Crystal plasticity reverse modeling and high-throughput prediction method and system

Abstract

The invention belongs to the field of high-temperature deformation and fracture, and discloses a crystal plasticity reverse modeling and high-throughput prediction method and system.The method comprises the steps that the morphology and phase change behavior of a sample at the first preset temperature are observed in situ; cooling the heated sample to obtain a sub-phase structure sample; the morphology and orientation information of the parent phase of the sample is reduced through the reconstruction technology; constructing a crystal plasticity RVE model; fitting to obtain high-temperature constitutive model parameters; obtaining crystallography and crystal deformation information of the sample; performing an SEM in-situ high-temperature tensile test on the sample; carrying out in-situ analysis on stress and strain evolution in a sample deformation process by utilizing a DIC technology; and verifying the prediction precision. According to the method, modeling of a high-temperature austenite parent phase structure is reversely completed based on a room-temperature sub-phase structure, orientation analysis, texture analysis, deformation morphology analysis, stress and strain analysis and the like in the high-temperature deformation process are achieved in combination with crystal plasticity simulation, and high-temperature deformation in-situ high-throughput characterization is achieved.

Description

Technical Field

[0001] The present invention belongs to the field of high temperature deformation and fracture, and in particular relates to a crystal plasticity inverse modeling and high-throughput prediction method and system. Background Art

[0002] In-service welding burn-through is essentially a high-temperature deformation and fracture problem under the coupling of welding multi-physics field and medium pressure in the pipe. Its dynamic failure process occurs inside the high-temperature metal, and undergoes dynamic evolution processes such as micro-defect initiation, micro-crack evolution, and macro-crack expansion. At present, there is still a lack of systematic understanding of the burn-through mechanism of in-service welding, which seriously restricts the development of burn-through criteria. There are three main difficulties in the experimental study of the burn-through mechanism of in-service welding: (1) Burn-through occurs in the high-temperature process, and the difficulties of high-temperature research need to be overcome; (2) From high-temperature metal deformation to micro-defect initiation and evolution into burn-through, it is a dynamic process that requires in-situ observation; (3) How to observe and analyze as many characteristic parameters as possible through an experimental system, such as comprehensive observation of crystal structure, orientation, stress strain, deformation, defect evolution, etc., that is, high-throughput characterization. Therefore, solving the experimental characterization of the burn-through mechanism of in-service welding requires solving three problems: high temperature, in-situ observation, and high-throughput characterization.

[0003] In-service welding burn-through mainly occurs in the temperature range of 982℃~1570℃. The test temperature range of the laser confocal microscope in-situ tensile system is generally 50℃~1150℃, and the test temperature range of the scanning electron microscope in-situ high-temperature tensile system is generally 20℃~1200℃. Combined with high-temperature speckle preparation and DIC analysis, the above two in-situ characterization methods can generally take into account in-situ tissue observation and strain analysis, but it is difficult to consider the influence of crystal orientation on high-temperature deformation and failure. The scanning electron microscope in-situ high-temperature tensile system can carry out EBSD analysis by carrying an EBSD probe, but the current temperature resistance limit of the EBSD phosphor screen is about 800℃. Considering the safety and service life of the equipment, EBSD in-situ analysis is generally only allowed within 750℃. The existing in-situ test equipment mainly performs temperature measurement by welding or contacting a thermocouple probe on the back of the sample. The test temperature refers to the test temperature of the thermocouple probe, and the observation surface of the sample is the upper surface. At present, it is still difficult to directly monitor the temperature change of the upper surface of the sample through the thermocouple probe. Affected by factors such as the heating system and sample heat dissipation, there is generally a certain temperature difference between the upper and lower surfaces of the sample. Therefore, it is difficult to make the upper surface of the sample undergo complete austenite transformation by high-temperature in-situ EBSD testing, and it is difficult to achieve in-situ deformation and failure analysis of the austenite phase region based on the in-situ high-temperature EBSD system.

[0004] Crystal plasticity finite element simulation technology can carry out deformation simulation based on actual crystal structure. At the same time, this method can also take into account information such as structure morphology, crystal orientation and strain distribution. It is a promising technology for high-throughput characterization and analysis. The actual crystal structure information required for crystal plasticity simulation modeling needs to be obtained through EBSD technology, but the existing EBSD characterization technology is basically unable to perform in-situ observation at temperatures of 750℃ and above, and cannot overcome the problem of crystal plasticity RVE modeling of real ultra-high temperature structures. The structure of the high temperature zone of in-service welding characteristics is different from that of the room temperature structure in three main aspects: (1) different phase state. At high temperature, the steel matrix structure of BCC (body-centered cubic) structure is transformed into the austenite phase of FCC (face-centered cubic) structure, and the deformation behaviors of the two are different; (2) different grain size. Austenite structure growth will occur at high temperature, and the austenite size is different at different temperatures; (3) different mechanical properties of materials at different temperatures. Therefore, it is impossible to obtain the structure information at temperatures of 750℃ and above based on the existing in-situ high-temperature EBSD system. Summary of the invention

