Sensors and methods for online monitoring of corrosion in vehicle body gaps

Abstract

This invention relates to the field of rail vehicle technology, providing an online monitoring sensor and method for car body crevice corrosion. The online monitoring sensor includes a base, a substrate sample, a first gasket, a reference sample, a second gasket, and a cable. The substrate sample is mounted on the base. The corrosion sample is mounted on the base, with a first gap formed between the corrosion sample and the substrate sample via the first gasket. The reference sample is mounted on the base, with a second gap formed between the reference sample and the corrosion sample via the second gasket. The cable passes through the base, with one end electrically connected to the substrate sample, the corrosion sample, and the reference sample within the base. The other end of the cable exits the base and is connected to a current measuring unit. The current measuring unit measures a first current value between the corrosion sample and the reference sample, and a second current value between the corrosion sample and the substrate sample. This enables online monitoring of car body crevice corrosion.

Description

Technical Field

[0001] This invention relates to the field of rail vehicle technology, and in particular to an online monitoring sensor and method for corrosion in car body gaps. Background Technology

[0002] Although anti-corrosion coatings are applied to both the inner and outer surfaces of rail vehicles during the design phase, some special areas, such as windows, doors, and the floor below the junction box, are prone to crevice corrosion due to their complex structures and the presence of riveted or threaded connections. These areas are also susceptible to moisture contact.

[0003] Currently, most studies on crevice corrosion in rail vehicles are still in the experimental simulation stage. During the service life of rail vehicles, crevice corrosion cannot be monitored, and corrosion risks cannot be identified in a timely manner. Therefore, there is an urgent need for an online monitoring sensor and method for crevice corrosion in rail vehicles to solve the technical problems existing in the current technology. Summary of the Invention

[0004] This invention provides an online monitoring sensor for crevice corrosion in rail vehicles, which solves the technical problem that existing technologies cannot perform online monitoring of crevice corrosion in rail vehicles during service. It enables online monitoring of crevice corrosion, timely identification and prediction of corrosion risks, guidance for daily maintenance of rail vehicles, and can also provide a basis for optimizing subsequent anti-corrosion processes.

[0005] This invention also provides a method for online monitoring of corrosion in vehicle body gaps.

[0006] This invention provides an online monitoring sensor for corrosion in vehicle body gaps, comprising:

[0007] Base;

[0008] The substrate specimen is mounted on the base;

[0009] A corrosion test piece is mounted on the base, and a first gap is formed between the corrosion test piece and the base test piece by a first gasket.

[0010] A reference test piece is mounted on the base, and a second gap is formed between the reference test piece and the corrosion test piece by a second gasket;

[0011] A cable is inserted into the base. One end of the cable is electrically connected to the substrate test piece, the corrosion test piece, and the reference test piece within the base. The other end of the cable extends out of the base and is connected to a current measuring unit. The current measuring unit is used to measure a first current value between the corrosion test piece and the reference test piece, and to measure a second current value between the corrosion test piece and the substrate test piece.

[0012] According to the present invention, an online monitoring sensor for corrosion of vehicle body gaps is provided, wherein mounting grooves are respectively constructed on opposite sides of the inner surface of the base, the mounting grooves are arranged along the width direction of the base, and the substrate test piece, the first gasket, the corrosion test piece, the second gasket and the reference test piece are sequentially overlapped and snapped into the mounting grooves.

[0013] According to the present invention, an online monitoring sensor for corrosion of vehicle body gaps is provided, wherein a through-hole is constructed on the base, the cable is adapted to pass through the through-hole, and the gap between the cable and the through-hole, the substrate test piece, the first gasket, the corrosion test piece, the second gasket and the reference test piece is filled by a potting unit.

