A temperature-controlled, one-step, quick-assembly / disassembly experimental device for in-situ monitoring of one-dimensional and two-dimensional pitting corrosion behavior and its usage method

Abstract

This invention discloses a temperature-controlled, one-step, quick-assembly / disassembly experimental device for in-situ monitoring of one-dimensional and two-dimensional pitting corrosion behavior, and its usage method. The device includes: a pitting electrode comprising an acrylic base plate and an acrylic cover plate filled with epoxy resin, the epoxy resin coating a metal wire or metal foil with one end connected to a copper conductor; a support including a support base and a support cover plate, the support base being adhered to a jacketed beaker, the pitting electrode being attached to the support base; a clamping assembly penetrating the support cover plate and clamping the surface of the pitting electrode; a jacketed beaker, the inlet and outlet of which are respectively connected to the inlet and outlet of a constant temperature water bath, the jacketed beaker containing an electrolyte with the liquid level flush with the acrylic cover plate, a reference electrode and a platinum electrode inserted in the electrolyte, and the copper conductor, reference electrode, and platinum electrode all being connected to an electrochemical workstation. This invention facilitates the capture of pit morphology changes in one-dimensional and two-dimensional pitting corrosion growth within the pits and allows for quick one-step assembly and disassembly of the pitting electrode.

Description

Technical Field

[0001] This invention belongs to the field of corrosion technology, specifically a temperature-controlled one-step quick-assembly and disassembly experimental device for in-situ monitoring of one-dimensional and two-dimensional pitting corrosion behavior and its usage method. Background Technology

[0002] LSF theory confirms the regularity of steady-state growth in pitting corrosion. When using LSF theory to study pitting corrosion behavior, it is necessary not only to obtain kinetic data by collecting electrochemical data, but also to simultaneously acquire images of the corrosion behavior inside the pit to verify the consistency between the kinetic data and the corrosion behavior. Starting with one-dimensional pitting corrosion growth, conducting electrochemical tests and monitoring the morphological changes inside the one-dimensional pit, and then conducting kinetic studies on two-dimensional pitting corrosion growth based on one-dimensional pitting corrosion research, is of great significance. However, currently, there is a lack of a simple and convenient in-situ temperature-controlled monitoring experimental device suitable for both one-dimensional and two-dimensional pitting corrosion behavior.

[0003] Most existing in-situ monitoring devices for pitting corrosion are based on the in-situ monitoring of the surface of three-dimensional block pits on metal blocks. On the one hand, they cannot observe the growth state inside the pits; on the other hand, the three-dimensional block pitting corrosion in-situ monitoring devices have complex structures, which is not conducive to multiple disassembly and assembly operations of samples during experiments, and temperature regulation is not possible. For example, patent CN119437852A discloses an in-situ localized corrosion system for metal surfaces and its usage method. It creates a localized corrosion environment on the surface of the metal structure being tested, and then uses a microscope to observe the localized corrosion of the metal structure in situ. This device involves multiple connections, and the metal structure and the corrosion environment chamber must be sealed, making the operation process relatively complex. Patent CN211043074U discloses a device for in-situ observation of the initiation process of localized corrosion on the surface of steel. This device can realize in-situ observation of the changes in corrosion morphology of microstructures such as inclusions in the material during the induction of localized corrosion initiation. This device has a simple structure and is easy to operate, but it does not consider the fixation of the sample, and the fit between the sample and the lifting platform may be reduced by buoyancy. Patent CN1072 Patent 28823A discloses an evaluation device for localized corrosion of aluminum alloys. By assembling a simulated environment unit and a real-time corrosion observation unit, it achieves real-time observation of the morphology of localized corrosion of aluminum alloys. However, the assembly process of this device is relatively complex, and the sealing performance of the device is closely related to the operating procedures. Improper sealing rubber inlay base may cause leakage or crevice corrosion. Patent CN202210080U discloses an in-situ, full-field early detection device for stainless steel pitting corrosion. Although the structure is simple and it can observe and detect the location and quantity of stainless steel pitting corrosion in real time through a microscope, the design of this device lacks standardization and does not consider the encapsulation of stainless steel samples, which cannot guarantee the repeatability of the experiment. Patent CN103969472A discloses an in-situ observation device and method for the pitting corrosion formation process. By preparing an electrolytic cell device and using an atomic force microscope to periodically scan the sample surface, the dynamic process of pitting corrosion formation can be obtained. This device uses accessories such as sealing gaskets, clamping bolts, and clamping nuts to fix the test sample. However, it significantly increases the complexity of sample assembly and is not suitable for experiments that require frequent sample disassembly and assembly.

[0004] In summary, existing in-situ monitoring devices for pitting corrosion have problems such as complex design, inconvenient operation, or poor experimental repeatability, and are not suitable for in-situ monitoring of one-dimensional and two-dimensional pitting corrosion. Therefore, it is urgent to design an experimental device that is simple to operate and has a standardized design to achieve in-situ monitoring of one-dimensional and two-dimensional pitting corrosion. Summary of the Invention

[0005] The purpose of this invention is to provide a temperature-controlled, one-step quick-assembly and disassembly experimental device and its usage method for in-situ monitoring of one-dimensional and two-dimensional pitting behavior. It not only facilitates the capture of changes in the morphological characteristics of one-dimensional and two-dimensional pitting growth inside the pit, but also allows for quick one-step assembly and disassembly of the pitting electrode. It has the advantages of convenient operation, strong experimental repeatability, and wide applicability.

[0006] This invention is achieved through the following technical solution:

[0007] A temperature-controlled, one-step, quick-assembly experimental device for in-situ monitoring of one-dimensional and two-dimensional pitting corrosion behavior includes a jacketed beaker, a support, a pitting electrode, a reference electrode, a platinum electrode, and a clamping assembly. The pitting electrode includes an acrylic base plate and an acrylic cover plate arranged parallel to each other, with an epoxy resin filling the space between the acrylic base plate and the acrylic cover plate. Specifically: when the pitting electrode is a one-dimensional pitting electrode, the epoxy resin is coated with metal wires; when the pitting electrode is a two-dimensional pitting electrode, the epoxy resin is coated with metal foil.

