the reaction vessel 100 includes a kettle cover 103 and a kettle body 102 having an opening. The kettle cover 103 covers the opening of the kettle body 102. The kettle body 102 defines a receiving cavity 101. The counter electrode assembly 200, the reference electrode 300 and the first connecting wire body 400 are all arranged on the kettle cover 103 to perform an electrochemical reaction.

[0054] In this embodiment, Figure 1 As shown, the kettle cover 103 is penetrated with openings for installing the electrode assembly 200, the reference electrode 300 and the first connecting wire body 400, so that the electrode assembly 200, the reference electrode 300 and the first connecting wire body 400 are partially located in the accommodating cavity 101, and the other part is located outside the kettle body 102. The connection between the electrode assembly 200, the reference electrode 300 and the first connecting wire body 400 and the kettle cover 103 needs to be sealed and insulated. For example, the electrode assembly 200, the reference electrode 300 and the first connecting wire body 400 are respectively installed on the kettle cover 103 through the electrical penetration 107 to achieve sealed insulation.

[0055] Alternatively, if Figure 1 As shown, the reaction container 100 is provided with a liquid inlet interface 104 and a liquid outlet interface 105 . Figure 1 In the figure, the straight arrows on the sides of the liquid inlet interface 104 and the liquid outlet interface 105 are used to indicate the flow direction of the corrosive medium. The external corrosive medium flows into the reaction container 100 through the liquid inlet interface 104, and the corrosive medium in the reaction container 100 flows out through the liquid outlet interface 105. The liquid inlet interface 104 and the liquid outlet interface 105 can be connected to a water chemical circulation loop system to stabilize the water chemical condition of the corrosive medium.

[0056] Specifically, the liquid inlet interface 104 and the liquid outlet interface 105 can be arranged on the kettle body 102. The connection method between the liquid inlet interface 104 and the liquid outlet interface 105 and the kettle body 102 is not limited. For example, the side wall of the kettle body 102 is opened, and the liquid inlet interface 104 and the liquid outlet interface 105 are threadedly connected to the opening of the kettle body 102.

[0057] Optionally, the reference electrode 300 comprises a silver / silver chloride (Ag / AgCl) electrode.

[0058] Optionally, the first connecting wire body 400 is provided with one or more. Figure 1As shown, when a plurality of first connecting wire bodies 400 are provided, the plurality of first connecting wire bodies 400 are all provided in the reaction container 100. The plurality of first connecting wire bodies 400 are connected to the plurality of metal samples 500 in a one-to-one correspondence, and are respectively used to measure the potential and current of the plurality of metal samples 500 to obtain the corrosion rate of the plurality of metal samples 500.

[0059] Optionally, the first connecting wire body 400 includes a conductive wire.

[0060] Optionally, the first connecting wire body 400 is a linear structure. The linear structure is made of a conductive material. The conductive material includes but is not limited to copper, zirconium alloy, etc.

[0061] Alternatively, if Figure 1 and Figure 2 As shown, the first end of the first connecting wire body 400 is welded to the metal sample 500. Further, the first end of the first connecting wire body 400 is connected to the metal sample 500 by precision welding, so that the connection between the first connecting wire body 400 and the metal sample 500 is a welding sealing point 106. In actual application, the precision welding connection can be achieved by laser spot welding or resistance spot welding.

[0062] Optionally, the connection between the first end of the first connecting wire body 400 and the metal sample 500 is insulated and sealed by a high-temperature sealant to reduce the influence of the solder joint and improve the accuracy of the current and potential measurement. The high-temperature sealant can be a sealant that is stable and insoluble in the corrosive medium, such as an inorganic ceramic high-temperature sealant.

[0063] Optionally, the material of the first connecting wire body 400 includes a nuclear grade zirconium alloy material, so that the first connecting wire body 400 forms a dense insulating oxide film in the corrosive medium, reducing signal interference to the metal sample 500. Of course, the first connecting wire body 400 can also be made of other materials that can form an insulating oxide film in a corrosive medium.

[0064] In a specific application example, the corrosive medium is a high-temperature and high-pressure aqueous solution at a temperature of 300°C to 360°C. The material of the metal sample 500 is a zirconium alloy. The material of the first connecting wire body 400 is a Zr-4 alloy. The first connecting wire body 400 can form a dense insulating oxide film in the high-temperature and high-pressure aqueous solution, reduce the signal interference to the metal sample 500, and significantly improve the accuracy of current and potential measurement.