[0014] According to the present invention, an online monitoring sensor for vehicle body crevice corrosion is provided, wherein the substrate sample is provided with a substrate connecting piece on the side near the potting unit, the corrosion sample is provided with a corrosion connecting piece on the side near the potting unit, and the reference sample is provided with a reference connecting piece on the side near the potting unit. The substrate connecting piece, the corrosion connecting piece, and the reference connecting piece are respectively used to connect the cable, and the vertical projections of the substrate connecting piece, the corrosion connecting piece, and the reference connecting piece are misaligned with each other.

[0015] According to the present invention, an online monitoring sensor for corrosion in vehicle body gaps includes a base comprising:

[0016] The base has a locking mechanism on its upper surface;

[0017] A top cover is attached to the top of the base body;

[0018] The substrate sample, the first gasket, the corrosion sample, the second gasket, and the reference sample are sequentially overlapped and snapped onto the locking block, and the top cover is attached to the substrate sample.

[0019] According to the present invention, an online monitoring sensor for corrosion in vehicle body gaps includes at least two arc blocks, and the at least two arc blocks are arranged at intervals along the circumferential direction on the upper surface of the base.

[0020] The substrate test piece, the first gasket, the corrosion test piece, the second gasket, and the reference test piece are each set in an arc shape and have an arc notch, so that the substrate test piece, the first gasket, the corrosion test piece, the second gasket, and the reference test piece are sequentially overlapped and snapped onto the at least two arc blocks, and then the cable is threaded through the arc notch;

[0021] The arc-shaped notch is suitable for being filled with a potting unit.

[0022] According to the present invention, an online monitoring sensor for vehicle body crevice corrosion is provided, wherein the inner circumferential surfaces of the substrate sample, the corrosion sample, and the reference sample are respectively provided with electrical connecting pieces for connecting cables, wherein the vertical projections of the electrical connecting pieces of the substrate sample, the corrosion sample, and the reference sample are misaligned with each other.

[0023] According to the present invention, an online monitoring sensor for corrosion of vehicle body gaps is provided, wherein the outer surface of the base is provided with a support column, the support column being adapted to be connected to the surface of the vehicle body for adjusting the gap value between the base and the surface of the vehicle body.

[0024] According to the present invention, an online monitoring sensor for corrosion in vehicle body gaps is provided, wherein the substrate sample is made of the same material as the component at the location to be monitored, the corrosion sample is made of the same material as the vehicle body, and the reference sample is made of the same material as the corrosion sample.

[0025] This invention also provides an online monitoring method for corrosion in vehicle body gaps, which uses the aforementioned online monitoring sensor for corrosion in vehicle body gaps for online monitoring, and includes the following steps:

[0026] The online monitoring sensor for corrosion of vehicle body gaps is installed at the location of the gaps in the vehicle body, and the first gap and the second gap are respectively positioned to correspond to the gaps in the vehicle body.

[0027] The first current value between the corrosion test piece and the reference test piece, and the second current value between the corrosion test piece and the substrate test piece are measured using a current measuring unit.

[0028] The instantaneous corrosion rate of the vehicle body gap and the cumulative corrosion loss at the current moment are obtained based on the first current value and the second current value.

[0029] The online monitoring sensor for vehicle body crevice corrosion provided in this invention forms a first gap between a substrate sample and a corrosion sample using a first gasket, and a second gap between the corrosion sample and a reference sample using a second gasket. This allows the first gap to fit the crevice structure of the vehicle body, and the second gap to completely insulate the corrosion sample and the reference sample. Once the base is installed around the crevice in the vehicle body, the corrosion status of the crevice structure can be simultaneously reflected by monitoring the corrosion of the first gap. Specifically, by monitoring a first current value between the corrosion sample and the reference sample, and a second current value between the corrosion sample and the substrate sample, and calculating the instantaneous corrosion rate and the cumulative corrosion loss at the current moment based on the first and second current values, online monitoring of the vehicle body crevice corrosion is achieved.

