Method and system for predicting fracture toughness of welding zone partition

Abstract

The invention provides a method and a system for predicting fracture toughness of a welding zone partition. The method comprises the following steps: establishing a fracture toughness prediction model containing crack propagation tortuosity; information of different tissue micro-areas of the welding area sample is obtained, heat treatment is conducted on the different tissue micro-areas through the same steel grade material, and test blocks of the different tissue micro-areas are correspondingly obtained; respectively testing the mechanical properties of the different tissue micro-area test blocks to correspondingly obtain the crack propagation morphology related to the fracture toughness of the different tissue micro-area test blocks; and performing information measurement and calculation based on the crack propagation morphology of the different tissue micro-area test blocks to obtain the crack propagation tortuosity of the different tissue micro-area test blocks, inputting the crack propagation tortuosity into the fracture toughness prediction model, and predicting the fracture toughness of the different tissue micro-area test blocks. And finally, the predicted distribution of the fracture toughness of different tissue micro-areas of the whole welding area sample is obtained. The fracture toughness of different tissue areas of the welding area can be accurately and efficiently predicted.

Description

Technical Field

[0001] The present disclosure relates to the technical field of pipeline detection and evaluation, and in particular to a method and system for predicting fracture toughness of weld zones. Background Art

[0002] In recent years, accidents caused by cracking in pipeline welds have occurred frequently. In the service safety evaluation of metal pipeline welds, fracture toughness is one of the input parameters in the safety evaluation model, and its accuracy is crucial to the evaluation results of metal pipeline welds.

[0003] At present, the fracture toughness of materials is mainly obtained through two methods: experiments and numerical simulations. One is to determine through experiments, which is divided into two methods: multi-specimen method and single-specimen method. The multi-specimen method requires a large number of samples to obtain a fracture toughness value, which is time-consuming and has large numerical dispersion; the single-specimen compliance method uses multiple loading / unloading on one sample to obtain the fracture toughness resistance curve, which involves test compliance correction, crack extension size calculation, fracture toughness formula derivation, etc. It has a strong theoretical basis and a complex calculation process, and is not easy to promote.

[0004] In addition, whether it is a single sample method or a multi-sample method, for weld zone samples, since the entire weld zone usually contains different micro-regions such as weld zone, coarse-grained fusion zone, and fine-grained fusion zone, the obtained test data can only qualitatively characterize the overall fracture toughness of the weld zone, and cannot accurately describe the fracture toughness of a certain micro-region of the weld zone. The second is to use finite element simulation calculations or even molecular dynamics and other methods to simulate the microstructure and atomic-scale behavior of the material, which can obtain indicators such as stress distribution, deformation, and fracture toughness of materials with different tissues at different temperatures, but this method involves a high degree of professionalism and is more difficult to promote.

[0005] At present, the existing technical methods usually do not consider the influence of the organization of different areas of the weld zone on the fracture toughness, and no quantitative prediction method suitable for the fracture toughness of different organizational areas has been established at home and abroad, and it is impossible to achieve accurate safety evaluation of the weld zone. Therefore, how to predict the fracture toughness of weld zones with different organizational micro-regions based on a single sample using a simple and reliable method is crucial in the service safety assessment of pipeline weld zones. Summary of the invention

[0006] The present disclosure aims to provide a method and system for predicting the fracture toughness of weld zones, so as to achieve accurate and efficient prediction of the fracture toughness of different tissue regions in the weld zone.

[0007] To achieve the above object, the present invention discloses a method for predicting the fracture toughness of weld zones, comprising:

[0008] Establish a fracture toughness prediction model that includes crack propagation tortuosity;

[0009] Obtain information on different microstructures of the weld zone specimens, and use the same steel grade material to perform heat treatment on different microstructures to obtain test blocks with different microstructures;

[0010] The mechanical properties of the test blocks with different tissue micro-regions were tested respectively, and the crack propagation morphologies related to the fracture toughness of the test blocks with different tissue micro-regions were obtained accordingly;

[0011] Based on the crack propagation morphology of the test blocks with different tissue micro-regions, information measurement and calculation are performed to obtain the crack propagation tortuosity of the test blocks with different tissue micro-regions, and input it into the fracture toughness prediction model to predict the fracture toughness of the test blocks with different tissue micro-regions, and finally obtain the predicted distribution of the fracture toughness of the different tissue micro-regions of the entire weld zone sample.

