Method, device and equipment for determining parameters of heat affected zone of circumferential weld of pipeline and medium

Abstract

The invention discloses a method, a device, equipment and a medium for determining parameters of a heat affected zone of a circumferential weld of a pipeline, which are applied to the technical field of computers, and the method comprises the following steps: acquiring an experimental welding joint and a simulation forming part of a to-be-tested annular pipeline under the same working condition; determining the width of the heat affected zone at the center line of the cross section of each welding layer in the experiment according to the heat affected zone range of each welding layer in the experiment welding joint; determining the temperature range of the heat affected zone of the simulated forming part according to the width of the heat affected zone at the center line of the cross section of each welding layer in the experiment; determining the width of the heat affected zone according to the temperature range of the heat affected zone; and the peak temperature and the cooling time t8 / 5 are obtained according to the thermal cycle data in the width range of the heat affected zone. According to the method, simulation results based on different process parameters can be analyzed to obtain the change rule of the parameters of the heat affected zone under the different process parameters, and certain guidance is provided for further optimizing the process parameters and improving the welding quality.

Description

Technical Field

[0001] The present invention relates to the field of computer technology, and in particular to a method, device, equipment and medium for determining parameters of a heat-affected zone of a pipeline girth weld. Background Art

[0002] During the pipeline welding process, rapid and uneven heating and cooling cause different areas of the heat-affected zone (HAZ) to undergo different welding thermal cycles, resulting in significant microstructural changes and performance degradation. This not only reduces the overall strength of the pipeline but also increases its susceptibility to corrosion, shortening its service life. Therefore, the HAZ becomes a weak link in welded joints. Researching and analyzing HAZ parameters is crucial for understanding stress, deformation, and mechanical properties, and is a key approach to improving welding quality.

[0003] At present, a large number of studies are mainly focused on the precise characterization and mastery of the strength and toughness distribution laws and microstructure properties of different characteristic areas of girth welds. There are few quantitative studies on the heat-affected zone parameters, and the numerical determination methods of the heat-affected zone parameters are not unified, and there is no clear determination method yet.

[0004] Therefore, how to determine the extraction method of heat-affected zone parameters and realize quantitative research on heat-affected zone parameters is a technical problem that needs to be solved urgently. Summary of the Invention

[0005] In view of this, the purpose of the present invention is to provide a method, device, equipment and medium for determining the parameters of the heat-affected zone of a pipeline girth weld, which solves the problem that there is no clear method for extracting the parameters of the heat-affected zone in the prior art. Therefore, how to realize quantitative research on the parameters of the heat-affected zone is a technical problem that urgently needs to be solved.

[0006] To solve the above technical problems, the present invention provides a method for determining parameters of a heat-affected zone of a pipeline girth weld, comprising:

[0007] Obtain the experimental welded joint and simulated formed part of the annular pipe to be tested under the same working conditions;

[0008] The width of the heat-affected zone at the center line of the cross section of each weld layer in the experimental weld joint is determined based on the range of the heat-affected zone of each weld layer in the experimental weld joint; each weld layer includes a hot weld layer, an intermediate filler weld layer, and a final filler weld layer; the cross section is a cross section along the radial direction of the pipeline; the center line of the cross section is the geometric center line of the cross section of a single weld layer in the experimental weld joint, that is, a straight line perpendicular to the thickness direction of the weld layer and located at the center of the weld layer;

[0009] Determine the temperature range of the heat-affected zone of the simulated formed part according to the width of the heat-affected zone at the center line of the cross section of each weld layer in the experiment; the temperature range of the heat-affected zone includes an upper limit temperature of the heat-affected zone and a lower limit temperature of the heat-affected zone; determine the width of the heat-affected zone according to the upper limit temperature of the heat-affected zone and the lower limit temperature of the heat-affected zone;

[0010] Taking the width of the heat-affected zone as a target area, extracting the peak temperature based on the thermal cycle data of the target area;

[0011] The cooling time t is calculated based on the thermal cycle data on the two isotherms. 8 / 5 ; The cooling time t 8 / 5 It is the time required for the temperature to cool from 800°C to 500°C; the two isotherms are two isotherms formed by the upper limit temperature of the heat affected zone and the lower limit temperature of the heat affected zone.

