A sample clamping device and test method for thin plate impact performance testing

Abstract

The present invention relates to a sample clamping device and a test method for testing the impact performance of a thin plate, and belongs to the field of metallurgical testing technology. The device comprises a jaw support block (1), a fastening bolt (2), a clamping hook (3), a gasket (4), and a sample recess (7). The device is fixed to a crossbeam (5) and an impact test bench (6) by means of the fastening bolt (2) and the clamping hook (3). By adopting a sample clamping device for testing the impact performance of a thin plate, a method for testing the impact performance of a thin plate is carried out, thereby solving the problem that the sample is prone to warping during the impact process when evaluating the low-temperature brittleness of a high-strength thin steel plate in a Charpy impact test, thereby achieving the evaluation of the low-temperature impact strength of the high-strength thin steel plate and ensuring the accuracy of the test results. The device is simple to manufacture and easy to operate.

Description

Technical Field

[0001] The invention relates to a sample clamping device and a test method for thin plate impact performance detection, belonging to the technical field of metallurgical detection. Background Art

[0002] The vehicle manufacturing industry has strict requirements on the low-temperature brittleness of high-strength thin steel plates. The secondary processing brittleness (SWE) test is a test method to evaluate the drop hammer impact performance of stamped mild steel plates under different temperature conditions. It can be used to evaluate the low-temperature brittleness performance of mild steel. This test uses machining to make a thin disc into a cup shape and make the cup edge flat. For high-strength steel plates, because their stamping performance is quite different from that of mild steel, cracking is easy to occur during the process of punching cup-shaped specimens. Therefore, secondary processing brittleness is not suitable for evaluating the low-temperature brittleness performance of high-strength thin steel plates.

[0003] The Charpy impact test is the most common method for evaluating toughness and ductile-brittle transition temperature. It can be used to evaluate the low-temperature brittleness of high-strength steel, but it has specific requirements for the thickness of the sample. According to the "Metal Charpy Notch Impact Test Method" (GB / T229-2007), the thickness of the standard sample is usually 10mm and the minimum thickness is 2.5mm. However, the thickness of advanced high-strength steel thin plates is generally less than 2.5mm, because the sample is prone to warping during the impact process (such as Figure 5 As shown in the figure, it affects the accuracy of the test results. Therefore, it is necessary to design an auxiliary device and test method for detecting the impact performance of thin plates on a pendulum impact tester to solve the problem that the sample is prone to warping during the impact process of the Charpy impact test to evaluate the low-temperature brittleness of high-strength thin steel plates, and ensure the accuracy of the test results. Summary of the invention

[0004] The technical problem to be solved by the present invention is a sample clamping device and a test method for thin plate impact performance testing, which solves the problem that sample warping is prone to occur during the impact process of the Charpy impact test for evaluating the low-temperature brittleness of high-strength thin steel plates, thereby ensuring the accuracy of the test results.

[0005] The technical solution to this technical problem is:

[0006] A sample clamping device for thin plate impact performance testing includes an impact test bench crossbeam, an impact test bench, and also includes a jaw support block, a fastening bolt, a clamping hook, a gasket, and a sample recess. The jaw support block is a long strip of steel plate, and a sample recess is arranged on one side of the steel plate. The shape of the gasket matches the sample. One end of the clamping hook is a connected steel plate with a bolt hole, and the other end is provided with a C-shaped hook structure hook body. The fastening bolt is matched and assembled with the bolt hole on the clamping hook.

[0007] The sample concave platform has a length of 23-30 mm and a depth of 0.01-0.4 mm. Since the thickness of the thin plate sample is not fixed, the function of the concave platform is to maintain a gap with the sample after the gasket of the same thickness as the sample is matched and the fastening bolts are tightened, so that the sample will not be stuck by the clamping device during impact. When used, it is used together with the gasket. The gasket and the sample are prepared at the same time and have the same thickness. The gap between the concave platform and the platform is greater than the thickness of the sample.

[0008] The clamping hook is provided with 2-3 C-shaped hook structures.

