Inter-crystalline corrosion test vessel suitable for aluminum alloy fastener

Abstract

The invention discloses an intergranular corrosion test vessel suitable for an aluminum alloy fastener, which comprises a bushing (1), a core sleeve (2) and a support rod (3). Threads are arranged in the lining (1), threads are arranged outside the core sleeve (2), the core sleeve (2) is screwed into the lining (1), and a plurality of supporting rods (3) are arranged in the core sleeve (2). According to the invention, the vertical height can be adjusted, the beaker does not need to be replaced, the solution is saved, the requirements in GB7998 that the ratio of the surface area of a sample to the volume of the test solution is less than 20mm < 2 > / ml and the sample and the container as well as the sample cannot be in contact with each other can be met, and the accuracy and the test efficiency of the salt spray test are improved.

Description

Technical Field

[0001] The invention belongs to the technical field of test vessels, and in particular relates to a test vessel suitable for intergranular corrosion of aluminum alloy fasteners. Background Art

[0002] Intergranular corrosion is a localized corrosion that mainly destroys the bonding between grains and greatly reduces the mechanical strength of the metal. After corrosion, the metal and alloy surfaces still maintain a certain metallic luster, and it is impossible to detect signs of damage in time. It is a very dangerous corrosion behavior. Therefore, intergranular corrosion is crucial in the inspection of aluminum alloy fasteners. Among the existing standards, GB7998 "Determination Method for Intergranular Corrosion of Aluminum Alloys" has detailed provisions on its specific methods and requirements, requiring a constant temperature of 35℃±2℃, the sample is suspended with a plastic wire and completely immersed in the test solution, and the ratio between the sample surface area and the volume of the test solution is less than 20mm 2 / ml, the sample cannot contact the container or each other. According to relevant standards, when each batch is less than 10,000 pieces, the intergranular corrosion test is 5 pieces, and when each batch is greater than 10,000 pieces, the intergranular corrosion test is 10 pieces. In the current test, it was found that when using plastic wire, the fasteners can only be tied and then hung in the beaker with a glass rod. When hanging, the test fasteners in the beaker are easy to contact with the inner wall of the beaker and the fasteners, affecting the accuracy of the test. Secondly, in order to meet the ratio of the sample surface area to the test solution volume is less than 20mm 2 / mlThis requirement requires that the beaker be replaced when testing large-size fasteners. However, there is currently no test vessel suitable for intergranular corrosion of aluminum alloy materials for fasteners. Summary of the invention

[0003] The purpose of the present invention is to overcome the above disadvantages and provide a beaker that can be adjusted up and down, without the need to replace the beaker, saving solution, and also meeting the requirement of GB7998 that the ratio between the surface area of ​​the sample and the volume of the test solution should be less than 20mm 2 / ml, the sample and container and the samples cannot contact each other, which improves the accuracy and efficiency of the salt spray test and is suitable for the intergranular corrosion test vessel of aluminum alloy fasteners.

[0004] The purpose of the present invention and the solution of its main technical problems are achieved by adopting the following technical solutions: The invention discloses an intergranular corrosion test vessel for aluminum alloy fasteners, comprising a bushing, a core sleeve and support rods, and is characterized in that threads are arranged inside the bushing, threads are arranged outside the core sleeve, the core sleeve is screwed into the bushing, and a plurality of support rods are arranged inside the core sleeve.

[0005] The bushing is made of glass.

[0006] The core sleeve is made of glass.

[0007] The core sleeve can be moved up and down in the bushing for adjustment.