[0030] The online monitoring method for vehicle body crevice corrosion provided in this invention employs the aforementioned online monitoring sensor for vehicle body crevice corrosion. A first gap is formed between the substrate sample and the corroded sample using a first gasket, and a second gap is formed between the corroded sample and the reference sample using a second gasket. This allows the first gap to adapt to the crevice structure of the vehicle body, and the second gap to completely insulate the corroded sample and the reference sample. Once the base is installed around the crevice of the vehicle body, the corrosion status of the crevice structure can be simultaneously reflected by monitoring the corrosion of the first gap. Specifically, by monitoring the first current value between the corroded sample and the reference sample, and the second current value between the corroded sample and the substrate sample, and calculating the instantaneous corrosion rate and the cumulative corrosion loss at the current moment based on the first and second current values, online monitoring of the vehicle body crevice corrosion is achieved. Attached Figure Description

[0031] To more clearly illustrate the technical solutions in this invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0032] Figure 1 This is one of the structural schematic diagrams of the online monitoring sensor for vehicle body gap corrosion provided by the present invention;

[0033] Figure 2 yes Figure 1 Exploded view of the online monitoring sensor for crevice corrosion in CRRC body;

[0034] Figure 3 This is the second schematic diagram of the structure of the online monitoring sensor for vehicle body gap corrosion provided by the present invention;

[0035] Figure 4 yes Figure 3 Exploded view of the online monitoring sensor for crevice corrosion in CRRC body;

[0036] Figure 5 This is a schematic diagram of the structure of the base provided by the present invention;

[0037] Figure 6 This is a schematic diagram of the top cover provided by the present invention;

[0038] Figure 7 The measurement principle diagram of the online monitoring method for vehicle body crevice corrosion provided by this invention;

[0039] Figure 8 A schematic flowchart of the online monitoring method for corrosion in vehicle body gaps provided by this invention.

[0040] Figure label:

[0041] 10. Base; 110. Mounting groove; 120. Through notch; 130. Encapsulation unit; 140. Seat body; 150. Top cover; 160. Locking block; 170. Support column; 20. Matrix specimen; 210. Matrix connecting piece; 30. Corrosion specimen; 310. Corrosion connecting piece; 40. Reference specimen; 410. Reference connecting piece; 50. Cable; 60. First gasket; 70. First gap; 80. Second gasket; 90. Second gap. Detailed Implementation

[0042] The embodiments of the present invention will be described in further detail below with reference to the accompanying drawings and examples. The following examples are for illustrative purposes only and should not be construed as limiting the scope of the invention.

[0043] In the description of the embodiments of the present invention, it should be noted that the terms "center," "longitudinal," "lateral," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing the embodiments of the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the embodiments of the present invention. In addition, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0044] In the description of the embodiments of the present invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "connected" and "linked" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium. Those skilled in the art can understand the specific meaning of the above terms in the embodiments of the present invention based on the specific circumstances.

[0045] In embodiments of the present invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can mean that the first feature is in direct contact with the second feature, or that the first feature is in indirect contact with the second feature through an intermediate medium. Furthermore, "above," "on top of," and "over" the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0046] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., refer to specific features, structures, materials, or characteristics described in connection with that embodiment or example, which are included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0047] The following is combined Figures 1-7 The present invention describes an online monitoring sensor for vehicle body gap corrosion, comprising a base 10, a substrate specimen 20, a first gasket 60, a reference specimen 40, a second gasket 80, and a cable 50. The substrate specimen 20 is mounted on the base 10. A corrosion specimen 30 is mounted on the base 10, and a first gap 70 is formed between the corrosion specimen 30 and the substrate specimen 20 via the first gasket 60. The reference specimen 40 is mounted on the base 10, and a second gap 90 is formed between the reference specimen 40 and the corrosion specimen 30 via the second gasket 80. A cable 50 is installed in the base 10. One end of the cable 50 is electrically connected to the substrate test piece 20, the corrosion test piece 30 and the reference test piece 40 inside the base 10. The other end of the cable 50 extends out of the base 10 and is connected to a current measuring unit. The current measuring unit is used to measure the first current value between the corrosion test piece 30 and the reference test piece 40, and to measure the second current value between the corrosion test piece 30 and the substrate test piece 20.

