Welding quality testing method, impact sample preparation method and impact sample

Abstract

The invention discloses a welding quality testing method, a preparation method of an impact sample and the impact sample, and relates to the technical field of welding quality tests.The method comprises the steps that the impact sample is prepared, and the area where a fusion line of the impact sample is located is thinned so that the fusion line can be the fracture position of the impact sample when the impact sample is subjected to an impact test; and performing an impact test on the impact sample, and determining the welding quality of the impact sample according to an impact test result. According to the invention, when the impact test is carried out on the impact sample, the fusion line of the impact sample is fractured, so that the obtained impact test result can completely reflect the performance of the fusion line, and the reliability and accuracy of the welding quality of the impact sample analyzed through the impact test result can be ensured.

Description

Technical Field

[0001] The invention relates to the technical field of welding quality testing, and in particular to a welding quality testing method, a method for preparing an impact specimen, and an impact specimen. Background Art

[0002] During the welding process, due to the different heat input, the material microstructure near the fusion line will undergo significant changes, and these changes have a profound impact on the mechanical properties of the welded joint. The weld area undergoes a process of recrystallization after melting, and is mostly columnar. The microstructure near the weld area changes due to the gradient of heat input. The farther away from the weld area, the lower the heat input, and the changes in the microstructure are also different. The heat affected zone (HAZ) near the weld area has a significant coarsening of the grains due to the large heat input.

[0003] The fusion line refers to the boundary between the weld and the heat-affected zone. The structure of the area where the fusion line is located is mostly columnar crystals. The grains of columnar crystals are coarse and clearly layered, but they are prone to damage when subjected to loads. In addition, the rapid cooling rate near the fusion line leads to uneven phase transformation, especially in low-alloy steel and carbon steel, where the high-temperature phase austenite may transform into hard and brittle martensite or softer pearlite. This uneven phase transformation leads to significant differences in the hardness and toughness of the material on a microscopic scale, resulting in local weakening of the mechanical properties. In addition, due to the extreme temperature gradient during welding and the difference in thermal expansion coefficients of different materials, the area where the fusion line is located often accumulates higher residual stresses. In the absence of proper stress relief treatment, these residual stresses may cause crack initiation and expansion during the use of the material. In addition, the metal flow and solidification process at the fusion line may introduce microscopic defects such as pores, inclusions, and unfused areas. These defects become stress concentration points on a microscopic scale, weakening the continuity and uniformity of the weld, and further reducing the overall performance of the welded joint. Therefore, the weld fusion line, as the weak link in the welded structure, has a crucial impact on the overall performance and safety of the welded structure.

[0004] At present, welding technology is widely used in many industries, such as aerospace, automobile manufacturing, shipbuilding and petrochemical industries. The welded structures in these industries often need to withstand high impact loads, such as vehicle collisions, hull impact waves, vibrations during spacecraft launch, etc. Therefore, the impact performance evaluation of welds is an important part of ensuring the safety of these critical structures.

[0005] In real-world applications, the quality of welded joints determines the reliability of the entire structure. Traditional welding quality testing methods, such as tensile testing and hardness testing, provide basic data for welding quality control, but these tests mainly focus on the static properties of materials. For dynamic loads, especially sudden impact loads, these traditional methods cannot fully predict the performance of materials. The weld fusion line is particularly prone to become an area of ​​stress concentration and defect accumulation in welded structures. Its performance under impact loads is particularly critical, but also the most difficult to predict.

[0006] Although the prior art provides a variety of technical solutions for testing welding performance (for example, the technical solution in the utility model patent with the patent publication number "CN214472273U" and the subject name "A Metal Material Charpy Impact Energy Test Support"; for another example, the technical solution in the utility model patent with the patent publication number "CN115615797A" and the subject name "A System and Method for Testing Lateral Expansion and Sectional Fiber Ratio of Impact Specimens"), these methods often fail to fully consider the extreme impact conditions that the weld fusion line may encounter in actual applications. However, none of them is specifically designed for the weld fusion line, so the welding test data in the prior art may not directly reflect the actual performance of the fusion line. In addition, traditional impact tests often ignore the unique microstructure and material behavior of the weld zone. As for how to reproduce the dynamic load environment in actual applications under laboratory conditions, the solutions provided by the prior art are still limited, and there is a lack of a reliable method to evaluate the impact performance of welds in actual applications. Summary of the invention

[0007] The technical problem to be solved by the present invention is to address the deficiencies of the prior art, and specifically provide a welding quality testing method, an impact specimen preparation method and an impact specimen, which are specifically as follows:

[0008] 1) In the first aspect, the present invention provides a welding quality testing method, and the specific technical scheme is as follows:

[0009] preparing an impact specimen, wherein the area of ​​the impact specimen where the fusion line is located is subjected to a thinning process so that the fusion line is: a fracture position of the impact specimen when the impact specimen is subjected to an impact test;

[0010] The impact test is performed on the impact specimen, and the welding quality of the impact specimen is determined based on the impact test result.

