Method for evaluating hydrogen induced cracking performance of high-strength steel

Abstract

The invention discloses a high-strength steel hydrogen induced cracking performance evaluation method which comprises the steps that a high-strength steel plate is prepared into a V-shaped sample with the angle being a first preset angle, so that the outer side of a bend angle of the V-shaped sample is free of microcracks; the angle of the V-shaped sample is adjusted to be a second preset angle in a stress loading mode, so that the outer side of the bending angle of the V-shaped sample is free of microcracks, and the second preset angle is smaller than the first preset angle; placing the V-shaped sample loaded with the stress in an acid solution for soaking to obtain target time when the micro-crack is generated on the outer side of the bending angle of the V-shaped sample; and evaluating the hydrogen induced cracking performance of the V-shaped sample according to the target time. The method can simulate the influence of stress on the high-strength steel, and improves the accuracy of hydrogen induced cracking performance evaluation of the high-strength steel.

Description

Technical Field

[0001] The present application relates to the technical field of high-strength steel, and in particular, to a method for evaluating hydrogen-induced cracking performance of high-strength steel. Background Art

[0002] When high-strength steel is in a hydrogen-containing environment for a long time, hydrogen atoms continue to penetrate into the steel matrix. As the hydrogen atoms diffuse and aggregate inside the steel matrix, the brittleness of the steel material increases, resulting in hydrogen-induced cracking or hydrogen-induced delayed cracking. In addition, during the processing and manufacturing process of high-strength steel, factors such as deformation and residual stress will be introduced to aggravate the occurrence of hydrogen-induced cracking, making high-strength steel prone to hydrogen-induced cracking in a hydrogen-containing environment. Therefore, in order to accurately evaluate the performance of high-strength steel, it is necessary to test the hydrogen-induced cracking performance of high-strength steel.

[0003] At present, there are many test methods for testing the hydrogen-induced cracking performance of steel materials, including slow strain rate tensile test, constant load test, U-bending test, four-point bending test, etc. However, the above test methods are mainly used to test the performance of high-strength steel itself, and none of them considers the influence of factors such as deformation and residual stress on the hydrogen-induced cracking performance of high-strength steel, so they cannot truly evaluate the risk of hydrogen-induced cracking of high-strength steel. Summary of the invention

[0004] The embodiments of the present application provide a method for evaluating the hydrogen-induced cracking performance of high-strength steel, which can simulate the situation where high-strength steel is affected by stress and improve the accuracy of the evaluation of the hydrogen-induced cracking performance of high-strength steel.

[0005] Other features and advantages of the present application will become apparent from the following detailed description, or may be learned in part by the practice of the present application.

[0006] According to a first aspect of an embodiment of the present application, a method for evaluating hydrogen-induced cracking performance of high-strength steel is provided, comprising:

[0007] The high-strength steel plate is prepared into a V-shaped specimen with an angle of a first preset angle, so that there are no microcracks on the outer side of the bending angle of the V-shaped specimen;

[0008] Adjusting the angle of the V-shaped specimen to a second preset angle by applying stress, so that there are no microcracks on the outer side of the bending angle of the V-shaped specimen, and the second preset angle is smaller than the first preset angle;

[0009] The V-shaped specimen loaded with stress is placed in an acid solution for immersion, and a target time for microcracks to be generated outside the bend of the V-shaped specimen is obtained;

[0010] Based on the target time, the hydrogen induced cracking performance of the V-shaped specimen is evaluated.

[0011] In some embodiments of the present application, based on the above scheme, the high-strength steel plate is prepared into a V-shaped specimen with an angle of a first preset angle so that there is no microcrack on the outer side of the bend of the V-shaped specimen, including:

[0012] A hemispherical indenter is used to prepare a plurality of high-strength steel plates into a plurality of V-shaped specimens with a first preset angle and an R angle, wherein the diameter of the hemispherical indenter corresponding to each high-strength steel plate is different; and it is determined whether microcracks are generated on the outer side of the bending angle of each V-shaped specimen, and whether to adjust the first preset angle based on the judgment result.

