Stress-electrochemical corrosion loading device

Abstract

The invention discloses a stress-electrochemical corrosion loading device, which relates to the technical field of building structure working environment simulation devices, and comprises a loading component and a corrosion device, the loading component comprises a stress ring, a test piece clamp, a shear bolt and a tensile bolt; wherein the stress ring is provided with a plurality of sample mounting grooves arranged at intervals, a test piece clamp for fixing a test piece is arranged in each sample mounting groove, and the two ends of each test piece clamp fix the test piece in the corresponding sample mounting groove through a vertical shear bolt and a horizontal tensile bolt respectively; the corrosion device comprises a sealed corrosion box, a sealing rubber ring gasket, a power supply, a wire and a graphite flake; wherein the power supply is connected with the test piece and the graphite flake through the lead to form an electrochemical corrosion loop. According to the invention, different corrosion environments can be truly and effectively simulated, and the corrosion period is shortened, so that the guiding significance of a test result on actual engineering is improved.

Description

Technical Field

[0001] The invention relates to the technical field of building structure working environment simulation devices, and more specifically to a stress-electrochemical corrosion loading device. Background Art

[0002] Corrosion is a problem that accompanies the entire life cycle of steel structures. The actual corrosion forms of space steel structures in strong corrosive environments are complex and diverse, including overall uniform corrosion and local non-uniform corrosion. Local corrosion includes pitting corrosion, crevice corrosion, intergranular corrosion, etc. Due to factors such as the mechanical response and uneven stress distribution of space steel structures under various environmental loads and mechanical loads (such as wave loads, machine vibrations, operating loads, etc.), the probability of local corrosion forms in structural components is far higher than that of uniform corrosion forms. On the other hand, local corrosion can cause stress concentration and weaken the cross-section of components, which is far more harmful to space steel structures than uniform corrosion.

[0003] Studies have shown that stress can amplify initial defects, intensify the expansion of corrosion cracks, and promote the occurrence and development of corrosion. Therefore, studying the harmfulness of stress corrosion is of utmost importance. Since the mechanism and simulation methods of stress corrosion are not yet mature, experimental methods have become an important means of studying stress corrosion problems.

[0004] Salt spray corrosion test is an environmental test that mainly uses artificial simulated salt spray environment conditions created by salt spray test equipment to evaluate the corrosion resistance of metal materials. Compared with the natural environment, the corrosion rate in the salt spray environment is greatly increased, and the time to obtain results is greatly shortened. However, since the salt spray accelerated corrosion test chamber cannot provide stress to the test object inside it, stress corrosion test cannot be performed.

[0005] In this regard, engineers came up with the idea of ​​using a reaction frame in a salt spray accelerated corrosion test chamber to provide stress to the test object and achieve stress corrosion of the test object. The reaction frame is a common mechanical device that can receive and balance external forces to maintain the balance and stability of the structure.

[0006] Although the existing test method of applying the reaction frame to the salt spray accelerated corrosion test chamber can simulate stress corrosion conditions to a certain extent, it has certain limitations: (1) Although the salt spray accelerated corrosion test can simulate the corrosion conditions in the marine environment or the salty atmospheric environment, its environmental simulation ability is relatively limited and it is difficult to fully reflect the actual corrosion process of the material in the complex and changeable natural environment; (2) The corrosion test cycle of the salt spray accelerated corrosion test is relatively long, and the stress corrosion test results cannot be obtained in a short time; (3) The components of the existing reaction frame are usually welded and fixed, and the volume specifications are large, and they cannot be disassembled or moved at will, which cannot meet the relatively flexible stress corrosion test requirements. Summary of the invention

[0007] The purpose of the present invention is to provide a stress-electrochemical corrosion loading device to alleviate the above technical problems existing in the prior art.

[0008] To achieve the above object, the present invention adopts the following technical solution:

[0009] A stress-electrochemical corrosion loading device comprises: a loading component and a corrosion device; the loading component comprises a stress ring, a specimen fixture, a shear bolt and a tensile bolt; wherein the stress ring is provided with a plurality of specimen mounting grooves arranged at intervals, a specimen fixture for fixing the specimen is provided in the specimen mounting groove, and the specimen is fixed in the specimen mounting groove at both ends of the specimen fixture by vertical shear bolts and horizontal tensile bolts respectively; the corrosion device comprises a sealed corrosion box, a sealing rubber ring gasket, a power supply, a wire and a graphite sheet; wherein the power supply is connected to the specimen and the graphite sheet through the wire to form an electrochemical corrosion circuit.

