A method of machining a charpy impact specimen

Abstract

The application belongs to the technical field of mechanical property test, and discloses a Charpy impact test sample processing method, which can obtain the impact test sample meeting the test standard by breaking the fracture groove on the second sample blank on the spot before the impact test, cancels the transfer and witness steps of the second transfer stamp, realizes the simplification of the witness process of the impact test sample processing, can effectively shorten the sample processing period, thereby guaranteeing the welding process evaluation progress and the timely feedback of the detection result of the production welding test plate, and further improving the production efficiency.

Description

Technical Field

[0001] This invention relates to the field of mechanical property testing technology, and in particular to a method for processing Charpy impact specimens. Background Technology

[0002] Charpy impact test is a dynamic mechanical property test method that utilizes the principle of energy conservation. A Charpy impact specimen of a specific shape and size, manufactured according to relevant standards, is broken under impact load in order to determine the impact energy absorbed during the fracture process.

[0003] The validity of Charpy impact test results depends on the traceability management of the specimens. Classification societies require that impact specimens be uniquely identified by a steel stamp during machining to ensure a unique and traceable association between the specimen and the corresponding welded test plate and welding process information, thus preventing specimen confusion or substitution. Current Charpy impact specimen machining methods require at least one original steel stamp and two subsequent stamp transfers, each requiring the presence of the classification society for witnessing. This complex process significantly extends the specimen machining cycle, impacting not only the progress of welding procedure qualification but also potentially delaying the timely feedback of test results from the production of welded test plates, ultimately negatively affecting the entire product production cycle.

[0004] Therefore, there is an urgent need to propose a Charpy impact test specimen processing method to solve the above problems. Summary of the Invention

[0005] The purpose of this invention is to provide a Charpy impact test specimen processing method to shorten the specimen processing cycle and ensure timely feedback of welding process qualification progress and production welding test plate test results.

[0006] To achieve this objective, the present invention adopts the following technical solution:

[0007] A method for processing Charpy impact test specimens includes the following steps:

[0008] S1: Welding is performed under the witness of the classification society to obtain a test plate, and the original steel stamp is struck next to the weld on the top of the test plate;

[0009] S2: Cut a first sample blank containing the weld and the original steel stamp along the height direction of the test plate;

[0010] S3: Under the witness of the classification society, the first transfer stamp is struck on the side of the first sample blank;

[0011] S4: Cut a second sample blank containing the weld and the first transfer stamp along the transverse direction of the first sample blank, so that the height of the second sample blank is h, wherein the transverse direction of the first sample blank is perpendicular to the height direction of the first sample blank.

[0012] S5: Cut a preparatory sample containing the weld and the first transfer stamp along the height direction of the second sample blank, so that the width of the preparatory sample is n, and process a fracture groove between the weld and the first transfer stamp of the preparatory sample, so that the distance between the fracture groove and the first side is m, and process a test notch between the first side and the fracture groove, wherein the first side is the side of the second sample blank away from the first transfer stamp;

[0013] S6: After the classification society checks that the first transfer stamp is correct, the prepared sample is broken through the fracture groove to obtain an impact sample with the test notch, and the impact sample is subjected to an impact test.

[0014] In some alternative embodiments, in step S5, the test notch is made on one side of the pre-test specimen along the direction of weld extension.

[0015] In some alternative embodiments, the fracture groove has the same opening direction as the test notch.

[0016] In some alternative embodiments, the fracture groove is a V-groove.

[0017] In some optional embodiments, the thickness H of the bottom of the fracture groove ranges from (1 ± 0.2) mm.

[0018] In some optional embodiments, m is (55±0.6) mm, n is (10±0.2) mm, and h is (10±0.2) mm.

[0019] In some alternative embodiments, the test notch is a V-shaped notch.

[0020] In some optional embodiments, the angle of the V-shaped notch is (45±2)°, the depth of the V-shaped notch is (2±0.05)mm, and the bottom radius of the V-shaped notch is (0.25±0.025)mm.

[0021] In some alternative embodiments, the test notch is a U-shaped notch.

[0022] In some optional embodiments, the depth of the U-shaped notch is (2±0.05) mm, and the bottom radius of the U-shaped notch is (1±0.1) mm.