[0012] Furthermore, a fracture toughness prediction model including crack propagation tortuosity is established, including:

[0013] Based on the theory of linear elastic fracture mechanics, the fracture toughness model is obtained according to the size of the plastic zone at the crack tip and the tortuosity of crack extension;

[0014] The fracture toughness prediction model is established based on the fracture toughness model and the fracture toughness relationship model under plane strain conditions.

[0015] Furthermore, the fracture toughness model is:

[0016]

[0017] In the formula, K IC represents fracture toughness, E represents elastic modulus, A v represents the uniform deformation, h represents the size of the plastic zone at the crack tip, l 0 represents the linear length of crack extension, v represents Poisson’s ratio, R path Indicates the tortuosity of crack growth;

[0018] The fracture toughness relationship model under the plane strain condition is:

[0019]

[0020] In the formula, δ IC represents the fracture toughness under plane strain conditions, σ y Indicates the yield strength of the material;

[0021] The fracture toughness prediction model is:

[0022]

[0023] Furthermore, different micro-region information of the weld zone sample is obtained, and the same steel grade material is used for heat treatment of different micro-regions to obtain test blocks of different micro-regions, including:

[0024] Cut the metallographic specimen of the welded joint including the entire weld zone and observe it through a metallographic microscope to obtain the microstructure type and grain size of the weld zone, coarse-grained heat-affected zone, and fine-grained heat-affected zone;

[0025] For the weld zone, coarse-grained heat-affected zone, and fine-grained heat-affected zone, the same steel grade material is used for heat treatment, and the weld zone test block, coarse-grained heat-affected zone test block, and fine-grained heat-affected zone test block with the same structure and grain size are obtained accordingly;

[0026] Among them, the different micro-organization zones of the weld zone specimen include: weld zone, coarse-grained heat-affected zone and fine-grained heat-affected zone.

[0027] Furthermore, the mechanical properties of the specimens with different microstructures were tested respectively, and the crack propagation morphologies related to the fracture toughness of the specimens with different microstructures were obtained, including:

[0028] The test blocks with different microstructures are processed to obtain standard tensile test pieces and fracture toughness test pieces of each microstructure;

[0029] Performing a standard tensile property test on the standard tensile specimen to obtain the yield strength and uniform deformation of the standard tensile specimen;

[0030] Performing a standard fracture toughness test on the fracture toughness specimen to obtain the size of the crack tip plastic zone and the fracture cross section of the fracture toughness specimen;

[0031] Preparing a fracture cross section sample based on the fracture toughness sample to obtain a fracture cross section sample, and observing the sample through an optical microscope to obtain the crack propagation morphology of the fracture toughness sample;

[0032] Among them, the mechanical properties tests include tensile properties test and fracture toughness test.

[0033] Furthermore, the crack extension morphology of the fracture toughness specimen is measured to obtain the crack linear length and the actual crack length of each micro-region specimen;

[0034] The crack propagation tortuosity of the corresponding tissue micro-area test block is calculated by using the crack linear length and the actual crack length of each tissue micro-area test block;

[0035] The crack propagation tortuosity, yield strength, uniform deformation, crack tip plastic zone size, and crack linear length of different tissue micro-area test blocks are input into the fracture toughness prediction model to obtain the fracture toughness prediction value of the corresponding tissue micro-area test block, that is, the fracture toughness prediction value of the corresponding tissue micro-area of ​​the weld zone sample is obtained.

[0036] Further, information measurement is performed based on the crack extension morphology of different tissue micro-area test blocks to obtain the crack linear length and actual crack length of each tissue micro-area test block, including:

[0037] Through optical microscope observation, multiple fields of view of fracture section specimens of different tissue micro-area specimens were randomly selected for measurement, and multiple initial crack linear lengths and multiple initial crack actual lengths of each tissue micro-area specimen were obtained and the average values ​​were calculated respectively to obtain the crack linear length and crack actual length of each tissue micro-area specimen.