[0010] Furthermore, through holes penetrating the side wall of the stress ring are provided at both ends of the sample mounting groove, the tensile bolt passes through the through holes, and the nut is connected to the protruding end of the tensile bolt and abuts against the outer wall of the stress ring.

[0011] Furthermore, the specimen fixture includes two end fixtures, which include a U-shaped piece and a reinforcement piece. Two clamps extend from the open end of the U-shaped piece. The end of the specimen and the reinforcement piece are fixed between the two clamps of the corresponding U-shaped piece through shear bolts and nuts in sequence. A threaded fixing hole is provided on the side wall of the non-open end of the U-shaped piece, and the tensile bolt extends through the threaded fixing hole and penetrates the through hole of the stress ring.

[0012] Furthermore, an opening for adding the corrosion solution and a specimen through-hole are provided on one side of the corrosion box, and the specimen can pass through the through-hole. The sealing rubber ring gasket is arranged between the specimen and the through-hole and is sealed with silicone glue.

[0013] Furthermore, the power supply adopts a DC regulated power supply, and the circuit is completed by connecting the test piece and the graphite sheet through the wire. The wire includes a positive wire and a negative wire. The positive wire is connected to the test piece by electric welding or tape fixing, and the negative wire is connected to the graphite sheet by electric welding or tape fixing, forming an electrochemical corrosion circuit.

[0014] Furthermore, the test piece is abutted against the tensile bolts on both sides, and torque is applied to the tensile bolts to adjust the load applied to the test piece, and the load is kept unchanged during the corrosion test.

[0015] Furthermore, four sample mounting grooves are evenly spaced on the stress ring, and the corrosion box is made of acrylic material.

[0016] Furthermore, the tensile bolts are arranged along the length direction of the specimen.

[0017] On the other hand, the present application also claims protection for a working method of the stress-electrochemical corrosion loading device as described above, comprising the following steps:

[0018] Step 1: Pass the graphite sheet and the test piece horizontally through the perforation of the acrylic corrosion box, and seal them with a sealing rubber ring and silicone glue. Connect the end of the test piece to the positive electrode wire by welding or tape fixing. Connect the graphite sheet to the negative electrode wire by the same fixing method and place it in the corrosion box.

[0019] Step 2, assembling the specimen and the stress ring; first, fix the specimen to the end clamps on both sides with shear bolts, then pass the tensile bolts through the end threaded fixing holes and the through holes, a nut is screwed on the protruding end of the tensile bolt, and torque is applied to the tensile bolt to adjust the load applied to the specimen;

[0020] Step 3: Pour the corrosion solution into the corrosion box, connect the positive wire to the positive pole of the power supply, connect the negative wire to the negative pole of the power supply, and turn on the power to form an electrochemical corrosion circuit.

[0021] Furthermore, the method further comprises the following steps:

[0022] Step 4: After the corrosion test is completed, the corrosion solution in the corrosion box is discharged to the wastewater treatment tank through a conduit, the shear bolts and tensile bolts are removed, the stress ring and the specimen fixture are disassembled, and the silicone glue on the corrosion box is removed before it can be reused.

[0023] Compared with the prior art, this application has achieved the following beneficial technical effects:

[0024] The stress-electrochemical corrosion loading device provided by the present invention can simulate different corrosion environments more realistically and effectively by adding different corrosion solutions into an acrylic corrosion box compared to the salt spray test of the prior art (different corrosion environments can be simulated by adding different corrosion solutions), and the electrochemical corrosion cycle is shorter than that of the salt spray test. After the stress ring provided by the present invention is assembled with the specimen, it can load prestress to the specimen in a self-balanced manner without the help of external force. Compared with the traditional reaction frame device, the device of the present application is small in size, easy to process, and simple and fast to operate. In addition, the stress-electrochemical corrosion loading device provided by the present invention can be disassembled and reused, and can be applied to specimens of different sizes by changing the thickness of the reinforcement, and has stronger applicability. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] In order to more clearly illustrate the specific implementation methods of the present invention or the technical solutions in the prior art, the drawings required for use in the specific implementation methods or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some implementation methods of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0026] Figure 1 It is an overall schematic diagram of the stress-electrochemical corrosion loading device according to an embodiment of the present invention;