[0008] One end of the metal wire and metal foil is welded with a copper wire, and the other end of the metal wire and metal foil is flush with the ends of the acrylic base plate and acrylic cover plate to form an exposed end.

[0009] The support is attached to the inside of the jacketed beaker. The support includes a support base and a support cover plate. Vertical baffles are fixedly installed on the left and right sides of the support base. The support cover plate is fixedly installed on the top of the baffles to form a receiving cavity for accommodating the pitting electrode. One end of the support is the electrode inlet. The pitting electrode is inserted into the receiving cavity through the electrode inlet, and the lower surface of the pitting electrode is in contact with the upper surface of the support base.

[0010] The clamping assembly includes an M10 threaded hole on the bracket cover plate, an M10 external hex bolt threaded into the M10 threaded hole, and the bottom end of the M10 external hex bolt clamping against the upper surface of the pitting electrode.

[0011] Alternatively, the clamping assembly includes a control rod, slots at the ends of two baffles, and a through hole on the bracket cover. The two slots are located at opposite ends of the two baffles. The quick-release control rod includes a round rod rivet inserted into the through hole. A spring is sleeved on the round rod rivet, and a screw rivet for clamping the pitting electrode is threaded to the lower end of the round rod rivet. The lower end of the spring is fixedly connected to the screw rivet, and the upper end of the spring abuts against the lower surface of the bracket cover. A round bar with two ends that can be respectively engaged in the two slots is fixedly connected to the lower end of the screw rivet.

[0012] The inlet and outlet of the jacketed beaker are connected to the outlet and inlet of the constant temperature water bath with circulation function. The jacketed beaker contains electrolyte, and the electrolyte level is flush with the upper surface of the acrylic cover plate. The reference electrode and platinum electrode are inserted in the electrolyte, and the copper wire, reference electrode and platinum electrode are all connected to the electrochemical workstation.

[0013] Furthermore, the baffle is glued to the left and right sides of the bracket base;

[0014] The length of the bracket cover plate is less than the length of the baffle, and the bracket cover plate is glued to one end of the top of the baffle.

[0015] Furthermore, the bracket base, baffle, and bracket cover are all made of acrylic sheet.

[0016] Furthermore, the dimensions of both the acrylic base plate and the acrylic cover plate are 75×25×0.8mm.

[0017] Furthermore, the diameter of the metal wire is 50 μm.

[0018] Furthermore, the metal foil has a thickness of 20 μm and a width of 3 mm.

[0019] Furthermore, both the metal wire and the metal foil are made of 304 or 316L stainless steel.

[0020] A working method for a temperature-controlled, one-step, quick-assembly / disassembly experimental device for in-situ monitoring of one-dimensional and two-dimensional pitting corrosion behavior includes the following steps:

[0021] Step 1: Fix the bracket cover plate to the top of the baffles on both sides of the bracket base. One end of the bracket is equipped with an electrode inlet.

[0022] Step 2: Place the support into the jacketed beaker and attach the bottom of the support base to the bottom of the jacketed beaker.

[0023] Step 3: Insert the one-dimensional or two-dimensional pitting electrode into the receiving cavity of the support from the electrode inlet, so that the one-dimensional or two-dimensional pitting electrode fits flat against the upper surface of the support base.

[0024] Step 4: Screw the M10 hex bolt into the M10 threaded hole, and press the bottom end of the M10 hex bolt against the upper surface of the pitting electrode; or, rotate the round rod rivet to drive the round rod out of the slot, loosen the round rod rivet, and the spring's restoring force will drive the screw rivet downwards until its lower end presses against the upper surface of the pitting electrode.

[0025] Step 5: Place the experimental apparatus assembled in Steps 1 to 4 onto the stage of the metallurgical microscope.

[0026] Step 6: Add electrolyte to the jacketed beaker until the electrolyte level is flush with the upper surface of the acrylic cover plate.

[0027] Step 7: Connect the inlet and outlet of the jacketed beaker to the outlet and inlet of the constant temperature water bath with circulation function, turn on the circulation system of the constant temperature water bath and set the temperature. The constant temperature water enters the jacket of the jacketed beaker from the inlet and is discharged from the outlet, flowing back to the constant temperature water bath, thereby adjusting the electrolyte temperature.

[0028] Step 8: Place the ends of the reference electrode and the platinum electrode in the electrolyte inside the jacketed beaker;

[0029] Step 9: Connect the copper wire, reference electrode, and platinum electrode to the electrochemical workstation;

[0030] Step 10: Turn on the metallurgical microscope and adjust the position of the objective lens so that the metal wire or metal foil is in the center of the field of view of the metallurgical microscope;

[0031] Step 11: Adjust the focal length of the metallurgical microscope objective lens to make the observed metal wire or metal foil appear in the clearest state.

[0032] Step 12: Turn on the electrochemical workstation, set the experimental program, and conduct one-dimensional or two-dimensional pitting corrosion experiments;

[0033] Step 13: Turn on the recording function of the metallographic microscope to monitor the growth of one-dimensional or two-dimensional pitting corrosion in situ.

[0034] Step 14: After the pitting test is completed, loosen the M10 hex bolts, then pull out the one-dimensional or two-dimensional pitting electrode from the electrode inlet. Polish and clean the exposed end of the one-dimensional or two-dimensional pitting electrode with sandpaper. After drying, repeat steps 3, 4 and steps 10 to 13 in sequence to complete the next pitting test.

[0035] Step 15: Repeat step 14 to perform multiple pitting experiments.

