Bimetal composite pipe bonding strength testing device

Abstract

The utility model discloses a bimetal composite pipe bonding strength testing device which comprises a base, and a shearing mandrel, an outer cylinder and a power device are arranged on the base. The outer cylinder is fixed on the base, the outer cylinder is used for placing a to-be-tested composite tube sample, a plurality of grooves are formed in the inner surface of the outer cylinder, and the to-be-tested composite tube sample is fixed by the grooves; the outer cylinder and the shearing mandrel are coaxially arranged, the shearing mandrel is arranged close to one end of the outer cylinder, and the power device can drive the shearing mandrel to move in the axial direction of the outer cylinder and stretch into the outer cylinder; the composite pipe sample comprises an inner layer and an outer layer, and the shearing mandrel can apply shearing force to the inner layer of the composite pipe sample. The device can sample from a bimetal composite pipe product object, test a plurality of samples taken from the same bimetal composite pipe at the same time under the same condition, and effectively judge the reliability and repeatability of test data, and the outer cylinder is provided with the groove which can be clamped and fixed with the samples, so that the samples are clamped stably, the device is convenient to operate, and the test efficiency is improved. The test efficiency is high.

Description

Technical Field

[0001] The utility model relates to the field of bimetallic composite pipes, in particular to a bimetallic composite pipe bonding strength testing device. Background Art

[0002] Bimetallic composite pipes are typically constructed by cladding a carbon steel layer with a corrosion-resistant alloy layer. The carbon steel layer serves as the load-bearing bulk of the pipe, while the corrosion-resistant layer provides the primary corrosion protection. Due to their superior cost-effectiveness and corrosion resistance compared to pure corrosion-resistant alloy pipes, bimetallic composite pipes are a popular alternative to pure stainless steel, copper, or other corrosion-resistant alloy pipes. They are increasingly used in the exploration, development, and transportation of energy sources such as oil, natural gas, and coalbed methane, as well as in water supply and drainage systems for public projects. Currently, various methods exist for cladding bimetallic composite pipes, including mechanical cladding, cladding, plate-welded metallurgical cladding, and seamless metallurgical cladding. The bond strength of bimetallic composite pipes is a key performance indicator, and measuring this strength remains a widespread concern within the industry. Currently, standards such as GB / T 28897 "Steel-Plastic Composite Pipes" and SY / T 6855 "Bimetallic Composite Pipes for Gathering and Transportation Pipelines in Natural Gas Fields Containing H2S / CO2" set specific requirements for bond strength. While the aforementioned standards provide specific requirements for bond strength testing methods, they lack unified regulations for test equipment and specific recommended practices. Regarding testing devices and methods for the bond strength of bimetallic composite pipes, various domestic institutions have proposed different devices and corresponding test methods. These methods often utilize flat specimens and single-specimen test devices, resulting in low test efficiency and uncertainty regarding the repeatability and reliability of test results.

[0003] Therefore, it is urgent to provide a solution for a bimetallic composite pipe bonding strength testing device. Utility Model Content

[0004] In order to solve the above problems, the technical solution of the present utility model provides a bimetallic composite pipe bonding strength testing device, which can improve the detection efficiency.

[0005] According to a first embodiment of the technical solution of the present utility model, there is provided a bimetallic composite pipe bonding strength testing device, comprising a base, on which a shear mandrel, an outer cylinder and a power device are provided;

[0006] The outer cylinder is fixed on the base, and the outer cylinder is used to place the composite pipe sample to be tested. The inner surface of the outer cylinder is provided with a plurality of grooves, and the grooves fix the composite pipe sample to be tested;

[0007] The outer cylinder is coaxially arranged with the shearing mandrel, and the shearing mandrel is arranged close to one end of the outer cylinder. The power device can drive the shearing mandrel to move along the axial direction of the outer cylinder and extend into the interior of the outer cylinder;

[0008] The composite pipe sample includes an inner layer and an outer layer, and the shear mandrel is capable of applying a shear force to the inner layer of the composite pipe sample.

[0009] In the above solution, the grooves are evenly distributed along the circumference of the inner surface of the outer cylinder.

[0010] In the above solution, the groove is a dovetail groove.

[0011] In the above solution, the groove opens from one end of the outer cylinder, is arranged along the axial direction, and extends to the other end of the outer cylinder and is blocked.

[0012] In the above solution, the distance between the end of the groove at the end blocked by the outer tube and the blocked end of the outer tube is greater than 20 mm.