[0027] Figure 2 is an overall schematic diagram of a loading device according to an embodiment of the present invention;

[0028] Figure 3 It is an exploded schematic diagram of a test piece and a test piece fixture according to an embodiment of the present invention;

[0029] Figure 4 is an overall schematic diagram of the corrosion device according to an embodiment of the present invention;

[0030] Icons: 1-stress ring; 11-specimen mounting groove; 12-through hole; 2-specimen fixture; 21-U-shaped piece; 211-threaded fixing hole; 22-reinforcement piece; 31-shear bolt; 32-tension bolt; 33-nut; 41-acrylic corrosion box; 411-specimen perforation; 42-sealing rubber ring gasket; 43-power supply; 44-wire; 441-positive wire; 442-negative wire; 45-graphite sheet; 5-specimen. DETAILED DESCRIPTION

[0031] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Generally, the components of the embodiments of the present invention described and shown in the drawings here can be arranged and designed in various different configurations.

[0032] Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the invention claimed for protection, but merely represents selected embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0033] It should be noted that like reference numerals and letters denote similar items in the drawings, and therefore, once an item is defined in one drawing, further definition and explanation thereof is not required in subsequent drawings.

[0034] In the description of the present invention, it should be noted that the terms "upper", "lower", "vertical", "horizontal", "inside", "outside", etc. indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, or are the orientations or positional relationships in which the inventive product is usually placed when used. They are only for the convenience of describing 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, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention.

[0035] In addition, the terms "horizontal" and "vertical" do not mean that the components must be absolutely horizontal or suspended, but can be slightly tilted. For example, "horizontal" only means that its direction is more horizontal than "vertical", which does not mean that the structure must be completely horizontal, but can be slightly tilted.

[0036] In the description of the present invention, it is also necessary to explain that, unless otherwise clearly specified and limited, the terms "setting", "installation" and "connection" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a direct connection, or an indirect connection through an intermediate medium, or it can be a communication between the two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0037] Some embodiments of the present invention are described in detail below in conjunction with the accompanying drawings. In the absence of conflict, the following embodiments and features in the embodiments can be combined with each other.

[0038] This embodiment provides a stress-electrochemical corrosion loading device, referring to Figures 1 to 4 , comprising: a loading component and a corrosion device 4; the loading component comprises a stress ring 1, a specimen fixture 2, a shear bolt 31 and a tensile bolt 32; wherein the stress ring 1 is provided with a plurality of specimen mounting grooves 11 arranged at intervals, the specimen mounting groove 11 is provided with a specimen fixture 2 for fixing the specimen 5, and the two ends of the specimen fixture 2 are respectively fixed to the specimen 5 in the specimen mounting groove 11 by means of a vertical shear bolt 31 and a horizontal tensile bolt 32;

[0039] The corrosion device 4 includes a sealed corrosion box 41, a sealing rubber ring gasket 42, a power supply 43, a wire 44 and a graphite sheet 45; wherein the power supply 43 is connected to the test piece 5 and the graphite sheet 45 through the wire 44 to form an electrochemical corrosion circuit.

[0040] Among them, Figure 1 and Figure 2As shown, the stress ring 1 is horizontally provided with four rounded rectangular sample mounting grooves 11 arranged in sequence and spaced apart along the length direction, and two through holes 12 penetrating the stress ring along the hole direction are provided in the middle position of the upper and lower ends of the sample mounting groove 11, and the tensile bolt 32 passes through the through hole 12, and a nut 33 is screwed on the protruding end of the tensile bolt 32, and the nut 33 abuts against the outer wall of the stress ring 1 to provide stress support, and a specimen fixture 2 for fixing the specimen 5 is provided in the sample mounting groove 11.

[0041] Reference Figures 1 to 3 The specimen fixture 2 includes two end fixtures, and the end fixtures include a U-shaped piece 21 and a reinforcement piece 22. The end of the specimen is fixed between the two clamps of the corresponding U-shaped piece 21 through a shear bolt 31 and a nut 33. A threaded fixing hole 211 is provided in the middle of the non-open end of the U-shaped piece 21, and the tensile bolt 32 passes through the threaded fixing hole 211 and penetrates the stress ring through hole 12 and extends out; the reinforcement piece 22 is placed between the specimen 5 and the U-shaped piece 21, and specimens of different thicknesses can be fixedly loaded by adjusting the thickness of the reinforcement piece; the two ends of the specimen are abutted against the end fixtures on both sides through the shear bolts 31, and a pre-tightening force is generated in the bolts by applying torque to the tensile bolts 32, thereby adjusting the load applied to the metal specimen 5, and keeping the load unchanged during the corrosion test.