[0009] Based on the thin plate impact performance testing method using the sample clamping device for thin plate impact performance testing, the testing steps are as follows:

[0010] a. Prepare thin plate impact specimens (8);

[0011] b. The gasket (4) is made of the same material, and the shape of the gasket (4) is consistent with the shape of the sample without a notch;

[0012] c. Place the jaw support block (1) on the impact test bench crossbeam (5) of the impact test bench (6), with the side with the sample recess (7) facing downwards, and place it on the inner side of the test bench crossbeam (5), and place the gasket (4) between the jaw support block (1) and the impact test bench crossbeam (5) on the side not on the sample recess (7); insert the clamping hook (3) into the jaw support block (1) and the impact test bench crossbeam (5), with the lower C-shaped hook structure hooking the lower end surface of the impact test bench crossbeam (5), and the upper part is fastened to the upper end surface of the jaw support block (1) by the fastening bolt (2), and the fastening bolt (2) is tightened; on the other side of the impact test bench crossbeam (5) of the impact test bench (6), set another set of sample clamping devices according to the above steps;

[0013] d. Adjust the position between the two sets of clamping devices to ensure that the upper surfaces of the two sets of sample concave tables (7) are at the same level;

[0014] e. Adjust the distance between the two sets of clamping devices to ensure that the distance between the opposite sides of the two sets of jaw support blocks (1) is 20-30 mm, and ensure that the platform spacing is greater than the thickness of the pendulum passing through the platform;

[0015] f. The thickness of the concave portion (7) of the test specimen should match that of the test specimen (8), which can be adjusted by adding a 0.1 mm thick steel plate;

[0016] g. Turn on the testing machine, perform 3 to 4 dry punches according to the test requirements, and then use the notched pliers provided with the testing machine to place the specimen (8) in the middle position along the gap between the clamping module and the platform to start the test.

[0017] The thickness of the test sample ranges from 0.5 to 2.5 mm.

[0018] The testing machine adopts a Charpy V-type (or U-type) notch impact testing machine, the blade arc radius is 2 mm, and the impact energy is 30-100 joules.

[0019] The beneficial effects of the present invention are as follows: the device has the characteristics of simple manufacture, convenient operation and stable results. By using the experimental method of the device, the problem of sample warping easily occurring during the impact process of the Charpy impact test for evaluating the low-temperature brittleness of high-strength thin steel plates is solved, and the evaluation of the low-temperature impact strength of high-strength thin steel plates is realized, thereby ensuring the accuracy of the test results. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 is a schematic diagram of the device of the present invention;

[0021] Figure 2 It is a front view of the device of the present invention;

[0022] Figure 3 is a side view of the device of the present invention;

[0023] Figure 4 It is a schematic diagram of the assembly of the device of the present invention and the impact test bench (single side);

[0024] Figure 5 It is a schematic diagram of the assembly of the device of the present invention and the impact test bench (double-sided and including samples);

[0025] Figure 6 This is a diagram of the assembly and use of the device of the present invention and a Charpy V-notch impact testing machine;

[0026] Figure 7 It is a partial enlarged view of the device of the present invention being assembled and used with a Charpy V-notch impact testing machine;

[0027] Figure 8 This is a front view of the jaw support block of the present invention;

[0028] Fig. 9 is a top view of the jaw support block of the present invention;

[0029] Fig.10 This is a front view of the clamping hook of the present invention;

[0030] Fig.11 is a side view of the clamping hook of the present invention;

[0031] Markings in the figure: jaw support block 1, fastening bolt 2, clamping hook 3, gasket 4, impact test bench crossbeam 5, impact test bench 6, sample concave table 7, test specimen 8. DETAILED DESCRIPTION

[0032] The invention is further described in detail below with reference to the accompanying drawings and specific implementation methods.

[0033] Example 1

[0034] The device was used to measure the impact of 1300MPa grade material samples in an undeformed state at 10 temperatures, 20℃, 10℃, 0℃, -10℃, -20℃, -30℃, -40℃, -50℃, -60℃, and -70℃. A non-standard sample of 55×1.2×10 mm was used, and the depth of the V-notch was 2 mm. The test machine used was a Charpy V-notch impact tester, with a blade arc radius of 2 mm and an impact energy of 100J.