[0036] Further, the specific process of step 1 is as follows: the bracket cover plate is glued to one end of the top of the baffle on the left and right sides of the bracket base, so that the other end of the bracket forms an electrode inlet for inserting a one-dimensional pitting electrode or a two-dimensional pitting electrode.

[0037] Furthermore, the specific process of polishing and cleaning the exposed end of the one-dimensional or two-dimensional pitting electrode with sandpaper in step 14 is as follows: first, polish the exposed end of the one-dimensional or two-dimensional pitting electrode with 400-grit sandpaper until the metal wire or metal foil is exposed, then polish the exposed end of the one-dimensional or two-dimensional pitting electrode with 800-grit and 1200-grit sandpaper, and then ultrasonically clean it with deionized water.

[0038] The present invention has the following beneficial technical effects:

[0039] Firstly, this invention encapsulates metal wires or foils with an acrylic base plate and an acrylic cover plate, which not only facilitates the microscopic capture of the morphological changes of one-dimensional and two-dimensional pitting growth, but also improves the bonding force between the metal wires / foils and the epoxy resin, making it convenient for repeated experiments. Secondly, with the electrolyte surface flush with the acrylic cover plate, in-situ observation perpendicular to the pitting electrode not only facilitates the observation of the growth state inside the pits, but also effectively prevents the impact of electrolyte surface fluctuations on image quality. Thirdly, using a glass jacketed beaker as the electrolytic cell effectively prevents leakage. Fourthly, the pitting electrode can be quickly and easily disassembled and assembled in one step by screwing on an M10 hex bolt, eliminating the tedious steps of repeatedly moving the experimental setup during multiple experiments. During the disassembly and assembly of the pitting electrode, the entire device does not need to leave the metallurgical microscope stage, minimizing disruption to the microscope's work. The experimental environment enhances the convenience and efficiency of the experiment, ensuring excellent repeatability. Furthermore, the vibration impact on the overall apparatus during assembly and disassembly is minimal, maximizing stability. Fifthly, the use of a bracket and M10 hex bolts allows for horizontal placement of the one-dimensional or two-dimensional pitting electrode, minimizing light scattering during in-situ observation with a microscope, resulting in clearer images and facilitating observation of pit morphology and salt film changes. Sixthly, the simple structure of the experimental setup, free from unnecessary accessories, maximizes the range of motion of the metallurgical microscope objective, covering the monitoring needs throughout the experiment. Seventhly, connecting the inlet and outlet of the jacketed beaker to the inlet and outlet of a circulating constant-temperature water bath facilitates electrolyte temperature control, making it suitable for in-situ observation of pitting behavior in different metals and improving applicability. Attached Figure Description

[0040] Figure 1 This is a schematic diagram of the cross-sectional structure of the one-dimensional pitting electrode of the present invention;

[0041] Figure 2 This is a top view schematic diagram of the one-dimensional pitting electrode of the present invention;

[0042] Figure 3 This is a schematic diagram of the cross-sectional structure of the two-dimensional pitting electrode of the present invention;

[0043] Figure 4 This is a top view of the two-dimensional pitting electrode of the present invention.

[0044] Figure 5 This is a three-dimensional structural diagram of the bolt quick-release experimental device of the present invention;

[0045] Figure 6This is an exploded structural diagram of the bolt quick-release experimental device of the present invention;

[0046] Figure 7 This is a three-dimensional structural diagram of the spring quick-release experimental device of the present invention when pressing the pitting electrode;

[0047] Figure 8 This is a three-dimensional structural diagram of the spring quick-release experimental device of the present invention when the pitting electrode is released.

[0048] Figure 9 This is an exploded structural diagram of the spring quick-release experimental device of the present invention;

[0049] Figure 10 This is a three-dimensional structural diagram of the control rod of the spring quick-release experimental device of the present invention;

[0050] Figure 11 This is an exploded structural diagram of the control rod of the spring quick-release experimental device of the present invention;

[0051] Figure 12 This is a photograph of the experimental apparatus of the present invention in use;

[0052] Figure 13 This is a photograph taken under a microscope during the potential step experiment of two-dimensional erosion pits according to the present invention.

[0053] In the diagram: 1. Acrylic base plate; 2. Epoxy resin; 3. Metal wire; 4. Metal foil; 5. Acrylic cover plate; 6. Copper wire; 7. Jacketed beaker; 8. Inlet; 9. Outlet; 10. Support base; 11. Support cover plate; 12. Electrode inlet; 13. M10 threaded hole; 14. M10 hex bolt; 15. Reference electrode; 16. Platinum electrode; 17. Through hole; 18. Control rod; 19. Spring; 20. Round bar; 21. Screw rivet; 22. Round rod rivet. Detailed Implementation

[0054] The present invention will be further described in detail below with reference to specific embodiments. These descriptions are for explanation purposes only and are not intended to limit the scope of the invention.

[0055] like Figures 5-9 As shown, a temperature-controlled one-step quick-assembly experimental device for in-situ monitoring of one-dimensional and two-dimensional pitting behavior includes a jacketed beaker 7, a support, a pitting electrode, a reference electrode 15, a platinum electrode 16, and a clamping assembly. The pitting electrode is either a one-dimensional pitting electrode or a two-dimensional pitting electrode.

[0056] like Figures 1-4As shown, the pitting electrode includes an acrylic base plate 1 and an acrylic cover plate 5 arranged parallel to each other. An epoxy resin 2 is filled between the acrylic base plate 1 and the acrylic cover plate 5. When the pitting electrode is a one-dimensional pitting electrode, the epoxy resin 2 is coated with a metal wire 3; when the pitting electrode is a two-dimensional pitting electrode, the epoxy resin 2 is coated with a metal foil 4.

[0057] One end of the metal wire 3 and the metal foil 4 is welded with a copper wire 6, and the other end of the metal wire 3 and the metal foil 4 is flush with the ends of the acrylic base plate 1 and the acrylic cover plate 5 to form an exposed end.