[0023] The beneficial effects of this invention are:

[0024] This invention provides a Charpy impact test specimen processing method. By processing a fracture groove on a second specimen blank, an impact specimen that meets the test standard can be obtained on-site before the impact test by breaking the fracture groove. This eliminates the transfer and witnessing steps of the second transfer stamp, simplifies the impact specimen processing witnessing process, effectively shortens the specimen processing cycle, and ensures the timely feedback of welding process qualification progress and production welding test plate test results, thereby improving production efficiency. Attached Figure Description

[0025] Figure 1 This is a flowchart of an existing Charpy impact test specimen processing method;

[0026] Figure 2 This is a schematic diagram of the structure of the test plate of the present invention;

[0027] Figure 3 This is a schematic diagram of the structure of the present invention for cutting the first sample blank from the test plate;

[0028] Figure 4 This is a schematic diagram of the structure of the first sample blank of the present invention;

[0029] Figure 5 This is a schematic diagram of the structure of the present invention for cutting the second sample blank from the first sample blank;

[0030] Figure 6 This is a schematic diagram of the structure of the second sample blank of the present invention;

[0031] Figure 7 This is a schematic diagram of the existing process for cutting impact specimens from the second specimen blank.

[0032] Figure 8 This is a schematic diagram of the structure of the impact specimen obtained by the existing process;

[0033] Figure 9 This is a flowchart of the Charpy impact test specimen processing method provided by the present invention;

[0034] Figure 10 This is a schematic diagram of the structure of the preparatory sample of the present invention;

[0035] Figure 11 This is a front view of the preparatory sample of the present invention.

[0036] In the picture:

[0037] 1. Test plate; 2. First specimen blank; 3. Second specimen blank; 4. Preparatory specimen; 41. First side; 5. Impact specimen; 6. Weld; 7. Original stamp; 8. First transfer stamp; 9. Second transfer stamp; 10. Fracture groove; 11. Test notch. Detailed Implementation

[0038] The present invention will now be described in further detail with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and not intended to limit it. Furthermore, it should be noted that, for ease of description, the accompanying drawings show only the parts relevant to the present invention, and not all of the structures.

[0039] In the description of this invention, unless otherwise explicitly specified and limited, the terms "connected," "linked," and "fixed" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0040] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on top" of the second feature includes the first feature directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature includes the first feature directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0041] In the description of this embodiment, the terms "upper," "lower," "right," etc., refer to the orientation or positional relationship shown in the accompanying drawings. They are used only for ease of description and simplification of operation, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the present invention. In addition, the terms "first" and "second" are used only for distinction in description and have no special meaning.

[0042] like Figures 1 to 8 As shown, existing Charpy impact test specimen processing methods include the following steps:

[0043] S01: Welding is carried out under the witness of the classification society to obtain test plate 1, and the original steel stamp 7 is struck next to the weld 6 on the top of test plate 1.

[0044] S02: Cut the first sample blank 2, which includes weld 6 and original steel stamp 7, along the height direction of the test plate 1;

[0045] S03: Under the witness of the classification society, the first transfer stamp 8 is struck on the side of the first sample blank 2;

[0046] S04: Cut a second sample blank 3 containing the weld 6 and the first transfer stamp 8 along the transverse direction of the first sample blank 2, so that the height of the second sample blank 3 is h, wherein the transverse direction of the first sample blank 2 is perpendicular to the height direction of the first sample blank 2. During this process, the original stamp 7 is processed and removed.

[0047] S05: Under the witness of the classification society, the second transfer stamp 9 is struck on the top of the second sample blank 3;

[0048] S06: An impact specimen 5 containing the weld 6 and the second transfer stamp 9 is cut along the height direction of the second specimen blank 3. During this process, the first transfer stamp 8 is processed and removed.

[0049] S07: After the classification society has checked that the second transfer stamp 9 is correct, the impact test is carried out on the impact specimen 5.

[0050] It should be noted that, for ease of understanding, Figures 2-8 as well as Figure 10 In the text, "Stamp 0" represents the original stamp 7, "Stamp 1" represents the first transferred stamp 8, and "Stamp 2" represents the second transferred stamp 9.