[0005] In order to overcome the defects of the above-mentioned prior art, the purpose of the present invention is to provide a crystal plasticity reverse modeling and high-throughput prediction method and system, which completes the modeling of high-temperature austenite parent phase structure based on the reverse modeling of room temperature sub-phase structure, and combines crystal plasticity simulation to realize orientation analysis, texture analysis, deformation morphology analysis, stress and strain analysis, etc. during high-temperature deformation, so as to realize in-situ high-throughput characterization of high-temperature deformation.

[0006] To achieve the above object, the present invention provides the following technical solutions:

[0007] A crystal plasticity inverse modeling and high-throughput prediction method, comprising:

[0008] The sample is heated to a first preset temperature, and the morphology and phase change behavior of the sample at the first preset temperature are observed in situ;

[0009] The heated sample is cooled to obtain a subphase structure sample;

[0010] Based on the orientation relationship between the daughter phase and the parent phase, the EBSD parent phase reconstruction technology is used to restore the morphology and orientation information of the sample parent phase;

[0011] The morphology and phase change behavior of the sample at the first preset temperature are compared with the morphology and orientation information of the mother phase reconstructed by the sample, and a crystal plasticity RVE model is constructed based on the morphology and orientation information of the mother phase reconstructed by the sample;

[0012] Set mechanical boundary conditions, and obtain high-temperature constitutive model parameters by fitting based on the high-temperature stress-strain curve and phenomenological constitutive model of the sample;

[0013] Based on crystal plasticity simulation technology, the crystallographic and crystal deformation information of the sample is obtained;

[0014] Carry out SEM in-situ high temperature tensile test on the samples to observe and photograph the changes in the organization and deformation morphology of the observation surface during the deformation process of the samples;

[0015] Based on the changes in the deformation morphology of the sample's structure and observation surface during deformation, the DIC technique is used to in-situ analyze the evolution of stress and strain during sample deformation.

[0016] Summarize the deformation, stress and strain evolution laws of the samples and verify the prediction accuracy of the laws.

[0017] Further, the sample is heated to a first preset temperature, and the morphology and phase change behavior of the sample at the first preset temperature are observed in situ, including:

[0018] The sample is prepared into an in-situ high temperature OM (optical microscope) tensile specimen, and EBSD observation is performed on the in-situ high temperature OM tensile specimen to ensure that the observation surface resolution of the in-situ high temperature OM specimen is above 95%;

[0019] An in-situ high-temperature OM tensile test is performed on the in-situ high-temperature OM tensile specimen, the in-situ high-temperature OM specimen is heated to a first preset temperature at a speed not exceeding 13° C. / s and a photograph of the observation surface is taken;

[0020] The heated in-situ high-temperature OM tensile specimen was cooled at a cooling rate greater than 30°C / s to obtain a sub-phase microstructure sample, and the phase change behavior of the in-situ high-temperature OM tensile specimen during the cooling process was observed.

[0021] Furthermore, the daughter phase is a martensite phase, and the mother phase is an austenite phase.

[0022] Furthermore, before using EBSD parent phase reconstruction technology to restore the morphology and orientation information of the sample parent phase, it includes:

[0023] Vacuum preserve subphase tissue samples.

[0024] Furthermore, mechanical boundary conditions are set, and based on the high-temperature stress-strain curve of the sample and the phenomenological constitutive model, high-temperature constitutive model parameters are obtained by fitting, including:

[0025] Based on the open source DAMASK framework, the mechanical boundary conditions and periodic boundary conditions are set using the same external loading conditions as the in-situ high-temperature OM tensile test.

[0026] The sample is prepared into a high-temperature tensile specimen and subjected to a high-temperature tensile test to obtain a high-temperature stress-strain curve of the sample;

[0027] Based on the open source DAMASK framework, the phenomenological constitutive model is used to describe the mechanical behavior of the sample, and the relevant parameters of the high-temperature constitutive model are obtained based on the high-temperature stress-strain curve fitting.

[0028] Furthermore, based on the crystal plasticity simulation technology, the crystallographic and crystal deformation information of the sample is obtained, including:

[0029] Perform crystal plasticity simulation calculation and data processing on samples;

[0030] The orientation, texture, stress and strain of the sample are obtained after crystal plasticity simulation calculation;

[0031] Visualize the orientation, texture, and stress-strain of your samples.