[0012] Optionally, the cooling time t is calculated based on the thermal cycle data on the two isotherms. 8 / 5 After that, it also includes:

[0013] Different process parameters are set for the finite element model of the pipeline girth weld that is consistent with the experiment to obtain simulation results under different process parameters, including the width of the heat affected zone, peak temperature and cooling time t 8 / 5 The pipeline girth weld finite element model is a model of the simulated formed part without welding heat transfer calculation;

[0014] Based on the simulation results under different process parameters, the width of the heat affected zone, peak temperature and cooling time t are obtained. 8 / 5 The prediction formula between and heat input.

[0015] Optionally, obtaining an experimental welded joint and a simulated formed part of the annular pipeline to be tested under the same working conditions includes:

[0016] Obtaining temperature information and actual weld morphology of the annular pipe to be tested during the welding experiment;

[0017] Constructing a three-dimensional pipeline model based on the structural information of the annular pipeline to be measured, and performing meshing on the three-dimensional pipeline model to obtain a meshed three-dimensional pipeline model;

[0018] Constructing a welding heat source model based on the process requirements and welding information of the annular pipeline to be tested;

[0019] Defining basic thermophysical parameters of the meshed three-dimensional pipeline model, setting the heat transfer coefficient of the heat transfer mode, and determining boundary conditions and initial conditions, and importing the welding heat source model to obtain a preliminary pipeline girth weld finite element model;

[0020] Based on thermo-solid coupling, energy conservation, and heat transfer equations, welding heat transfer calculations are performed on the preliminary pipeline girth weld finite element model to obtain the temperature field distribution in each region and the simulated weldment morphology; the regions are the weld zone, heat-affected zone, and base metal zone;

[0021] The process parameters are adjusted based on the temperature information in the welding experiment and the temperature field distribution obtained by the simulation, and the welding heat source shape parameters are adjusted based on the actual weldment morphology and the simulated weldment morphology to obtain a pipeline girth weld finite element model that is consistent with the experiment, and the simulation forming result corresponding to the pipeline girth weld finite element model is used as the simulated formed part.

[0022] Optionally, determining the width of the heat-affected zone at the center line of the cross section of each weld layer in the experimental weld joint according to the range of the heat-affected zone of each weld layer in the experimental weld joint includes:

[0023] Performing metallographic sampling of each weld layer in the experimental weld joint and obtaining material microstructural changes; the material microstructural changes include differences in grain morphology, precipitate phase distribution, and structural transformation characteristics between the base material region, heat-affected zone, and weld region;

[0024] Determine a first boundary position between the heat-affected zone and the base material zone and a second boundary position between the heat-affected zone and the weld zone according to the material structure change;

[0025] The vertical distance between the first boundary position and the second boundary position is used as the width value, and the width of the heat-affected zone at the center line of the cross section of each welding layer in the experiment is determined according to the width value.

[0026] Optionally, determining the temperature range of the heat-affected zone of the simulated formed part according to the width of the heat-affected zone at the center line of the cross section of each weld layer in the experiment includes:

[0027] The temperature corresponding to the liquidus line of the material of the annular pipe to be tested is used as the upper limit temperature of the heat-affected zone, and the upper limit temperature of the heat-affected zone is the starting point temperature of the heat-affected zone at the center line of the cross section of each weld layer of the simulated formed part;

[0028] According to the same spatial coordinate positioning principle and the width of the heat-affected zone at the center line of the cross section of each weld layer in the experiment, the end point temperature of the heat-affected zone at the center line of the cross section of each weld layer of the simulated formed part is determined based on the starting point temperature;

[0029] The average value of the termination point temperature of the heat-affected zone at the center line of the cross section of each welding layer of the simulated formed part is used as the lower limit temperature of the heat-affected zone.

[0030] Optionally, constructing a welding heat source model based on the process requirements and welding information of the annular pipeline to be tested includes:

[0031] Obtaining process requirements for welding experiments; the process requirements include welding methods and process parameters;

[0032] Obtain welding information of the welding experiment; the welding information includes at least the number of welding guns, the spacing between welding guns, the starting time and starting position of the welding guns at each welding layer;

[0033] The welding heat source model is constructed based on the process requirements and the welding information.