[0058] like Figure 5 and Figure 6 As shown, the bracket includes a bracket base 10 and a bracket cover plate 11. Vertical baffles are fixedly installed on the left and right sides of the bracket base 10. The bracket cover plate 11 is glued to the top of the baffle to form a receiving cavity for accommodating a one-dimensional pitting electrode or a two-dimensional pitting electrode. The length of the bracket cover plate 11 is less than the length of the baffle. An electrode inlet 12 for inserting a one-dimensional pitting electrode or a two-dimensional pitting electrode is formed at one end of the bracket base 10. The one-dimensional pitting electrode or two-dimensional pitting electrode is inserted into the receiving cavity through the electrode inlet 12, and the lower surface of the one-dimensional pitting electrode or two-dimensional pitting electrode is in contact with the upper surface of the bracket base 10.

[0059] The clamping assembly includes an M10 threaded hole 13 opened on the bracket cover plate 11, an M10 external hex bolt 14 threadedly connected to the M10 threaded hole 13, and the bottom end of the M10 external hex bolt 14 is pressed against the upper surface of the one-dimensional pitting electrode or the two-dimensional pitting electrode, so that the one-dimensional pitting electrode or the two-dimensional pitting electrode is kept in a tight horizontal state.

[0060] Or, such as Figures 7-11As shown, the clamping assembly includes a control rod 18, slots at the ends of two baffles, and a through hole 17 on the bracket cover plate 11. The two slots are located at opposite ends of the two baffles. The control rod 18 includes a round rod rivet 22 inserted into the through hole 17. A spring 19 is sleeved on the round rod rivet 22, and a screw rivet 21 is threaded to the lower end of the round rod rivet 22. The lower end of the spring 19 is fixedly connected to the screw rivet 21, and the upper end of the spring 19 abuts against the lower surface of the bracket cover plate 11. A round rod with two ends that can be respectively engaged in the two slots is fixedly connected to the lower end of the screw rivet 21. 20; When installing a one-dimensional or two-dimensional pitting electrode, rotate the round rod rivet 22 to dislodge the round rod 20 from the slot, loosen the round rod rivet 22, and the elastic restoring force of the spring 19 pushes the screw rivet 21 downward until the lower end of the screw rivet 21 presses against the upper surface of the one-dimensional or two-dimensional pitting electrode; When removing the one-dimensional or two-dimensional pitting electrode, pull upward and rotate the round rod rivet 22 to drive the two ends of the round rod 20 into the two slots opened in the baffle respectively, the spring is in a compressed state, and the lower end of the screw rivet 21 leaves the upper surface of the one-dimensional or two-dimensional pitting electrode;

[0061] Specifically, such as Figures 10-11 As shown, the lower end of the round rod rivet 22 is provided with an internal threaded hole, and the screw rivet 21 includes a base plate. A screw is fixedly installed on the upper end of the base plate. The screw is threaded into the internal threaded hole, so that the round rod rivet 22 and the screw rivet 21 are threadedly connected. The base plate is provided with a transverse through hole, and the round rod 20 is fixedly inserted into the through hole.

[0062] The slots opened at the ends of the two baffles are U-shaped slots arranged at an angle. The opening of the U-shaped slot is higher than the end position, which makes it easy to stably engage the round rod 20 inside the U-shaped slot and effectively prevent the round rod 20 from sliding out of the U-shaped slot.

[0063] The bracket is attached to the inside of the jacketed beaker 7, that is, the bottom surface of the bracket base 10 is attached to the inner bottom of the jacketed beaker 7. The jacketed beaker 7 contains electrolyte, and the liquid level of the electrolyte is flush with the upper surface of the acrylic cover plate 5. The reference electrode 15 and the platinum electrode 16 are inserted into the electrolyte, and the copper wire 6, the reference electrode 15 and the platinum electrode 16 are all connected to the electrochemical workstation.

[0064] The inlet 8 and outlet 9 of the jacketed beaker 7 are both connected to the outlet and inlet of the constant temperature water bath with circulation function. When the circulation system of the constant temperature water bath is turned on, the constant temperature water enters the jacket of the jacketed beaker 7 from the inlet 8 and flows back to the constant temperature water bath from the outlet 9, thereby regulating the temperature of the electrolyte.

[0065] Preferably, the bracket base 10, the baffle and the bracket cover 11 are all made of acrylic sheet.

[0066] Preferably, the round bar 20 is made of stainless steel.

[0067] like Figure 1 and Figure 2 As shown, the fabrication process of the one-dimensional pitting electrode includes the following steps:

[0068] Step 1.1: Take a metal wire 3 of the required length and ultrasonically clean it in acetone;

[0069] Step 1.2: Solder one end of the cleaned metal wire 3 to one end of the copper wire 6 to establish a circuit connection for subsequent electrochemical testing.

[0070] Step 1.3: Place the metal wire 3 above the acrylic base plate 1, ensuring that it does not contact the surface of the acrylic base plate 1;

[0071] Step 1.4: Slowly pour epoxy resin 2 onto the upper surface of the acrylic base plate 1 so that the epoxy resin 2 completely covers the metal wire 3;

[0072] Step 1.5: Cover the epoxy resin 2 with the acrylic cover plate 5, aligning the acrylic cover plate 5 with the perimeter of the acrylic base plate 1.

[0073] Step 1.6: After the epoxy resin 2 has cured, apply a heavy object to the acrylic cover plate 5 to make the epoxy resin 2 and the metal wire 3 in close contact.

[0074] Step 1.7: After the epoxy resin 2 has completely cured, a one-dimensional pitting electrode in the shape of a "sandwich" is obtained;

[0075] Step 1.8: Use 400-grit sandpaper to polish the short side of one side of the one-dimensional pitting electrode until the other end of the metal wire 3 is exposed. Then, use 800-grit and 1200-grit sandpaper to polish the short side of one side of the one-dimensional pitting electrode in turn, so that the end of the other end of the metal wire 3 is flush with the ends of the acrylic base plate 1 and the acrylic cover plate 5 to form an exposed end. Then, use deionized water for ultrasonic cleaning, and after drying, it is ready for use.

