Stress corrosion cracking test device for pipes

Abstract

The utility model discloses a stress corrosion cracking test device for tubing, which comprises a container for holding corrosive medium, a fixing mechanism and a stress applying mechanism, a to-be-tested sample is installed in the container, the fixing mechanism is used for fixing the to-be-tested sample, and the stress applying mechanism is used for applying stress to the to-be-tested sample. And the stress applying mechanism is used for applying a tensile force along the axial direction of the to-be-tested sample to the to-be-tested sample. According to the stress corrosion testing device, gravity serves as stress, the stress applying mode is simple and effective, the stress size is convenient to adjust, and the diversified requirements of the stress corrosion testing device are met.

Description

Technical Field

[0001] The utility model relates to the technical field of stress corrosion cracking test, in particular to a stress corrosion cracking test device for pipes. Background Art

[0002] Stress corrosion cracking is caused by the combined effects of stress and corrosion. It involves three factors: metal, stress and environment. It is one of the main causes of component failure and has no obvious signs. It often brings catastrophic losses to the project. Accidents caused by stress corrosion occur frequently in various industries of industrial production, such as chemical, petroleum, aviation, papermaking and civil construction.

[0003] Stress corrosion cracking research is an important field of equipment anti-corrosion and safety and reliability research. Stress corrosion performance evaluation tests are usually carried out under continuous, high stress levels, and highly corrosive media conditions. According to different combinations of specimen types and loading forms, a variety of stress corrosion evaluation methods are given in existing corrosion standards. Each evaluation method has its focus and scope of application. For the same material, the results of different evaluation methods are sometimes not completely consistent. It is necessary to select the appropriate specimen type and loading form according to the actual situation in order to correctly evaluate the material performance.

[0004] Since the environmental media, stress forms and corrosion processes of components in actual service are not the same, each test device and method can only approximately simulate one type of stress corrosion situation. Therefore, the demand for stress corrosion test devices is very diverse, and the existing technology lacks stress corrosion cracking test devices for pipes. Utility Model Content

[0005] The purpose of the utility model is to provide a stress corrosion cracking test device for pipes.

[0006] The device is used to apply stress and corrosion to the pipe to obtain accurate test data results, so as to correctly evaluate the material performance.

[0007] The utility model is realized through the following technical solutions.

[0008] A stress corrosion cracking test device for pipes comprises a container for containing corrosive media, a fixing mechanism and a stress applying mechanism, wherein a sample to be tested is installed in the container, the fixing mechanism is used to fix the sample to be tested, and the stress applying mechanism is used to apply a tensile force along the axial direction of the sample to be tested to the sample to be tested.

[0009] As a further improvement of the present invention, the fixing mechanism includes two fixing components arranged in the container, and the two fixing components are respectively used to fix the upper and lower ends of the sample to be tested. One end of the fixing component fixed to the upper end of the sample to be tested is fixedly connected to the top of the container, and the other end is connected to the upper end of the sample to be tested. One end of the fixing component fixed to the lower end of the sample to be tested is connected to the lower end of the sample to be tested, and the other end is connected to the stress applying mechanism. The stress applying mechanism applies a tensile force to the sample to be tested in an axial downward direction along the sample to be tested.

[0010] As a further improvement of the utility model, a quantitative piece is detachably connected to the stress applying mechanism.

[0011] As a further improvement of the present invention, the stress applying mechanism includes a connecting rod and a tray sleeved on the connecting rod, the top end of the connecting rod is connected to the fixing assembly located at the lower end of the sample to be tested, and the tray is used to support the quantitative member.

[0012] As a further improvement of the present invention, the fixing assembly includes a fixedly connected mounting portion and a connecting portion, the mounting portion is connected to the sample to be tested, the connecting portion of the fixing assembly fixed to the upper end of the sample to be tested is fixedly connected to the top end of the container, and the connecting portion of the fixing assembly fixed to the lower end of the sample to be tested passes through the bottom end of the container and is connected to the connecting rod.