[0013] In the above solution, the power device includes a hydraulic cylinder and a hydraulic system. The hydraulic cylinder is fixedly arranged on the base, and the hydraulic system is connected to the hydraulic cylinder to drive the shear spindle to move.

[0014] In the above solution, the outer diameter of the shear mandrel is 0 to 0.2 mm smaller than the inner diameter of the outer cylinder.

[0015] In the above solution, a lubricating layer is provided on the inner surface of the outer cylinder and the outer surface of the shearing mandrel.

[0016] In the above solution, the shear mandrel is a solid cylindrical structure.

[0017] In the above solution, the shear mandrel is a hollow cylindrical structure with one end sealed and the other end open, and the open end faces the direction of the outer cylinder.

[0018] Beneficial effects of the utility model:

[0019] The utility model discloses a bimetallic composite pipe bonding strength testing device, which includes a shear mandrel, an outer cylinder and a power device. Samples can be taken from the actual bimetallic composite pipe product, and multiple samples taken from the same bimetallic composite pipe can be tested simultaneously under the same conditions, effectively judging the reliability and repeatability of the test data. The outer cylinder has a groove that can be engaged and fixed with the sample, so the sample clamping is stable, the device is easy to operate, and the testing efficiency is high. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the structures shown in these drawings without paying any creative work.

[0021] Figure 1 This is a schematic diagram of the overall structure of the bimetallic composite pipe bonding strength testing device provided by the utility model;

[0022] Figure 2 This is a schematic circumferential cross-sectional view of the outer cylinder of the bimetallic composite pipe bonding strength testing device provided by the present invention;

[0023] Figure 3 This is a schematic structural diagram of the outer cylinder of the bimetallic composite pipe bonding strength testing device provided by the present invention;

[0024] Figure 4 This is a schematic diagram of the structure of a group of test specimens of the bimetallic composite pipe bonding strength testing device provided by the utility model when assembled into the outer tube;

[0025] Figure 5 A schematic cross-sectional view of a composite pipe sample of the bimetallic composite pipe bonding strength testing device provided by the present invention;

[0026] Figure 6 This is a structural schematic diagram of a group of test specimens of the bimetallic composite pipe bonding strength testing device provided by the utility model.

[0027] Including: base-10; shear mandrel-20; outer cylinder-30; groove-31; hydraulic cylinder-40; hydraulic system-41; hydraulic gauge-411; composite pipe sample-50; outer layer-51; inner layer-52.

[0028] The realization of the purpose, functional features and advantages of the present invention will be further explained in conjunction with embodiments and with reference to the accompanying drawings. DETAILED DESCRIPTION

[0029] Exemplary embodiments will be described in detail herein, with examples illustrated in the accompanying drawings. In the following description, when referring to the drawings, identical numerals in different figures represent identical or similar elements, unless otherwise indicated. The embodiments described in the following exemplary embodiments are not intended to represent all possible embodiments consistent with the present disclosure. Rather, they are merely examples of apparatus and methods consistent with certain aspects of the present disclosure, as detailed in the appended claims.

[0030] The terms "first," "second," and the like in the description and claims of the present disclosure are used to distinguish similar objects and are not necessarily used to describe a particular order or precedence. It should be understood that the terms used in this manner are interchangeable where appropriate, such that the embodiments of the present disclosure described herein can, for example, be implemented in orders other than those illustrated or described herein.

[0031] In addition, the terms "comprises" and "having" and any variations thereof are intended to cover a non-exclusive inclusion. For example, a process, method, system, product or apparatus that includes a series of steps or elements is not necessarily limited to those steps or elements expressly listed but may include other steps or elements not expressly listed or inherent to such process, method, product or apparatus.

[0032] Multiple includes two or more.

[0033] It should be understood that the term "and / or" as used in this disclosure simply describes an association between related objects, indicating that three possible relationships exist. For example, "A and / or B" can represent three situations: A exists alone, A and B exist simultaneously, and B exists alone.

[0034] like Figures 1 to 3 As shown, an embodiment of the technical solution of the present utility model provides a bimetallic composite pipe bonding strength testing device, including a base 10, on which a shear mandrel 20, an outer cylinder 30 and a power device are provided.

[0035] The outer cylinder 30 is fixed on the base 10. The outer cylinder 30 is used to place the composite pipe sample 50 to be tested. The inner surface of the outer cylinder 30 is provided with a plurality of grooves 31, and the grooves 31 fix the composite pipe sample 50 to be tested. The outer cylinder 30 is coaxially arranged with the shear mandrel 20. The shear mandrel 20 is arranged close to one end of the outer cylinder 30. The power device can drive the shear mandrel 20 to move along the axial direction of the outer cylinder 30 and extend into the interior of the outer cylinder 30. The composite pipe sample 50 to be tested includes an outer layer 51 and an inner layer 52. The shear mandrel 20 can apply shear force to the inner layer 52.