[0013] In some embodiments of the present application, based on the above solution, determining whether to adjust the first preset angle according to the judgment result includes:

[0014] If microcracks are generated on the outer side of the bend of the V-shaped test specimen, the first preset angle is increased;

[0015] If no microcracks are generated on the outer side of the bend of the V-shaped test specimen, the first preset angle is reduced.

[0016] In some embodiments of the present application, based on the above-mentioned solution, the angle of the V-shaped specimen is adjusted to a second preset angle by loading stress so that there are no microcracks on the outer side of the bend of the V-shaped specimen, including:

[0017] The angle of the V-shaped specimen is adjusted to a second preset angle by loading stress, and it is determined whether microcracks are generated on the outer side of the bend of the V-shaped specimen. According to the determination result, it is determined whether to adjust the first preset angle and the second preset angle.

[0018] In some embodiments of the present application, based on the above solution, determining whether to adjust the first preset angle and the second preset angle according to the judgment result includes:

[0019] If microcracks are generated on the outer side of the bend of the V-shaped test specimen, the first preset angle and the second preset angle are increased;

[0020] If no microcracks are generated on the outer side of the bend of the V-shaped test specimen, the first preset angle and the second preset angle are reduced.

[0021] In some embodiments of the present application, based on the above solution, adjusting the angle of the V-shaped test specimen to a second preset angle by applying stress includes:

[0022] The angle of the V-shaped specimen is adjusted to a second preset angle by a fixture, and stress is applied to the V-shaped specimen.

[0023] In some embodiments of the present application, based on the above solution, the clamp includes:

[0024] The fixed plate and the movable plate are parallel to each other and are used to clamp the two ends of the V-shaped specimen;

[0025] The spacing adjustment mechanism is used to adjust the spacing between the fixed plate and the movable plate to adjust the angle of the V-shaped specimen and load stress on the V-shaped specimen.

[0026] In some embodiments of the present application, based on the above solution, the spacing adjustment mechanism includes:

[0027] The adjusting screw is perpendicular to the fixed plate, one end of which is fixedly connected to the fixed plate, and the other end of which passes through the movable plate;

[0028] The adjusting nut is threadedly connected to the adjusting screw rod, and the adjusting nut and the fixing plate are located on both sides of the moving plate.

[0029] In some embodiments of the present application, based on the above solution, the clamp further includes:

[0030] The gasket is made of insulating non-metallic material, is sleeved on the adjusting screw, is located on the opposite side of the fixed plate and the movable plate, and is used to clamp the two ends of the V-shaped specimen to prevent the V-shaped specimen from directly contacting the fixed plate and the movable plate.

[0031] In some embodiments of the present application, based on the aforementioned scheme, the acidic solution is an acetic acid solution with a concentration of 0.1-1 mol / L.

[0032] The beneficial effects of this application are as follows:

[0033] The V-shaped specimen loaded with stress is placed in an acidic solution for immersion, thereby simulating the hydrogen-containing environment affected by stress after high-strength steel pipe making, thereby improving the accuracy of the hydrogen-induced cracking performance evaluation of the high-strength steel.

[0034] It should be understood that the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] The drawings herein are incorporated into the specification and constitute a part of the specification, showing embodiments consistent with the present application, and together with the specification, are used to explain the principles of the present application. Obviously, the drawings described below are only some embodiments of the present application, and for ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work. In the drawings:

[0036] Figure 1 A flow chart of a method for evaluating hydrogen-induced cracking performance of high-strength steel in an embodiment of the present application is shown;

[0037] Figure 2 A schematic diagram of preparing a V-shaped specimen in an embodiment of the present application is shown;

[0038] Figure 3 A schematic structural diagram of a clamp in an embodiment of the present application is shown. DETAILED DESCRIPTION

[0039] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0040] In addition, described feature, structure or characteristic can be combined in one or more embodiments in any suitable manner. In the following description, many specific details are provided to provide a full understanding of the embodiments of the present application. However, those skilled in the art will appreciate that the technical scheme of the present application can be put into practice without one or more of the specific details, or other methods, components, devices, steps, etc. can be adopted. In other cases, known methods, devices, realizations or operations are not shown or described in detail to avoid blurring the various aspects of the application.