[0011] The beneficial effects of a welding quality testing method provided by the present invention are as follows:

[0012] When the impact test is performed on the impact specimen, a fracture occurs at the fusion line of the impact specimen, so that the obtained impact test result can fully reflect the performance of the fusion line, and can ensure the reliability and accuracy of the welding quality of the impact specimen analyzed through the impact test result.

[0013] On the basis of the above scheme, a welding quality testing method of the present invention can also be improved as follows.

[0014] Furthermore, it also includes:

[0015] The design of opening side grooves is used to thin the area where the fusion line on the preset component is located to obtain an impact specimen.

[0016] The beneficial effect of adopting the above further solution is that it can further ensure that when the impact test is performed on the impact specimen, a fracture occurs at the fusion line of the impact specimen.

[0017] Furthermore, it also includes:

[0018] The weld joint to be inspected is processed to obtain at least one preset component.

[0019] Further, the weld joint to be inspected is processed to obtain at least one preset component, including:

[0020] The weld position of the weld joint to be inspected is polished and corroded in sequence to expose the weld arrangement, weld, fusion line, heat-affected zone, boundary of the parent material and the position of the parent material of the weld joint to be inspected;

[0021] Sampling is performed on the welding joint to be inspected after being polished and corroded to obtain at least one preset component.

[0022] Furthermore, it also includes:

[0023] An impact test is performed on each impact specimen, and the welding quality of the welded joint to be tested is determined based on the impact test result of each impact specimen.

[0024] 2) In the second aspect, the present invention also provides a method for preparing an impact specimen, and the specific technical scheme is as follows:

[0025] An impact specimen is prepared with a thinning treatment performed on the area where the fusion line is located, so that the fusion line is: the fracture position of the impact specimen when the impact specimen is subjected to an impact test.

[0026] The beneficial effects of the method for preparing an impact specimen provided by the present invention are as follows:

[0027] When the impact test is performed on the impact specimen, a fracture occurs at the fusion line of the impact specimen, so that the obtained impact test result can fully reflect the performance of the fusion line, and can ensure the reliability and accuracy of the welding quality of the impact specimen analyzed through the impact test result.

[0028] On the basis of the above scheme, the method for preparing an impact specimen of the present invention can also be improved as follows.

[0029] Furthermore, it also includes:

[0030] The design of opening side grooves is used to thin the area where the fusion line on the preset component is located to obtain an impact specimen.

[0031] The beneficial effect of adopting the above further solution is that it can further ensure that when the impact test is performed on the impact specimen, a fracture occurs at the fusion line of the impact specimen.

[0032] Furthermore, it also includes:

[0033] The weld joint to be inspected is processed to obtain at least one preset component.

[0034] Further, the weld joint to be inspected is processed to obtain at least one preset component, including:

[0035] The weld position of the weld joint to be inspected is polished and corroded in sequence to expose the weld arrangement, weld, fusion line, heat-affected zone, boundary of the parent material and the position of the parent material of the weld joint to be inspected;

[0036] Sampling is performed on the welding joint to be inspected after being polished and corroded to obtain at least one preset component.

[0037] 3) In a third aspect, the present invention also provides an impact specimen prepared by any of the above-mentioned impact specimen preparation methods. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for describing the embodiments of the present invention:

[0039] Figure 1 A flowchart for implementing the overall method of the present invention;

[0040] Figure 2 This is a schematic diagram of sampling of plate components;

[0041] Figure 3 This is a schematic diagram of sampling of pipe components;

[0042] Figure 4 Schematic diagram of adjusting sampling for impact specimen;

[0043] Figure 5 Schematic diagram of impact specimen;

[0044] Figure 6 A side corrosion image after a test of an embodiment provided by the present invention;

[0045] Figure 7A fracture image after a test of an embodiment provided by the present invention;

[0046] Figure 8 This is a numerical comparison image after a test of an embodiment provided by the present invention. DETAILED DESCRIPTION

[0047] The principles and features of the present invention are described below. The examples given are only used to explain the present invention and are not used to limit the scope of the present invention.

[0048] The technical solution of the present invention and how the technical solution of the present invention solves the above-mentioned technical problems are described in detail below with specific embodiments. The following specific embodiments can be combined with each other, and the same or similar concepts or processes may not be repeated in some embodiments. The embodiments of the present invention will be described below in conjunction with the accompanying drawings.