[0038] Furthermore, when the standard tensile specimen and the fracture toughness specimen are subjected to elongation test and fracture toughness test respectively, the tests are conducted at different temperatures to obtain the yield strength, the uniform deformation, the size of the crack tip plastic zone, the fracture cross section, and the crack extension morphology at different temperatures;

[0039] By measuring and calculating the information of the crack extension morphology, the linear length of the crack, the actual length of the crack and the tortuosity of the crack extension of the micro-area test blocks with different structures at different temperatures are obtained;

[0040] The crack propagation tortuosity, yield strength, uniform deformation, crack tip plastic zone size, and crack linear length of different tissue micro-area test blocks at different temperatures are input into the fracture toughness prediction model to obtain the corresponding fracture toughness prediction values ​​of the tissue micro-area test blocks at different temperatures.

[0041] Based on the same inventive concept, the present disclosure also provides a prediction system for weld zone fracture toughness, comprising:

[0042] Establishing a model unit for establishing a fracture toughness prediction model including crack propagation tortuosity;

[0043] The heat treatment unit is used to obtain information on different micro-organisms of the weld zone sample, and to perform heat treatment on different micro-organisms using the same steel grade material to obtain test blocks with different micro-organisms;

[0044] The test acquisition unit is used to test the mechanical properties of different tissue micro-area test blocks respectively, and obtain the crack extension morphology related to the fracture toughness of different tissue micro-area test blocks;

[0045] The prediction unit is used to measure and calculate information based on the crack extension morphology of the test blocks with different tissue micro-regions, obtain the crack extension tortuosity of the test blocks with different tissue micro-regions, and input it into the fracture toughness prediction model to predict the fracture toughness of the test blocks with different tissue micro-regions, and finally obtain the predicted distribution of the fracture toughness of the different tissue micro-regions of the entire weld zone sample.

[0046] Based on the same inventive concept, an embodiment of the present invention further provides an electronic device, comprising: a memory, a processor; the processor is used to read and execute a computer program stored in the memory to implement the aforementioned method for predicting fracture toughness of weld zones.

[0047] Based on the same inventive concept, an embodiment of the present invention further provides a computer storage medium, wherein the computer storage medium stores computer executable instructions, and when the computer executable instructions are executed, the aforementioned method for predicting fracture toughness of weld zones is implemented.

[0048] The technical effects and advantages disclosed in the present invention are as follows: by comprehensively considering the effects of intrinsic fracture resistance and extrinsic fracture resistance on the fracture toughness of different tissue regions in the weld zone, a fracture toughness prediction model based on the tensile properties of the weld zone and the tortuosity of crack propagation is established. The fracture toughness of different tissue micro-regions in the weld zone at different temperatures is predicted through efficient and concise methods and means, which can provide more accurate data for weld safety evaluation, thereby improving the accuracy of the evaluation.

[0049] Other features and advantages of the present disclosure will be described in the following description, and partly become apparent from the description, or be understood by implementing the present disclosure. The purpose and other advantages of the present disclosure can be realized and obtained by the structures pointed out in the description, claims and drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0050] In order to more clearly illustrate the technical solutions in the embodiments of the present disclosure, the drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present disclosure. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0051] Figure 1 A method for predicting fracture toughness of weld zones according to an embodiment of the present disclosure;

[0052] Figure 2 is a schematic diagram of the tensile properties of the weld zone in an embodiment of the present disclosure;

[0053] Figure 3 Schematic diagram of the actual length and linear length of crack extension in the weld zone in the embodiment of the present disclosure;

[0054] Figure 4 A schematic diagram showing a comparison of crack propagation paths in a weld zone at different temperatures in an embodiment of the present disclosure;

[0055] Figure 5 A schematic diagram showing a comparison between the predicted value and the measured value of the fracture toughness of the weld zone at different temperatures in the embodiment of the present disclosure;

[0056] Figure 6 This is a schematic diagram of the structure of a prediction system for fracture toughness of weld zones according to an embodiment of the present disclosure;

[0057] Figure 7 The figure is a schematic diagram of the structure of an electronic device according to an embodiment of the present invention. DETAILED DESCRIPTION

[0058] The following will be combined with the drawings in the embodiments of the present disclosure to clearly and completely describe the technical solutions in the embodiments of the present disclosure. Obviously, the described embodiments are only part of the embodiments of the present disclosure, not all of the embodiments. Based on the embodiments in the present disclosure, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present disclosure.