[0034] The present invention also provides a device for determining parameters of a heat-affected zone of a pipeline girth weld, comprising:

[0035] An acquisition module is used to obtain the experimental welded joint and simulated formed part of the annular pipeline to be tested under the same working conditions;

[0036] A module for determining the width of the heat-affected zone of an experimental weld joint is configured to determine the width of the heat-affected zone at the center line of the cross section of each weld layer in the experimental weld joint based on the range of the heat-affected zone of each weld layer in the experimental weld joint; each weld layer includes a hot weld layer, an intermediate filler weld layer, and a final filler weld layer; the cross section is a cross section along the radial direction of the pipeline; and the center line of the cross section is the geometric center line of the cross section of a single weld layer in the experimental weld joint, i.e., a straight line perpendicular to the thickness direction of the weld layer and located at the center of the weld layer;

[0037] a temperature range determination module, configured to determine a temperature range of a heat-affected zone of a simulated formed part according to a width of the heat-affected zone at a center line of a cross section of each weld layer in the experiment; the temperature range of the heat-affected zone includes an upper limit temperature of the heat-affected zone and a lower limit temperature of the heat-affected zone;

[0038] A module for determining the width of a heat-affected zone of a simulated formed part, configured to determine the width of the heat-affected zone according to an upper limit temperature of the heat-affected zone and a lower limit temperature of the heat-affected zone;

[0039] a peak temperature determination module, configured to take the width of the heat-affected zone as a target area and extract the peak temperature based on the thermal cycle data of the target area;

[0040] The cooling time determination module is used to calculate the cooling time t based on the thermal cycle data on the two isotherms. 8 / 5 ; The cooling time t 8 / 5 It is the time required for the temperature to cool from 800°C to 500°C; the two isotherms are two isotherms formed by the upper limit temperature of the heat affected zone and the lower limit temperature of the heat affected zone.

[0041] Optionally, it also includes:

[0042] The simulation result acquisition module is used to set different process parameters for the finite element model of the pipeline girth weld that matches the experiment to obtain simulation results under different process parameters, including the width of the heat affected zone, peak temperature and cooling time t 8 / 5 The pipeline girth weld finite element model is a model of the simulated formed part without welding heat transfer calculation;

[0043] The prediction formula determination module is used to analyze the simulation results under different process parameters to obtain the heat affected zone width, peak temperature and cooling time t 8 / 5 The prediction formula between and heat input.

[0044] The present invention also provides a device for determining parameters of a heat-affected zone of a pipeline girth weld, comprising:

[0045] memory for storing computer programs;

[0046] The processor is configured to implement the above-mentioned method for determining the heat-affected zone parameters of a pipeline girth weld when executing the computer program.

[0047] The present invention also provides a readable storage medium, in which computer-executable instructions are stored. When the computer-executable instructions are loaded and executed by a processor, the above-mentioned method for determining the heat-affected zone parameters of a pipeline girth weld is implemented.

[0048] It can be seen that the present invention obtains the experimental welding joint and the simulated formed part of the annular pipe to be tested under the same working conditions; determines the width of the heat affected zone at the center line of the cross section of each experimental weld layer according to the range of the heat affected zone of each weld layer in the experimental welding joint; each weld layer includes a hot weld layer, an intermediate layer filling weld layer and a final layer filling weld layer; the cross section is a cross section along the radial direction of the pipe; the center line of the cross section is the geometric center line of the cross section of a single weld layer of the experimental welding joint, that is, a straight line perpendicular to the thickness direction of the weld layer and located at the center of the weld layer; determines the temperature range of the heat affected zone of the simulated formed part according to the width of the heat affected zone at the center line of the cross section of each weld layer in the experiment; the temperature range of the heat affected zone includes the upper limit temperature of the heat affected zone and the lower limit temperature of the heat affected zone; determines the width of the heat affected zone according to the upper limit temperature of the heat affected zone and the lower limit temperature of the heat affected zone; takes the range of the width of the heat affected zone as the target area, and extracts the peak temperature according to the thermal cycle data of the target area; calculates the cooling time t according to the thermal cycle data on the two isotherms 8 / 5 ; Cooling time t 8 / 5It is the time required for the temperature to cool from 800°C to 500°C; the two isotherms are two isotherms formed by the upper limit temperature of the heat-affected zone and the lower limit temperature of the heat-affected zone. The present invention provides a method for extracting parameters of the heat-affected zone of a pipeline girth weld, by which the temperature range of the width of the heat-affected zone of any welding process and welding material can be determined with high accuracy. The present invention determines a quantitative extraction method for the heat-affected zone parameters of a pipeline girth weld through numerical simulation and experimental calibration, and can be applied to simulations with different process parameters, which greatly saves time and economic costs; the simulation results based on different process parameters are analyzed to obtain the changing rules of the heat-affected zone parameters under different process parameters, providing certain guidance for further optimizing process parameters and improving welding quality.