[0032] Furthermore, before performing the SEM in-situ high temperature tensile test on the sample, the following steps are included:

[0033] Use sample preparation to prepare the observation surface that meets metallographic observation or EBSD observation;

[0034] Use 4% nitric acid alcohol to pre-etch the observation surface;

[0035] The microstructure of the observation surface after high-temperature phase transformation is taken as high-temperature speckle, which is used for in-situ analysis using DIC technology.

[0036] Furthermore, the sample was subjected to an SEM in-situ high temperature tensile test, including:

[0037] The sample is heated to a second preset temperature, and the tensile test is started directly without heat preservation treatment, and the strain rate is controlled to be consistent with the in-situ high-temperature OM tensile test;

[0038] Observe and photograph the morphological changes of the organization and observation surface during the sample stretching process based on SEM

[0039] Furthermore, the prediction accuracy of the verification rules includes:

[0040] Conduct verification tests on samples and control the characteristic peak temperature of the verification tests to be no higher than 750°C;

[0041] The test temperature of the control verification test is between 982℃ and 1570℃.

[0042] In another aspect, the present invention discloses a crystal plasticity inverse modeling and high-throughput prediction system, comprising:

[0043] In-situ observation unit: used to heat the sample to a first preset temperature, and in-situ observe the morphology and phase change behavior of the sample at the first preset temperature;

[0044] Sub-phase tissue sample acquisition unit: used for cooling the heated sample to obtain the sub-phase tissue sample;

[0045] Parent phase reconstruction unit: used to restore the morphology and orientation information of the sample parent phase based on the orientation relationship between the daughter phase and the parent phase using EBSD parent phase reconstruction technology;

[0046] Crystal plasticity RVE model building unit: used to compare the morphology and phase change behavior of the sample at the first preset temperature with the morphology and orientation information of the mother phase reconstructed by the sample, and build a crystal plasticity RVE model based on the morphology and orientation information of the mother phase reconstructed by the sample;

[0047] Phenomenological constitutive model parameter acquisition unit: used to set mechanical boundary conditions, and obtain the phenomenological constitutive model parameters by fitting based on the high-temperature stress-strain curve of the sample and the phenomenological constitutive model;

[0048] Crystallographic and crystal deformation information acquisition unit: used to obtain the crystallographic and crystal deformation information of the sample based on crystal plasticity simulation technology;

[0049] SEM in-situ high temperature tensile unit: used to perform SEM in-situ high temperature tensile test on samples, and observe and photograph the deformation morphology changes of the organization and observation surface during the deformation process of the sample;

[0050] DIC in-situ analysis unit: used to analyze the stress and strain evolution of the sample in situ during deformation based on the changes in the deformation morphology of the sample's organization and observation surface during deformation using DIC technology;

[0051] Precision verification unit: used to summarize the deformation, stress and strain evolution laws of the sample and verify the prediction accuracy of the laws.

[0052] Technical effects and advantages of the present invention:

[0053] 1. The present invention adopts crystal plasticity finite element simulation technology, which can obtain the conventional result types that can be obtained by EBSD, SEM, OM and in-situ DIC characterization methods, and can perform simulation only based on the real tissue morphology and mechanical properties. The test cost of in-situ high-temperature EBSD and other characterization methods is generally 2,000 yuan / hour, the cost of one test is about 10,000-20,000 yuan, and there is a certain failure rate. Crystal plasticity simulation technology only needs a small amount of cheap test data to obtain more research results, which is a more efficient and cheap research method.

[0054] 2. The present invention combines the theory that the sub-phase structure after phase transformation has an orientation relationship with the original austenite structure at high temperature, and uses the EBSD parent phase reconstruction technology to restore the original austenite structure and orientation information at high temperature based on the sub-phase structure cooled to room temperature, thereby realizing the reverse RVE modeling of the low-temperature sub-phase to the high-temperature parent phase. Then, based on the high-temperature stress-strain curve and the phenomenological constitutive model, the high-temperature mechanical properties parameters (high-temperature constitutive model parameters) of the austenite phase can be fitted, and then through crystal plasticity simulation, the orientation analysis, texture analysis, deformation morphology analysis, stress and strain analysis, etc. in the high-temperature deformation process can be realized, thereby achieving the purpose of in-situ high-throughput characterization of high-temperature deformation and making up for the shortcomings of in-situ experiments.

[0055] 3. The present invention is not only suitable for the study of high-temperature zones of in-service welding, but also provides a new idea for studying the deformation behavior of materials under high temperature or extreme conditions. It plays an important role in clarifying the deformation mechanism of materials under extreme or high temperature conditions and related product development.