[0059] To address the deficiencies of the prior art, the present disclosure provides a method for predicting the fracture toughness of weld zones. Figure 1 As shown, the following steps are included:

[0060] Step S1: Establishing a fracture toughness prediction model including crack extension tortuosity, specifically including:

[0061] Based on the theory of linear elastic fracture mechanics, according to the size of the plastic zone at the crack tip (i.e., crack propagation resistance) and the tortuosity of crack propagation (i.e., crack propagation path), the fracture toughness model is obtained as follows:

[0062]

[0063] In the formula, K IC represents fracture toughness, E represents elastic modulus, A v represents the uniform deformation, h represents the size of the plastic zone at the crack tip, l 0 represents the linear length of crack extension, v represents Poisson’s ratio, R path Indicates the tortuosity of crack growth.

[0064] The fracture toughness prediction model is established based on the fracture toughness model and the fracture toughness relationship model under plane strain conditions.

[0065] Among them, the fracture toughness relationship model under plane strain conditions is:

[0066]

[0067] In the formula, δ IC represents the fracture toughness under plane strain conditions, σ y Indicates the material yield strength, K IC represents fracture toughness, E represents elastic modulus, which is 210 GPa; v represents Poisson's ratio, which is 0.3.

[0068] The fracture toughness prediction model is obtained by combining formula (1) and formula (2):

[0069]

[0070] In the formula, K IC A is the fracture toughness. v represents the uniform deformation, h represents the size of the plastic zone at the crack tip, l 0 represents the linear length of crack extension, R path represents the crack extension tortuosity, σ y Represents the yield strength of the material.

[0071] Step S2: obtaining information of different micro-organizations of the weld zone sample, and using the same steel grade material to perform heat treatment on different micro-organizations to obtain test blocks of different micro-organizations; specifically comprising:

[0072] Cut the metallographic specimen of the welded joint including the entire weld zone and observe it through a metallographic microscope to obtain the weld zone, coarse-grained heat-affected zone, and fine-grained heat-affected zone, as well as the organizational types and grain sizes of these three micro-zones;

[0073] For the weld zone, coarse-grained heat-affected zone, and fine-grained heat-affected zone, the same steel grade material is used for heat treatment, and the weld zone test block, coarse-grained heat-affected zone test block, and fine-grained heat-affected zone test block are obtained accordingly;

[0074] Among them, the different micro-organization zones of the weld zone specimen include: weld zone, coarse-grained heat-affected zone and fine-grained heat-affected zone.

[0075] It should be noted that the size of the test block should at least ensure that the number of specimens required for the tensile test and the fracture toughness test can be processed.

[0076] Step S3: testing the mechanical properties of the test blocks with different tissue micro-regions respectively, and obtaining the crack propagation morphologies related to the fracture toughness of the test blocks with different tissue micro-regions; specifically comprising:

[0077] Step S301: Process different tissue micro-area test blocks to obtain standard tensile test specimens and fracture toughness test specimens for each tissue micro-area test block; perform standard tensile property tests on the standard tensile test specimens, such as Figure 2As shown, the yield strength and uniform deformation of the standard tensile specimen are obtained; the standard fracture toughness test is performed on the fracture toughness specimen to obtain the size of the crack tip plastic zone and the fracture cross section of the fracture toughness specimen. Specifically:

[0078] The different tissue micro-area test blocks are sampled and processed into standard tensile specimens in the shape of round rods. The diameter of the standard tensile specimens is 8 mm and the gauge length is 40 mm. The standard tensile specimens are placed on a tensile testing machine, and the temperature change is controlled by an environmental chamber. In this embodiment, liquid nitrogen is used to control the temperature. According to the standard of GB / T228.1-2021, the standard tensile specimens are subjected to tensile performance tests at different temperatures to obtain the yield strength and uniform deformation of the standard tensile specimens at different temperatures.