[0041] The block diagrams shown in the accompanying drawings are merely functional entities and do not necessarily correspond to physically independent entities. That is, these functional entities may be implemented in software form, or in one or more hardware modules or integrated circuits, or in different networks and / or processor devices and / or microcontroller devices.

[0042] The flowcharts shown in the accompanying drawings are only exemplary and do not necessarily include all the contents and operations / steps, nor must they be executed in the order described. For example, some operations / steps can be decomposed, and some operations / steps can be combined or partially combined, so the actual execution order may change according to actual conditions.

[0043] In the description of this application, it should be understood that the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the feature. In the description of this application, unless otherwise specified, "plurality" means two or more.

[0044] Figure 1 A flow chart of a method for evaluating hydrogen-induced cracking performance of high-strength steel in an embodiment of the present application is shown. Figure 2 A schematic diagram of preparing a V-shaped specimen in an embodiment of the present application is shown, see Figure 1 and Figure 2 The present application provides a method for evaluating the hydrogen-induced cracking performance of high-strength steel, which includes at least S1 to S4, which are described in detail as follows:

[0045] In step S1, a high-strength steel plate is prepared into a V-shaped specimen with an angle of a first preset angle, so that there are no microcracks on the outer side of the bending angle of the V-shaped specimen.

[0046] In step S2, the angle of the V-shaped specimen is adjusted to a second preset angle by applying stress, so that there are no microcracks on the outer side of the bend of the V-shaped specimen, and the second preset angle is smaller than the first preset angle;

[0047] In step S3, the V-shaped specimen loaded with stress is placed in an acidic solution for immersion, and a target time for microcracks to be generated outside the bend of the V-shaped specimen is obtained;

[0048] In step S4, the hydrogen induced cracking performance of the V-shaped specimen is evaluated according to the target time.

[0049] Specifically, the longer the target time is, the better the hydrogen induced cracking performance of the V-shaped specimen. For example, for high-strength steel No. 1 and high-strength steel No. 2, the first preset angle and the second preset angle are the same. When high-strength steel No. 1 and high-strength steel No. 2 are placed in the same acidic solution in the same way, the corresponding target time for high-strength steel No. 1 is 16 hours, and the corresponding target time for high-strength steel No. 2 is 24 hours. Then, the hydrogen induced cracking performance of high-strength steel No. 2 is better than that of high-strength steel No. 1.

[0050] Optionally, the step of preparing the high-strength steel plate into a V-shaped specimen having a first preset angle so that there are no microcracks on the outer side of the bend of the V-shaped specimen comprises:

[0051] The plurality of high-strength steel plates are prepared into a plurality of V-shaped test pieces with a first preset angle and an R angle by using a hemispherical indenter, wherein the diameter of the hemispherical indenter corresponding to each high-strength steel plate is different;

[0052] It is determined whether microcracks are generated on the outer side of the bend angle of each V-shaped test piece, and whether to adjust the first preset angle is determined according to the determination result.

[0053] Specifically, the hemispherical indenter can be installed on a hydraulic universal testing machine, and the high-strength steel plate can be prepared into a V-shaped specimen by a cold bending process. When the hemispherical indenter prepares the high-strength steel plate into a V-shaped specimen with a first preset angle, the bending angle of the V-shaped specimen is an R angle, that is, a rounded angle. The diameter of the hemispherical indenter is different, and the R angle of the V-shaped specimen is different, thereby simulating square tubes or bent parts with different R angles, and by changing the R angle, the influence of different R angles on hydrogen embrittlement cracking performance can be determined, see Figure 2 , the bending angle of the V-shaped specimen is Figure 2The convex part of the V-shaped specimen, the outer side of the bend of the V-shaped specimen is Figure 2 The lower surface of the raised portion of the V-shaped specimen.

[0054] See also Figure 2 The hemispherical indenter includes a cylindrical portion and a hemispherical portion, the end surfaces of the hemispherical portion and the cylindrical portion are integrally formed, and the spherical portion of the hemispherical portion is used to press the V-shaped sample.