[0036] The present invention can take samples from the actual product of the composite pipe sample 50, and test multiple samples taken from the same composite pipe at the same time under the same conditions, effectively judging the reliability and repeatability of the test data. In addition, the outer cylinder 30 is provided with a groove 31, which can be engaged and fixed with the composite pipe sample 50, so that the composite pipe sample 50 is stably clamped, the device is easy to operate, and the test efficiency is high.

[0037] In this embodiment, the grooves 31 are preferably evenly distributed along the circumference of the inner surface of the outer cylinder 30. Multiple grooves 31 can secure multiple composite pipe samples 50, allowing multiple composite pipe samples 50 to be tested in a single test. This improves testing efficiency and provides multiple test data points, making the test results more accurate. Preferably, there are 2 to 6 grooves 31, and more preferably, there are 6 grooves 31. Each groove 31 has the same size and spacing. Because each groove 31 has the same size and spacing, processing the composite pipe sample 50 is facilitated, allowing the composite pipe sample 50 to be secured within the outer cylinder 30.

[0038] In this embodiment, the groove 31 is preferably a dovetail groove, so the bottom area of ​​the figure formed by the groove 31 along the circumferential cross-section is larger than the opening area, presenting a trapezoidal shape. Therefore, the composite tube sample 50 will not fall after being fixed to the outer cylinder 30, ensuring that the outer cylinder 30 and the composite tube sample 50 remain stable during the test process, thereby improving the accuracy of the test results.

[0039] Specifically, one end of the outer cylinder 30 is open in the groove 31, which is arranged axially and extends to the other end of the outer cylinder 30, where it is blocked. That is, the groove 31 does not penetrate the other end of the outer cylinder 30. The distance between the end of the groove 31 at the end blocked by the outer cylinder 30 and the blocked end of the outer cylinder 30 is greater than 20 mm. Since the groove 31 is a dovetail groove, the composite tube sample 50 is inserted into the outer cylinder 30 through the groove 31 of the outer cylinder 30 for fixation. Moreover, the groove 31 is a non-through groove. During testing, the non-through portion of the outer cylinder 30 can resist the composite tube sample 50, providing a counterforce to the composite tube sample 50, thereby ensuring the axial stability of the composite tube sample 50 and preventing the composite tube sample 50 from falling out of the outer cylinder 30 due to the force applied to the composite tube sample 50. When fixing, it is necessary to first process the outer layer 51 of the composite tube sample 50 into a structure that is compatible with the groove 31.

[0040] Furthermore, the shearing mandrel 20 is located at an open end of the groove 31 .

[0041] In this embodiment, the power unit preferably includes a cylinder 40 and a hydraulic system 41. The cylinder 40 is fixedly mounted on the base 10. The hydraulic system 41 is connected to the cylinder 40 and is used to drive the shear mandrel 20. The hydraulic system 41 includes a hydraulic pressure gauge 411, which displays the hydraulic pressure during the process of driving the shear mandrel 20. Of course, the present invention can also use other power units to drive the shear mandrel 20, such as a motor.

[0042] In this embodiment, the outer diameter of the shearing mandrel 20 is preferably 0-0.2 mm smaller than the inner diameter of the outer cylinder 30 , so that the shearing mandrel 20 can move inside the outer cylinder 30 .

[0043] In this embodiment, a lubricating layer is preferably provided on the inner surface of the outer cylinder 30 and the outer surface of the shear mandrel 20. The lubricating layer is formed by applying lubricating oil to the inner surface of the outer cylinder 30 and the outer surface of the shear mandrel 20 to form an oil film. The lubricating layer facilitates the sliding of the shear mandrel 20 within the outer cylinder 30 and prevents excessive friction between the outer cylinder 30 and the shear mandrel 20 from affecting the experimental results.

[0044] In this embodiment, the shear mandrel 20 is a solid cylindrical structure, or a hollow cylindrical structure with one end sealed and the other open, with the open end of the shear mandrel 20 facing toward the outer cylinder 30. Regardless of the structure of the shear mandrel 20, the wall thickness of the shear mandrel 20 must be greater than the thickness of the inner layer 52 of the composite pipe specimen 50 to be tested. This ensures uniform stress on the inner layer 52 and ensures accurate test results.