[0079] Similarly, different tissue micro-area test blocks are sampled and processed into fracture toughness specimens, the length of the fracture toughness specimens is 60 mm, the thickness is 5 mm, and the width is 10 mm; the fracture toughness specimens are placed on an MTS testing machine, and the temperature change is controlled by an environmental chamber. In this embodiment, liquid nitrogen is used to control the temperature. According to the standard of GB / T21143-2014, the fracture toughness specimens are subjected to fracture toughness tests at different temperatures to obtain the size of the crack tip plastic zone and the fracture cross-section of the fracture toughness specimens at different temperatures.

[0080] It should be noted that during the tensile property test and fracture toughness test of the standard tensile specimen and the fracture toughness specimen, the test temperature of the two tests was kept consistent each time the test temperature was changed for testing.

[0081] Step S302: Prepare samples based on the fracture cross sections of the fracture toughness sample at different temperatures to obtain fracture cross section samples, and observe them through an optical microscope to obtain the crack extension morphology of the corresponding fracture cross section samples at different temperatures. Specifically:

[0082] A 10×10×2 mm thin slice was taken near the fracture section of the fracture toughness specimen, polished with metallographic sandpaper, and then mechanically polished with 1.5 μm diamond paste, and then electrolytically polished. After polishing, the fracture toughness specimen was rinsed with ethanol solution, and after drying, the fracture section specimen was placed under an optical microscope to obtain the crack propagation morphology.

[0083] The specific conditions of electrolytic polishing are: voltage of 35V, time of 40s, and electrolyte of 4% perchloric acid and ethanol solution.

[0084] Step S4: measuring and calculating the crack propagation morphology of the crack toughness specimens of different tissue micro-areas at different temperatures, obtaining the crack propagation tortuosity of the different tissue micro-areas at different temperatures, and inputting it into the fracture toughness prediction model to predict the predicted values ​​of the fracture toughness of the different tissue micro-areas at different temperatures, that is, finally obtaining the predicted distribution of the fracture toughness of the different tissue micro-areas of the entire weld area specimen at different temperatures.

[0085] Step S401, measuring and calculating information on the crack propagation morphology of crack toughness samples of different micro-organization test blocks at different temperatures, and obtaining the crack propagation tortuosity of different micro-organization test blocks at different temperatures, including:

[0086] Through optical microscope observation, 5 fields of view of the fracture section specimens of different micro-region test blocks were randomly selected for measurement at each temperature, and multiple initial crack linear lengths and multiple initial crack actual lengths of each micro-region test block at each temperature were obtained and the average values ​​were calculated respectively, and the crack linear length and crack actual length of each micro-region test block at each temperature were obtained, such as Figure 3 shown.

[0087] Step S402, calculating the crack extension tortuosity of the corresponding tissue micro-area test block at different temperatures through the crack linear length and the actual crack length of each tissue micro-area test block at different temperatures;

[0088] The crack propagation tortuosity, yield strength, uniform deformation, size of the plastic zone at the crack tip, and crack linear length of different micro-region specimens at different temperatures are input into the fracture toughness prediction model to obtain the fracture toughness prediction values ​​of the corresponding micro-region specimens at different temperatures, that is, the fracture toughness prediction values ​​of the corresponding micro-regions of the weld zone specimens at different temperatures are obtained.

[0089] The predicted fracture toughness value of each micro-region test block can represent the predicted fracture toughness value of the micro-region of the weld zone test block with the same structure, and the measured value and predicted value of the fracture toughness value of different micro-regions of the weld zone test block are compared, such as Figure 5 As shown; the maximum error of this embodiment is less than 8%, that is, the prediction method disclosed in the present invention has high accuracy.

[0090] Based on the same inventive concept, the embodiment of the present disclosure also provides a prediction system for the fracture toughness of weld zones, such as Figure 6 As shown, including:

[0091] Establishing a model unit for establishing a fracture toughness prediction model including crack propagation tortuosity;

[0092] The heat treatment unit is used to obtain information on different micro-organisms of the weld zone sample, and to perform heat treatment on different micro-organisms using the same steel grade material to obtain test blocks with different micro-organisms;

[0093] The test acquisition unit is used to test the mechanical properties of different tissue micro-area test blocks respectively, and obtain the crack extension morphology related to the fracture toughness of different tissue micro-area test blocks;

[0094] The prediction unit is used to measure and calculate information based on the crack extension morphology of the test blocks with different tissue micro-regions, obtain the crack extension tortuosity of the test blocks with different tissue micro-regions, and input it into the fracture toughness prediction model to predict the fracture toughness of the test blocks with different tissue micro-regions, and finally obtain the predicted distribution of the fracture toughness of the different tissue micro-regions of the entire weld zone sample.