[0065] Optionally, the measurement system 600 includes a corrosion electrochemical workstation, which is connected to the second end of the first connecting wire body 400 , the counter electrode assembly 200 and the reference electrode 300 , respectively, for measuring the potential and current of the metal sample 500 .

[0066] In some embodiments, Figure 1 and Figure 3As shown, the electrode assembly 200 includes a second connecting wire body 201 and an auxiliary electrode 202. The second connecting wire body 201 is inserted into the reaction container 100. One end of the second connecting wire body 201 is connected to the measurement system 600. The auxiliary electrode 202 is disposed in the accommodating cavity 101, and the auxiliary electrode 202 is connected to one end of the second connecting wire body 201 away from the measurement system 600.

[0067] In this embodiment, the second connecting wire body 201 is inserted into the reaction container 100. Specifically, the second connecting wire body 201 can be installed in the kettle cover 103 through the electrical penetration piece 107. The auxiliary electrode 202 is arranged in the accommodating cavity 101 and can be used to complete the flow of electrons in the circuit. One end of the second connecting wire body 201 is connected to the measurement system 600, and the other end of the second connecting wire body 201 is connected to the auxiliary electrode 202, so as to realize the measurement of the potential and current of the metal sample 500.

[0068] In this embodiment, the shape of the auxiliary electrode 202 is not limited, for example, a sheet shape, a mesh shape, etc. The material of the auxiliary electrode 202 is not limited, for example, platinum (Pt), copper (Cu), etc.

[0069] Optionally, the second connecting wire body 201 includes a wire. The material of the second connecting wire body 201 includes but is not limited to platinum (Pt), copper (Cu), etc., so as to achieve high temperature corrosion resistance.

[0070] Optionally, the second connecting wire body 201 is a linear structure. The linear structure is made of a conductive material. The conductive material includes but is not limited to platinum (Pt) and copper (Cu).

[0071] Exemplarily, the second connecting wire body 201 and the auxiliary electrode 202 are both made of Pt. Figure 1 and Figure 3 As shown, the auxiliary electrode 202 is a mesh structure, which can reduce costs.

[0072] Alternatively, if Figure 3 As shown, the end of the second connecting wire body 201 is welded to the auxiliary electrode 202. Further, the end of the second connecting wire body 201 is connected to the auxiliary electrode 202 by precision welding, so that the connection between the second connecting wire body 201 and the auxiliary electrode 202 is a welding sealing point 106. For example, the precision welding connection is achieved by laser spot welding or resistance spot welding.

[0073] Optionally, the connection between the end of the second connecting wire 201 and the auxiliary electrode 202 is insulated and sealed by high-temperature sealant to reduce the influence of the solder joint and improve the accuracy of current and potential measurement. The high-temperature sealant can be a sealant that is stable and insoluble in corrosive media, such as inorganic ceramic high-temperature sealant.

[0074] In some embodiments, Figure 2 and Figure 3 As shown, the corrosion rate in-situ monitoring device 1 further includes an insulating portion 700. The insulating portion 700 is disposed outside the first connecting wire body 400 and the second connecting wire body 201.

[0075] In this embodiment, the first connecting wire body 400 and the second connecting wire body 201 are insulated and sealed by the insulating part 700, so as to avoid or reduce the interference with the electrochemical reaction and improve the reliability and stability of monitoring.

[0076] Alternatively, if Figure 2 and Figure 3 As shown, the insulating part 700 includes a first insulating tube 701 and a second insulating tube 702, and the first connecting wire body 400 and the second connecting wire body 201 are insulated and sealed by the first insulating tube 701 and the second insulating tube 702. The first insulating tube 701 is provided at the portion of the first connecting wire body 400 and the second connecting wire body 201 located outside the reaction container 100. The second insulating tube 702 is provided at the portion of the first connecting wire body 400 and the second connecting wire body 201 located inside the reaction container 100.

[0077] In this embodiment, the first insulating tube 701 is disposed at the portion of the first connecting wire body 400 and the second connecting wire body 201 located outside the reaction vessel 100, which can be understood as the first insulating tube 701 being located at the cold end side of the kettle cover 103. Exemplarily, the temperature outside the reaction vessel 100 is lower than 260° C., which is conducive to the insulation and sealing performance of the first insulating tube 701.

[0078] In this embodiment, the second insulating tube 702 is disposed at the portion where the first connecting wire body 400 and the second connecting wire body 201 are located in the reaction vessel 100. It can be understood that the second insulating tube 702 is located in the reaction vessel 100 and can be in contact with the corrosive medium. Exemplarily, the temperature of the corrosive medium in the reaction vessel 100 is 300° C. to 360° C., and the second insulating tube 702 can play an insulating and sealing role in the high-temperature and high-pressure corrosive medium.