[0049] like Figure 1 As shown, a welding quality testing method according to an embodiment of the present invention comprises the following steps:

[0050] S1. preparing an impact specimen, wherein the area where the fusion line of the impact specimen is located is subjected to a thinning process so that the fusion line is: a fracture position of the impact specimen when the impact specimen is subjected to an impact test;

[0051] S2. Perform an impact test on the impact specimen and determine the welding quality of the impact specimen based on the impact test result.

[0052] A beneficial effect of a welding quality testing method according to an embodiment of the present invention is that when an impact test is performed on an impact specimen, a fracture occurs at the fusion line of the impact specimen, so that the obtained impact test results can fully reflect the performance of the fusion line, and can ensure the reliability and accuracy of the welding quality of the impact specimen analyzed through the impact test results.

[0053] Optionally, in the above technical solution, it also includes:

[0054] The design of opening side grooves is adopted to thin the area where the fusion line of the preset component is located to obtain an impact specimen. This can further ensure that when the impact specimen is subjected to an impact test, a fracture occurs at the fusion line of the impact specimen.

[0055] Optionally, in the above technical solution, it also includes:

[0056] S01. Process the welding joint to be inspected to obtain at least one preset component.

[0057] Optionally, in S01, the weld joint to be inspected is processed to obtain at least one preset component, including:

[0058] S010, polishing and etching the weld position of the weld joint to be inspected in sequence to expose the weld bead arrangement, weld, fusion line, heat-affected zone, boundary of the base material and the position of the base material of the weld joint to be inspected;

[0059] S011. Sampling is performed on the welding joint to be inspected after being polished and corroded to obtain at least one preset component.

[0060] Optionally, in the above technical solution, it also includes:

[0061] An impact test is performed on each impact specimen, and the welding quality of the welded joint to be tested is determined based on the impact test result of each impact specimen.

[0062] Through the following embodiments, the specific implementation process of a welding quality testing method of the present invention is described as follows:

[0063] S101, obtaining a welding joint to be inspected, specifically:

[0064] A welding joint of a certain size suitable for processing is cut out from the welding component as the welding joint to be tested.

[0065] The welded component may be a plate or a pipe, etc. The welded joint to be tested may be a lap joint, a butt joint, a fillet joint or a cross joint. The structure of the welded component of the plate is as follows: Figure 2 As shown, the structure of the welded component of the pipe is as follows Figure 3 shown.

[0066] S102, polishing and etching are performed on the weld position of the weld joint to be inspected in sequence, specifically:

[0067] First, the weld position of the weld joint to be tested is polished to remove the rough layer and oxide layer on the surface of the weld joint to be tested, so that the microstructure of the weld is exposed. Then, the weld joint to be tested after polishing is corroded to further reveal the grain boundaries of the metal of the weld joint to be tested and the heat-affected zone of the weld area, as well as possible defects such as microcracks, pores and inclusions. For welds that are well-formed and have no defects, after polishing and corroding treatments in turn, the tester can clearly see the weld bead arrangement, weld, fusion line, heat-affected zone, parent material boundary and parent material position of the weld joint to be tested, in preparation for subsequent sampling.

[0068] S103. Determine the size of the impact specimen, specifically:

[0069] The national standard GB / T229-2020 specifies the size of the impact specimen. The size of the impact specimen that meets the impact test requirements is designed based on the size of the welded joint to be tested after polishing and corrosion treatment and the number of impact specimens required. In short, when the size of the welded joint to be tested after polishing and corrosion treatment is large, or the number of impact specimens required is not large, the size of the impact specimen often used is: height 10mm, width 10mm and length 55mm. When the size of the welded joint to be tested after polishing and corrosion treatment is small, or the number of impact specimens required is large, the size of the impact specimen often used is: height 5mm, width 10mm and length 55mm, or 2.5mm, width 10mm and length 55mm, to ensure that the number of impact specimens can meet the impact test requirements.

[0070] S104, blanking:

[0071] According to the size of the impact specimen determined in S103, the position of the impact specimen blank to be taken is drawn on the cross section of the weld joint to be tested after polishing and corrosion treatment. The conventional sampling method is to sample the specimen parallel to the direction of the plate. During the welding process, the base material will be grooved for better forming quality, resulting in a certain angle between the weld fusion line and the plate after welding. When parallel sampling is performed, only part of the fusion line area can be sampled for the specimen at the test position fusion line, resulting in inaccurate impact test results. Therefore, when drawing the line, the sampling angle will be adjusted according to the specific position and direction of the weld fusion line, such as Figure 4 Make sure the fusion line is completely located in the center of the specimen, so that in the subsequent test process, the test results can fully reflect the impact performance of the fusion line and improve the accuracy of the results.