[0049] In addition, the present invention also provides a device, equipment and medium for determining parameters of the heat-affected zone of a pipeline girth weld, which also have the above-mentioned beneficial effects. BRIEF DESCRIPTION OF THE DRAWINGS

[0050] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are merely embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the provided drawings without paying any creative work.

[0051] Figure 1 A flow chart of a method for determining parameters of a heat-affected zone of a pipeline girth weld provided by an embodiment of the present invention;

[0052] Figure 2 An example diagram of a temperature range provided by an embodiment of the present invention;

[0053] Figure 3 A flowchart illustrating a method for obtaining a simulated formed part according to an embodiment of the present invention;

[0054] Figure 4 An example diagram of a weld cross-section groove shape and weld bead distribution provided in an embodiment of the present invention;

[0055] Figure 5 An example diagram of the grid division of various areas of an annular pipeline provided by an embodiment of the present invention;

[0056] Figure 6 An example diagram of a welding heat source model provided by an embodiment of the present invention;

[0057] Figure 7 An example diagram of heat source movement provided by an embodiment of the present invention;

[0058] Figure 8An exemplary diagram of a weld cross section for a punch-mounted thermocouple provided in an embodiment of the present invention;

[0059] Figure 9 An example diagram of a thermal cycle curve provided by an embodiment of the present invention;

[0060] Figure 10 A schematic structural diagram of a device for determining parameters of a heat-affected zone of a pipeline girth weld provided by an embodiment of the present invention;

[0061] Figure 11 A schematic structural diagram of a device for determining parameters of a heat-affected zone of a pipeline girth weld provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0062] To make the objectives, technical solutions, and advantages of the embodiments of the present invention more clear, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings 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 making creative efforts shall fall within the scope of protection of the present invention.

[0063] First, let’s analyze some of the terms used in this application:

[0064] Heat-affected zone: The area where the material properties on both sides of the girth weld change unevenly due to high-intensity heat input and complex heat treatment process during the welding of the pipeline girth weld is called the "Heat Affected Zone (HAZ)".

[0065] Welded joint: mainly composed of weld area, heat affected zone and base material area.

[0066] Material liquidus: The material liquidus refers to the critical temperature curve at which a substance changes from solid to liquid under a specific pressure.

[0067] Currently, there are three main methods for measuring the width of the heat-affected zone (HAZ) in welds: metallographic microstructural observation, microhardness testing, and numerical simulation. The first two experimental methods require welding, cutting, polishing, and microstructural observation of multiple specimens, which is labor-intensive and costly. Numerical simulation offers significant advantages in determining the HAZ width. However, there is currently no unified method for determining the HAZ width temperature range based on numerical simulation.

[0068] In order to solve the above problems, this application provides a pipeline girth weld heat affected zone parameter extraction method, and then extracts data to quantitatively analyze the heat affected zone parameters. For details, please refer to Figure 1 , Figure 1A flow chart of a method for determining parameters of a heat-affected zone of a pipeline girth weld provided in an embodiment of the present invention. The method may include:

[0069] S101: Obtain an experimental welded joint and a simulated formed part of the annular pipe to be tested under the same working conditions.

[0070] The executor of this embodiment is a terminal. This embodiment does not limit the type of terminal, as long as it can complete the operation of the method for determining the parameters of the heat-affected zone of the pipeline girth weld. The experimental welding joints and simulation formed parts in this embodiment are both welding joints. In order to distinguish between experiments and simulations, they are specially distinguished as experimental welding joints and simulation formed parts. In this embodiment, the experimental welding joint is an actual product obtained through welding experiments, and the simulation formed part refers to a simulation product of numerical simulation. The experimental welding joint and the simulation formed part are produced under the same conditions, so this simulation formed part can simulate the actual welding state and should be consistent with the experimental welding joint. This embodiment does not limit the method of obtaining the simulation formed part, as long as a simulation product consistent with the experimental welding joint can be obtained through simulation.

[0071] S102: Determine the width of the heat-affected zone at the center line of the cross section of each weld layer in the experimental weld joint according to the range of the heat-affected zone of each weld layer in the experimental weld joint.