[0079] Optionally, the first insulating tube 701 includes a heat shrinkable insulating tube. The material of the first insulating tube 701 includes but is not limited to high temperature resistant polytetrafluoroethylene. In actual application, the first insulating tube 701 can be matched with the electrical penetration piece 107 to achieve good insulation sealing.

[0080] Optionally, the second insulating tube 702 comprises a high temperature resistant ceramic insulating tube. The material of the second insulating tube 702 includes but is not limited to element-doped stable tetragonal zirconia ceramics, such as yttria-stabilized tetragonal zirconia ceramics (3YTZP material), so as to play an insulating and sealing role in high temperature and high pressure corrosive media.

[0081] A specific application example:

[0082] Next, the assembly process of the corrosion rate in-situ monitoring device 1 is described by taking the reaction vessel 100 including the kettle body 102 and the kettle cover 103 as an example.

[0083] The electrode assembly 200, the reference electrode 300 and the first connecting wire body 400 connected to the metal sample 500 are installed on the kettle cover 103 through the electrical penetration piece 107. Specifically, the first connecting wire body 400 is respectively inserted into the heat shrinkable insulating tube and the high-temperature resistant ceramic insulating tube, and the heat shrinkable insulating tube is attached to the first connecting wire body 400 by hot blowing. One end of the first connecting wire body 400 is connected to the metal sample 500 by precision welding, and the high-temperature sealant is evenly applied to the welding sealing point 106 to solidify the high-temperature sealant. Similarly, the second connecting wire body 201 is respectively inserted into the heat shrinkable insulating tube and the high-temperature resistant ceramic insulating tube, and the heat shrinkable insulating tube is attached to the second connecting wire body 201 by hot blowing. One end of the second connecting wire body 201 is connected to the auxiliary electrode 202 by precision welding, and the high-temperature sealant is evenly applied to the welding sealing point 106 to solidify the high-temperature sealant. Then, the counter electrode assembly 200, the reference electrode 300 and the first connecting wire body 400 connected with the metal sample 500 are insulated and installed on the kettle cover 103 by using the insulating electrical penetration piece 107 configured with polytetrafluoroethylene. The heat shrinkable insulating tubes of the first connecting wire body 400 and the second connecting wire body 201 are both located on the outside of the kettle cover 103. The high temperature resistant ceramic insulating tubes of the first connecting wire body 400 and the second connecting wire body 201 are both located in the kettle body 102.

[0084] The kettle cover 103 is installed on the kettle body 102. The kettle is connected to the water chemical circulation loop system through the liquid inlet interface 104 and the liquid outlet interface 105, so that the corrosive medium is filled in the containing cavity 101 of the reaction container 100. The reaction container 100 can be checked by pressure filling to ensure that there is no leakage.

[0085] The electrode assembly 200, the reference electrode 300 and the first connecting wire body 400 connected to the metal sample 500 can be inspected for insulation by a multimeter. The electrode assembly 200, the reference electrode 300, the first connecting wire body 400 connected to the metal sample 500, the kettle cover 103 and the kettle body 102 are insulated from each other.

[0086] When the corrosive medium reaches the preset control index, the measuring system 600 is connected to the second end of the first connecting wire body 400 , the electrode assembly 200 and the reference electrode 300 respectively to measure the potential and current of the metal sample 500 .

[0087] In some embodiments, the corrosion rate in-situ monitoring device 1 further includes a control device 800. The control device 800 is electrically connected to the measurement system 600. The control device 800 is used to obtain the corrosion rate of the metal sample 500 according to the potential and current measured by the measurement system 600.

[0088] In this embodiment, the control device 800 is electrically connected to the measurement system 600 so that the control device 800 can obtain the corrosion rate of the metal sample 500 based on the potential and current measured by the measurement system 600, realize online in-situ monitoring of the corrosion rate, and more accurately, reliably and efficiently realize in-situ online research on the high-temperature electrochemical behavior and corrosion resistance of the metal sample 500.

[0089] Alternatively, if Fig.11 As shown, the control device 800 includes a processor 802 (processor) and a memory 804 (memory). The control device 800 may also include a communication interface 806 (Communication Interface) and a bus 808.

[0090] like Figure 4 As shown, the embodiment of the present disclosure also provides a corrosion rate in-situ monitoring method, which is applied to the corrosion rate in-situ monitoring device 1 of any of the previous embodiments. The corrosion rate in-situ monitoring method includes the following steps:

[0091] S401. The processor obtains corrosion characteristic data in response to a monitoring request, where the corrosion characteristic data includes a plurality of standard electrode potentials and a plurality of current densities.