[0056] Other features and advantages of the present invention will be described in the following description, and partly become apparent from the description, or understood by practicing the present invention. The purpose and other advantages of the present invention can be realized and obtained by the structures pointed out in the description, claims and drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0057] Figure 1 The present invention is a flow chart of a crystal plasticity inverse modeling and high-throughput prediction method. DETAILED DESCRIPTION

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

[0059] like Figure 1 As shown, the present invention provides a crystal plasticity inverse modeling and high-throughput prediction method, comprising:

[0060] The sample is heated to a first preset temperature, and the morphology and phase change behavior of the sample at the first preset temperature are observed in situ;

[0061] The heated sample is cooled to obtain a subphase structure sample;

[0062] Based on the orientation relationship between the daughter phase and the parent phase, the EBSD parent phase reconstruction technology is used to restore the morphology and orientation information of the sample parent phase;

[0063] The morphology and phase change behavior of the sample at the first preset temperature are compared with the morphology and orientation information of the reconstructed parent phase of the sample, and a crystal plasticity RVE (representative volume unit) model is constructed based on the morphology and orientation information of the reconstructed parent phase of the sample;

[0064] Set mechanical boundary conditions, and obtain high-temperature constitutive model parameters by fitting based on the high-temperature stress-strain curve and phenomenological constitutive model of the sample;

[0065] Based on crystal plasticity simulation technology, the crystallographic and crystal deformation information of the sample is obtained;

[0066] Carry out SEM in-situ high temperature tensile test on the samples to observe and photograph the changes in the organization and deformation morphology of the observation surface during the deformation process of the samples;

[0067] Based on the changes in the deformation morphology of the sample's structure and observation surface during deformation, the DIC technique is used to in-situ analyze the evolution of stress and strain during sample deformation.

[0068] Summarize the deformation, stress and strain evolution laws of the samples and verify the prediction accuracy of the laws.

[0069] In some embodiments of the present invention, heating the sample to a first preset temperature and in-situ observing the morphology and phase change behavior of the sample at the first preset temperature comprises:

[0070] The sample is prepared into an in-situ high temperature OM (optical microscope) tensile specimen, and EBSD observation is performed on the in-situ high temperature OM tensile specimen to ensure that the observation surface resolution of the in-situ high temperature OM specimen is above 95%;

[0071] An in-situ high-temperature OM tensile test is performed on the in-situ high-temperature OM tensile specimen, the in-situ high-temperature OM specimen is heated to a first preset temperature at a speed not exceeding 13°C / s (preferably the fastest heating speed allowed by the equipment) and a photograph of the observation surface is taken to simulate the material heating behavior during in-service welding;

[0072] The heated in-situ high-temperature OM tensile specimen was cooled at a cooling rate greater than 30°C / s to obtain a sub-phase microstructure sample, and the phase change behavior of the in-situ high-temperature OM tensile specimen during the cooling process was observed.

[0073] It should be noted that rapid cooling can retain the grain morphology of high-temperature austenite to the greatest extent, obtain clearer original austenite grain boundaries, and obtain martensitic structure. The martensitic structure has a good orientation relationship with the austenitic parent phase, which can ensure the accuracy of subsequent reconstruction to the greatest extent.

[0074] In some embodiments of the present invention, the daughter phase is a martensite phase, and the parent phase is an austenite phase.

[0075] In some embodiments of the present invention, before using the EBSD parent phase reconstruction technology to restore the morphology and orientation information of the sample parent phase, the following steps are included:

[0076] Vacuum storage of sub-phase structure samples. After cooling, the sub-phase structure samples are stored in a vacuum box and EBSD tests are arranged as soon as possible to ensure that the observation surface after cooling still has a high EBSD resolution without the need for re-sampling.

[0077] In some embodiments of the present invention, mechanical boundary conditions are set, and high-temperature constitutive model parameters are obtained by fitting based on the high-temperature stress-strain curve of the sample and the phenomenological constitutive model, including:

[0078] Based on the open source DAMASK framework, the mechanical boundary conditions and periodic boundary conditions are set using the same external loading conditions as the in-situ high-temperature tensile test.

[0079] The sample is prepared into a high-temperature tensile specimen and subjected to a high-temperature tensile test to obtain a high-temperature stress-strain curve of the sample;

[0080] Based on the open source DAMASK framework, the phenomenological constitutive model is used to describe the mechanical behavior of the sample, and the relevant parameters of the high-temperature constitutive model are obtained based on the high-temperature stress-strain curve fitting.