[0013] As a further improvement of the present invention, the mounting portion is recessed inwardly near one end of the sample to be tested to form a receiving groove, and at least one mounting hole is opened on the receiving groove. Both ends of the sample to be tested have connecting holes corresponding to the mounting holes, and fasteners pass through the mounting holes and the connecting holes to fix the sample to be tested on the fixing assembly.

[0014] As a further improvement of the utility model, at least one guide tube connected to the interior of the container is provided at the top of the container, and the guide tube is used to introduce or export the corrosive medium.

[0015] As a further improvement of the present invention, the flow guide tube includes a first flow guide tube and a second flow guide tube, and the length of the first flow guide tube passing into the container is greater than the length of the second flow guide tube passing into the container.

[0016] As a further improvement of the utility model, the corrosive medium is liquid or gas.

[0017] Beneficial effects of the utility model:

[0018] 1. The utility model provides a stress corrosion cracking test device for pipes, which uses gravity as stress. The stress application method is simple and effective, and the stress size is convenient to adjust, meeting the diversified needs of stress corrosion test devices.

[0019] 2. In the present invention, the fixing member passes through the mounting hole and the connecting hole to fix the sample to be tested on the fixing assembly, which not only has a stable structure but also makes it convenient to install and disassemble the fixing assembly and the sample to be tested. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] The following is a detailed description of the preferred implementation examples of the present invention with reference to the accompanying drawings to help understand the purpose and advantages of the present invention, wherein:

[0021] Figure 1 It is a schematic diagram of the structure of the utility model;

[0022] Figure 2 for Figure 1 A cross-sectional view of

[0023] Figure 3 This is a diagram of the connection structure between the fixing mechanism and the sample to be tested in the utility model;

[0024] Figure 4 It is a structural schematic diagram of the fixing component in the utility model;

[0025] Figure 5 It is a schematic diagram of the structure of the sample to be tested in the utility model;

[0026] In the figure:

[0027] 1. Container; 3. Fixing assembly; 31. Mounting portion; 31a. Receiving groove; 31b. Mounting hole; 32. Connecting portion; 4. Stress applying mechanism; 41. Connecting rod; 42. Tray; 5. Quantitative block; 61. First flow guide tube; 62. Second flow guide tube; 7. Sample to be tested; 71. Connecting hole; 8. Fixing member. DETAILED DESCRIPTION

[0028] The utility model is further described in detail below based on the accompanying drawings and implementation cases.

[0029] The directional terms such as up, down, left, right, front, back, front, back, top, bottom, etc. mentioned or may be mentioned in this specification are defined relative to the structures shown in the drawings. The words "inside" and "outside" refer to the direction toward or away from the geometric center of a specific component, respectively. They are relative concepts, and therefore may change accordingly according to different locations and different usage conditions. Therefore, these or other directional terms should not be interpreted as restrictive terms.

[0030] This embodiment provides a stress corrosion cracking test device for pipes, referring to Figures 1 to 5 , including a container 1 for containing corrosive media, a fixing mechanism and a stress applying mechanism 4. A sample 7 to be tested is installed in the container 1. The fixing mechanism is arranged in the container 1 and is used to fix the sample 7 to be tested. The stress applying mechanism 4 is used to apply a tensile force along the axial direction of the sample 7 to the sample 7 to be tested. When used specifically, it is only necessary to place the corrosive medium in the container and apply a tensile force to the sample to be tested to perform a stress corrosion cracking test on the sample to be tested.