[0092] In this embodiment, by obtaining multiple standard electrode potentials and multiple current densities, reliable characteristic parameters are provided for online monitoring of corrosion rate.

[0093] Optionally, a plurality of standard electrode potentials and a plurality of current densities correspond one to one.

[0094] S402. The processor determines the open circuit potential and the Tafel line according to the corrosion characteristic data.

[0095] In this embodiment, the Tafel line, namely the Tafel line, is used to determine the open circuit potential and the Tafel line according to the corrosion characteristic data to realize the cathode Tafel kinetic polarization analysis.

[0096] S403. The processor obtains the corrosion rate according to the open circuit potential and the Tafel line.

[0097] In this embodiment, the corrosion rate is obtained based on the open circuit potential and the Tafel line, and the three-electrode system is combined with the cathode Tafel kinetic polarization analysis to perform online monitoring of the corrosion rate of the metal sample 500 in the high-temperature and high-pressure corrosive medium, thereby improving the monitoring efficiency of the corrosion resistance and realizing a more accurate, reliable and efficient in-situ online study of the high-temperature electrochemical behavior and corrosion resistance of the metal sample 500.

[0098] In some embodiments, Figure 5As shown, a method for determining open circuit potential based on corrosion characteristic data is provided, comprising the following steps:

[0099] S501. The processor obtains a minimum value among multiple current densities to obtain a minimum current density.

[0100] In this embodiment, the minimum current density can be used to obtain the open circuit potential to obtain the corrosion rate.

[0101] S502: The processor obtains a standard electrode potential corresponding to a minimum current density to obtain an open circuit potential.

[0102] In this embodiment, the open circuit potential is a standard electrode potential corresponding to the minimum current density, which can be used to determine the corrosion tendency of the metal sample 500 to obtain the corrosion rate.

[0103] Optionally, the step of determining the open circuit potential according to the corrosion characteristic data in the aforementioned corrosion rate in-situ monitoring method may adopt the method of determining the open circuit potential according to the corrosion characteristic data in this embodiment.

[0104] In some embodiments, Figure 6 As shown, a method for determining the Tafel line based on corrosion characteristic data is provided, comprising the following steps:

[0105] S601. The processor draws a polarization curve according to a plurality of standard electrode potentials and a plurality of current densities.

[0106] In this embodiment, Fig. 9 The standard electrode potential (unit: V vs. SHE) is used as the ordinate and the current density (unit: A / cm 2 ) is the horizontal axis, and the polarization curve is drawn according to the corresponding relationship between multiple standard electrode potentials and multiple current densities. Fig. 9 The line L1 in FIG. 1 is used to illustrate the polarization curve.

[0107] S602: The processor obtains a cathode strong polarization region, where the cathode strong polarization region corresponds to a portion of the polarization curve.

[0108] In this embodiment, the cathode strong polarization region corresponds to a portion of the polarization curve, which can be used to obtain the standard electrode potential and current density of the cathode located in the extremely strong polarization region.

[0109] In some embodiments, the step of obtaining the cathode strong polarization region includes: obtaining an equipotential line where the open circuit potential is located to obtain a reference line, and determining a preset potential range on the polarization curve side of the reference line to obtain the cathode strong polarization region.

[0110] In this embodiment, Fig. 9 As shown, Fig. 9 Medium E corris the open circuit potential, and line L2 is used to illustrate the reference line. The reference line is used to provide a reference axis for subsequent electrochemical behavior analysis. For example, the range of the cathode strong polarization zone is obtained based on the reference line. Relative to the reference line, the preset potential range is selected on the polarization curve side of the reference line so that the cathode strong polarization zone corresponds to a portion of the polarization curve.

[0111] Optionally, the preset potential range is -50 mV to -100 mV.

[0112] For example, Fig. 9 As shown, the cathode current is defined as negative. The open circuit potential E corr The corresponding standard electrode potential is -0.7 V vs. SHE, and line L2 is used to illustrate the reference line. When the preset potential range is -50 mV to -100 mV, the corresponding standard electrode potential range is -0.75 V vs. SHE to -0.8 V vs. SHE. Fig. 9 In the figure, line S1 is used to indicate the equipotential line of -0.75 V vs. SHE, and line S2 is used to indicate the equipotential line of -0.8 V vs. SHE. The area between line S1 and line S2 is the cathode strong polarization area. Fig. 9 The middle region S is used for the cathode strong polarization region.