[0008] Compared with the prior art, the present invention has obvious beneficial effects; it can be known from the above technical scheme that: by providing a thread inside the bushing, providing a thread outside the core sleeve, screwing the core sleeve into the bushing, and providing a plurality of support rods inside the core sleeve. Through the cooperation of the internal and external thread structures on the external glass bushing and the internal glass core sleeve, the height of the sample in the solution can be adjusted to ensure that the sample does not contact the container wall. There are several support rods. During the intergranular corrosion test, the glass bushing is first placed in a constant temperature water bath. If the fastener to be tested has a cavity, such as a nut, a washer, etc., it can be directly hung on the support rod of the glass core sleeve. If it is a fastener without a cavity structure, it is hung on the support rod of the glass core sleeve with the assistance of a plastic rope, and then the core sleeve and the bushing are assembled and adjusted to a suitable height according to the size of the sample to be tested. The bushing has an external dimension of 250mm in diameter and 180mm in height, and a groove dimension of 230mm in diameter and 160mm in height. The internal thread is tapped downward from the end face of the groove, with a thread dimension of M12 and a depth of 100mm. See the schematic diagram of the external glass bushing for details. Figure 2 Internal glass core sleeve: Its external dimensions are 230mm in diameter, 160mm in height, M12 in outer thread at the lower end, and 100mm in depth. There are several support rods on the inner wall of the core sleeve, which can adjust the height up and down, without changing the beaker, saving solution, and meeting the requirement of GB7998 that the ratio of the sample surface area to the test solution volume should be less than 20mm 2 / ml, the sample and container and the samples cannot contact each other, which improves the accuracy and efficiency of the salt spray test. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] Figure 1 It is a schematic diagram of the structure of the present invention; Figure 2 It is a structural schematic diagram of the bushing of the present invention; Figure 3 It is a structural schematic diagram of the core sleeve of the present invention; Figure 4 It is a usage state diagram of the present invention.

[0010] Marking in the figure 1. Bushing, 2. Core sleeve, 3. Support rod, 4. Cavity fastener. DETAILED DESCRIPTION

[0011] The specific implementation methods, structures, features and functions of the present invention are described in detail below in conjunction with the accompanying drawings and preferred embodiments.

[0012] The present invention is a test vessel for intergranular corrosion of aluminum alloy fasteners, comprising a bushing 1, a core sleeve 2, and a support rod 3, and is characterized in that: a thread is arranged inside the bushing 1, a thread is arranged outside the core sleeve 2, the bushing 1 is screwed into the core sleeve 2, a plurality of support rods 3 are arranged inside the core sleeve 2, the bushing 1 is made of glass, the core sleeve 2 is made of glass, and the core sleeve 2 can be moved up and down in the bushing 1 for adjustment.

[0013] When using, first put the glass bushing 1 in a constant temperature water bath. If the cavity fastener 4 to be tested, such as a nut or washer, can be directly hung on the support rod 3 of the glass core sleeve 2. If it is a fastener without a cavity structure, use a plastic rope to help hang it on the support rod 3 of the glass core sleeve 2. Then assemble the core sleeve 2 and bushing 3, adjust the cavity fastener 4 or the fastener without a cavity structure to a suitable height, and then add a certain amount of test solution.

[0014] The above description is only a preferred embodiment of the present invention and does not limit the present invention in any form. Any simple modification, equivalent change and modification made to the above embodiment according to the technical essence of the present invention without departing from the technical solution of the present invention still falls within the scope of the technical solution of the present invention.

Claims

1. A vessel suitable for an intergranular corrosion test of aluminum alloy fasteners, comprising a bushing (1), a core sleeve (2), and a support rod (3), characterized in that: The bushing (1) is provided with a thread inside, the core sleeve (2) is provided with a thread outside, the bushing (1) is screwed into the core sleeve (2), and a plurality of support rods (3) are provided inside the core sleeve (2).

2. The intergranular corrosion test vessel for aluminum alloy fasteners according to claim 1, characterized in that: The bushing (1) is made of glass.

3. The intergranular corrosion test vessel for aluminum alloy fasteners according to claim 1, characterized in that: The core sleeve (2) is made of glass.

4. The intergranular corrosion test vessel for aluminum alloy fasteners according to claim 1, characterized in that: The core sleeve (2) can be moved up and down in the bushing (1) for adjustment.

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