[0072] According to the position of the impact specimen blank to be taken, a workpiece with a certain processing allowance, namely, the impact specimen blank, is taken out from the weld joint to be tested after polishing and corrosion treatment by wire cutting or flame cutting. Then, according to the size of the impact specimen determined in S103, each impact specimen blank is divided and polished to be processed into a certain number of rectangular components that meet the requirements. The rectangular components are the preset components.

[0073] S105, performing fine processing on the cuboid component, specifically:

[0074] The rectangular component obtained by S104 is beveled according to the bevel style and bevel size specified in the national standard GB / T229-2020. A milling cutter is used to machine a bevel that meets the requirements. For the specimens with bevels, in order to ensure that the fracture position is completely located in the weld fusion line area during impact, the fusion line area is further locally thinned by opening side grooves. According to the side groove depth recommended in the relevant standard ASTM E1820 of the American Society of Mechanical Engineers, the side groove depth is determined to be 5% to 10% of the width. In the present invention, the side groove depth is in the range of 0.5 to 1 mm in width, thereby preparing a plurality of impact specimens, and the structure of the impact specimens is as follows: Figure 5 shown.

[0075] S106, Acceptance:

[0076] The dimensions of the multiple impact specimens obtained in S105 are measured, and according to the dimensions and machining tolerance table of the impact specimens determined in S103, it is determined whether the dimensions meet the requirements, and the impact specimens that have passed the acceptance are numbered and can also be classified.

[0077] S107, impact test:

[0078] Conduct impact tests on each impact specimen that passes the acceptance test, and collect statistics on the impact test results and the fracture morphology images of each impact specimen that passes the acceptance test. Figure 6 Specifically, there are four figures: A1, A2, B1 and B2, showing the corrosion images of different sides of the impact specimen after the impact test; Figure 7 Specifically, there are four pictures, A1 left (left side of A1), A1 right (right side of A1), A2 left (left side of A2) and A2 (right side of A2), showing the fracture images of the impact specimens after the impact test. Figure 8 A numerical comparison graph of the Charpy impact energy after the impact test is shown.

[0079] It should be noted that the fusion line of the impact specimen can be located at the center of the impact specimen, which is more convenient for impact testing.

[0080] The beneficial effects of the present invention are as follows:

[0081] 1) Ability to obtain more accurate impact test results:

[0082] By using the impact specimen prepared by the present invention, the fusion line of the impact specimen can be located at the center of the impact specimen, and the area where the fusion line of the impact specimen is located is thinned (specifically, the area where the fusion line is located is thinned by opening a side groove design). When the impact specimen is subjected to an impact test, a fracture occurs at the fusion line of the impact specimen, which is more helpful to accurately simulate the impact response of the fusion line in actual applications, thereby providing more accurate impact test data, so that the obtained impact test results can fully reflect the performance of the fusion line, and can ensure the reliability and accuracy of the welding quality of the impact specimen analyzed through the impact test results.

[0083] 2) High adaptability: It is suitable for welded structures of different shapes and sizes, whether it is a plate or a pipe, and regardless of the form of the welded joint (for example, lap joint, butt joint, corner joint or cross joint, etc.), accurate impact performance testing can be performed, making the present invention highly adaptable in a variety of industrial applications.

[0084] 3) Improve process optimization and defect prevention: The ability to accurately locate and test the impact toughness of the fusion line enables engineers to adjust welding parameters and processes based on the test results to optimize weld quality. This targeted data feedback helps identify potential structural defects in the early stages of production, thereby preventing possible welding failures and reducing rework and scrap rates caused by welding quality issues.

[0085] 4) Improve the reliability and durability of the structure: By accurately evaluating the impact performance of the weld fusion line, the method of the present invention can help designers and engineers understand the ability of welded joints to withstand sudden impact loads in actual working environments, such as vehicle collisions, accidental impacts of industrial equipment, etc. The in-depth analysis of this test ensures that the welded structure can maintain its integrity and function in a high-stress environment, thereby improving the reliability and life of the overall structure.

[0086] 5) Enhanced design and evaluation standards for welded joints: This invention provides a new scientific basis for the performance evaluation of weld fusion lines, and these data can be used to develop or update welding standards and specifications, especially in safety-sensitive industries. Accurate impact test data not only improves the accuracy of design, but also helps in the development of industry standards to ensure that welded structures using these standards can maintain performance under extreme conditions.