[0095] Regarding the system in the above embodiment, the specific manner in which each unit module performs operations has been described in detail in the embodiment of the method, and will not be elaborated here.

[0096] Based on the same inventive concept, the present disclosure also provides an electronic device, the structure of which is as follows: Figure 7 As shown, it includes: a memory and a processor, wherein the processor is used to read and execute a computer program stored in the memory to implement the aforementioned method for predicting fracture toughness of weld zones.

[0097] Based on the same inventive concept, an embodiment of the present disclosure further provides a computer storage medium, wherein the computer storage medium stores computer executable instructions, and when the computer executable instructions are executed, the aforementioned method for predicting fracture toughness of weld zones is implemented.

[0098] Finally, it should be noted that the above is only a preferred embodiment of the present disclosure and is not intended to limit the present disclosure. Although the present disclosure has been described in detail with reference to the aforementioned embodiments, it is still possible for those skilled in the art to modify the technical solutions described in the aforementioned embodiments, or to make equivalent substitutions for some of the technical features therein. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present disclosure shall be included in the protection scope of the present disclosure.

Claims

1. A method for predicting fracture toughness of weld zones, characterized in that: include: Establish a fracture toughness prediction model that includes crack propagation tortuosity; Obtain information on different micro-organisms of the weld zone specimens, and use the same steel grade material to perform heat treatment on different micro-organisms to obtain test blocks with different micro-organisms; The mechanical properties of the test blocks with different tissue micro-regions were tested respectively, and the crack propagation morphologies related to the fracture toughness of the test blocks with different tissue micro-regions were obtained accordingly; Based on the crack propagation morphology of the test blocks with different tissue micro-regions, information measurement and calculation are performed to obtain the crack propagation tortuosity of the test blocks with different tissue micro-regions, and input it into the fracture toughness prediction model to predict the fracture toughness of the test blocks with different tissue micro-regions, and finally obtain the predicted distribution of the fracture toughness of the different tissue micro-regions of the entire weld zone sample.

2. A method for predicting weld zone fracture toughness according to claim 1, characterized in that: Establish a fracture toughness prediction model that includes crack propagation tortuosity, including: Based on the theory of linear elastic fracture mechanics, the fracture toughness model is obtained according to the size of the plastic zone at the crack tip and the tortuosity of crack extension; The fracture toughness prediction model is established based on the fracture toughness model and the fracture toughness relationship model under plane strain conditions.

3. A method for predicting weld zone fracture toughness according to claim 2, characterized in that: The fracture toughness model is: In the formula, K IC represents fracture toughness, E represents elastic modulus, A represents v represents the uniform deformation, h represents the size of the plastic zone at the crack tip, l0 represents the linear length of crack extension, v represents Poisson's ratio, R path Indicates the tortuosity of crack growth; The fracture toughness relationship model under the plane strain condition is: In the formula, δ IC represents the fracture toughness under plane strain conditions, σ y Indicates the yield strength of the material; The fracture toughness prediction model is:

4. A method for predicting weld zone fracture toughness according to claim 1 or 3, characterized in that: Obtain different micro-region information of the weld zone sample, and use the same steel grade material to perform heat treatment on different micro-regions to obtain test blocks with different micro-regions, including: Cut the metallographic specimen of the welded joint including the entire weld zone and observe it through a metallographic microscope to obtain the microstructure type and grain size of the weld zone, coarse-grained heat-affected zone, and fine-grained heat-affected zone; For the weld zone, coarse-grained heat-affected zone, and fine-grained heat-affected zone, the same steel grade material is used for heat treatment, and the weld zone test block, coarse-grained heat-affected zone test block, and fine-grained heat-affected zone test block with the same structure and grain size are obtained accordingly; Among them, the different micro-organization zones of the weld zone specimen include: weld zone, coarse-grained heat-affected zone and fine-grained heat-affected zone.