[0076] like Figure 3 and Figure 4 As shown, the fabrication process of the two-dimensional pitting electrode includes the following steps:

[0077] Step 2.1: Take a metal foil sheet 4 of the required length and clean it ultrasonically in acetone;

[0078] Step 2.2: Solder one end of the cleaned metal foil 4 to one end of the copper wire 6 to establish a circuit connection for subsequent electrochemical testing;

[0079] Step 2.3: Place the metal foil 4 above the acrylic base plate 1, ensuring that it does not contact the surface of the acrylic base plate 1;

[0080] Step 2.4: Slowly pour epoxy resin 2 onto the upper surface of the acrylic base plate 1 so that the epoxy resin 2 completely covers the metal foil 4.

[0081] Step 2.5: Cover the epoxy resin 2 with the acrylic cover plate 5, aligning the acrylic cover plate 5 with the perimeter of the acrylic base plate 1.

[0082] Step 2.6: After the epoxy resin 2 has cured, apply a heavy object to the acrylic cover plate 5 to make the epoxy resin 2 and the metal foil 4 in close contact.

[0083] Step 2.7: After the epoxy resin 2 has completely cured, a "sandwich" shaped two-dimensional pitting electrode is obtained;

[0084] Step 2.8: Use 400-grit sandpaper to polish the short side of one side of the two-dimensional pitting electrode sample until the other end of the metal foil 4 is exposed. Then, use 800-grit and 1200-grit sandpaper to polish the short side of one side of the two-dimensional pitting electrode in turn, so that the end of the other end of the metal foil 4 is flush with the ends of the acrylic base plate 1 and the acrylic cover plate 5 to form an exposed end. Then, use deionized water for ultrasonic cleaning, dry it, and set it aside for use.

[0085] Preferably, the dimensions of the acrylic base plate 1 and the acrylic cover plate 5 are both 75×25×0.8mm.

[0086] Preferably, the diameter of the metal wire 3 is 50 μm.

[0087] Preferably, the metal wire 3 and the metal foil 4 are both made of 304 or 316L stainless steel. Alternatively, depending on the specific experiment, the metal wire 3 and the metal foil 4 can be made of other metal materials.

[0088] Preferably, the metal foil 4 has a thickness of 20 μm and a width of 3 mm.

[0089] To more clearly describe the working method of the temperature-controlled one-step quick-release experimental device for in-situ monitoring of one-dimensional and two-dimensional pitting behavior proposed in this embodiment, the quick-release experimental device is divided into a bolt quick-release experimental device and a spring quick-release experimental device according to the specific structure of the clamping component. The working methods of the two are as follows:

[0090] 1) For bolt quick-release experimental devices

[0091] like Figure 5 and 12 As shown, a method for using a temperature-controlled, one-step, quick-assembly / disassembly experimental device for in-situ monitoring of one-dimensional and two-dimensional pitting corrosion behavior includes the following steps:

[0092] Step 1: Glue the bracket cover plate 11 to the baffles on the left and right sides of the bracket base 10, with the bracket cover plate 11 located on the side above the bracket base 10, so that the other side of the bracket forms an electrode inlet 12 for inserting a one-dimensional pitting electrode or a two-dimensional pitting electrode.

[0093] Step 2: Place the support into the jacketed beaker 7 and attach the bottom of the support base 10 to the bottom of the jacketed beaker 7.

[0094] Step 3: Insert a one-dimensional pitting electrode or a two-dimensional pitting electrode from the electrode inlet 12, so that the one-dimensional pitting electrode or the two-dimensional pitting electrode is flush with the upper surface of the support base 10.

[0095] Step 4: Screw the M10 hex bolt 14 into the M10 threaded hole 13. The bottom end of the M10 hex bolt 14 is pressed against the upper surface of the pitting electrode, so that the one-dimensional pitting electrode or the two-dimensional pitting electrode is kept in a tight and horizontal state.

[0096] Step 5: Place the experimental apparatus assembled in Steps 1 to 4 onto the stage of the metallurgical microscope.

[0097] Step 6: Add electrolyte to the jacketed beaker 7 so that the electrolyte level is flush with the upper surface of the acrylic cover plate 5.

[0098] Step 7: Connect the inlet 8 and outlet 9 of the jacketed beaker 7 to the outlet and inlet of the constant temperature water bath with circulation function, turn on the circulation system of the constant temperature water bath, and set the temperature. The constant temperature water enters the jacket of the jacketed beaker 7 from the inlet 8 and is discharged from the outlet 9, flowing back to the constant temperature water bath, thereby regulating the temperature of the electrolyte.

[0099] Step 8: Place the ends of the reference electrode 15 and the platinum electrode 16 into the electrolyte inside the jacketed beaker 7;

[0100] Step 9: Connect the copper wire 6, the reference electrode 15, and the platinum electrode 16 to the electrochemical workstation;

[0101] Step 10: Turn on the metallurgical microscope and adjust the position of the objective lens so that the metal wire 3 or metal foil 4 is in the center of the field of view of the metallurgical microscope.

[0102] Step 11: Adjust the focal length of the metallurgical microscope objective lens to make the observed metal wire 3 or metal foil 4 appear in the clearest state.

[0103] Step 12: Turn on the electrochemical workstation, set the experimental program, and conduct one-dimensional or two-dimensional pitting corrosion experiments.

[0104] Step 13: Turn on the recording function of the metallographic microscope to monitor the growth of one-dimensional or two-dimensional pitting corrosion in situ.