[0113] S603: The processor takes the logarithm of the absolute value of each current density in the cathode strong polarization region to obtain a plurality of logarithmic current densities.

[0114] In this embodiment, the current density is converted into a logarithmic current density, so that the logarithmic current density and the standard electrode potential are approximately linearly related, so as to perform cathode Tafel kinetic polarization analysis.

[0115] S604: The processor performs linear fitting on multiple standard electrode potentials and corresponding multiple logarithmic current densities in the cathode strong polarization region to obtain a Tafel straight line.

[0116] In this embodiment, Fig. 9 As shown, Fig. 9 The center line L3 is used to illustrate the Tafel line. In the cathode strong polarization region, the Tafel line is obtained by linearly fitting multiple standard electrode potentials and corresponding multiple logarithmic current densities, which is used to analyze the corrosion rate by combining the three-electrode system with the cathode Tafel kinetic polarization analysis method.

[0117] It is understandable that the method of performing linear fitting is not limited, for example, linear fitting can be performed by the least squares method.

[0118] Optionally, the step of determining the Tafel line according to the corrosion characteristic data in the aforementioned in-situ corrosion rate monitoring method may adopt the method of determining the Tafel line according to the corrosion characteristic data in this embodiment.

[0119] like Figure 7 As shown, in some embodiments, a method for obtaining corrosion characteristic data is provided, comprising the following steps:

[0120] S701: In response to a monitoring request, the processor controls a measurement system to measure a potential and a current of a metal sample to obtain a plurality of measured potentials and a plurality of measured currents.

[0121] In this embodiment, when the corrosion rate of the metal sample 500 is monitored online, the potential and the current are measured by the measurement system 600 to obtain a plurality of measured potentials and a plurality of measured currents, thereby providing more accurate measurement data for analyzing the corrosion rate.

[0122] Optionally, the multiple measurement potentials and the multiple measurement currents correspond one to one.

[0123] S702: The processor obtains the surface area of ​​the metal sample.

[0124] In this embodiment, the surface area of ​​the metal sample 500 can be used to calculate the current density.

[0125] In this embodiment, the method of obtaining the surface area of ​​the metal sample is not limited. In practical application, the surface area of ​​the metal sample can be pre-stored in a memory for the processor to retrieve and use.

[0126] S703: The processor performs potential standardization on the multiple measurement potentials to obtain multiple standard electrode potentials; the processor obtains multiple current densities according to the multiple measurement currents and the surface areas of the metal samples.

[0127] In this embodiment, by obtaining the standard electrode potential and current density, the corrosion characteristic data is obtained, thereby providing reliable characteristic parameters for the online monitoring of the corrosion rate.

[0128] Optionally, the step of acquiring corrosion characteristic data in response to a monitoring request in the aforementioned corrosion rate in-situ monitoring method may adopt the method for acquiring corrosion characteristic data in this embodiment.

[0129] Optionally, the step of performing potential standardization on a plurality of measured potentials to obtain a plurality of standard electrode potentials comprises:

[0130] Standard electrode potential = measurement potential + equilibrium potential of the reference electrode at the measurement temperature.

[0131] In this embodiment, the standard electrode potential is specifically the potential relative to the standard hydrogen electrode (unit: Vvs.SHE). The standard electrode potential is equal to the measurement potential plus the equilibrium potential of the reference electrode at the measurement temperature, so that the measurement potential is standardized.

[0132] Optionally, the step of obtaining a plurality of current densities according to a plurality of measured currents and a surface area of ​​the metal sample comprises:

[0133] Current density (unit: A / cm 2 ) = measurement current (unit: A) ÷ surface area of ​​metal sample (cm 2 )

[0134] In this embodiment, quotients of a plurality of measurement currents and the surface area of ​​the metal sample 500 are calculated respectively to obtain a plurality of current densities.

[0135] like Figure 8 As shown, in some embodiments, a method for in-situ monitoring of corrosion rate is provided, comprising the following steps:

[0136] S801. The processor obtains corrosion characteristic data in response to a monitoring request, where the corrosion characteristic data includes a plurality of standard electrode potentials and a plurality of current densities.

[0137] S802. The processor determines the open circuit potential and the Tafel line according to the corrosion characteristic data.

[0138] S803. On the Tafel line, the processor determines the current density corresponding to the open circuit potential to obtain the corrosion current density.

[0139] In this embodiment, Fig. 9 As shown in Figure 2, the current density at the intersection of the extended line of the Tafel line and the reference line is the corrosion current density. Fig. 9 Point I corr is the corrosion current density.