[0042] like Figure 4 As shown, the acrylic corrosion box 41 has an opening on one side for pouring the corrosion solution, and specimen through-holes 411 are arranged on both sides along the width direction, and the specimen 5 can pass through the through-holes. The sealing rubber ring gasket 42 is arranged between the specimen 5 and the through-holes 411, and is sealed with silicone glue to prevent leakage during the electrochemical corrosion process. The acrylic corrosion box 41 has a simple structure and is easy to produce, process and reuse.

[0043] like Figure 1 and Figure 4 As shown, the power supply 43 adopts a DC regulated power supply, and is connected to the test piece 5 and the graphite sheet 45 through the wire 44 to complete the circuit. The wire 44 includes a positive wire 441 and a negative wire 442. The positive wire 441 is connected to the test piece 5 by welding or tape fixing, and the negative wire 442 is also connected to the graphite sheet 45 by welding or tape fixing to realize the electrochemical corrosion circuit.

[0044] The test specimen stress-electrochemical corrosion test method comprises the following steps:

[0045] Step 1, pass the test piece 5 horizontally through the perforation 411 of the acrylic etching box, and seal it with a sealing rubber ring gasket 42 and silicone glue, connect the end of the test piece to the positive electrode wire 441 by welding or tape fixing, and connect the graphite sheet 45 to the negative electrode wire 442 by the same fixing method and place it in the acrylic etching box;

[0046] Step 2, assemble the test piece 5 and the stress ring 1 according to the above assembly relationship, first use the shear bolts 31 to fix the test piece to the test piece fixtures on both sides, then make the tension bolts 32 pass through the end fixture threaded fixing holes 211 and the stress ring through holes 12, and the nut 33 is screwed on the protruding end of the tension bolt 32, and the load applied to the metal test piece is adjusted by applying torque to the tension bolt 32;

[0047] Step 3, pour the corrosion solution into the acrylic corrosion box 41, connect the positive wire 441 to the positive electrode of the power supply, connect the negative wire 442 to the negative electrode of the power supply, and turn on the power supply 43 to form an electrochemical corrosion circuit;

[0048] Step 4: After the corrosion test is completed, the corrosion solution in the corrosion box 41 is discharged to the wastewater treatment tank through a conduit, the shear bolts 31 and the tensile bolts 32 are removed, the stress ring 1 and the specimen fixture 2 are disassembled, and the silicone glue on the corrosion box is removed and can be reused.

[0049] In addition, in some embodiments, during the process of applying torque to the tensile bolt to stress the test specimen, the magnitude of the applied torque can be determined according to the following formula:

[0050] M t =K·P0·d

[0051] Among them, M t is the tightening torque of the tensile bolt; K is the tightening torque coefficient, which can be confirmed by strain gauge calibration before formal loading, and the value range is 0.18~0.21; P0 is the target stress on the surface of the test section of the specimen; d is the nominal diameter of the nut.

[0052] Finally, it should be noted that: the various embodiments in this specification are described in a progressive manner, and each embodiment focuses on the differences from other embodiments, and the same or similar parts between the various embodiments can be referenced to each other; the above embodiments in this specification are only used to illustrate the technical solution of the present invention, rather than to limit it; although the present invention has been described in detail with reference to the aforementioned embodiments, ordinary technicians in this field should understand that: it is still possible to modify the technical solutions recorded in the aforementioned embodiments, or to replace some or all of the technical features therein with equivalents; and these modifications or replacements do not make the essence of the corresponding technical solution deviate from the scope of the technical solution of the embodiments of the present invention.

Claims

1. A stress-electrochemical corrosion loading device, characterized in that: include: Loading components and corrosion devices (4); The loading component comprises a stress ring (1), a specimen fixture (2), a shear bolt (31) and a tensile bolt (32); wherein the stress ring (1) is provided with a plurality of specimen installation grooves (11) arranged at intervals, a specimen fixture (2) for fixing a specimen (5) is provided in the specimen installation groove (11), and the specimen fixture (2) is used to fix the specimen (5) in the specimen installation groove (11) at both ends thereof by means of vertical shear bolts (31) and horizontal tensile bolts (32); The corrosion device (4) comprises a sealed corrosion box (41), a sealing rubber ring gasket (42), a power source (43), a wire (44) and a graphite sheet (45); wherein the power source (43) is connected to the test piece (5) and the graphite sheet (45) via the wire (44) to form an electrochemical corrosion circuit.