[0081] In some embodiments of the present invention, the crystallographic and crystal deformation information of the sample is obtained based on the crystal plasticity simulation technology, including:

[0082] Perform crystal plasticity simulation calculation and data processing on samples;

[0083] The orientation, texture, stress and strain of the sample are obtained after crystal plasticity simulation calculation;

[0084] Visualize the orientation, texture, and stress-strain of your samples.

[0085] In some embodiments of the present invention, before performing a SEM in-situ high temperature tensile test on a sample, the following steps are included:

[0086] Use the sample to prepare the observation surface that meets metallographic observation or EBSD observation;

[0087] The observation surface was pre-etched with 4% nitric acid alcohol to obtain fine tissue morphology;

[0088] The microstructure of the observation surface after high-temperature phase transformation is taken as high-temperature speckle, which is used for in-situ analysis using DIC technology.

[0089] In some embodiments of the present invention, a SEM in-situ high temperature tensile test is performed on a sample, comprising:

[0090] The sample is heated to a second preset temperature, and the tensile test is started directly without heat preservation treatment, and the strain rate is controlled to be consistent with the in-situ high-temperature OM tensile test;

[0091] Observe and photograph the morphological changes of the organization and observation surface during the sample stretching process based on SEM

[0092] In some embodiments of the present invention, verifying the prediction accuracy of the rule includes:

[0093] Conduct verification tests on samples and control the characteristic peak temperature of the verification test to be no higher than 750°C, so that the test conditions are as consistent as possible with the boundary conditions of crystal plasticity, and the reliability of the crystal plasticity method is verified to the greatest extent;

[0094] The test temperature of the verification test was controlled between 982℃ and 1570℃, which was used to verify the reliability of the crystal plasticity reverse modeling and high-throughput prediction method in the characteristic high-temperature zone of in-service welding.

[0095] In another aspect, the present invention discloses a crystal plasticity inverse modeling and high-throughput prediction system, comprising:

[0096] In-situ observation unit: used to heat the sample to a first preset temperature, and in-situ observe the morphology and phase change behavior of the sample at the first preset temperature;

[0097] Subphase tissue sample acquisition unit: used to cool the heated sample to obtain the subphase tissue sample; parent phase reconstruction unit: used to restore the morphology and orientation information of the sample parent phase based on the orientation relationship between the subphase and the parent phase using EBSD parent phase reconstruction technology;

[0098] Crystal plasticity RVE model building unit: used to compare the morphology and phase change behavior of the sample at the first preset temperature with the morphology and orientation information of the mother phase reconstructed by the sample, and build a crystal plasticity RVE model based on the morphology and orientation information of the mother phase reconstructed by the sample;

[0099] Phenomenological constitutive model parameter acquisition unit: used to set mechanical boundary conditions, and obtain the phenomenological constitutive model parameters by fitting based on the high-temperature stress-strain curve of the sample and the phenomenological constitutive model;

[0100] Crystallographic and crystal deformation information acquisition unit: used to obtain the crystallographic and crystal deformation information of the sample based on crystal plasticity simulation technology;

[0101] SEM in-situ high temperature tensile unit: used to perform SEM in-situ high temperature tensile test on samples, and observe and photograph the deformation morphology changes of the organization and observation surface during the deformation process of the sample;

[0102] DIC in-situ analysis unit: used to analyze the stress and strain evolution of the sample in situ during deformation based on the changes in the deformation morphology of the sample's organization and observation surface during deformation using DIC technology;

[0103] Precision verification unit: used to summarize the deformation, stress and strain evolution laws of the sample and verify the prediction accuracy of the laws.

[0104] In order to better illustrate the present solution, the following embodiments are also provided.

[0105] Example

[0106] This embodiment takes the deformation behavior study of X65 pipeline steel at 1150°C as an example, and describes in detail the specific implementation method of the inverse modeling of crystal plasticity in the high temperature zone of in-service welding characteristics and the high-throughput prediction method as follows.

[0107] Step 1: Conduct an in-situ high-temperature OM tensile test, heat the sample to a first preset temperature (1150°C), observe the high-temperature morphology and phase change behavior in situ, and then obtain the sub-phase structure by rapid cooling, which specifically includes the following steps:

[0108] (1) Samples were taken from X65 pipeline steel pipes and processed into the sample size required for the OM in-situ high-temperature tensile test. Since the sample thickness was very thin, the sample was glued to an ultra-flat sample block for grinding and mechanical polishing. Then, the observation surface was vibrated and polished to remove the surface stress layer.