[0140] S804. The processor calculates the corrosion rate according to the corrosion current density.

[0141] In this embodiment, the corrosion rate is calculated according to the corrosion current density, so as to realize the online in-situ monitoring of the corrosion rate of the metal sample 500.

[0142] Alternatively, the corrosion rate may be calculated according to the corrosion current density using the following formula (ASTM G102, 1994, published by the American Society for Testing and Materials):

[0143]

[0144] Where CR is the corrosion rate, unit: mmpy; K is a constant, unit: mm g / μA cm yr; I corr is the corrosion current density, unit: μA / cm 2 ; ρ is the density of the corrosive medium, unit: g / cm 3 ; EW is equivalent mass.

[0145] Alternatively, K = 3.27 × 10 -3 mm g / μA cm yr.

[0146] A specific application example:

[0147] The material of the metal sample 500 is zirconium alloy. The corrosive medium is a high-temperature and high-pressure aqueous solution. The temperature of the corrosion reaction is 300°C to 360°C. The pressure of the corrosion reaction is 18.5MPa to 19.5MPa. Through the corrosion rate in-situ monitoring device 1 of the present application, the corrosion rate of the zirconium alloy metal sample 500 can be monitored online, and the real-time corrosion reaction kinetic behavior can be reflected in real time.

[0148] In this example, at high temperatures of 300°C to 360°C, the cathode reaction process of the zirconium-water reaction is the electron loss and hydrogen evolution reaction of water molecules, which is controlled by the electrode activation reaction, satisfies the Butler-Volmer premise assumption, and conforms to the Tafel kinetic law. The anode is diffusion controlled and does not meet the Butler-Volmer premise assumption. Therefore, the corrosion current density can be obtained through a separate cathode Tafel kinetic polarization analysis, and then the corrosion rate can be obtained.

[0149] In this example, the cathode Tafel kinetic polarization analysis method establishes the relationship between the cathode standard electrode potential and the logarithmic current density by fitting the cathode strong polarization region. The principle of the cathode Tafel kinetic polarization analysis method is as follows:

[0150] According to the Butler-Volmer equation:

[0151]

[0152] Where i is the current density, i0 is the exchange (corrosion) current density, α is the number of transferred electrons, F is the Faraday constant, R is the gas constant, T is the absolute temperature, and η is the overpotential.

[0153] In the cathode strong polarization region (when the overpotential η is too negative), due to The anode current can be neglected, and we have:

[0154]

[0155] Right now:

[0156]

[0157] The standard electrode potential is:

[0158]

[0159] Where, E is the standard electrode potential; E corris the open circuit potential.

[0160] The above equation can be simplified to:

[0161] E=a+blog|i|

[0162] In the formula, a and b are both constants.

[0163] Therefore, in the cathode strong polarization region, the standard electrode potential E and the logarithmic current density log|i| are linearly related. In other words, the standard electrode potential and the logarithmic current density can be linearly fitted to obtain the Tafel line. The intersection of the Tafel line extension line and the reference line (the equipotential line where the open circuit potential is located), that is, when the overpotential is 0, the current density i is equal to the corrosion current density i0.

[0164] This example breaks through the limitation of related technologies that only electrochemical analysis such as high-temperature open circuit potential and impedance spectrum can be carried out. For high temperature (300℃ to 360℃) and high pressure (18.5MPa to 19.5MPa) environments, the corrosion rate of zirconium alloy is monitored online by combining a stable three-electrode system with the cathode Tafel kinetic polarization analysis method, which improves the monitoring efficiency and provides a more accurate, reliable and efficient in-situ online monitoring method for corrosion rate of metals such as zirconium alloys with high operating corrosion temperatures (300℃ to 360℃) and high pressures (18.5MPa to 19.5MPa).

[0165] Another specific application example:

[0166] The corrosion rate of six metal samples 500 is linearly monitored by the corrosion rate in-situ monitoring device 1 and the corrosion rate in-situ monitoring method. The six metal samples 500 are represented by N1, N2, N3, N4, N5 and N6 respectively. The material of the six metal samples 500 is N36 zirconium alloy. Among them, N1 is a pre-corrosion blank sample (pre-generated oxide film), N2 is a pre-corrosion high-temperature proton injection of 1dpa, N3 is a high-temperature proton injection of 1dpa, N4 is a room-temperature proton injection of 5dpa, N5 is a room-temperature proton injection of 1dpa, and N6 is a blank sample. The temperature of the corrosion reaction is 360°C. The pressure of the corrosion reaction is 19MPa.