[0055] Optionally, the thickness of the high-strength steel plate is a preset thickness, such as 2 mm, to facilitate bending of the high-strength steel plate. When the initial thickness of the high-strength steel plate is greater than the preset thickness, the thickness of the high-strength steel plate is changed to the preset thickness. When the initial thickness of the high-strength steel plate is less than or equal to the preset thickness, the thickness of the high-strength steel plate is not changed.

[0056] Optionally, before preparing the high-strength steel plate into a V-shaped test specimen having an angle of a first preset angle, the method further includes:

[0057] The high-strength steel plate is prepared into a long strip-shaped steel plate, for example, a steel plate with a length of 100 mm, a width of 20 mm, and a thickness of 2 mm.

[0058] Optionally, the step of preparing the high-strength steel plate into a V-shaped specimen having a first preset angle so that there are no microcracks on the outer side of the bend of the V-shaped specimen comprises:

[0059] Get a first initial angle;

[0060] The high-strength steel plate is prepared into a V-shaped specimen with a first initial angle, and it is determined whether microcracks are generated on the outer side of the bending angle of the V-shaped specimen, and whether to adjust the first preset angle is determined according to the determination result.

[0061] Optionally, whether microcracks are generated on the outer side of the bend of the V-shaped specimen may be determined by visual inspection or observation using a metallographic microscope.

[0062] Optionally, determining whether to adjust the first preset angle according to the judgment result includes:

[0063] If microcracks are generated on the outer side of the bend of the V-shaped test specimen, the first preset angle is increased;

[0064] If no microcracks are generated on the outer side of the bend of the V-shaped test specimen, the first preset angle is reduced.

[0065] Optionally, when the first angle is increased, it may be increased by 15° each time, and when the first preset angle is decreased, it may be decreased by 15° each time.

[0066] Optionally, the adjusting the angle of the V-shaped specimen to a second preset angle by applying stress so that there are no microcracks on the outer side of the bend of the V-shaped specimen includes:

[0067] The angle of the V-shaped specimen is adjusted to a second preset angle by loading stress, and it is determined whether microcracks are generated on the outer side of the bend of the V-shaped specimen. According to the determination result, it is determined whether to adjust the first preset angle and the second preset angle.

[0068] Optionally, determining whether to adjust the first preset angle and the second preset angle according to the judgment result includes:

[0069] If microcracks are generated on the outer side of the bend of the V-shaped test specimen, the first preset angle and the second preset angle are increased;

[0070] If no microcracks are generated on the outer side of the bend of the V-shaped test specimen, the first preset angle and the second preset angle are reduced.

[0071] Optionally, adjusting the angle of the V-shaped test specimen to a second preset angle by applying stress comprises:

[0072] The angle of the V-shaped specimen is adjusted to a second preset angle by a fixture, and stress is applied to the V-shaped specimen.

[0073] Figure 3 Schematic diagram of the structure of the clamp in the embodiment of the present application is shown. Figure 3 In the figure, 1 is a fixed plate, 2 is an adjusting nut, 3 is a movable plate, and 4 is a gasket.

[0074] Alternatively, see Figure 3 , the fixture comprises:

[0075] The fixed plate and the movable plate are parallel to each other and are used to clamp the two ends of the V-shaped specimen;

[0076] The spacing adjustment mechanism is used to adjust the spacing between the fixed plate and the movable plate to adjust the angle of the V-shaped specimen and load stress on the V-shaped specimen.

[0077] Optionally, the spacing adjustment mechanism includes:

[0078] The adjusting screw is perpendicular to the fixed plate, one end of which is fixedly connected to the fixed plate, and the other end of which passes through the movable plate;

[0079] The adjusting nut is threadedly connected to the adjusting screw rod, and the adjusting nut and the fixing plate are located on both sides of the moving plate.

[0080] Optionally, the fixture further comprises:

[0081] The gasket is made of insulating non-metallic material, is sleeved on the adjusting screw, and is located on the opposite side of the fixed plate and the movable plate. It is used to clamp the two ends of the V-shaped specimen to prevent the V-shaped specimen from directly contacting the fixed plate and the movable plate. When the fixed plate and the movable plate are made of metal materials, galvanic corrosion of the V-shaped specimen can be avoided, which affects the evaluation accuracy.