[0087] A method for preparing an impact specimen according to an embodiment of the present invention comprises the following steps:

[0088] An impact specimen is prepared with a thinning treatment performed on the area where the fusion line is located, so that the fusion line is: the fracture position of the impact specimen when the impact specimen is subjected to an impact test.

[0089] The beneficial effect of a method for preparing an impact specimen in an embodiment of the present invention is that when the impact specimen is subjected to an impact test, a fracture occurs at the fusion line of the impact specimen, so that the obtained impact test results can fully reflect the performance of the fusion line, and can ensure the reliability and accuracy of the welding quality of the impact specimen analyzed through the impact test results.

[0090] Optionally, in the above technical solution, it also includes:

[0091] The design of opening side grooves is used to thin the area where the fusion line on the preset component is located to obtain an impact specimen.

[0092] Optionally, in the above technical solution, it also includes:

[0093] The weld joint to be inspected is processed to obtain at least one preset component.

[0094] Optionally, in the above technical solution, the weld joint to be inspected is processed to obtain at least one preset component, including:

[0095] The weld position of the weld joint to be inspected is polished and corroded in sequence to expose the weld arrangement, weld, fusion line, heat-affected zone, boundary of the parent material and the position of the parent material of the weld joint to be inspected;

[0096] Sampling is performed on the welding joint to be inspected after being polished and corroded to obtain at least one preset component.

[0097] The specific implementation process of the method for preparing an impact specimen of the present invention is described in detail in the embodiment of the welding quality testing method described above, and will not be described in detail here.

[0098] An impact specimen according to an embodiment of the present invention is prepared by using any of the above-mentioned methods for preparing an impact specimen.

[0099] In the above embodiments, although the steps are numbered S1, S2, etc., these are only specific embodiments given by the present invention. Those skilled in the art may adjust the execution order of S1, S2, etc. according to actual conditions, which is also within the protection scope of the present invention. It can be understood that in some embodiments, some or all of the above embodiments may be included.

[0100] Although the embodiments of the present invention have been shown and described above, it is to be understood that the above embodiments are exemplary and are not to be construed as limitations of the present invention. A person skilled in the art may change, modify, replace and vary the above embodiments within the scope of the present invention.

Claims

1. A welding quality testing method, characterized in that: include: preparing an impact specimen, wherein the region where the fusion line of the impact specimen is located is subjected to a thinning process so that the fusion line is: the fracture position of the impact specimen when the impact specimen is subjected to an impact test; An impact test is performed on the impact specimen, and the welding quality of the impact specimen is determined according to the impact test result.

2. A welding quality testing method according to claim 1, characterized in that: Also includes: The impact specimen is obtained by thinning the area where the fusion line on the preset component is located by adopting the design of opening side grooves.

3. A welding quality testing method according to claim 2, characterized in that: Also includes: The weld joint to be inspected is processed to obtain at least one of the preset components.

4. A welding quality testing method according to claim 3, characterized in that: Processing the weld joint to be inspected to obtain at least one of the preset components includes: The weld position of the weld joint to be inspected is polished and corroded in sequence to expose the weld bead arrangement, weld, fusion line, heat-affected zone, boundary of the base material and the position of the base material of the weld joint to be inspected; Sampling is performed on the welding joint to be inspected after being polished and corroded to obtain at least one of the preset components.

5. A welding quality testing method according to claim 4, characterized in that: Also includes: An impact test is performed on each impact specimen, and the welding quality of the welded joint to be tested is determined according to the impact test result of each impact specimen.

6. A method for preparing an impact specimen, characterized in that: include: An impact specimen is prepared in which a thinning treatment is performed in the area where a fusion line is located, so that the fusion line is the fracture position of the impact specimen when an impact test is performed on the impact specimen.

7. The method for preparing an impact specimen according to claim 6, characterized in that: Also includes: The impact specimen is obtained by thinning the area where the fusion line on the preset component is located by adopting the design of opening side grooves.

8. The method for preparing an impact specimen according to claim 7, characterized in that: Also includes: The weld joint to be inspected is processed to obtain at least one of the preset components.

9. The method for preparing an impact specimen according to claim 8, characterized in that: Processing the weld joint to be inspected to obtain at least one of the preset components includes: The weld position of the weld joint to be inspected is polished and corroded in sequence to expose the weld bead arrangement, weld, fusion line, heat-affected zone, boundary of the base material and the position of the base material of the weld joint to be inspected; Sampling is performed on the welding joint to be inspected after being polished and corroded to obtain at least one of the preset components.

10. An impact specimen prepared by the method for preparing an impact specimen according to any one of claims 6 to 9.

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