5. The method for predicting the fracture toughness of weld zones according to claim 1, characterized in that: The mechanical properties of the specimens with different microstructures were tested respectively, and the corresponding crack propagation morphologies related to fracture toughness of the specimens with different microstructures were obtained, including: The test blocks with different microstructures are processed to obtain standard tensile test pieces and fracture toughness test pieces of each microstructure; Performing a standard tensile property test on the standard tensile specimen to obtain the yield strength and uniform deformation of the standard tensile specimen; Performing a standard fracture toughness test on the fracture toughness specimen to obtain the size of the crack tip plastic zone and the fracture cross section of the fracture toughness specimen; Preparing a fracture cross section sample based on the fracture toughness sample to obtain a fracture cross section sample, and observing the sample through an optical microscope to obtain the crack propagation morphology of the fracture toughness sample; Among them, the mechanical properties tests include tensile properties test and fracture toughness test.

6. A method for predicting weld zone fracture toughness according to claim 5, characterized in that: Measuring the crack extension morphology of the fracture toughness specimen to obtain the crack linear length and the actual crack length of each micro-region test block; The crack propagation tortuosity of the corresponding tissue micro-area test block is calculated by using the crack linear length and the actual crack length of each tissue micro-area test block; The crack propagation tortuosity, yield strength, uniform deformation, crack tip plastic zone size, and crack linear length of different tissue micro-area test blocks are input into the fracture toughness prediction model to obtain the fracture toughness prediction value of the corresponding tissue micro-area test block, that is, the fracture toughness prediction value of the corresponding tissue micro-area of ​​the weld zone sample is obtained.

7. A method for predicting weld zone fracture toughness according to claim 6, characterized in that: Based on the crack extension morphology of different tissue micro-area test blocks, information measurement is performed to obtain the crack linear length and actual crack length of each tissue micro-area test block, including: Through optical microscope observation, multiple fields of view of fracture section specimens of different tissue micro-area specimens were randomly selected for measurement, and multiple initial crack linear lengths and multiple initial crack actual lengths of each tissue micro-area specimen were obtained and the average values ​​were calculated respectively to obtain the crack linear length and crack actual length of each tissue micro-area specimen.

8. A method for predicting weld zone fracture toughness according to claim 6 or 7, characterized in that: When the standard tensile specimen and the fracture toughness specimen are subjected to elongation test and fracture toughness test respectively, the tests are conducted at different temperatures to obtain the yield strength, the uniform deformation, the size of the plastic zone at the crack tip, the fracture cross section, and the crack extension morphology at different temperatures; By measuring and calculating the information of the crack extension morphology, the linear length of the crack, the actual length of the crack and the tortuosity of the crack extension of the micro-area test blocks with different structures at different temperatures are obtained; The crack propagation tortuosity, yield strength, uniform deformation, crack tip plastic zone size, and crack linear length of different tissue micro-area test blocks at different temperatures are input into the fracture toughness prediction model to obtain the corresponding fracture toughness prediction values ​​of the tissue micro-area test blocks at different temperatures.

9. A prediction system for fracture toughness of weld zones, characterized in that: include: Establishing a model unit for establishing a fracture toughness prediction model including crack propagation tortuosity; The heat treatment unit is used to obtain information on different micro-organisms of the weld zone sample, and to perform heat treatment on different micro-organisms using the same steel grade material to obtain test blocks with different micro-organisms; The test acquisition unit is used to test the mechanical properties of different tissue micro-area test blocks respectively, and obtain the crack extension morphology related to the fracture toughness of different tissue micro-area test blocks; The prediction unit is used to measure and calculate information based on the crack extension morphology of the test blocks with different tissue micro-regions, obtain the crack extension tortuosity of the test blocks with different tissue micro-regions, and input it into the fracture toughness prediction model to predict the fracture toughness of the test blocks with different tissue micro-regions, and finally obtain the predicted distribution of the fracture toughness of the different tissue micro-regions of the entire weld zone sample.

10. An electronic device, characterized in that: include: Memory, processor; The processor is used to read and execute the computer program stored in the memory to implement the method for predicting the fracture toughness of weld zones according to any one of claims 1-8.

11. A computer-readable storage medium, characterized in that: The computer-readable storage medium stores computer-executable instructions, and when the computer-executable instructions are executed, the method for predicting the fracture toughness of weld zones according to any one of claims 1 to 8 is implemented.

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