[0048] In this embodiment, a first gap 70 is formed between the substrate sample 20 and the corrosion sample 30 by a first gasket 60, and a second gap 90 is formed between the corrosion sample 30 and the reference sample 40 by a second gasket 80. This allows the first gap 70 to fit the gap structure of the vehicle body, and the second gap 90 to completely insulate the corrosion sample 30 and the reference sample 40. After the base 10 is installed around the gap of the vehicle body, the corrosion status of the gap structure of the vehicle body can be simultaneously reflected by monitoring the corrosion of the first gap 70. Specifically, by monitoring the first current value between the corrosion sample 30 and the reference sample 40 and the second current value between the corrosion sample 30 and the substrate sample 20, and calculating the instantaneous corrosion rate and the cumulative corrosion loss at the current moment based on the first and second current values, online monitoring of the corrosion status of the vehicle body gap is achieved.

[0049] like Figure 7As shown, the above structure can be used to obtain the first current value I1 between the corrosion test piece 30 and the reference test piece 40, and the second current value I2 between the corrosion test piece 30 and the substrate test piece 20. The formula for calculating the instantaneous corrosion rate of the vehicle body gap is as follows:

[0050]

[0051] Where v is the instantaneous corrosion rate (g / cm³) 2 M is the molar mass of the vehicle body material (g), I1 is the first current value (A) between the corrosion test piece 30 and the reference test piece 40, I2 is the second current value (A) between the corrosion test piece 30 and the substrate test piece 20, n is the number of electrons released by the vehicle body element, e is the electron charge (C), N is Avogadro's constant, and S is the area of ​​the corrosion test piece in the sensor gap (cm²). 2 (square centimeters).

[0052] The formula for calculating the cumulative corrosion loss at the current moment is as follows:

[0053]

[0054] Where V is the cumulative corrosion loss (g / cm³) 2 M is the molar mass of the vehicle body material (g), I1 is the first current value (A) between the corrosion test piece 30 and the reference test piece 40, I2 is the second current value (A) between the corrosion test piece 30 and the substrate test piece 20, n is the number of electrons released by the vehicle body element, e is the electron charge (C), N is Avogadro's constant, and S is the area of ​​the corrosion test piece in the sensor gap (cm²). 2 , square centimeters), t is the cumulative time (s, seconds).

[0055] Since the base 10 is installed around the gaps in the vehicle body, the corrosion environment between the substrate sample 20, corrosion sample 30 and reference sample 40 inside the base 10 will be exactly the same as the corrosion environment of the gaps in the vehicle body. Therefore, the instantaneous corrosion rate and cumulative corrosion loss calculated above can fully reflect the corrosion situation at the gaps in the vehicle body, thereby realizing online monitoring of corrosion in the gaps in the vehicle body.

[0056] The cable 50 is a three-core shielded tin-plated cable. The three inner cores inside the cable 50 are respectively connected to the substrate test piece 20, the corrosion test piece 30, and the reference test piece 40. Specifically, the three inner cores can be fixedly installed on the substrate test piece 20, the corrosion test piece 30, and the reference test piece 40 with cross screws to ensure good electrical connection between the inner cores and each test piece.

[0057] In this embodiment, the first gasket 60 is made of a non-metallic material. The length and width of the first gasket 60 are adapted to the length and width of the substrate test piece 20, and the thickness of the first gasket 60 is consistent with the actual gap width of the train. Different thicknesses of the first gasket 60 can be selected based on different train models, so that the thickness of the first gap 70 is completely consistent with the thickness of the gap in the train body. Simultaneously, the first gasket 60 can also adjust the gap area. The first gasket 60 can be bonded between the corrosion test piece 30 and the substrate test piece 20 using strong adhesive to ensure a stable connection between the three and form the first gap 70, while also ensuring complete insulation between the corrosion test piece 30 and the substrate test piece 20. The gap area of ​​the first gap 70 is the area difference between the corrosion test piece 30 and the first gasket 60, i.e., the portion of the corrosion test piece 30 that is not bonded to the first gasket 60.