[0072] It should be noted that in this embodiment, each weld layer includes a hot weld layer, an intermediate filler weld layer, and a final filler weld layer; the cross section is a cross section along the radial direction of the pipe; and the centerline of the cross section is the geometric centerline of the cross section of a single weld layer in the experimental weld joint, that is, a line perpendicular to the thickness direction of the weld layer and located at the center of the weld layer. Based on the calibrated heat-affected zone ranges of the three weld layers of the experimental weld joint (hot weld, intermediate filler weld, and final filler weld), the heat-affected zone width at the centerline of the cross section of each weld layer in the experiment was obtained.

[0073] It should be further explained that the above-mentioned determination of the width of the heat-affected zone at the center line of the cross section of each weld layer in the experimental weld joint based on the range of the heat-affected zone of each weld layer in the experimental weld joint may specifically include:

[0074] Step 11: Prepare metallographic samples of each weld layer in the experimental weld joint and obtain the changes in the material microstructure; the changes in the material microstructure include the differences in grain morphology, precipitate phase distribution, and structural transformation characteristics between the base material area, heat-affected zone, and weld area;

[0075] Step 12: Determine the first boundary position between the heat-affected zone and the base material zone and the second boundary position between the heat-affected zone and the weld zone according to the material structure change;

[0076] Step 13: The vertical distance between the first boundary position and the second boundary position is used as the width value, and the width of the heat-affected zone at the center line of the cross section of each weld layer in the experiment is determined according to the width value.

[0077] Specifically, taking the heat-welded layer as an example: After the heat-welded layer is welded, take any radial cross-section of the weld joint (along the radial direction of the pipe) for metallographic sample preparation (cutting, grinding, polishing, and etching). Use an optical microscope or electron microscope to observe the changes in the material microstructure. Based on the differences in grain morphology, precipitate phase distribution, and structural transformation characteristics between the base material area, heat-affected zone, and weld area, determine the boundary position between the heat-affected zone, the base material area, and the weld area. Identify the boundary and calibrate the range of the heat-affected zone. Then, use a microscopic measurement ruler or image analysis software to measure the vertical distance between the two boundaries to obtain the width value, and further extract the heat-affected zone width at the center line of the cross-section of the heat-welded layer. Similarly, use the same method to obtain the heat-affected zone width at the center line of the cross-section of the intermediate layer filler weld and the final layer filler weld.

[0078] S103: Determine the temperature range of the heat-affected zone of the simulated formed part according to the width of the heat-affected zone at the center line of the cross section of each weld layer in the experiment; the temperature range of the heat-affected zone includes an upper limit temperature of the heat-affected zone and a lower limit temperature of the heat-affected zone.

[0079] This example determines the temperature range of the heat-affected zone (HAZ) of the simulated part based on the width of the HAZ at the centerline of the cross-section of the three weld layers (hot weld, intermediate filler weld, and final filler weld) of the experimental weld joint. The HAZ temperature range includes an upper and lower HAZ temperature limit.

[0080] For details, please refer to Figure 2 , Figure 2 An example diagram of a temperature range provided by an embodiment of the present invention is shown below. Figure 2 The right half is the simulation forming result obtained through numerical simulation model calculation.

[0081] It should be further explained that the temperature range of the heat-affected zone of the simulated formed part is determined based on the width of the heat-affected zone at the center line of the cross section of each weld layer in the experiment, which may specifically include:

[0082] Step 21: The temperature corresponding to the liquidus line of the material of the annular pipe to be tested is used as the upper limit temperature of the heat-affected zone. The upper limit temperature of the heat-affected zone is the starting point temperature of the heat-affected zone at the center line of the cross section of each weld layer of the simulated formed part;

[0083] Step 22: Based on the same spatial coordinate positioning principle and the width of the heat-affected zone at the center line of the cross section of each weld layer of the experimental part, the end point temperature of the heat-affected zone at the center line of the cross section of each weld layer of the simulated formed part is determined based on the starting point temperature;

[0084] Step 23: The average value of the end point temperature of the heat-affected zone at the center line of the cross section of each weld layer of the simulated formed part is used as the lower limit temperature of the heat-affected zone.

[0085] Specifically, taking the hot weld layer as an example: obtain the radial cross section (along the radial direction of the pipe) corresponding to when the center of the heat source in the hot weld layer of the simulated formed part moves to a certain point (the same pipe position in the experiment), and mark it at the center line of the cross section of the hot weld layer according to the same spatial coordinate positioning principle; take the liquidus line of the material as the upper limit temperature of the heat-affected zone, and first find the liquidus line temperature at the center line of the cross section of the hot weld layer and mark it as the starting point. Extend the width along the axial direction of the pipe until it is consistent with the width of the heat-affected zone of the experimental hot weld layer, mark this position as the end point, and record the temperature corresponding to the end point as T1. Similarly, use the same method to obtain the temperatures T2 and T3 corresponding to the end points at the center lines of the cross sections of the intermediate layer filler weld and the final layer filler weld, respectively, and take the average value of T1, T2, and T3 as the lower limit temperature of the heat-affected zone.