[0109] (2) Use nanoindentation or microhardness method to mark the observation position so that the marked position can be found more quickly during subsequent observation;

[0110] (3) Soak the ultra-flat specimen block with the specimen in an acetone solution for 6-12 hours. After the acetone dissolves the glue, remove the specimen and use sandpaper to remove the small amount of glue remaining on the back. This process requires spraying an alcohol solution on the surface of the specimen to protect the observation surface from oxidation. Then, place the specimen in an alcohol solution for ultrasonic cleaning and dry it for storage.

[0111] (4) The prepared sample was mounted on the OM high-temperature in-situ tensile test bench and heated to the first preset temperature (1150°C) at the fastest heating rate allowed by the equipment (~13°C / s). No insulation treatment was performed after heating to simulate the material heating behavior during in-service welding. The heating and cooling processes of the sample were completed in ultrapure argon gas to prevent oxidation of the sample surface.

[0112] (5) After the sample is heated to a first preset temperature (1150° C.), an automatic camera system is used to take a picture, and focusing and other processing are performed during the picture taking to ensure the picture clarity;

[0113] (6) The sample is rapidly cooled at a cooling rate greater than 30°C / s to obtain a sub-phase structure. The phase transformation behavior is observed during the cooling process, and the sub-phase structure after cooling is ensured to be a martensite phase as much as possible. Rapid cooling can retain the grain morphology of high-temperature austenite to the greatest extent, obtain clearer original austenite grain boundaries, and obtain a martensite structure. The martensite structure has a good orientation relationship with the austenite parent phase, which can maximize the accuracy of subsequent reconstruction.

[0114] Step 2: Based on the orientation relationship between the subphase and the parent phase, the EBSD parent phase reconstruction technology is used to restore the morphology and orientation information of the sample parent phase, which specifically includes the following steps:

[0115] (1) After completing the OM high-temperature in-situ tensile test, remove the sample and place it on the EBSD observation system to find the position of the nanoindentation or microhardness mark, and find the corresponding position by comparing the image taken by OM;

[0116] (2) Perform EBSD scanning on the observation position to ensure that the sample observation position still has a high resolution. If the sample surface resolution drops significantly, precision polishing can be used for polishing, but it is necessary to ensure that the morphology of the observation surface is not changed as much as possible.

[0117] (3) The morphology and phase change behavior of the sample at the first preset temperature (1150°C) are compared with the morphology and orientation information of the reconstructed matrix of the sample. While ensuring accuracy, a crystal plasticity RVE (representative volume unit) model is constructed based on the morphology and orientation information of the reconstructed matrix of the sample.

[0118] Step 3: Constructing a crystal plasticity RVE (representative volume unit) model based on the morphology and orientation information of the reconstructed parent phase of the sample

[0119] (1) Use EBSD parent phase reconstruction technology to match the corresponding orientation relationship, reconstruct the morphology and orientation information of the high-temperature original austenite structure (parent phase), and export the results as a *.ctf file;

[0120] (2) Remove the zero resolution points in the *.ctf file and make the location of the zero resolution points match the surrounding crystal structure;

[0121] (3) Import the *.ctf file without zero resolution points into the open source Dream.3D software to reconstruct the RVE model required for DAMASK crystal plasticity calculation.

[0122] Step 4: Set the mechanical boundary conditions, and obtain the high-temperature constitutive model parameters by fitting based on the high-temperature stress-strain curve of the sample and the phenomenological constitutive model, which specifically includes the following steps:

[0123] (1) Based on the open source DAMASK framework, the same external loading conditions as the in-situ high-temperature OM tensile test are adopted to apply mechanical boundary conditions and periodic boundary conditions. DAMASK uses tensor method to apply loads. The load file is *.load file. The deformation rate tensor is expressed in 3×3 tensor form, as shown in the following formula:

[0124]

[0125] In the formula, F dot is the deformation gradient rate tensor.

[0126] (2) Set parameters such as strain rate and incremental step in *.load.

[0127] Step 5: Based on the crystal plasticity simulation technology, the crystallographic and crystal deformation information of the sample is obtained, which specifically includes the following steps:

[0128] (1) Reasonably set the analysis steps to balance the calculation time, convergence and calculation accuracy;

[0129] (2) Perform crystal plasticity simulation calculation and data processing on the sample; after the crystal plasticity simulation calculation, use the command to obtain the sample's orientation, texture, stress and strain files

[0130] (3) Use visualization software to visualize orientation, texture, and stress-strain.

[0131] Step 6: Prepare the SEM in-situ high temperature tensile specimen and prepare to carry out the SEM in-situ high temperature tensile test;

[0132] (1) Process the sample into the required size and glue it to an ultra-flat experimental block to prepare a sample observation surface that meets metallographic observation or EBSD observation;

[0133] (2) The observation surface of the sample was pre-etched with 4% nitric acid to obtain fine microstructure morphology;

[0134] (3) Soak the sample and the super-flat sample block in an acetone solution for 6-12 hours, then remove the sample;

[0135] (4) The fine microstructure morphology after high-temperature phase transformation can be used as high-temperature speckle to facilitate in-situ DIC analysis in subsequent steps.