[0058] The second gasket 80 is also made of non-metallic material. The length and width of the second gasket 80 are matched with the length and width of the corrosion test piece 30. The thickness of the second gasket 80 can be set to 2.5 mm. The second gasket 80 can be bonded between the corrosion test piece 30 and the reference test piece 40 with strong adhesive to ensure a stable connection between the three and form a second gap 90. Based on the formation of the second gap 90, the corrosion test piece 30 and the reference test piece 40 can be in a completely insulating state without pores.

[0059] According to the online monitoring sensor for vehicle body crevice corrosion provided by the present invention, mounting grooves 110 are respectively constructed on opposite sides of the inner surface of the base 10. The mounting grooves 110 are arranged along the width direction of the base 10. The substrate sample 20, the first gasket 60, the corrosion sample 30, the second gasket 80 and the reference sample 40 are sequentially overlapped and snapped into the mounting grooves 110.

[0060] Understandably, by constructing the mounting groove 110, the two ends of the substrate specimen 20, the first gasket 60, the corrosion specimen 30, the second gasket 80, and the reference specimen 40 can be respectively engaged in the mounting groove 110. During assembly, the substrate specimen 20, the first gasket 60, the corrosion specimen 30, the second gasket 80, and the reference specimen 40 can be assembled first, and then the two ends of the shaped body can be respectively engaged in the mounting grooves 110 on both sides to achieve the assembly of the substrate specimen 20, the first gasket 60, the corrosion specimen 30, the second gasket 80, and the reference specimen 40.

[0061] Based on this structure, the base 10, the substrate sample 20, the first gasket 60, the corrosion sample 30, the second gasket 80, and the reference sample 40 are all set as rectangular sheet structures to facilitate the interconnection between the substrate sample 20, the first gasket 60, the corrosion sample 30, the second gasket 80, and the reference sample 40, and to facilitate the assembly of the substrate sample 20, the first gasket 60, the corrosion sample 30, the second gasket 80, and the reference sample 40 into the mounting groove 110.

[0062] like Figure 1 and Figure 2 As shown, a through-hole 120 is also constructed on the base 10. The cable 50 is adapted to pass through the through-hole 120 and the gap between the cable 50 and the through-hole 120, the substrate test piece 20, the first gasket 60, the corrosion test piece 30, the second gasket 80 and the reference test piece 40 is filled by the potting unit 130.

[0063] By constructing a through-hole 120, one end of the cable 50 is located inside the base 10, and the other end is located outside the base 10 for connection. After the substrate test piece 20, the first gasket 60, the corrosion test piece 30, the second gasket 80, the reference test piece 40, and the cable 50 are assembled inside the base 10, the gaps inside the base 10 are filled by the potting unit 130 to ensure internal sealing.

[0064] The potting unit 130 can be made of epoxy resin, rubber or plastic, and the epoxy resin, rubber or plastic is injected into the voids inside the base 10 by injection molding.

[0065] The base 10 has an open structure on the side where the first gap 70 and the second gap 90 are formed on each test piece, so that the first gap 70 can be installed in accordance with the gap structure of the vehicle body.

[0066] Please continue to refer to this. Figure 2 The substrate specimen 20 has a substrate connecting piece 210 on the side near the potting unit 130, the corrosion specimen 30 has a corrosion connecting piece 310 on the side near the potting unit 130, and the reference specimen 40 has a reference connecting piece 410 on the side near the potting unit 130. The substrate connecting piece 210, the corrosion connecting piece 310 and the reference connecting piece 410 are used to connect the cable 50, and the vertical projections of the substrate connecting piece 210, the corrosion connecting piece 310 and the reference connecting piece 410 are staggered.