[0031] The fixing mechanism includes two fixing components 3, which are respectively arranged at the top and bottom ends of the container 1. The two fixing components 3 are respectively used to fix the two ends of the sample to be tested 7. The two fixing components 3 are relatively arranged so that the sample to be tested 7 is arranged in a vertical state. One end of the fixing component 3 located at one end of the sample to be tested 7 is fixedly connected to the top of the container 1, and the other end is connected to the upper end of the sample to be tested 7. One end of the fixing component 3 located at the other end of the sample to be tested is connected to the lower end of the sample to be tested 7, and the other end is connected to the stress applying mechanism 4, that is, the stress applied by the stress applying mechanism 4 to the sample to be tested 7 is a tensile force axially downward to the sample to be tested 7. In this case, the stress applied by the stress applying mechanism 4 to the sample to be tested 7 is gravity.

[0032] At the same time, the stress applying mechanism 4 is detachably connected with a quantitative component 5, which has a certain mass. The magnitude of the tensile force can be changed by replacing the quantitative components 5 with different masses. Not only is the implementation simple, but the magnitude of the tensile force can be accurately controlled by using gravity, which helps to improve the accuracy of the test.

[0033] Furthermore, the stress applying mechanism 4 includes a connecting rod 41 and a tray 42 sleeved on the outside of the connecting rod 41. The top end of the connecting rod 41 is connected to the fixing component 3 located at the lower end of the sample 7 to be tested. The tray 42 is used to support the quantitative piece 5 so that the gravity of the quantitative piece 5 can be directly applied to the stress applying mechanism 4. The stress applying mechanism 4 provides a downward tensile force to the sample 7 to be tested through the fixing component 3 fixed to the lower end of the sample 7 to be tested. When it is necessary to change the stress according to the test standard, it is only necessary to replace the quantitative piece 5 that meets the standard.

[0034] In this embodiment, the fixing component 3 includes an integrally formed mounting portion 31 and a connecting portion 32. The mounting portions 31 of the two fixing components 3 are connected to the sample to be tested 7. The connecting portion 32 of the fixing component 3 for fixing the upper end of the sample to be tested 7 is fixedly connected to the top of the container 1, and the upper end of the sample to be tested 7 is fixed to the top of the container 1. The connecting portion 32 of the fixing component 3 for fixing the lower end of the sample to be tested 7 passes through the bottom end of the container 1 and is connected to the connecting rod 41, so that the stress applying mechanism 4 can apply a downward tensile force to the sample to be tested 7.

[0035] Furthermore, the mounting portion 31 is recessed inwardly at one end close to the sample 7 to be tested to form a receiving groove 31a, into which the sample 7 to be tested can be inserted. The receiving groove 31a is provided with at least one mounting hole 31b, and both ends of the sample 7 to be tested have connecting holes 71 corresponding to the mounting holes 31b. The fixing component 3 and the sample 7 to be tested are fixedly connected by a fixing member 8 passing through the mounting hole 31b and the connecting hole 71. When the sample 7 to be tested needs to be replaced, the fixing component 3 and the sample 7 to be tested can be separated by pulling out the fixing member 8.

[0036] In this embodiment, the corrosive medium in the container 1 can be selected according to different test standards, and the corrosive medium can be gas or liquid; at the same time, the mass of the quantitative component 5 can also be selected according to different test standards. The quantitative component 5 is preferably a weight. Since different weights have different calibrated masses, different stresses can be applied to the sample 7 to be tested by arranging weights of different masses on the tray 42. The implementation is simple and the operation is convenient.

[0037] At the same time, in order to facilitate the transmission of corrosive media, at least one guide pipe is provided at the top of the container 1, which leads from the outside of the container 1 to the inside of the container 1. Through the guide pipe, the corrosive medium can be introduced into the container 1 or discharged out of the container 1 without removing the upper cover of the container 1.

[0038] Preferably, the flow guide pipe includes a first flow guide pipe 61 and a second flow guide pipe 62. The first flow guide pipe 61 is closer to the bottom of the container 1 than the second flow guide pipe 62. When the corrosive medium is a gas, the corrosive medium is transported into the container 1 by the first flow guide pipe 61. Since the first flow guide pipe 61 is closer to the bottom of the container 1 than the second flow guide pipe 62, the corrosive medium input into the container 1 from the first flow guide pipe 61 gradually fills the entire container 1 from the bottom of the container 1, so that the impurity gas in the container 1 is discharged from the second flow guide pipe 62.