[0105] Step 14: After the pitting experiment is completed, loosen the M10 hex bolt 14, and then pull out the one-dimensional pitting electrode or two-dimensional pitting electrode from the electrode inlet 12. Use 400-grit sandpaper to polish the exposed end of the one-dimensional pitting electrode or two-dimensional pitting electrode until the metal wire 3 or metal foil 4 is exposed. Continue to polish the exposed end of the one-dimensional pitting electrode or two-dimensional pitting electrode with 800-grit and 1200-grit sandpaper. Then, use deionized water for ultrasonic cleaning. After drying, repeat steps 3, 4 and steps 10 to 13 in sequence to complete the next pitting experiment.

[0106] Step 15: Repeat step 14 to perform multiple pitting experiments.

[0107] 2) For spring quick-release experimental devices

[0108] like Figures 7-9 and Figure 12 As shown, a method for using a temperature-controlled, one-step, quick-assembly / disassembly experimental device for in-situ monitoring of one-dimensional and two-dimensional pitting corrosion behavior includes the following steps:

[0109] Step 1: Glue the bracket cover plate 11 to the baffles on the left and right sides of the bracket base 10, with the bracket cover plate 11 located on the side above the bracket base 10, so that the other side of the bracket forms an electrode inlet 12 for inserting a one-dimensional pitting electrode or a two-dimensional pitting electrode.

[0110] Step 2: Place the support into the jacketed beaker 7 and attach the bottom of the support base 10 to the bottom of the jacketed beaker 7.

[0111] Step 3: Pull up and rotate the round rod rivet 22, causing both ends of the round rod 20 to be respectively inserted into the two slots opened in the baffle, and the spring is in a compressed state;

[0112] Step 4: Insert the one-dimensional or two-dimensional pitting electrode into the electrode inlet 12, so that the one-dimensional or two-dimensional pitting electrode is flush with the upper surface of the support base 10. Rotate the round rod rivet 22 to drive the two ends of the round rod 20 to disengage from the two slots opened in the baffle. Loosen the round rod rivet 22. Under the elastic restoring force of the spring 19, the screw rivet 21 moves downward until its lower end presses against the upper surface of the one-dimensional or two-dimensional pitting electrode, so that the one-dimensional or two-dimensional pitting electrode is kept in a tight horizontal state.

[0113] Step 5: Place the experimental apparatus assembled in Steps 1 to 4 onto the stage of the metallurgical microscope.

[0114] Step 6: Add electrolyte to the jacketed beaker 7 so that the electrolyte level is flush with the upper surface of the acrylic cover plate 5.

[0115] Step 7: Connect the inlet 8 and outlet 9 of the jacketed beaker 7 to the outlet and inlet of the constant temperature water bath with circulation function, turn on the circulation system of the constant temperature water bath, and set the temperature. The constant temperature water enters the jacket of the jacketed beaker 7 from the inlet 8 and is discharged from the outlet 9, flowing back to the constant temperature water bath, thereby regulating the temperature of the electrolyte.

[0116] Step 8: Place the ends of the reference electrode 15 and the platinum electrode 16 into the electrolyte inside the jacketed beaker 7;

[0117] Step 9: Connect the copper wire 6, the reference electrode 15, and the platinum electrode 16 to the electrochemical workstation;

[0118] Step 10: Turn on the metallurgical microscope and adjust the position of the objective lens so that the metal wire 3 or metal foil 4 is in the center of the field of view of the metallurgical microscope.

[0119] Step 11: Adjust the focal length of the metallurgical microscope objective lens to make the observed metal wire 3 or metal foil 4 appear in the clearest state.

[0120] Step 12: Turn on the electrochemical workstation, set the experimental program, and conduct one-dimensional or two-dimensional pitting corrosion experiments.

[0121] Step 13: Turn on the recording function of the metallographic microscope to monitor the growth of one-dimensional or two-dimensional pitting corrosion in situ.

[0122] Step 14: After the pitting experiment is completed, pull up and rotate the round rod rivet 22 to drive the two ends of the round rod 20 into the two slots opened in the baffle respectively. Then, pull out the one-dimensional pitting electrode or two-dimensional pitting electrode from the electrode inlet 12. Use 400-grit sandpaper to polish the exposed end of the one-dimensional pitting electrode or two-dimensional pitting electrode until the metal wire 3 or metal foil 4 is exposed. Continue to polish the exposed end of the one-dimensional pitting electrode or two-dimensional pitting electrode with 800-grit and 1200-grit sandpaper. Then, use deionized water for ultrasonic cleaning. After drying, repeat steps 4 and steps 10 to 13 in sequence to complete the next pitting experiment.

[0123] Step 15: Repeat step 14 to perform multiple pitting experiments.

[0124] Application examples

[0125] Step 1: Prepare a two-dimensional pitting electrode. The specific process is as follows:

[0126] Step 1.1: Make metal foil 4 of the required size from 304 stainless steel and ultrasonically clean it in acetone;

[0127] Step 1.2: Solder one end of the metal foil 4 to one end of the copper wire 6;

[0128] Step 1.3: Place the metal foil 4 above the acrylic base plate 1, ensuring that it does not contact the surface of the acrylic base plate 1;

[0129] Step 1.4: Slowly pour epoxy resin 2 onto the upper surface of the acrylic base plate 1 so that the epoxy resin 2 completely covers the metal foil 4.

[0130] Step 1.5: Cover the epoxy resin 2 with the acrylic cover plate 5, aligning the acrylic cover plate 5 with the perimeter of the acrylic base plate 1.

[0131] Step 1.6: After the epoxy resin 2 has cured, apply a heavy object to the acrylic cover plate 5 to make the epoxy resin 2 and the metal foil 4 in close contact.