[0086] Finally, the temperature corresponding to the liquidus line of the material of the annular pipe to be tested is taken as the upper limit temperature of the heat affected zone, and the average value of the end point temperatures T1, T2, and T3 is taken as the lower limit temperature of the heat affected zone.

[0087] S104: Determine the width of the heat-affected zone according to the upper limit temperature and the lower limit temperature of the heat-affected zone.

[0088] It can be understood that the upper limit temperature of the heat-affected zone and the lower limit temperature of the heat-affected zone correspond to two isotherms, and the area between the two isotherms is the heat-affected zone, and its width is the width of the heat-affected zone.

[0089] S105: Taking the width of the heat-affected zone as the target area, extracting the peak temperature based on the thermal cycle data of the target area.

[0090] In this embodiment, the peak temperature refers to the highest temperature reached by the heated area of ​​the material during the welding process. In this embodiment, the width of the heat-affected zone is used as the target area, and the peak temperature is extracted based on the thermal cycle data of the target area to determine the peak temperature extraction method.

[0091] S106: Calculate the cooling time t based on the thermal cycle data on the two isotherms 8 / 5 ; Cooling time t 8 / 5 is the time required to cool from 800°C to 500°C; the two isotherms are formed by the upper and lower temperature limits of the heat-affected zone. It should be noted that this embodiment does not limit the order in which steps S104 and S105 are executed. For example, they can be executed simultaneously or sequentially.

[0092] In this embodiment, the cooling time t 8 / 5Refers to the time required for the material temperature to cool from 800°C to 500°C. In this embodiment, considering the width of the heat affected zone, peak temperature, cooling time t 8 / 5 Heat affected zone parameters such as the width of the heat affected zone, the peak temperature, and the cooling time t 8 / 5 In this embodiment, the thermal cycle data on the two isotherms are extracted based on the upper and lower temperature limits of the heat-affected zone, and the cooling time t is calculated from the thermal cycle data. 8 / 5 , and determine the cooling time t 8 / 5 extraction method.

[0093] It should be further explained that, in the above-mentioned process of extracting the thermal cycle data on the two isotherms and calculating the cooling time t from the thermal cycle data, 8 / 5 Afterwards, you can also include:

[0094] Step 31: Set different process parameters for the finite element model of the pipe girth weld that matches the experiment to obtain simulation results under different process parameters. The simulation results include the width of the heat-affected zone, peak temperature, and cooling time t 8 / 5 The finite element model of the pipeline girth weld is a model that simulates the formed part without welding heat transfer calculation;

[0095] Step 32: Analyze the simulation results under different process parameters to obtain the heat affected zone width, peak temperature and cooling time t 8 / 5 The prediction formula between and heat input.

[0096] After the above-mentioned simulation forming part is obtained, the extraction method of the heat-affected zone parameters has been determined. In the later stage, by changing the different process parameters of the pipeline girth weld finite element model, there is no need to determine the parameter extraction method. According to the previously determined extraction method, the heat-affected zone parameter data under different process parameters are extracted to further establish the relationship between the heat-affected zone parameters and heat input. Based on the extracted heat-affected zone parameters, the variation pattern of the heat-affected zone parameter data of each weld layer at all positions under different heat inputs (heat input is related to process parameters) is observed, and the relationship between the heat-affected zone parameters and welding heat input is fitted and analyzed, and the heat-affected zone width, peak temperature, and cooling time t are further proposed. 8 / 5 The prediction formula of heat input is developed and the accuracy of the prediction formula is verified to provide a reliability reference for engineering practice.