[0051] After the above steps, the existing Charpy impact test specimen processing method requires at least two steel stamp transfers, each of which requires the presence of the classification society to witness. On the one hand, the arrangement of classification society inspectors is uncertain, which can easily lead to delays in witnessing and processing stagnation. On the other hand, subsequent processing procedures need to be completed between the two steel stamp transfers. If there are process adjustments or equipment failures, the time consumption will be further increased, resulting in a significant extension of the specimen processing cycle. This will not only affect the progress of welding procedure qualification, but may also lead to the inability to provide timely feedback on the test results of the production welding test plate 1, thereby adversely affecting the entire product production cycle.

[0052] To address the aforementioned technical problems, this embodiment provides a Charpy impact specimen processing method, specifically as follows: Figures 8-11 , combined Figures 2-8 As shown, it includes the following steps:

[0053] S1: Welding is carried out under the witness of the classification society to obtain test plate 1, and the original steel stamp 7 is struck next to the weld 6 on the top of test plate 1.

[0054] S2: Cut the first sample blank 2, which includes weld 6 and original steel stamp 7, along the height direction of the test plate 1;

[0055] S3: Under the witness of the classification society, the first transfer stamp 8 is struck on the side of the first sample blank 2;

[0056] S4: Cut a second sample blank 3 containing the weld 6 and the first transfer stamp 8 along the transverse direction of the first sample blank 2, so that the height of the second sample blank 3 is h, wherein the transverse direction of the first sample blank 2 is perpendicular to the height direction of the first sample blank 2. During this process, the original stamp 7 is processed and removed.

[0057] S5: Cut a preparatory sample 4 containing the weld 6 and the first transfer stamp 8 along the height direction of the second sample blank 3, so that the width of the preparatory sample 4 is n, and process a fracture groove 10 between the weld 6 and the first transfer stamp 8 of the preparatory sample 4, so that the distance between the fracture groove 10 and the first side 41 is m, and process a test notch 11 between the first side 41 and the fracture groove 10, wherein the first side 41 is the side of the second sample blank 3 away from the first transfer stamp 8.

[0058] S6: After the classification society checks that the first transfer stamp 8 is correct, the prepared sample 4 is broken through the fracture groove 10 to obtain the impact sample 5 with the test notch 11, and the impact sample 5 is subjected to an impact test.

[0059] By machining the fracture groove 10 on the second sample blank 3, the impact sample 5 that meets the test standard can be obtained on the spot by breaking the fracture groove 10 before the impact test. This eliminates the transfer and witnessing steps of the second transfer stamp 9, simplifies the processing and witnessing process of the impact sample 5, and can effectively shorten the sample processing cycle, thereby ensuring the progress of welding process evaluation and timely feedback of the test results of the production welding test plate 1, and thus improving production efficiency.

[0060] It should be noted that the specific methods for cutting the first sample blank 2, the second sample blank 3, and the preparatory sample 4, including but not limited to sawing or grinding, are not limited here.

[0061] like Figure 6 Combination Figure 10 As shown, in some optional embodiments, in step S5, the test notch 11 is opened on one side of the pre-test specimen 4 along the extension direction of the weld 6. The side allows for a clear observation of the complete structure of the weld 6 metal, the fusion line (the interface between the weld 6 and the base metal), and the heat-affected zone (the area of ​​the base metal subjected to welding heat), which is beneficial for accurately controlling the notch to fall within the preset evaluation area specified by industry standards.

[0062] like Figure 10 and Figure 11As shown, in some optional embodiments, the fracture groove 10 and the test notch 11 have the same opening direction. On the one hand, since they have the same opening direction, they can be processed in the same or similar processing steps, which helps to simplify the processing flow and reduce tooling adjustments; on the other hand, the bottom of the fracture groove 10 is located on the side away from the test notch 11, which can minimize the influence of the stress generated when the fracture groove 10 is broken on the test results, and help to ensure the accuracy of the test results.

[0063] The methods for breaking the fracture groove 10 include, but are not limited to, breaking it by hand, breaking it with pliers, or cutting it with a saw, and are not limited here.

[0064] In some optional embodiments, the fracture groove 10 is a V-shaped groove, which has a simple structure, is easy to process, and is easy to break. Optionally, the fracture groove 10 can also be a U-shaped groove.