[0045] In this embodiment, the outer tube 30 and the liquid cylinder 40 are welded and fixed on the base 10, wherein the outer tube 30 and the liquid cylinder 40 can be coaxially arranged in the horizontal direction or in the vertical direction, which is not limited here.

[0046] In this embodiment, outer cylinder 30 is made of carbon steel, with its inner surface chrome-plated, and shear mandrel 20 is made of cemented carbide. The outer cylinder 30 is hard and strong, providing strong support. Chromium also has strong wear resistance, and the chrome plating of the outer cylinder 30 increases its service life. The shear mandrel 20 is made of cemented carbide, offering high strength and preventing deformation and wear during testing that could affect test results.

[0047] like Figure 4 and Figure 5 As shown, in this embodiment, the test specimen is a section cut from the composite pipe specimen 50 to be tested and machined into an arc shape. The outer layer 51 is adapted to the groove 31, and the interface between the outer layer 51 and the inner layer 52 is flush with the circumferential opening of the groove 31. This allows the shear mandrel 20 to apply a shear force to the inner layer 52 after entering the outer cylinder 30 to test the bond strength between the inner layer 52 and the outer layer 51. The outer layer 51 is made of carbon steel and serves as the load-bearing body of the composite pipe specimen 50, while the inner layer 52 is made of a corrosion-resistant alloy and serves as the corrosion-resistant layer of the composite pipe specimen 50.

[0048] like Figures 1 to 6 As shown, according to the second embodiment of the technical solution of the present utility model, a testing method of the bonding strength testing device of the bimetallic composite pipe sample 50 as described above is provided, comprising:

[0049] S1. Select the outer cylinder 30 and the shear mandrel 20 according to the outer diameter and wall thickness of the composite pipe to be tested;

[0050] S2. Cutting a plurality of composite tube samples 50 from the composite tube to be tested according to the cross-sectional dimensions, axial depth, and number of the grooves of the outer cylinder 30;

[0051] S3. Setting the axial length of the inner layer 52 of the composite tube sample 50 and the axial spacing between the inner layers 52 of each composite tube sample 50;

[0052] S4, processing the inner layer 52 of the composite tube sample 50 according to the set value;

[0053] S5. Calculate the bonding interface area between the outer layer 51 and the inner layer 52 of the composite tube sample 50;

[0054] S6. Fix the composite tube samples 50 in the grooves 31 of the outer cylinder 30 in sequence at equal intervals according to the positions of the remaining inner layers 52 of the composite tube sample 50;

[0055] S7, start the power device to drive the shearing mandrel 20 to move axially along the outer cylinder 30 to shear the inner layer 52 of the composite tube sample 50, and record the data value of the power device during shearing;

[0056] S8. Calculate the bonding strength between the outer layer 51 and the inner layer 52 of the composite tube sample 50 based on the data value of the power device and the bonding interface area between the outer layer 51 and the inner layer 52 of the composite tube sample 50.

[0057] In step S1 , the outer cylinder 30 and the shear mandrel 20 with the most matching sizes are selected according to the outer diameter and the wall thickness of the composite tube sample 50 to be tested, thereby reducing the reprocessing of the composite tube sample 50 .

[0058] In step S2, the composite tube sample 50 is processed as follows: the curvature of the outer surface of the composite tube sample 50 is the same as the curvature of the groove 31, the thickness of the outer layer 51 is the same as the depth of the groove 31, the length of the composite tube sample 50 is the same as the axial depth of the groove 31, and the composite tube sample 50 is cut into an arc-shaped cylindrical sample in which the outer layer 51 matches the groove 31.

[0059] In step S3, specifically, the thickness of the inner layer 52 is greater than 1 mm, and the axial length is 4 to 6 mm, preferably 5 mm. During the test, the axial spacing between the inner layers 52 of two adjacent composite pipe samples 50 is greater than 10 mm, preferably 20 mm.

[0060] In step S4 , a section of the inner layer 52 needs to be retained according to the setting, and the remaining inner layer 52 is removed.

[0061] In step S6, the order in which the composite tube samples 50 are placed in the grooves 31 is determined based on the positions of the remaining inner layers 52. During the experiment, each inner layer 52 portion of the composite tube sample 50 is sheared one by one using the shear mandrel 20. This allows multiple composite tube samples 50 to be tested in a single test, which provides a more accurate calculation of the bond strength.