[0097] Specifically, based on the above-mentioned pipeline girth weld finite element model, numerical simulation technology can be used to calculate and analyze the temperature field distribution and heat transfer law of the weld zone, heat-affected zone and parent material zone of the pipeline girth weld finite element model under different process parameters. Because the simulated formed part is the result of simulation and calculation of the pipeline girth weld finite element model under certain process parameters. Based on the simulation results under different process parameters, the heat-affected zone parameter data is extracted and the relevant prediction formula is established. For example, this embodiment provides a prediction formula between the width of the heat-affected zone and the heat input, which is as follows:

[0098] ;

[0099] ;

[0100] Where W is the width of the heat-affected zone; E is the heat input in kJ / mm, which is determined by the process parameters; T0 is the initial temperature in °C; A is the energy coefficient, and B is the temperature coefficient, which can be obtained by fitting the curve; T1 is the lower limit temperature of the heat-affected zone; T2 is the upper limit temperature of the heat-affected zone; U is the welding voltage; I is the welding current; and V is the welding speed.

[0101] The method for determining the heat-affected zone parameters of a pipe girth weld provided by an embodiment of the present invention is applied, by obtaining an experimental welding joint and a simulated formed part of the annular pipe to be tested under the same working conditions; the width of the heat-affected zone at the center line of the cross section of each experimental weld layer is determined according to the heat-affected zone range of each weld layer in the experimental welding joint; each weld layer includes a hot weld layer, an intermediate filler weld layer and a final filler weld layer; the cross section is a cross section along the radial direction of the pipe; the center line of the cross section is the geometric center line of the cross section of a single weld layer of the experimental welding joint, that is, a straight line perpendicular to the thickness direction of the weld layer and located at the center of the weld layer; the temperature range of the heat-affected zone of the simulated formed part is determined according to the heat-affected zone width at the center line of the cross section of each weld layer in the experiment; the temperature range of the heat-affected zone includes the upper limit temperature of the heat-affected zone and the lower limit temperature of the heat-affected zone; the width of the heat-affected zone is determined according to the upper limit temperature of the heat-affected zone and the lower limit temperature of the heat-affected zone; the range of the width of the heat-affected zone is used as the target area, and the peak temperature is extracted according to the thermal cycle data of the target area; the cooling time t is calculated according to the thermal cycle data on two isotherms 8 / 5 ; Cooling time t 8 / 5It is the time required for the temperature to cool from 800°C to 500°C; the two isotherms are two isotherms formed by the upper limit temperature of the heat-affected zone and the lower limit temperature of the heat-affected zone. The present invention provides a method for extracting parameters of the heat-affected zone of a pipeline girth weld, by which the temperature range of the width of the heat-affected zone of any welding process and welding material can be determined with high accuracy. The present invention determines a quantitative extraction method for the heat-affected zone parameters of a pipeline girth weld through numerical simulation and experimental calibration, and can be applied to simulations with different process parameters, which greatly saves time and economic costs; the simulation results based on different process parameters are analyzed to obtain the changing rules of the heat-affected zone parameters under different process parameters, providing certain guidance for further optimizing process parameters and improving welding quality.

[0102] Based on the previous embodiment, it can be seen that the present application can obtain a simulated formed part that is consistent with the experimental welded joint based on the actual annular pipe to be tested. To this end, this embodiment will describe in detail the process of obtaining the simulated formed part. Figure 3 , Figure 3 This is an example flow chart of a method for obtaining a simulated formed part provided in an embodiment of the present invention.

[0103] S201: Obtaining temperature information and actual weld morphology of the annular pipe to be tested during the welding experiment.

[0104] The actual temperature field distribution in each area and the actual weld morphology are obtained during the welding experiment. Specifically, before conducting the girth weld test on the annular pipe to be tested, holes are drilled at different locations in the pipe's heat-affected zone. Thermocouple temperature sensors are installed in the holes. The temperature changes at different locations throughout the welding process are recorded, and thermal cycle curves are extracted at the measurement points at different locations. These thermal cycle curves can characterize the local dynamic characteristics of the welding temperature field.

[0105] S202: Constructing a three-dimensional pipeline model based on the structural information of the annular pipeline to be measured, and performing meshing on the three-dimensional pipeline model to obtain a meshed three-dimensional pipeline model.

[0106] It is understood that pipeline welding process parameters and basic material thermophysical properties are acquired at the construction site, and pipeline structural information is obtained based on process objectives to construct the geometric model. Process parameters may include welding voltage, welding current, and welding speed. Basic material thermophysical properties may include density, specific heat capacity, thermal conductivity, thermal expansion coefficient, latent heat of fusion, solidus temperature, and liquidus temperature. Structural information may include pipeline dimensions, groove type, joint design, weld sequence, welding process type, preheat temperature, interpass temperature, interpass cooling time, and pipeline position (flat, vertical, and overhead). Figure 4 This is an example diagram of a weld cross-section groove shape and weld bead distribution provided in an embodiment of the present invention.