[0035] A sample clamping device for thin plate impact performance testing includes an impact test bench crossbeam 5, an impact test bench 6, a jaw support block 1, a fastening bolt 2, a clamping hook 3, a gasket 4, and a sample recess 7. The jaw support block 1 is a long strip of steel plate, and a sample recess 7 is provided on one side of the steel plate. The shape of the gasket 4 matches the sample 8. The end of the clamping hook 3 is a conjoined steel plate, which is provided with a bolt hole, and a C-shaped hook structure is provided at one end. The fastening bolt 2 is matched with the bolt hole on the clamping hook 3. The sample recess 7 has a length of 25 mm and a depth of 0.2 mm. The clamping hook 3 is provided with two C-shaped hook structures.

[0036] Based on the thin plate impact performance testing method using this device, the testing steps are:

[0037] a. Prepare a thin plate impact specimen 8, the specimen is a non-standard specimen of 55×1.2×10 mm, and the depth of the V-notch is 2 mm;

[0038] b. The gasket 4 is made of the same material as the sample, and the shape of the gasket 4 is consistent with the shape of the sample without a notch;

[0039] c. Place the jaw support block 1 on the impact test bench crossbeam 5 of the impact test bench 6, with the side with the sample recess 7 facing downwards, on the inner side of the test bench crossbeam 5, and place the gasket 4 on the side between the jaw support block 1 and the impact test bench crossbeam 5 that is not the sample recess 7; insert the clamping hook 3 into the jaw support block 1 and the impact test bench crossbeam 5, with the lower C-shaped hook structure hook body hooking the lower end surface of the impact test bench crossbeam 5, and the upper part is fastened to the upper end surface of the jaw support block 1 by the fastening bolt 2, and the fastening bolt 2 is tightened; set another set of sample clamping devices on the other side of the impact test bench crossbeam 5 of the impact test bench 6 according to the above steps;

[0040] d. Adjust the position between the two sets of clamping devices to ensure that the upper surfaces of the two sets of sample concave tables 7 are on the same horizontal plane;

[0041] e. Adjust the distance between the two sets of clamping devices to ensure that the distance between the opposite sides of the two sets of jaw support blocks (1) is 20 mm;

[0042] f. Whether the thickness of the concave portion 7 of the test sample matches that of the sample 8 can be adjusted by adding a 0.1mm thick thin steel plate;

[0043] g. Turn on the testing machine, and after performing three dry strikes according to the test requirements, use the notched pliers provided with the testing machine to place the specimen 8 in the middle position along the gap between the clamping module and the platform to start the test.

[0044] The test results are shown in Table 1

[0045] Table 1 Result data of sample impact test

[0046]

[0047] Example 2

[0048] The device was used to measure the impact of 1300MPa grade material samples under 3% pre-stretching conditions at 20℃, 10℃, 0℃, -10℃, -20℃, -30℃, -40℃, -50℃, -60℃, and -70℃, a total of 10 temperature conditions. A 55×1.2×10mm non-standard sample was used, and the V-notch depth was 2mm. The test machine used was a Charpy V-notch impact tester, the blade arc radius was R2, and the impact energy was 50J.

[0049] A sample clamping device for thin plate impact performance testing includes an impact test bench crossbeam 5, an impact test bench 6, a jaw support block 1, a fastening bolt 2, a clamping hook 3, a gasket 4, and a sample recess 7. The jaw support block 1 is a long strip of steel plate, and a sample recess 7 is provided on one side of the steel plate. The shape of the gasket 4 matches the sample 8. The end of the clamping hook 3 is a conjoined steel plate, which is provided with a bolt hole, and a C-shaped hook structure is provided at one end. The fastening bolt 2 is matched with the bolt hole on the clamping hook 3. The sample recess 7 has a length of 23 mm and a depth of 0.01 mm. The clamping hook 3 is provided with two C-shaped hook structures.