[0082] Optionally, the gasket is in a flange shape.

[0083] For a better understanding of the embodiments of the present application, see Figure 3 , explain the use of the fixture:

[0084] The V-shaped specimen is placed in an inverted V shape, with both ends in contact with the gaskets. The adjusting nut is turned to reduce the distance between the moving plate and the fixed plate. Figure 3 The left side of the V-shaped specimen is moved, and a clamping force is applied to the V-shaped specimen to reduce the angle of the V-shaped specimen. At this time, the V-shaped specimen is deformed and affected by the stress, and the angle of the V-shaped specimen is adjusted from the first preset angle to the second preset angle. It can be understood that when the adjusting bolt is rotated to loosen the clamping of the V-shaped specimen so that the V-shaped specimen is in a free state, the V-shaped specimen will rebound, for example, the angle of the V-shaped specimen rebounds from the second preset angle to the target angle, and the target angle is greater than the second preset angle.

[0085] Optionally, the fixed plate, the movable plate, the adjusting screw and the adjusting nut are made of stainless steel to prevent the clamp from being corroded in an acidic solution, and the gasket is made of polytetrafluoroethylene.

[0086] Optionally, the acidic solution is an acetic acid solution with a concentration of 0.1-1 mol / L.

[0087] In an embodiment of the present application, the V-shaped specimen is clamped by a clamp so that the V-shaped specimen is affected by stress, and the V-shaped specimen affected by stress is placed in an acidic solution for immersion, thereby simulating the hydrogen-containing environment in which high-strength steel is affected by stress, thereby improving the accuracy of the hydrogen-induced cracking performance evaluation of high-strength steel.

[0088] The functions described herein may be implemented in hardware, software executed by a processor, firmware, or any combination thereof. If implemented in software executed by a processor, the functions may be stored as one or more instructions or codes on a computer-readable medium or transmitted via a computer-readable medium. Other examples and implementations are within the scope and spirit of the present application and the appended claims. For example, due to the nature of software, the functions described above may be implemented using software executed by a processor, hardware, firmware, hard wiring, or a combination of any of these. In addition, each functional unit may be integrated into a processing unit, each unit may exist physically separately, or two or more units may be integrated into one unit.

[0089] In the several embodiments provided in this application, it should be understood that the disclosed technical content can be implemented in other ways. Among them, the device embodiments described above are only schematic. For example, the division of the units can be a logical function division. There may be other division methods in actual implementation. For example, multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be through some interfaces, indirect coupling or communication connection of units or modules, which can be electrical or other forms.

[0090] The units described as separate components may or may not be physically separated, and the components of the control device may or may not be physical units, that is, they may be located in one place or distributed in multiple units. Some or all of the units may be selected according to actual needs to achieve the purpose of the present embodiment.

[0091] If the integrated unit is implemented in the form of a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present application can be essentially or partly or all or partly embodied in the form of a software product that contributes to the prior art. The computer software product is stored in a storage medium, including several instructions for a computer device (which can be a personal computer, server or network device, etc.) to perform all or part of the steps of the method described in each embodiment of the present application. The aforementioned storage medium includes: U disk, read-only memory (ROM, Read-Only Memory), random access memory (RAM, Random Access Memory), mobile hard disk, disk or optical disk, etc., which can store program code.

[0092] The above description is only an embodiment of the present application and is not intended to limit the present application. For those skilled in the art, the present application may have various modifications and variations. Any modification, equivalent substitution, improvement, etc. made within the spirit and principle of the present application shall be included in the scope of the claims of the present application.