[0062] In step S7, since the distance between the inner layer 52 of each sample and the open end of the outer cylinder 30 is different, the shearing mandrel 20 shears the inner layer 52 of each sample in turn, and records the hydraulic pressure value of the hydraulic pressure gauge 411 when each sample is sheared.

[0063] In step S8 , the bonding strength is calculated as follows: bonding strength = shear force / shear area, where the shear force is the hydraulic pressure value * the cross-sectional area of ​​the shear mandrel 20 , and the shear area is the bonding interface area between the outer layer 51 and the inner layer 52 .

[0064] It should be noted that, in this document, the terms "comprises," "includes," or any other variations thereof are intended to encompass non-exclusive inclusion, such that a process, method, article, or apparatus comprising a series of elements includes not only those elements but also other elements not explicitly listed, or elements inherent to such process, method, article, or apparatus. In the absence of further limitations, an element defined by the phrase "comprising a ..." does not exclude the presence of other identical elements in the process, method, article, or apparatus comprising the element.

[0065] The serial numbers of the above embodiments of the present invention are for description only and do not represent the advantages or disadvantages of the embodiments.

[0066] Through the description of the above embodiments, those skilled in the art can clearly understand that the above implementation method can be implemented by means of software plus the necessary general hardware platform, or of course by hardware, but in many cases the former is a better implementation method. Based on this understanding, the technical solution of the present invention, or the part that contributes to the prior art, can be embodied in the form of a software product. The computer software product is stored in a storage medium (such as ROM / RAM, magnetic disk, optical disk), and includes a number of instructions for enabling a terminal (which can be a mobile phone, computer, server, air conditioner, or network device, etc.) to execute the methods described in each embodiment of the present invention.

[0067] The embodiments of the present invention are described above in conjunction with the accompanying drawings, but the present invention is not limited to the above-mentioned specific implementation methods. The above-mentioned specific implementation methods are merely illustrative and not restrictive. Under the guidance of the present invention, ordinary technicians in this field can also make many forms without departing from the scope of protection of the purpose of the present invention and the claims, which are all within the protection of the present invention.

Claims

1. A bimetallic composite pipe bonding strength testing device, characterized in that: It comprises a base, on which a shearing mandrel, an outer cylinder and a power device are arranged; The outer cylinder is fixed on the base, and the outer cylinder is used to place the composite pipe sample to be tested. The inner surface of the outer cylinder is provided with a plurality of grooves, and the grooves fix the composite pipe sample to be tested; The outer cylinder is coaxially arranged with the shearing mandrel, and the shearing mandrel is arranged close to one end of the outer cylinder. The power device can drive the shearing mandrel to move along the axial direction of the outer cylinder and extend into the interior of the outer cylinder; The composite pipe sample includes an inner layer and an outer layer, and the shear mandrel is capable of applying a shear force to the inner layer of the composite pipe sample.

2. The bimetallic composite pipe bonding strength testing device according to claim 1, characterized in that: The grooves are evenly distributed along the circumference of the inner surface of the outer cylinder.

3. The bimetallic composite pipe bonding strength testing device according to claim 1, characterized in that: The groove is a dovetail groove.

4. The bimetallic composite pipe bonding strength testing device according to claim 1, characterized in that: The groove opens from one end of the outer tube, is arranged along the axial direction, and extends to the other end of the outer tube and is blocked.

5. The bimetallic composite pipe bonding strength testing device according to claim 4, characterized in that: The distance between the end of the groove at the end blocked by the outer tube and the blocked end of the outer tube is greater than 20 mm.

6. The bimetallic composite pipe bonding strength testing device according to claim 1, characterized in that: The power device includes a hydraulic cylinder and a hydraulic system. The hydraulic cylinder is fixedly arranged on the base. The hydraulic system is connected to the hydraulic cylinder and is used to drive the shearing spindle to move.

7. The bimetallic composite pipe bonding strength testing device according to claim 1, characterized in that: The outer diameter of the shear mandrel is 0 to 0.2 mm smaller than the inner diameter of the outer cylinder.

8. The bimetallic composite pipe bonding strength testing device according to claim 1, characterized in that: A lubricating layer is provided on the inner surface of the outer cylinder and the outer surface of the shear mandrel.

9. The bimetallic composite pipe bonding strength testing device according to claim 1, characterized in that: The shearing mandrel is a solid cylindrical structure.

10. The bimetallic composite pipe bonding strength testing device according to claim 1, characterized in that: The shear mandrel is a hollow cylindrical structure with one end sealed and the other end open, and the open end faces the direction of the outer cylinder.

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