[0067] The three inner cores of the three-core shielded tin-plated cable are electrically connected to the base connecting piece 210, the etched connecting piece 310, and the reference connecting piece 410, respectively. Each of the base connecting piece 210, the etched connecting piece 310, and the reference connecting piece 410 has threaded holes, and the three inner cores of the three-core shielded tin-plated cable are fixedly installed in these threaded holes using Phillips head screws. Alternatively, welding or other mechanical connections can be used to achieve the electrical connection between the three inner cores of the three-core shielded tin-plated cable and the base connecting piece 210, the etched connecting piece 310, and the reference connecting piece 410. Because the vertical projections of the base connecting piece 210, the etched connecting piece 310, and the reference connecting piece 410 are misaligned, their electrical connections do not interfere with each other.

[0068] like Figure 3-6 As shown, the base 10 is not limited to the above-described frame structure; the base 10 may also include a seat 140 and a top cover 150. A locking block 160 is constructed on the upper surface of the seat 140, and the top cover 150 is attached to the top of the seat 140. The substrate sample 20, the first gasket 60, the corrosion sample 30, the second gasket 80, and the reference sample 40 are sequentially overlapped and locked onto the locking block 160, and the top cover 150 is attached to the substrate sample 20.

[0069] The inner rings of the substrate specimen 20, the first gasket 60, the corrosion specimen 30, the second gasket 80, and the reference specimen 40 are limited by the locking block 160. The upper and lower positions of the substrate specimen 20, the first gasket 60, the corrosion specimen 30, the second gasket 80, and the reference specimen 40 are limited by the seat 140 and the top cover 150, so that the substrate specimen 20, the first gasket 60, the corrosion specimen 30, the second gasket 80, and the reference specimen 40 can be stably installed between the seat 140 and the top cover 150. The first gasket 60 and the second gasket 80 can form a first gap 70 and a second gap 90 between the substrate specimen 20, the corrosion specimen 30, and the reference specimen 40.

[0070] The outer diameters of the first gasket 60 and the second gasket 80 are smaller than the outer diameters of the substrate sample 20, the corrosion sample 30 and the reference sample 40, so as to facilitate the formation of the first gap 70 and the second gap 90.

[0071] like Figure 5 As shown, the locking block 160 includes at least two arc-shaped blocks, which are spaced apart along the circumference on the upper surface of the base 10. The substrate sample 20, the first gasket 60, the corrosion sample 30, the second gasket 80, and the reference sample 40 are each arc-shaped and have arc-shaped notches. These notches allow the substrate sample 20, the first gasket 60, the corrosion sample 30, the second gasket 80, and the reference sample 40 to be sequentially overlapped and locked onto at least two arc-shaped blocks, with the cable 50 threaded through the arc-shaped notches. The arc-shaped notches are suitable for being filled with potting units 130.

[0072] A circular arc notch is constructed so that one end of the cable 50 is located inside the base 10 and the other end is located outside the base 10 for connection. After the substrate test piece 20, the first gasket 60, the corrosion test piece 30, the second gasket 80, the reference test piece 40, and the cable 50 are assembled in the base 10, the circular arc notch is filled by the potting unit 130 to ensure overall sealing.

[0073] The potting unit 130 can be made of epoxy resin, rubber or plastic, and the epoxy resin, rubber or plastic can be injected into the arc-shaped notch by injection molding.

[0074] like Figure 4As shown, the inner circumferential surfaces of the substrate specimen 20, the corrosion specimen 30, and the reference specimen 40 are respectively provided with electrical connecting pieces for connecting the cable 50. The vertical projections of the electrical connecting pieces of the substrate specimen 20, the corrosion specimen 30, and the reference specimen 40 are misaligned.

[0075] The three inner cores of the three-core shielded tin-plated cable are electrically connected to the electrical connection plates of the substrate test piece 20, the corrosion test piece 30, and the reference test piece 40, respectively. Each of the substrate test piece 20, the corrosion test piece 30, and the reference test piece 40 has threaded holes, and the three inner cores of the three-core shielded tin-plated cable are fixedly installed in these threaded holes using Phillips head screws. Alternatively, welding or other mechanical connections can be used to achieve the electrical connection between the three inner cores of the three-core shielded tin-plated cable and the electrical connection plates of the substrate test piece 20, the corrosion test piece 30, and the reference test piece 40. Because the vertical projections of the electrical connection plates of the substrate test piece 20, the corrosion test piece 30, and the reference test piece 40 are misaligned, their electrical connections do not interfere with each other.