[0132] Step 1.7: After the epoxy resin 2 has completely cured, a "sandwich" shaped two-dimensional pitting electrode is obtained;

[0133] Step 1.8: Use 400-grit sandpaper to polish the short side of one side of the two-dimensional pitting electrode sample until the other end of the metal foil 4 is exposed. Then, use 800-grit and 1200-grit sandpaper to polish the short side of one side of the two-dimensional pitting electrode in turn, so that the end of the other end of the metal foil 4 is flush with the ends of the acrylic base plate 1 and the acrylic cover plate 5 to form an exposed end. Then, use deionized water for ultrasonic cleaning, dry, and set aside for use.

[0134] Step 2: Attach the bracket cover plate 11 to the baffles on the left and right sides of the bracket base 10 with glue, and place the bracket cover plate 11 on the side above the bracket base 10, so that the other side of the bracket forms an electrode inlet 12 for inserting a one-dimensional pitting electrode or a two-dimensional pitting electrode.

[0135] Step 3: Place the support into the jacketed beaker 7 and attach the bottom of the support base 10 to the bottom of the jacketed beaker 7.

[0136] Step 4: Insert the two-dimensional pitting electrode from the electrode inlet 12, so that the two-dimensional pitting electrode is flush with the upper surface of the support base 10.

[0137] Step 5: Screw the M10 hex bolt 14 into the M10 threaded hole 13. The bottom end of the M10 hex bolt 14 is pressed against the upper surface of the two-dimensional pitting electrode to keep the two-dimensional pitting electrode in a tight and horizontal state.

[0138] Step 6: Place the experimental apparatus assembled in steps 2 to 5 onto the stage of the metallurgical microscope.

[0139] Step 7: Add electrolyte to the jacketed beaker 7 so that the electrolyte level is flush with the upper surface of the acrylic cover plate 5.

[0140] Step 8: Connect the inlet 8 and outlet 9 of the jacketed beaker 7 to the outlet and inlet of the constant temperature water bath with circulation function, turn on the circulation system of the constant temperature water bath, and set the temperature to 25°C. The constant temperature water enters the jacket of the jacketed beaker 7 from the inlet 8 and is discharged from the outlet 9, flowing back to the constant temperature water bath.

[0141] Step 9: Place the ends of the reference electrode 15 and the platinum electrode 16 into the electrolyte inside the jacketed beaker 7;

[0142] Step 10: Connect the copper wire 6, the reference electrode 15, and the platinum electrode 16 to the electrochemical workstation;

[0143] Step 11: Turn on the metallurgical microscope and adjust the position of the objective lens so that the metal foil 4 is in the center of the field of view of the metallurgical microscope.

[0144] Step 12: Adjust the focal length of the metallurgical microscope objective lens to make the observed metal foil 4 appear in the clearest state;

[0145] Step 13: Turn on the electrochemical workstation, set the constant potential experimental mode, activate the pit at 1.2V, then grow it at a constant potential of 0.7V for 200s, and then step to 0.3V for constant potential growth.

[0146] Step 14: Turn on the recording function of the metallographic microscope to monitor the two-dimensional pitting growth in situ. The results are as follows: Figure 13 As shown.

[0147] from Figure 13 It can be seen that during the potential step experiment on the two-dimensional pit, after the potential decreases, a new two-dimensional pit will be formed at the bottom of the initial pit.

Claims

1. A temperature-controlled, one-step, quick-assembly / disassembly experimental device for in-situ monitoring of one-dimensional and two-dimensional pitting behavior, characterized in that, The assembly includes a jacketed beaker (7), a support, a pitting electrode, a reference electrode (15), a platinum electrode (16), and a clamping assembly. The pitting electrode includes an acrylic base plate (1) and an acrylic cover plate (5) arranged parallel to each other. An epoxy resin layer (2) is filled between the acrylic base plate (1) and the acrylic cover plate (5). When the pitting electrode is a one-dimensional pitting electrode, the epoxy resin (2) is coated with metal wire (3); when the pitting electrode is a two-dimensional pitting electrode, the epoxy resin (2) is coated with metal foil (4). One end of the metal wire (3) and metal foil (4) is welded with a copper wire (6), and the other end of the metal wire (3) and metal foil (4) is flush with the ends of the acrylic base plate (1) and acrylic cover plate (5) to form an exposed end; The bracket is attached to the inside of the jacketed beaker (7). The bracket includes a bracket base (10) and a bracket cover plate (11). Vertical baffles are fixedly installed on the left and right sides of the bracket base (10). The bracket cover plate (11) is fixedly installed on the top of the baffle to form a cavity for accommodating the pitting electrode. One end of the bracket is the electrode inlet (12). The pitting electrode is inserted into the cavity through the electrode inlet (12), and the lower surface of the pitting electrode is in contact with the upper surface of the bracket base (10). The clamping assembly includes a control rod (18), slots at the ends of two baffles, and a through hole (17) on the bracket cover plate (11). The two slots are located at opposite ends of the two baffles. The quick-release control rod (18) includes a round rod rivet (22) inserted into the through hole (17). A spring (19) is sleeved on the round rod rivet (22), and a screw rivet (21) for clamping the pitting electrode is threaded to the lower end of the round rod rivet (22). The lower end of the spring (19) is fixedly connected to the screw rivet (21), and the upper end of the spring (19) abuts against the lower surface of the bracket cover plate (11). A round rod (20) with two ends that can be respectively clamped into the two slots is fixedly connected to the lower end of the screw rivet (21). The inlet (8) and outlet (9) of the jacketed beaker (7) are connected to the outlet and inlet of the constant temperature water bath with circulation function. The jacketed beaker (7) contains electrolyte. The electrolyte level is flush with the upper surface of the acrylic cover plate (5). The reference electrode (15) and platinum electrode (16) are inserted in the electrolyte. The copper wire (6), the reference electrode (15) and the platinum electrode (16) are all connected to the electrochemical workstation.