Claims

1. A method for evaluating hydrogen-induced cracking performance of high-strength steel, characterized in that: include: The high-strength steel plate is prepared into a V-shaped specimen with an angle of a first preset angle, so that there are no microcracks on the outer side of the bending angle of the V-shaped specimen; Adjusting the angle of the V-shaped specimen to a second preset angle by applying stress, so that there are no microcracks on the outer side of the bending angle of the V-shaped specimen, and the second preset angle is smaller than the first preset angle; The V-shaped specimen loaded with stress is placed in an acid solution for immersion, and a target time for microcracks to be generated outside the bend of the V-shaped specimen is obtained; Based on the target time, the hydrogen induced cracking performance of the V-shaped specimen is evaluated.

2. A method for evaluating hydrogen-induced cracking performance of high-strength steel according to claim 1, characterized in that: The step of preparing the high-strength steel plate into a V-shaped specimen having a first preset angle so that there are no microcracks on the outer side of the bending angle of the V-shaped specimen comprises: The plurality of high-strength steel plates are prepared into a plurality of V-shaped test pieces with a first preset angle and an R angle by using a hemispherical indenter, wherein the diameter of the hemispherical indenter corresponding to each high-strength steel plate is different; It is determined whether microcracks are generated on the outer side of the bend angle of each V-shaped test piece, and whether to adjust the first preset angle is determined according to the determination result.

3. A method for evaluating hydrogen-induced cracking performance of high-strength steel according to claim 2, characterized in that: The step of determining whether to adjust the first preset angle according to the judgment result includes: If microcracks are generated on the outer side of the bend of the V-shaped test specimen, increasing the first preset angle; If no microcracks are generated on the outer side of the bend of the V-shaped test specimen, the first preset angle is reduced.

4. A method for evaluating hydrogen-induced cracking performance of high-strength steel according to claim 1, characterized in that: The step of adjusting the angle of the V-shaped specimen to a second preset angle by applying stress so that there are no microcracks on the outer side of the bending angle of the V-shaped specimen comprises: The angle of the V-shaped specimen is adjusted to a second preset angle by loading stress, and it is determined whether microcracks are generated on the outer side of the bend of the V-shaped specimen. According to the determination result, it is determined whether to adjust the first preset angle and the second preset angle.

5. A method for evaluating hydrogen-induced cracking performance of high-strength steel according to claim 4, characterized in that: The determining whether to adjust the first preset angle and the second preset angle according to the judgment result includes: If microcracks are generated on the outer side of the bend of the V-shaped specimen, the first preset angle and the second preset angle are increased; If no microcracks are generated on the outer side of the bend of the V-shaped test specimen, the first preset angle and the second preset angle are reduced.

6. A method for evaluating hydrogen-induced cracking performance of high-strength steel according to claim 1, characterized in that: The step of adjusting the angle of the V-shaped test specimen to a second preset angle by applying stress comprises: The angle of the V-shaped specimen is adjusted to a second preset angle by a fixture, and stress is applied to the V-shaped specimen.

7. A method for evaluating hydrogen-induced cracking performance of high-strength steel according to claim 6, characterized in that: The fixture comprises: The fixed plate and the movable plate are parallel to each other and are used to clamp the two ends of the V-shaped specimen; The spacing adjustment mechanism is used to adjust the spacing between the fixed plate and the movable plate to adjust the angle of the V-shaped specimen and load stress on the V-shaped specimen.

8. A method for evaluating hydrogen-induced cracking performance of high-strength steel according to claim 7, characterized in that: The spacing adjustment mechanism comprises: The adjusting screw is perpendicular to the fixed plate, one end of which is fixedly connected to the fixed plate, and the other end of which passes through the movable plate; The adjusting nut is threadedly connected to the adjusting screw rod, and the adjusting nut and the fixing plate are located on both sides of the moving plate.

9. A method for evaluating hydrogen-induced cracking performance of high-strength steel according to claim 7, characterized in that: The fixture also includes: The gasket is made of insulating non-metallic material, is sleeved on the adjusting screw, is located on the opposite side of the fixed plate and the movable plate, and is used to clamp the two ends of the V-shaped specimen to prevent the V-shaped specimen from directly contacting the fixed plate and the movable plate.

10. The method for evaluating hydrogen-induced cracking performance of high-strength steel according to claim 1, wherein the acidic solution is an acetic acid solution with a concentration of 0.1-1 mol / L.

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