[0050] Based on the thin plate impact performance testing method using this device, the testing steps are:

[0051] a. Prepare a thin plate impact specimen 8, the specimen is a non-standard specimen of 55×0.5×10 mm, and the V-notch depth is 2 mm;

[0052] b. The gasket 4 is made of the same material as the sample, and the shape of the gasket 4 is consistent with the shape of the sample without a notch;

[0053] c. Place the jaw support block 1 on the impact test bench crossbeam 5 of the impact test bench 6, with the side with the sample recess 7 facing downwards, on the inner side of the test bench crossbeam 5, and place the gasket 4 on the side between the jaw support block 1 and the impact test bench crossbeam 5 that is not the sample recess 7; insert the clamping hook 3 into the jaw support block 1 and the impact test bench crossbeam 5, with the lower C-shaped hook structure hook body hooking the lower end surface of the impact test bench crossbeam 5, and the upper part is fastened to the upper end surface of the jaw support block 1 by the fastening bolt 2, and the fastening bolt 2 is tightened; set another set of sample clamping devices on the other side of the impact test bench crossbeam 5 of the impact test bench 6 according to the above steps;

[0054] d. Adjust the position between the two sets of clamping devices to ensure that the upper surfaces of the two sets of sample concave stages 7 are at the same level;

[0055] e. Adjust the distance between the two sets of clamping devices to ensure that the distance between the opposite sides of the two sets of jaw support blocks (1) is 30 mm;

[0056] f. Test whether the thickness of the concave portion 7 of the sample matches that of the sample 8;

[0057] g. Turn on the testing machine, perform three dry strikes according to the test requirements, and then use the notched pliers provided with the testing machine to place the specimen 8 in the middle position along the gap between the clamping module and the platform to start the test.

[0058] The test results are shown in Table 2

[0059] Table 2 Result data of impact test of 3% pre-stretched specimen

[0060]

[0061] Example 3

[0062] The device was used to measure the impact of 1300MPa grade material samples under 6% pre-stretching conditions at 20℃, 10℃, 0℃, -10℃, -20℃, -30℃, -40℃, -50℃, -60℃, and -70℃. A non-standard sample of 55×1.2×10mm was used, and the depth of the V-notch was 2mm. The test machine used was a Charpy V-notch impact tester, with a blade arc radius of R2 and an impact energy of 30J.

[0063] A sample clamping device for thin plate impact performance testing includes an impact test bench crossbeam 5, an impact test bench 6, a jaw support block 1, a fastening bolt 2, a clamping hook 3, a gasket 4, and a sample recess 7. The jaw support block 1 is a long strip of steel plate, and a sample recess 7 is provided on one side of the steel plate. The shape of the gasket 4 matches the sample 8. The end of the clamping hook 3 is a conjoined steel plate, which is provided with a bolt hole, and a C-shaped hook structure is provided at one end. The fastening bolt 2 is matched with the bolt hole on the clamping hook 3. The sample recess 7 has a length of 30 mm and a depth of 0.4 mm. The clamping hook 3 is provided with two C-shaped hook structures.

[0064] Based on the thin plate impact performance testing method using this device, the testing steps are:

[0065] a. Prepare a thin plate impact specimen 8, the specimen is a non-standard specimen of 55×2.5×10 mm, and the depth of the V-notch is 2 mm;

[0066] b. The gasket 4 is made of the same material as the sample, and the shape of the gasket 4 is consistent with the shape of the sample without a notch;

[0067] c. Place the jaw support block 1 on the impact test bench crossbeam 5 of the impact test bench 6, with the side with the sample recess 7 facing downwards, on the inner side of the test bench crossbeam 5, and place the gasket 4 between the jaw support block 1 and the impact test bench crossbeam 5 on the side other than the sample recess 7; insert the clamping hook 3 into the jaw support block 1 and the impact test bench crossbeam 5, with the lower C-shaped hook structure hook body hooking the lower end surface of the impact test bench crossbeam 5, and the upper part fastened to the upper end surface of the jaw support block 1 by the fastening bolt 2, and tighten the fastening bolt 2; set another set of sample clamping devices on the other side of the impact test bench crossbeam 5 of the impact test bench 6 according to the above steps;

[0068] d. Adjust the position between the two sets of clamping devices to ensure that the upper surfaces of the two sets of sample concave tables 7 are on the same horizontal plane;

[0069] e. Adjust the distance between the two sets of clamping devices to ensure that the distance between the opposite sides of the two sets of jaw support blocks (1) is 25 mm;

[0070] f. Check whether the thickness of the concave portion 7 of the test specimen matches that of the specimen 8. This can be adjusted by adding a 0.1 mm thin steel plate;

[0071] g. Turn on the testing machine, perform three dry strikes according to the test requirements, and then use the notched pliers provided with the testing machine to place the specimen 8 in the middle position along the gap between the clamping module and the platform to start the test.