2. The in-situ temperature-controlled one-step quick-assembly and disassembly experimental device for monitoring one-dimensional and two-dimensional pitting corrosion behavior according to claim 1, characterized in that, The baffle is glued to the left and right sides of the bracket base (10); The length of the bracket cover plate (11) is less than the length of the baffle, and the bracket cover plate (11) is glued to one end of the top of the baffle.

3. The in-situ temperature-controlled one-step quick-assembly and disassembly experimental device for monitoring one-dimensional and two-dimensional pitting corrosion behavior according to claim 1 or 2, characterized in that, The bracket base (10), baffle and bracket cover (11) are all made of acrylic sheet.

4. The in-situ temperature-controlled one-step quick-assembly and disassembly experimental device for monitoring one-dimensional and two-dimensional pitting corrosion behavior according to claim 1 or 2, characterized in that, The dimensions of the acrylic base plate (1) and the acrylic cover plate (5) are both 75×25×0.8 mm.

5. The in-situ temperature-controlled one-step quick-assembly and disassembly experimental device for monitoring one-dimensional and two-dimensional pitting corrosion behavior according to claim 1 or 2, characterized in that, The diameter of the metal wire (3) is 50 μm.

6. The in-situ temperature-controlled one-step quick-assembly and disassembly experimental device for monitoring one-dimensional and two-dimensional pitting corrosion behavior according to claim 1 or 2, characterized in that, The metal foil (4) has a thickness of 20 μm and a width of 3 mm.

7. The in-situ temperature-controlled one-step quick-assembly and disassembly experimental device for monitoring one-dimensional and two-dimensional pitting behavior according to claim 1 or 2, characterized in that, The metal wire (3) and metal foil (4) are both made of 304 or 316L stainless steel.

8. A method for operating the in-situ temperature-controlled one-step quick-assembly and disassembly experimental device for monitoring one-dimensional and two-dimensional pitting behavior as described in claim 2, characterized in that, Includes the following steps: Step 1: Fix the bracket cover plate (11) to the top of the baffles on the left and right sides of the bracket base (10). One end of the bracket is provided with an electrode inlet (12). Step 2: Place the support into the jacketed beaker (7) and attach the bottom of the support base (10) to the bottom of the jacketed beaker (7); Step 3: Insert the one-dimensional pitting electrode or the two-dimensional pitting electrode into the receiving cavity of the support from the electrode inlet (12) so that the one-dimensional pitting electrode or the two-dimensional pitting electrode fits flat against the upper surface of the support base (10). Step 4: Screw the M10 hex bolt (14) into the M10 threaded hole (13), and press the bottom end of the M10 hex bolt (14) against the upper surface of the pitting electrode; or, rotate the round rod rivet (22) to drive the round rod (20) out of the slot, loosen the round rod rivet (22), and the spring restoring force of the spring (19) will drive the screw rivet (21) to move downwards until its lower end presses against the upper surface of the pitting electrode; Step 5: Place the experimental apparatus assembled in steps 1 to 4 onto the stage of the metallurgical microscope. Step 6: Add electrolyte to the jacketed beaker (7) so that the electrolyte level is flush with the upper surface of the acrylic cover plate (5); Step 7: Connect the inlet (8) and outlet (9) of the jacketed beaker (7) to the outlet and inlet of the constant temperature water bath with circulation function, turn on the circulation system of the constant temperature water bath, and set the temperature. The constant temperature water enters the jacket of the jacketed beaker (7) from the inlet (8) and is discharged from the outlet (9) and flows back to the constant temperature water bath, thereby adjusting the electrolyte temperature. Step 8: Place the ends of the reference electrode (15) and the platinum electrode (16) into the electrolyte inside the jacketed beaker (7); Step 9: Connect the copper wire (6), the reference electrode (15), and the platinum electrode (16) to the electrochemical workstation; Step 10: Turn on the metallurgical microscope and adjust the position of the objective lens so that the metal wire (3) or metal foil (4) is in the center of the field of view of the metallurgical microscope. Step 11: Adjust the focal length of the metallurgical microscope objective lens to make the observed metal wire (3) or metal foil (4) appear in the clearest state; Step 12: Turn on the electrochemical workstation, set the experimental program, and conduct one-dimensional or two-dimensional pitting corrosion experiments; Step 13: Turn on the recording function of the metallographic microscope to monitor the growth of one-dimensional or two-dimensional pitting corrosion in situ. Step 14: After the pitting experiment is completed, loosen the M10 external hex bolt (14), and then pull out the one-dimensional pitting electrode or two-dimensional pitting electrode from the electrode inlet (12). Polish and clean the exposed end of the one-dimensional pitting electrode or two-dimensional pitting electrode with sandpaper. After drying, repeat steps 3, 4 and steps 10 to 13 in sequence to complete the next pitting experiment. Step 15: Repeat step 14 to perform multiple pitting experiments.

9. The working method of the controllable temperature one-step quick-assembly and disassembly experimental device for in-situ monitoring of one-dimensional and two-dimensional pitting behavior as described in claim 8, characterized in that, The specific process of step 1 is as follows: glue the bracket cover plate (11) to one end of the top of the baffle on both sides of the bracket base (10) so that the other end of the bracket forms an electrode inlet (12) for inserting a one-dimensional pitting electrode or a two-dimensional pitting electrode.

10. The working method of the controllable temperature one-step quick-assembly and disassembly experimental device for in-situ monitoring of one-dimensional and two-dimensional pitting corrosion behavior as described in claim 8, characterized in that, The specific process of polishing and cleaning the exposed end of the one-dimensional pitting electrode or the two-dimensional pitting electrode in step 14 is as follows: first, polish the exposed end of the one-dimensional pitting electrode or the two-dimensional pitting electrode with 400-grit sandpaper until the metal wire (3) or metal foil (4) is exposed, then polish the exposed end of the one-dimensional pitting electrode or the two-dimensional pitting electrode with 800-grit and 1200-grit sandpaper, and then clean it with deionized water using ultrasound.

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