2. The stress-electrochemical corrosion loading device according to claim 1, characterized in that: Through holes (12) penetrating the side wall of the stress ring (1) are provided at both ends of the sample installation groove (11); the tension bolt (32) passes through the through hole (12); and a nut (33) is connected to the protruding end of the tension bolt (32) and abuts against the outer wall of the stress ring (1).

3. The stress-electrochemical corrosion loading device according to claim 2, characterized in that: The specimen fixture (2) comprises two end fixtures, each of which comprises a U-shaped piece (21) and a reinforcement piece (22). Two clamps extend from the open end of the U-shaped piece (21). The end of the specimen (5) and the reinforcement piece (22) are fixed between the two clamps of the corresponding U-shaped piece (21) through shear bolts (31) and nuts (33) in sequence. A threaded fixing hole (211) is provided on the side wall of the non-open end of the U-shaped piece (21). The tension bolt (32) passes through the threaded fixing hole (211) and extends through the through hole (12) of the stress ring (1).

4. The stress-electrochemical corrosion loading device according to claim 3, characterized in that: An opening for adding a corrosion solution and a specimen through-hole (411) are provided on one side of the corrosion box (41), and the specimen (5) can pass through the through-hole (411). The sealing rubber ring gasket (42) is provided between the specimen (5) and the through-hole (411) and is sealed with silicone glue.

5. The stress-electrochemical corrosion loading device according to claim 4, characterized in that: The power source (43) is a DC regulated power source, and is connected to the test piece (5) and the graphite sheet (45) through the wire (44) to complete a circuit. The wire (44) includes a positive wire (441) and a negative wire (442). The positive wire (441) is connected to the test piece (5) by welding or fixing with an adhesive tape, and the negative wire (442) is connected to the graphite sheet (45) by welding or fixing with an adhesive tape, thereby forming an electrochemical corrosion circuit.

6. The stress-electrochemical corrosion loading device according to claim 5, characterized in that: The test piece (5) is in contact with the tensile bolts (32) on both sides, and torque is applied to the tensile bolts (32) to adjust the load applied to the test piece (5), and the load is kept unchanged during the corrosion test.

7. The stress-electrochemical corrosion loading device according to claim 6, characterized in that: The stress ring (1) is provided with four sample installation grooves (11) at equal intervals, and the corrosion box (41) is made of acrylic material.

8. The stress-electrochemical corrosion loading device according to claim 7, characterized in that: The tensile bolts (32) are arranged along the length direction of the test piece (5).

9. A working method of the stress-electrochemical corrosion loading device according to claim 8, characterized in that: The steps include: Step 1, passing the graphite sheet (45) and the test piece (5) horizontally through the through hole (411) of the acrylic etching box (41), and sealing with a sealing rubber ring gasket (42) and silicone adhesive, connecting the end of the test piece to the positive electrode wire (441) by electric welding or tape fixing, and connecting the graphite sheet (45) to the negative electrode wire (442) by the same fixing method and placing it in the etching box (41); Step 2, assembling the test piece (5) and the stress ring (1); first, using the shear bolts (31) to fix the test piece (5) to the end clamps on both sides, and then passing the tension bolts (32) through the end threaded fixing holes (211) and the through holes (12), a nut is screwed on the protruding end of the tension bolt (32), and a torque is applied to the tension bolt (32) to adjust the load applied to the test piece (5); Step 3: Pour the corrosion solution into the corrosion box (41), connect the positive wire (441) to the positive electrode of the power supply, connect the negative wire (442) to the negative electrode of the power supply, and turn on the power supply (43) to form an electrochemical corrosion circuit.

10. A working method of the stress-electrochemical corrosion loading device according to claim 9, characterized in that: The following steps are also included: Step 4: After the corrosion test is completed, the corrosion solution in the corrosion box (41) is discharged to the wastewater treatment tank through a conduit, the shear bolts (31) and the tension bolts (32) are removed, the stress ring (1) and the specimen fixture (2) are disassembled, and the silicone glue on the corrosion box (41) is removed and can be reused.

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