Testing device and measuring method for percentage elongation after fracture in tensile test

Abstract

The invention relates to a testing device and a measuring method for percentage elongation after fracture in a tensile test, and belongs to the technical field of steel inspection and measurement equipment and methods in the metallurgical industry. According to the technical scheme, a stop block (2) is perpendicularly fixed to a base (1), a ruler (3) is fixed to the side face of the stop block (2) along the stop block (2) and located on one side of a sample (8) on the base (1), a clamping device (4) makes clamping contact with the sample (8), a data collector (6) is fixed over the sample (8), a sample information card (5) is placed on the base (1), and the ruler (3), the sample (8) and the sample information card (5) are located in the view of the data collector (6). And the output end of the data acquisition unit (6) is connected with the data processing module (7). The method has the beneficial effects that the data measurement precision is improved, a data archiving system can be established after image acquisition, and subsequent data tracing is facilitated.

Description

TECHNICAL FIELD

[0001] The present application relates to a kind of tensile test post-elongation test device and measurement method, belong to metallurgical industry steel testing and measuring equipment and method technical field. BACKGROUND

[0002] In tensile test test, the measurement mode for post-elongation is usually to manually splice the tensile sample after being pulled off, and then measure the length of post-elongation gauge length Lu using vernier caliper. However, due to the influence of factors such as skill level of operator, post-elongation gap state of tensile sample, post-elongation gap state, sample splicing effect, data reading deviation, etc., measurement data deviation of post-elongation gauge length Lu often occurs during measurement. Therefore, it is necessary to optimize and improve the existing post-elongation measurement method, design a kind of post-elongation measurement test device, reduce the measurement deviation of post-elongation gauge length Lu, and improve the data measurement accuracy. SUMMARY

[0003] The present application aims to provide a kind of tensile test post-elongation test device and measurement method, by fixing clamping, photographing and image processing of sample, which can effectively avoid the influence of sample displacement, gap splicing state and data reading deviation during manual measurement, avoid the influence of skill level of operator on measurement results, improve the data measurement accuracy, and at the same time, after image acquisition, data archiving system can be established, which is convenient for subsequent data tracing, and effectively solves the above problems existing in the background art.

[0004] The technical scheme of the present application is: a kind of tensile test post-elongation test device, comprising base, block, scale, clamp, sample information card, data collector, data processing module and sample, the block is vertically fixed on the base, the scale is fixed on the base along the block, one side of the sample is attached to the side surface of the block, the clamp is in contact with the sample, the data collector is fixed above the sample, the sample information card is placed on the base, the scale, the sample and the sample information card are in the field of view of the data collector, and the output end of the data collector is connected to the data processing module.

[0005] The sample contact surface of the base and the block is smooth and flat.

[0006] The sample contact end of the clamp is a soft contact structure.

[0007] A kind of tensile test post-elongation measurement method, comprising the following steps: (1) pretreating the sample, and marking the original gauge length on the sample; (2) clamping and fixing the sample marked with clamp, and placing the sample information card near the sample, and photographing the sample using the data collector; (3) on the tensile testing machine to carry out tensile test; (4) the half of the tensile sample after being pulled off is clamped and fixed by the clamp, then the other half of the pulled-off sample is spliced according to the fracture gap, the sample information card is placed near the sample, and the data collector is used to take a photo; (5) the photos taken before and after the tensile test are processed by the software processing module to complete the calculation of the elongation after fracture.

[0008] In the step (1), the original gauge mark is marked on the sample by small marks, fine lines, fine ink lines or strain grids, and the marks should not cause the sample to have a gap or to be broken prematurely.

[0009] In the step (2) and the step (4), the sample clamped and fixed is completely attached to the side surface of the block.

[0010] In the step (4), the side of the sample is always completely attached to the side surface of the block during splicing, so as to ensure that the axial direction of the sample is always on a straight line.

[0011] In the step (5), the photos taken are processed by image processing to identify the original gauge mark, the gauge mark after fracture, the scale and the sample information data.

[0012] The present application has the advantages that the sample is clamped, photographed and processed by image processing, the influences of sample displacement, gap splicing state and data reading deviation during manual measurement are effectively avoided, the influence of the skill level of the operator on the measurement result is avoided, the data measurement accuracy is improved, and the data archiving system can be established after image acquisition, so that the subsequent data tracing is facilitated. BRIEF DESCRIPTION OF DRAWINGS

[0013] Figure 1 is the front view of the present application; Figure 2 is the top view of the present application; In the figure: base 1, block 2, scale 3, clamp 4, sample information card 5, data collector 6, data processing module 7, sample 8. DETAILED DESCRIPTION

[0014] In order to make the purpose, technical scheme and advantages of the embodiment of the present application clearer, the technical scheme of the embodiment of the present application will be described clearly and completely in combination with the drawings in the embodiment, obviously, the embodiment expressed is only a part of the embodiment of the present application, but not all the embodiments of the present application, all other embodiments obtained by the person skilled in the art without creative labor based on the embodiment of the present application belong to the protection scope of the present application.

[0015] A testing device for elongation at break in a tensile test includes a base 1, a block 2, a scale 3, a clamp 4, a sample information card 5, a data acquisition unit 6, a data processing module 7, and a sample 8. The block 2 is vertically fixed on the base 1, the scale 3 is fixed on the base 1 along the block 2, one side of the sample 8 is abutted against the side of the block 2, the clamp 4 is in contact with the sample 8, the data acquisition unit 6 is fixed directly above the sample 8, the sample information card 5 is placed on the base 1, the scale 3, the sample 8, and the sample information card 5 are within the field of view of the data acquisition unit 6, and the output end of the data acquisition unit 6 is connected to the data processing module 7.