[0076] The outer surface of the base 10 is provided with support columns 170, which are adapted to connect to the surface of the vehicle body for adjusting the gap between the base 10 and the surface of the vehicle body. The support columns 170 can be configured as slender cylindrical structures, and four support columns 170 can be used. Four connecting holes are constructed on the outer surface of the base 10, and the four support columns 170 are respectively snapped into the four connecting holes. The support columns 170 connect the base 10 and the vehicle body, and are used to adjust the gap between the online monitoring sensor for vehicle body crevice corrosion and the vehicle body.

[0077] The substrate specimen 20 is made of the same material as the component at the location to be monitored, the corrosion specimen 30 is made of the same material as the vehicle body, and the reference specimen 40 is made of the same material as the corrosion specimen 30. This ensures that after installation, the substrate specimen 20, corrosion specimen 30, and reference specimen 40 not only have the same corrosion environment as the gap in the vehicle body, but also use the same corrosion material, which can fully reflect the corrosion situation at the gap in the vehicle body without the need for any other conversions.

[0078] The online monitoring method for vehicle body crevice corrosion provided by the present invention is described below. The online monitoring method for vehicle body crevice corrosion described below can be referred to in correspondence with the online monitoring sensor for vehicle body crevice corrosion described above.

[0079] like Figure 8 As shown, the online monitoring method for vehicle body crevice corrosion in this embodiment uses the online monitoring sensor for vehicle body crevice corrosion from the aforementioned embodiment for online monitoring, and includes the following steps:

[0080] S100. Install the vehicle body gap corrosion online monitoring sensor at the location of the vehicle body gap, and make the first gap 70 and the second gap 90 correspond to the vehicle body gap respectively.

[0081] S200. Measure the first current value between the corrosion test piece 30 and the reference test piece 40, and the second current value between the corrosion test piece 30 and the substrate test piece 20 using the current measurement unit.

[0082] S300: Based on the first current value and the second current value, obtain the instantaneous corrosion rate of the vehicle body gap and the cumulative corrosion loss at the current moment.

[0083] In this embodiment, the online monitoring sensor for vehicle body crevice corrosion described in the previous embodiment is used. A first gap 70 is formed between the substrate sample 20 and the corrosion sample 30 using a first gasket 60, and a second gap 90 is formed between the corrosion sample 30 and the reference sample 40 using a second gasket 80. This allows the first gap 70 to fit the crevice structure of the vehicle body, and the second gap 90 to completely insulate the corrosion sample 30 and the reference sample 40. After the base 10 is installed around the crevice of the vehicle body, the corrosion status of the crevice structure of the vehicle body can be simultaneously reflected by monitoring the corrosion of the first gap 70. Specifically, by monitoring the first current value between the corrosion sample 30 and the reference sample 40 and the second current value between the corrosion sample 30 and the substrate sample 20, and calculating the instantaneous corrosion rate and the cumulative corrosion loss at the current moment based on the first and second current values, online monitoring of the vehicle body crevice corrosion is achieved.

[0084] Specifically, the first current value between the corrosion test piece 30 and the reference test piece 40 is I1, the second current value between the corrosion test piece 30 and the substrate test piece 20 is I2, and the formula for calculating the instantaneous corrosion rate of the vehicle body gap is as follows:

[0085]

[0086] Where v is the instantaneous corrosion rate (g / cm³) 2 M is the molar mass of the vehicle body material (g), I1 is the first current value (A) between the corrosion test piece 30 and the reference test piece 40, I2 is the second current value (A) between the corrosion test piece 30 and the substrate test piece 20, n is the number of electrons released by the vehicle body element, e is the electron charge (C), N is Avogadro's constant, and S is the area of ​​the corrosion test piece in the sensor gap (cm²). 2 (square centimeters).