[0136] Step 7: Perform an SEM in-situ high-temperature tensile test on the sample prepared in step 6, and observe and photograph the deformation morphology changes of the organization and observation surface during the deformation of the sample, which specifically includes the following steps;

[0137] (1) The sample is heated to a second preset temperature at the fastest heating rate allowed by the equipment to simulate the material heating behavior during in-service welding. The heating and cooling processes are completed in an argon protective atmosphere to prevent oxidation of the sample surface;

[0138] (2) After heating to the second preset temperature, the tensile test is started directly without insulation treatment, and the strain rate is consistent with the in-situ high-temperature OM tensile test;

[0139] (3) During the stretching process, if SEM observation and photography are required, the stretching process needs to be stopped and the sample needs to be locked. The photo can be taken after the time-stress curve of the sample is stable.

[0140] (4) Observe and photograph the changes in the sample's structure and deformation morphology during deformation using SEM.

[0141] Step 8: Based on the deformation morphology changes of the sample structure and the observation surface during deformation obtained in step 7, the stress and strain evolution of the sample during deformation is analyzed in situ using DIC technology. The specific steps are as follows:

[0142] (1) Select the undeformed initial tissue as the reference photo;

[0143] (2) Based on the reference photo, the microscopic stress-strain cloud map during the deformation process is calculated using the reference photo and the previous photo as references.

[0144] Step 9: Summarize the deformation, stress and strain evolution laws of the sample and verify the prediction accuracy of the laws, which specifically includes the following steps:

[0145] (1) Conduct verification tests on samples and control the characteristic peak temperature of the verification test to be no higher than 750°C, so that the test conditions are as consistent as possible with the boundary conditions of crystal plasticity, thereby verifying the reliability of the crystal plasticity method to the greatest extent;

[0146] (2) The test temperature of the verification test is controlled between 982℃ and 1570℃ to verify the reliability of the inverse modeling and high-throughput prediction method of crystal plasticity in the high-temperature zone of in-service welding.

[0147] Finally, it should be noted that the above is only a preferred embodiment of the present invention and is not intended to limit the present invention. Although the present invention 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 invention should be included in the protection scope of the present invention.

Claims

1. A crystal plasticity inverse modeling and high-throughput prediction method, characterized in that: include: Heating the sample to a first preset temperature, and in-situ observing the morphology and phase change behavior of the sample at the first preset temperature; Cooling the heated sample to obtain a subphase structure sample; Based on the orientation relationship between the sub-phase and the parent phase, the EBSD parent phase reconstruction technology is used to restore the morphology and orientation information of the sample parent phase; Comparing the morphology and phase change behavior of the sample at the first preset temperature with the morphology and orientation information of the reconstructed parent phase of the sample, and constructing a crystal plasticity RVE model based on the morphology and orientation information of the reconstructed parent phase of the sample; Setting mechanical boundary conditions, and fitting and obtaining high-temperature constitutive model parameters based on the high-temperature stress-strain curve and phenomenological constitutive model of the sample; Based on crystal plasticity simulation technology, obtaining crystallographic and crystal deformation information of the sample; Performing an SEM in-situ high-temperature tensile test on the sample to observe and photograph the deformation morphology changes of the organization and observation surface of the sample during deformation; Based on the deformation morphology changes of the tissue and the observation surface during the deformation of the sample, the DIC technology is used to in-situ analyze the stress and strain evolution during the deformation of the sample; The deformation, stress and strain evolution laws of the samples were summarized, and the prediction accuracy of the laws was verified.

2. A crystal plasticity inverse modeling and high-throughput prediction method according to claim 1, characterized in that: The step of heating the sample to a first preset temperature and in-situ observing the morphology and phase change behavior of the sample at the first preset temperature comprises: The sample is prepared into an in-situ high-temperature OM tensile specimen, and EBSD observation is performed on the in-situ high-temperature OM tensile specimen to ensure that the observed surface resolution of the in-situ high-temperature OM specimen is above 95%; Performing an in-situ high-temperature OM tensile test on the in-situ high-temperature OM tensile specimen, heating the in-situ high-temperature OM specimen to a first preset temperature at a speed not exceeding 13° C. / s and taking a photograph of the observation surface; The heated in-situ high-temperature OM tensile specimen is cooled at a cooling rate greater than 30° C. / s to obtain a sub-phase structure sample, and the phase change behavior of the in-situ high-temperature OM tensile specimen during the cooling process is observed.