[0039] Finally, it should be noted that the above implementation cases are only used to illustrate the technical solutions of the utility model, rather than to limit it. Although the utility model has been described in detail with reference to the above implementation cases, ordinary technicians in this field should understand that they can still modify the technical solutions recorded in the above implementation cases, or replace some of the technical features therein with equivalents. These modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the implementation cases of the utility model.

Claims

1. A stress corrosion cracking test device for pipes, characterized in that: The invention comprises a container (1) for containing a corrosive medium, a fixing mechanism and a stress applying mechanism (4); a sample to be tested (7) is installed in the container (1); the fixing mechanism is used to fix the sample to be tested (7); and the stress applying mechanism (4) is used to apply a tensile force along the axial direction of the sample to be tested (7) to the sample to be tested (7).

2. A stress corrosion cracking test device for pipes according to claim 1, characterized in that: The fixing mechanism comprises two fixing components (3) arranged in the container (1), the two fixing components (3) being used to fix the upper and lower ends of the sample to be tested (7) respectively; the fixing component (3) fixed to the upper end of the sample to be tested (7) has one end fixedly connected to the top of the container (1) and the other end connected to the upper end of the sample to be tested (7); the fixing component (3) fixed to the lower end of the sample to be tested (7) has one end connected to the lower end of the sample to be tested (7) and the other end connected to the stress applying mechanism (4); the stress applying mechanism (4) applies a tensile force to the sample to be tested (7) in a downward direction along the axial direction of the sample to be tested (7).

3. A stress corrosion cracking test device for pipes according to claim 2, characterized in that: The stress applying mechanism (4) is detachably connected to a quantitative component (5).

4. A stress corrosion cracking test device for pipes according to claim 3, characterized in that: The stress applying mechanism (4) comprises a connecting rod (41) and a tray (42) sleeved on the connecting rod (41); the top end of the connecting rod (41) is connected to the fixing assembly (3) located at the lower end of the sample to be tested (7); and the tray (42) is used to support the quantitative member (5).

5. A stress corrosion cracking test device for pipes according to claim 4, characterized in that: The fixing assembly (3) comprises a mounting portion (31) and a connecting portion (32) which are fixedly connected, the mounting portion (31) being connected to the sample to be tested (7), the connecting portion (32) of the fixing assembly (3) fixed to the upper end of the sample to be tested (7) being fixedly connected to the top end of the container (1), and the connecting portion (32) of the fixing assembly (3) fixed to the lower end of the sample to be tested (7) passing through the bottom end of the container (1) and being connected to the connecting rod (41).

6. A stress corrosion cracking test device for pipes according to claim 5, characterized in that: The mounting portion (31) is recessed inwardly at one end close to the sample to be tested (7) to form a receiving groove (31a), and at least one mounting hole (31b) is provided on the receiving groove (31a). Both ends of the sample to be tested (7) are provided with connecting holes (71) corresponding to the mounting holes (31b), and a fastener (8) passes through the mounting holes (31b) and the connecting holes (71) to fix the sample to be tested (7) on the fixing assembly (3).

7. A stress corrosion cracking test device for pipes according to claim 1, characterized in that: The top of the container (1) is provided with at least one guide pipe connected to the interior of the container (1), and the guide pipe is used to introduce or export the corrosive medium.

8. A stress corrosion cracking test device for pipes according to claim 7, characterized in that: The flow guide pipe comprises a first flow guide pipe (61) and a second flow guide pipe (62), and the length of the first flow guide pipe (61) passing into the container (1) is greater than the length of the second flow guide pipe (62) passing into the container (1).

9. A stress corrosion cracking test device for pipes according to any one of claims 1 to 8, characterized in that: The corrosive medium is liquid or gas.

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