[0087] The formula for calculating the cumulative corrosion loss at the current moment is as follows:

[0088]

[0089] Where V is the cumulative corrosion loss (g / cm³) 2 M is the molar mass of the vehicle body material (g), I1 is the first current value (A) between the corrosion test piece 30 and the reference test piece 40, I2 is the second current value (A) between the corrosion test piece 30 and the substrate test piece 20, n is the number of electrons released by the vehicle body element, e is the electron charge (C), N is Avogadro's constant, and S is the area of ​​the corrosion test piece in the sensor gap (cm²). 2 , square centimeters), t is the cumulative time (s, seconds).

[0090] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. An online monitoring sensor for corrosion in vehicle body gaps, characterized in that, include: Base; A substrate specimen is mounted on the base, and the substrate specimen is made of the same material as the component at the location to be monitored. A corrosion test piece is installed on the base. The corrosion test piece is made of the same material as the vehicle body. A first gap is formed between the corrosion test piece and the base test piece by a first gasket. The thickness of the first gap is the same as the thickness of the gap in the vehicle body. A reference test piece is mounted on the base. The reference test piece is made of the same material as the corrosion test piece. A second gap is formed between the reference test piece and the corrosion test piece by a second gasket. Based on the formation of the second gap, the corrosion test piece and the reference test piece are in an insulating state and are free of pores. A cable is installed in the base. One end of the cable is electrically connected to the substrate test piece, the corrosion test piece, and the reference test piece inside the base. The other end of the cable extends out of the base and is connected to a current measuring unit. The current measuring unit is used to measure a first current value between the corrosion test piece and the reference test piece, and to measure a second current value between the corrosion test piece and the substrate test piece. The instantaneous corrosion rate of the vehicle body gap and the cumulative corrosion loss at the current moment are obtained based on the first current value and the second current value. The inner surface of the base has mounting grooves on opposite sides, which are arranged along the width of the base. The substrate test piece, the first gasket, the corrosion test piece, the second gasket, and the reference test piece are sequentially overlapped and snapped into the mounting grooves.

2. The online monitoring sensor for vehicle body crevice corrosion according to claim 1, characterized in that, The base is also provided with a through-hole, the cable is adapted to pass through the through-hole, and the gap between the cable and the through-hole, the substrate test piece, the first gasket, the corrosion test piece, the second gasket and the reference test piece is filled by a potting unit.

3. The online monitoring sensor for vehicle body crevice corrosion according to claim 2, characterized in that, The substrate specimen has a substrate connecting piece on the side near the potting unit, the corrosion specimen has a corrosion connecting piece on the side near the potting unit, and the reference specimen has a reference connecting piece on the side near the potting unit. The substrate connecting piece, the corrosion connecting piece, and the reference connecting piece are used to connect the cable, and the vertical projections of the substrate connecting piece, the corrosion connecting piece, and the reference connecting piece are misaligned with each other.

4. The online monitoring sensor for vehicle body crevice corrosion according to any one of claims 1-3, characterized in that, The outer surface of the base is provided with a support column, which is adapted to be connected to the surface of the vehicle body to adjust the gap between the base and the surface of the vehicle body.

5. A method for online monitoring of corrosion in vehicle body crevice, characterized in that, Online monitoring of vehicle body gap corrosion using the online monitoring sensor as described in any one of claims 1-4 includes the following steps: The online monitoring sensor for corrosion of vehicle body gaps is installed at the location of the gap in the vehicle body, and the first gap is aligned with the gap in the vehicle body. The first current value between the corrosion test piece and the reference test piece, and the second current value between the corrosion test piece and the substrate test piece are measured using a current measuring unit. The instantaneous corrosion rate of the vehicle body gap and the cumulative corrosion loss at the current moment are obtained based on the first current value and the second current value.

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