[0065] In some optional embodiments, the thickness H of the bottom of the fracture groove 10 ranges from (1±0.2) mm. On the one hand, H is not less than 0.8 mm, which can ensure the structural strength of the prepared sample 4 and prevent accidental breakage before the classification society inspection; on the other hand, H is not greater than 1.2 mm, which makes it easy to break and avoids excessive stress generated during breakage from affecting the experimental results.

[0066] In some optional embodiments, m is (55±0.6) mm, n is (10±0.2) mm, and h is (10±0.2) mm, which conforms to the current national and industry standards (GB / T 229-2020, ISO 148-1:2020, ASTM E23-23) for the size specifications of Charpy impact test specimens, ensuring that the test results are of reference value.

[0067] According to current national and industry standards, the test notch 11 can be a V-shaped notch or a U-shaped notch.

[0068] When the test notch 11 is a V-shaped notch, the angle of the V-shaped notch is (45±2)°, the depth of the V-shaped notch is (2±0.05)mm, and the bottom radius of the V-shaped notch is (0.25±0.025)mm.

[0069] When the test notch 11 is a U-shaped notch, the depth of the U-shaped notch is (2±0.05) mm, and the bottom radius of the U-shaped notch is (1±0.1) mm.

[0070] Obviously, the above embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not intended to limit the implementation of the present invention. Those skilled in the art will be able to make various obvious changes, readjustments, and substitutions without departing from the scope of protection of the present invention. It is neither necessary nor possible to exhaustively describe all embodiments here. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the scope of protection of the claims of the present invention.

Claims

1. A method for processing Charpy impact test specimens, characterized in that, Includes the following steps: S1: Welding is performed under the witness of the classification society to obtain a test plate (1), and the original steel stamp (7) is struck next to the weld (6) on the top of the test plate (1); S2: Cut a first sample blank (2) containing the weld (6) and the original steel stamp (7) along the height direction of the test plate (1); S3: Under the witness of the classification society, the first transfer stamp (8) is struck on the side of the first sample blank (2); S4: Cut a second sample blank (3) containing the weld (6) and the first transfer stamp (8) along the transverse direction of the first sample blank (2), so that the height of the second sample blank (3) is h, wherein the transverse direction of the first sample blank (2) is perpendicular to the height direction of the first sample blank (2). S5: Cut a preparatory sample (4) containing the weld (6) and the first transfer stamp (8) along the height direction of the second sample blank (3), so that the width of the preparatory sample (4) is n, and process a fracture groove (10) between the weld (6) and the first transfer stamp (8) of the preparatory sample (4), so that the distance between the fracture groove (10) and the first side (41) is m, and process a test notch (11) between the first side (41) and the fracture groove (10), wherein the first side (41) is the side of the second sample blank (3) away from the first transfer stamp (8); S6: After the classification society checks that the first transfer stamp (8) is correct, the preparatory sample (4) is broken through the fracture groove (10) to obtain the impact sample (5) with the test notch (11), and the impact sample (5) is subjected to an impact test.

2. The Charpy impact specimen processing method according to claim 1, characterized in that, In step S5, the test notch (11) is opened on one side of the pre-test specimen (4) along the extension direction of the weld (6).

3. The Charpy impact specimen processing method according to claim 2, characterized in that, The fracture groove (10) has the same opening direction as the test notch (11).

4. The Charpy impact specimen processing method according to claim 1, characterized in that, The fracture groove (10) is a V-shaped groove.

5. The Charpy impact specimen processing method according to claim 1, characterized in that, The thickness H of the bottom of the fracture groove (10) is in the range of (1±0.2) mm.

6. The Charpy impact specimen processing method according to claim 1, characterized in that, m is (55±0.6) mm, n is (10±0.2) mm, and h is (10±0.2) mm.

7. The Charpy impact specimen processing method according to claim 1, characterized in that, The test notch (11) is a V-shaped notch.

8. The Charpy impact specimen processing method according to claim 7, characterized in that, The angle of the V-shaped notch is (45±2)°, the depth of the V-shaped notch is (2±0.05)mm, and the bottom radius of the V-shaped notch is (0.25±0.025)mm.

9. The Charpy impact specimen processing method according to claim 1, characterized in that, The test notch (11) is a U-shaped notch.

10. The Charpy impact specimen processing method according to claim 9, characterized in that, The depth of the U-shaped notch is (2±0.05) mm, and the bottom radius of the U-shaped notch is (1±0.1) mm.

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