[0167] In this example, the corrosion rate of N36 zirconium alloy after ion irradiation changes with time. Fig.10 shown. Fig.10In the figure, the black squares are used to illustrate the results of the corrosion rate of metal sample N1 changing with time; the red dots are used to illustrate the results of the corrosion rate of metal sample N2 changing with time; the blue triangles are used to illustrate the results of the corrosion rate of metal sample N3 changing with time; the green triangles are used to illustrate the results of the corrosion rate of metal sample N4 changing with time; the purple diamonds are used to illustrate the results of the corrosion rate of metal sample N5 changing with time; and the yellow triangles are used to illustrate the results of the corrosion rate of metal sample N6 changing with time.

[0168] It can be found that as the corrosion time increases, the corrosion rates of metal samples N1, N2, N3, N4, N5 and N6 all show a downward trend. In the early stage of corrosion, the corrosion rate decreases significantly, and then tends to stabilize. After a period of corrosion, the zirconium alloy gradually forms a protective oxide film.

[0169] The results show that the results obtained in this example are consistent with the long-term corrosion weight gain law of zirconium alloy. That is to say, for a high-temperature and high-pressure aqueous solution environment, the corrosion rate in-situ monitoring device 1 and the corrosion rate in-situ monitoring method can effectively monitor the corrosion rate in-situ of zirconium alloy, thereby improving the corrosion rate monitoring efficiency.

[0170] It can be understood that the corrosion rate in-situ monitoring device 1 and the corrosion rate in-situ monitoring method of the present application are also applicable to the online monitoring of the corrosion rate of metal samples in other temperature and pressure environments, for example, an environment with a temperature of 30°C to 300°C.

[0171] like Fig.11 As shown, the embodiment of the present disclosure also provides a control device 800, which includes a processor 802 (processor) and a memory 804 (memory). The control device 800 may also include a communication interface 806 (Communication Interface) and a bus 808. The processor 802, the communication interface 806, and the memory 804 may communicate with each other through the bus 808. The communication interface 806 may be used for information transmission. The processor 802 may call the logic instructions in the memory 804 to execute the corrosion rate in-situ monitoring method of the above embodiment.

[0172] The memory 804 is a computer-readable storage medium that can be used to store software programs and computer executable programs, such as program instructions / modules corresponding to the method in the embodiment of the present disclosure. The processor 802 executes the program instructions / modules stored in the memory 804 to perform functional applications and data processing, that is, to implement the corrosion rate in-situ monitoring method in the above method embodiment. Therefore, all the beneficial effects of the above embodiments are achieved, which will not be repeated here.

[0173] The memory 804 may include a program storage area and a data storage area, wherein the program storage area may store an operating system and an application required for at least one function; the data storage area may store data created according to the use of the terminal device, etc. In addition, the memory 804 may include a high-speed random access memory and may also include a non-volatile memory.

[0174] The embodiments of the present disclosure also provide a computer-readable storage medium, which includes a stored program, wherein when the program is run, the method for in-situ monitoring of corrosion rate as in any of the previous embodiments is executed.

[0175] The computer-readable storage medium mentioned above may be a transient computer-readable storage medium or a non-transitory computer-readable storage medium.

[0176] The above description and the accompanying drawings fully illustrate the embodiments of the present disclosure to enable those skilled in the art to practice them. Other embodiments may include structural, logical, electrical, process and other changes. The embodiments represent only possible variations. Unless explicitly required, separate components and functions are optional, and the order of operations may vary. Parts and features of some embodiments may be included in or replace parts and features of other embodiments. The scope of the embodiments of the present disclosure includes the entire scope of the claims, and all available equivalents of the claims.

[0177] The flowcharts and block diagrams in the accompanying drawings show the possible architecture, functions and operations of the system, method and computer program product according to the embodiments of the present disclosure. In this regard, each box in the flowchart or block diagram can represent a module, a program segment or a part of a code, and the module, program segment or a part of the code contains one or more executable instructions for implementing the specified logical function. In some alternative implementations, the functions marked in the box can also occur in an order different from that marked in the accompanying drawings. For example, two consecutive boxes can actually be executed substantially in parallel, and they can also be executed in the opposite order in some cases, which can depend on the functions involved. In the description corresponding to the flowchart and block diagram in the accompanying drawings, the operations or steps corresponding to different boxes can also occur in an order different from that disclosed in the description, and there is no specific order between different operations or steps in some cases. For example, two consecutive operations or steps can actually be executed substantially in parallel, and they can also be executed in the opposite order in some cases, which can depend on the functions involved. Each block in the block diagrams and / or flowcharts, and combinations of blocks in the block diagrams and / or flowcharts, may be implemented by a dedicated hardware-based system that performs the specified functions or actions, or may be implemented by a combination of dedicated hardware and computer instructions.