[0016] The sample contact surfaces of the base 1 and the block 2 are both smooth and flat.

[0017] The sample contact end of the clamp 4 has a soft contact structure.

[0018] A method for measuring elongation at fracture in a tensile test, comprising the following steps: (1) Pre-treat the specimen and mark the original gauge length on the specimen; (2) The marked sample is clamped and fixed with a clamp, and the sample information card is placed near the sample. The sample is photographed using a data acquisition device. (3) Perform a tensile test on a tensile testing machine; (4) Clamp and fix the broken half of the tensile specimen with a clamp, and then splice the other half of the broken specimen according to the fracture gap. Simultaneously place the sample information card near the specimen and take pictures of it using a data acquisition device. (5) Use the software processing module to perform graphic processing on the photos taken before and after stretching, and complete the calculation of the elongation after fracture.

[0019] In step (1), the original gauge length is marked on the specimen using small marks, fine lines, fine ink lines or strain grids. The markings must not cause gaps in the specimen or cause premature fracture of the specimen.

[0020] In steps (2) and (4), one side of the fixed clamped sample is completely against the side of the block.

[0021] In step (4), during splicing, one side of the sample is always completely against the side of the block to ensure that the axial direction of the sample is always in a straight line.

[0022] In step (5), the photographs are processed to identify the original gauge length, the gauge length after the break, the scale, and the sample information data.

[0023] In practical applications, before tensile testing, the specimen is first pretreated by marking the original gauge length on the specimen with small marks, fine lines, fine ink lines or strain grids. The markings should not cause gaps in the specimen or cause premature fracture.

[0024] The marked sample is then placed on the test apparatus designed in this invention, with one side of the sample completely against the side of the block 2. The sample is clamped and fixed in place by the clamp 4, and the sample information card 5 is placed near the sample simultaneously. The data acquisition device 6 is used to take pictures of the sample.

[0025] Tensile tests shall be conducted on a tensile testing machine in accordance with the relevant provisions of GB / T 228.

[0026] The broken specimen is placed on the testing apparatus designed in this invention. First, the broken half of the tensile specimen is fixedly clamped onto the apparatus, ensuring that one side of the specimen is completely against the side of the block 2 before clamping. Then, the other half of the broken specimen is spliced ​​together according to the fracture notch, ensuring that one side of the specimen remains completely against the side of the block 2 during splicing, guaranteeing that the specimen's axis remains in a straight line. The sample information card 5 is placed near the specimen. The data acquisition device 6 is used to photograph the specimen.

[0027] The software processing module performs graphic processing on the photos taken before and after stretching, identifies data such as the original gauge length, the gauge length after fracture, the scale, and sample information, and calculates the elongation after fracture.

[0028] The manual calibration described in this invention involves manually measuring the sample held in the testing device using vernier calipers after taking a photograph, manually reading the original gauge length and the gauge length after the break, and comparing it with the photographic data.

[0029] This invention effectively avoids the adverse effects of sample displacement, notch splicing status, and data reading deviation during manual measurement by fixing and clamping the sample, taking pictures, and processing the images. It also avoids the influence of the operator's skill level on the measurement results, improves the accuracy of data measurement, and establishes a data archiving system after image acquisition, which facilitates subsequent data traceability.

[0030] The above are merely preferred embodiments of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. A testing apparatus for elongation at fracture in a tensile test, characterized in that: The device includes a base (1), a stop block (2), a scale (3), a clamp (4), a sample information card (5), a data acquisition device (6), a data processing module (7), and a sample (8). The stop block (2) is vertically fixed on the base (1), the scale (3) is fixed on the base (1) along the stop block (2), one side of the sample (8) is against the side of the stop block (2), the clamp (4) is in contact with the sample (8), the data acquisition device (6) is fixed directly above the sample (8), the sample information card (5) is placed on the base (1), and the scale (3), the sample (8), and the sample information card (5) are within the field of view of the data acquisition device (6). The output end of the data acquisition device (6) is connected to the data processing module (7).

2. The testing apparatus for elongation after fracture in a tensile test according to claim 1, characterized in that: The sample contact surfaces of the base (1) and the block (2) are both smooth and flat.

3. The testing apparatus for elongation after fracture in a tensile test according to claim 1, characterized in that: The sample contact end of the clamp (4) has a soft contact structure.

4. A method for measuring elongation after fracture in a tensile test, characterized in that... Includes the following steps: (1) Pre-treat the specimen and mark the original gauge length on the specimen; (2) The marked sample is clamped and fixed with a clamp, and the sample information card is placed near the sample. The sample is photographed using a data acquisition device. (3) Perform a tensile test on a tensile testing machine; (4) Clamp and fix the broken half of the tensile specimen with a clamp, and then splice the other half of the broken specimen according to the fracture gap. Simultaneously place the sample information card near the specimen and take pictures of it using a data acquisition device. (5) Use the software processing module to perform graphic processing on the photos taken before and after stretching, and complete the calculation of the elongation after fracture.

5. The method for measuring elongation after fracture in a tensile test according to claim 4, characterized in that: In step (1), the original gauge length is marked on the specimen using small marks, fine lines, fine ink lines or strain grids. The markings must not cause gaps in the specimen or cause premature fracture of the specimen.

6. The method for online maintenance of a static pressure device according to claim 4, characterized in that: In steps (2) and (4), one side of the fixed clamped sample is completely against the side of the block.

7. The method for online maintenance of a static pressure device according to claim 4, characterized in that: In step (4), during splicing, one side of the sample is always completely against the side of the block to ensure that the axial direction of the sample is always in a straight line.

8. The method for online maintenance of a static pressure device according to claim 4, characterized in that: In step (5), the photographs are processed to identify the original gauge length, the gauge length after the break, the scale, and the sample information data.

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