3. The crystal plasticity inverse modeling and high-throughput prediction method according to claim 1, characterized in that: The sub-phase is a martensite phase, and the parent phase is an austenite phase.

4. The crystal plasticity inverse modeling and high-throughput prediction method according to claim 1, characterized in that: Before the EBSD parent phase reconstruction technology is used to restore the morphology and orientation information of the sample parent phase, the method includes: The subphase tissue sample is preserved under vacuum.

5. The crystal plasticity reverse modeling and high-throughput prediction method according to claim 2, characterized in that: The setting of mechanical boundary conditions, based on the high temperature stress-strain curve and phenomenological constitutive model of the sample, fitting and obtaining high temperature constitutive model parameters, includes: Based on the open source DAMASK framework, the mechanical boundary conditions and periodic boundary conditions are set using the same external loading conditions as the in-situ high-temperature OM tensile test. The sample is prepared into a high temperature tensile specimen and subjected to a high temperature tensile test to obtain a high temperature stress-strain curve of the sample; Based on the open source DAMASK framework, a phenomenological constitutive model is used to describe the mechanical behavior of the sample, and relevant parameters of the high-temperature constitutive model are obtained based on the high-temperature stress-strain curve fitting.

6. The crystal plasticity inverse modeling and high-throughput prediction method according to claim 1, characterized in that: The crystal plasticity simulation technology is used to obtain the crystallographic and crystal deformation information of the sample, including: Performing crystal plasticity simulation calculation and data processing on the sample; The orientation, texture and stress-strain of the sample are obtained after the crystal plasticity simulation calculation; The orientation, texture, and stress-strain of the samples were visualized.

7. The crystal plasticity inverse modeling and high-throughput prediction method according to claim 1, characterized in that: Before the SEM in-situ high temperature tensile test is performed on the sample, the method comprises: Using the sample preparation method, an observation surface that meets metallographic observation or EBSD observation is prepared; The observation surface is pre-etched using 4% nitric acid alcohol; The organizational morphology of the observation surface after high-temperature phase transformation is used as high-temperature speckle, and the high-temperature speckle is used for in-situ analysis using the DIC technology.

8. The crystal plasticity reverse modeling and high-throughput prediction method according to claim 2, characterized in that: The SEM in-situ high temperature tensile test on the sample comprises: The sample is heated to a second preset temperature, and the tensile test is directly started without heat preservation treatment, and the strain rate is controlled to be consistent with the in-situ high temperature OM tensile test; The changes in the structure and morphology of the observation surface during the stretching process of the sample were observed and photographed based on SEM.

9. The crystal plasticity inverse modeling and high-throughput prediction method according to claim 1, characterized in that: The verification of the prediction accuracy of the rule includes: Conducting a verification test on the sample, and controlling the characteristic peak temperature of the verification test to be no higher than 750° C.; The test temperature of the control verification test is between 982℃ and 1570℃.

10. A crystal plasticity inverse modeling and high-throughput prediction system, characterized in that: include: In-situ observation unit: used for heating the sample to a first preset temperature, and in-situ observing the morphology and phase change behavior of the sample at the first preset temperature; Subphase tissue sample acquisition unit: used for cooling the heated sample to obtain a subphase tissue sample; Parent phase reconstruction unit: used to restore the morphology and orientation information of the parent phase of the sample by using EBSD parent phase reconstruction technology based on the orientation relationship between the daughter phase and the parent phase; A crystal plasticity RVE model building unit: used to compare the morphology and phase change behavior of the sample at the first preset temperature with the morphology and orientation information of the reconstructed parent phase of the sample, and to build a crystal plasticity RVE model based on the morphology and orientation information of the reconstructed parent phase of the sample; A phenomenological constitutive model parameter acquisition unit is used to set mechanical boundary conditions and obtain phenomenological constitutive model parameters by fitting based on the high temperature stress-strain curve of the sample and the phenomenological constitutive model; A crystallographic and crystal deformation information obtaining unit: used for obtaining the crystallographic and crystal deformation information of the sample based on crystal plasticity simulation technology; SEM in-situ high temperature tensile unit: used to perform SEM in-situ high temperature tensile test on the sample, and observe and photograph the deformation morphology changes of the organization and observation surface during the deformation process of the sample; DIC in-situ analysis unit: used to analyze in-situ the evolution of stress and strain during the deformation of the sample using DIC technology based on the deformation morphology changes of the tissue and the observation surface during the deformation of the sample; Precision verification unit: used to summarize the deformation, stress and strain evolution laws of the sample and verify the prediction accuracy of the laws.

Images