[0072] The test results are shown in Table 3

[0073] Table 3 Result data of impact test of 6% pre-stretched specimen

[0074]

[0075] The device has the characteristics of simple production, easy operation and stable results. By using the experimental method of the device, the problem of sample warping easily occurring during the impact process of the Charpy impact test for evaluating the low-temperature brittleness of high-strength thin steel plates is solved, and the low-temperature impact strength of high-strength thin steel plates is evaluated, thereby ensuring the accuracy of the test results.

Claims

1. A sample clamping device for thin plate impact performance testing, characterized in that The invention comprises a jaw support block (1), a fastening bolt (2), a clamping hook (3), a gasket (4), and a sample recess (7). The jaw support block (1) is a long strip of steel plate, and a sample recess (7) is arranged on one side of the steel plate. The gasket (4) is located between the jaw support block (1) and the impact test bench crossbeam (5) on the side other than the sample recess (7), and its shape matches that of the test specimen (8). One end of the clamping hook (3) is a connected steel plate, and a bolt hole is arranged on the other end. A C-shaped hook structure is arranged on the other end. The fastening bolt (2) is assembled to match the bolt hole on the clamping hook (3). After the sample recess (7) is matched with a gasket (4) of the same thickness as the test specimen (8), when the fastening bolt is tightened, a gap can be maintained between the sample recess (7) and the test specimen (8), so that the test specimen will not be stuck by the clamping device during impact.

2. The sample clamping device for thin plate impact performance testing as claimed in claim 1, characterized in that The sample concave platform (7) has a length of 23-30 mm and a depth of 0.01-0.4 mm.

3. The sample clamping device for thin plate impact performance testing as claimed in claim 1, characterized in that The clamping hook (3) is provided with 2-3 C-shaped hook structures.

4. A method for testing the impact performance of a thin plate based on the sample clamping device for testing the impact performance of a thin plate according to claim 1, 2 or 3, characterized in that: The detection steps are: a. Prepare thin plate impact specimens (8); b. The gasket (4) is made of the same material, and the shape of the gasket (4) is consistent with the shape of the sample without a notch; c. Place the jaw support block (1) on the impact test bench crossbeam (5) of the impact test bench (6), with the side with the sample recess (7) facing downwards, and place it on the inner side of the test bench crossbeam (5), and place the gasket (4) between the jaw support block (1) and the impact test bench crossbeam (5) on the side not on the sample recess (7); insert the clamping hook (3) into the jaw support block (1) and the impact test bench crossbeam (5), with the lower C-shaped hook structure hooking the lower end surface of the impact test bench crossbeam (5), and the upper part is fastened to the upper end surface of the jaw support block (1) by the fastening bolt (2), and the fastening bolt (2) is tightened; on the other side of the impact test bench crossbeam (5) of the impact test bench (6), set another set of sample clamping devices according to the above steps; d. Adjust the position between the two sets of clamping devices to ensure that the upper surfaces of the two sets of sample concave tables (7) are at the same level; e. Adjust the distance between the two sets of clamping devices to ensure that the distance between the opposite sides of the two sets of jaw support blocks (1) is 20-30 mm; f. The thickness of the concave portion (7) of the test specimen should match that of the test specimen (8), which can be adjusted by adding a 0.1 mm thick steel plate; g. Turn on the testing machine, perform 3 to 4 dry punches according to the test requirements, and then use the notched pliers provided with the testing machine to place the specimen (8) in the middle position along the gap between the clamping module and the platform to start the test.

5. The method for testing the impact performance of a thin plate as claimed in claim 4, characterized in that The thickness of the test specimen (8) ranges from 0.5 to 2.5 mm.

6. The method for testing the impact performance of a thin plate according to claim 4, characterized in that The testing machine adopts a Charpy V-type or U-type notch impact testing machine, the blade arc radius is 2 mm, and the impact energy is 30-100 joules.

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