Claims

1. A corrosion rate in-situ monitoring device, characterized in that: include: A reaction container, comprising a containing cavity capable of storing a corrosive medium, wherein the reaction container is provided with a counter electrode assembly and a reference electrode; A first connecting wire body, which is passed through the reaction container, and includes a first end and a second end, wherein the first end is used to connect to the metal sample in the containing cavity, and the metal sample can be used as a working electrode; A measuring system is connected to the second end of the first connecting wire body, the counter electrode assembly and the reference electrode respectively, and is used to measure the potential and current of the metal sample.

2. The corrosion rate in-situ monitoring device according to claim 1, characterized in that: The electrode assembly comprises: A second connecting wire body is passed through the reaction container, and one end of the second connecting wire body is connected to the measurement system; The auxiliary electrode is arranged in the accommodating cavity and connected to an end of the second connecting wire body away from the measuring system.

3. The corrosion rate in-situ monitoring device according to claim 2, characterized in that: Also includes: The insulating portion is disposed outside the first connecting wire body and the second connecting wire body.

4. The corrosion rate in-situ monitoring device according to any one of claims 1 to 3, characterized in that: Also includes: A control device is electrically connected to the measurement system, and is used to obtain the corrosion rate of the metal sample according to the potential and the current measured by the measurement system.

5. A method for in-situ monitoring of corrosion rate, applied to the in-situ monitoring device for corrosion rate as claimed in any one of claims 1 to 4, characterized in that: The corrosion rate in-situ monitoring method comprises the following steps: In response to a monitoring request, acquiring corrosion characteristic data, the corrosion characteristic data comprising a plurality of standard electrode potentials and a plurality of current densities; Determining the open circuit potential and the Tafel line according to the corrosion characteristic data; The corrosion rate is obtained based on the open circuit potential and the Tafel line.

6. The corrosion rate in-situ monitoring method according to claim 5, characterized in that: According to the corrosion characteristic data, the step of determining the open circuit potential comprises: Obtaining a minimum value among the multiple current densities to obtain a minimum current density; The standard electrode potential corresponding to the minimum current density is obtained to obtain the open circuit potential.

7. The method for in-situ monitoring of corrosion rate according to claim 5, characterized in that: According to the corrosion characteristic data, the steps of determining the Tafel line include: Drawing a polarization curve according to the plurality of standard electrode potentials and the plurality of current densities; Acquire a cathode strong polarization region, wherein the cathode strong polarization region corresponds to a portion of the polarization curve; Taking the logarithm of the absolute value of each current density in the cathode strong polarization region to obtain a plurality of logarithmic current densities; Performing linear fitting on a plurality of the standard electrode potentials in the cathode strong polarization region and a plurality of the corresponding logarithmic current densities to obtain a Tafel straight line; The step of obtaining the cathode strong polarization zone includes: Obtaining the equipotential line where the open circuit potential is located to obtain a reference line; On the polarization curve side of the reference line, a preset potential range is determined to obtain a cathode strong polarization region.

8. The method for in-situ monitoring of corrosion rate according to any one of claims 5 to 7, characterized in that: In response to a monitoring request, the steps of obtaining corrosion characteristic data include: In response to a monitoring request, controlling the measurement system to measure the potential and current of the metal sample to obtain a plurality of measured potentials and a plurality of measured currents; Obtaining the surface area of ​​the metal sample; The plurality of measured potentials are all subjected to potential standardization to obtain a plurality of standard electrode potentials; and a plurality of current densities are obtained according to the plurality of measured currents and the surface area of ​​the metal sample.

9. The method for in-situ monitoring of corrosion rate according to any one of claims 5 to 7, characterized in that: According to the open circuit potential and the Tafel line, the step of obtaining the corrosion rate comprises: On the Tafel line, determining the current density corresponding to the open circuit potential to obtain the corrosion current density; The corrosion rate is calculated based on the corrosion current density.

10. The corrosion rate in-situ monitoring method according to claim 9, characterized in that: According to the corrosion current density, the corrosion rate is calculated according to the following formula: Where CR is the corrosion rate; K is a constant; I corr is the corrosion current density; ρ is the density of the corrosive medium; EW is the equivalent mass.

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