[0107] The annular pipeline consists of three parts: the weld zone, the heat-affected zone, and the parent material zone. The calculation focuses on the weld zone where each weld layer is heated and transferred, and the heat-affected zone that contacts the weld zone for heat transfer and undergoes structural transformation. Therefore, according to the calculation focus, a grid with higher precision can be divided at the position of the pipeline three-dimensional model corresponding to the weld zone and the heat-affected zone. The parent material area farther away from the heat-affected zone adopts a grid with slightly lower precision than the weld area, thereby forming a gradually sparse grid division form from the weld area to both sides of the parent material area; the grid type is selected as heat transfer. This grid division method can accurately reflect the changing laws of heat transfer calculations in key areas, saving calculation costs and time costs. It can be understood that the grid is divided on the established three-dimensional pipeline model, and the grid density can be adjusted independently without regenerating the geometry, so the grid density can be changed independently and freely. The mesh division process can be found in Figure 5 , Figure 5 This is an example diagram of the grid division of various areas of an annular pipeline provided by an embodiment of the present invention.

[0108] S203: Constructing a welding heat source model based on the process requirements and welding information of the annular pipeline to be tested.

[0109] The welding heat source model is a mathematical expression of the heat input distribution characteristics acting on the weldment in the time domain and space domain. The heat input is characterized by local concentration. The size and shape of the weld should be taken into account when establishing the welding heat source model. In the actual welding process, since the arc moves along the welding direction, the arc heat flux is asymmetrically distributed. Due to the influence of welding speed, the heating area in front of the arc is smaller than that behind the arc, and the heating area is not symmetrical about the arc center. In this case, a double ellipsoid heat source can be used, and the initial heat source shape parameters can be determined based on the weld width and weld depth. Specifically, the welding heat source model can be found in Figure 6 , Figure 6 This is an example diagram of a welding heat source model provided by an embodiment of the present invention.

[0110] It should be noted that the welding heat source model constructed based on the process requirements and welding information of the annular pipeline to be tested may specifically include:

[0111] Step 41: Obtain process requirements for the welding experiment; the process requirements include welding methods and process parameters;

[0112] Step 42: Obtain welding information of the welding experiment; the welding information at least includes the number of welding guns, the spacing between welding guns, the start time and the start position of the welding guns at each welding layer;

[0113] Step 43: Construct a welding heat source model based on process requirements and welding information.

[0114] The welding information represents the actual pipeline welding process in the project. The welding heat source model constructed based on this welding information simulates the welding process (the actual welding process) during the welding experiment using the welding gun. It should be noted that the welding method (upward welding, downward welding) determines the direction of heat source movement (clockwise, counterclockwise); the process parameters (welding voltage, welding current, and welding speed) determine the voltage, current, and speed of the heat source. Based on the actual pipeline welding process, a double ellipsoid heat source is used in finite element calculations of temperature fields for various fusion welding processes. The heat source shape parameters of the double ellipsoid heat source model are set based on the geometric dimensions of the pipeline girth weld. The number of heat sources is determined by the number of welding guns at the actual welding site. The starting position and time of each heat source layer are determined based on the welding gun spacing and start-up time. The welding time of each layer is calculated based on the welding speed of each layer. The heat source distribution is determined based on the heat source's X, Y, and Z coordinates and heat source shape parameters.

[0115] At the starting position of the heat source of each welding layer, the radius size of the welding layer is decomposed in the XYZ direction to obtain the starting coordinates of the heat source movement; in the root welding layer, the starting time of the heat source in the welding layer is determined according to the early preheating time. In the subsequent welding layers, the welding speed of each welding layer is determined according to the experimental information, and then the arc length that the welding heat source needs to move is calculated from the diameter of the welding layer. Then, the movement time of the welding layer is obtained from the arc length and the welding speed. The starting movement time of the heat source in each welding layer can be calculated by superimposing the movement time of the heat source on the welding layer and the interlayer cooling time on the early time; the central angle of the circle swept by is calculated according to the pipeline radius and the arc of the heat source movement at different times. The function relationship between the position coordinates of the heat source in the XYZ direction and the time is obtained by using the Pythagorean theorem of triangles from the obtained starting position coordinates and central angles of the heat source, as shown in the figure: Figure 7 As shown. In circular motion, , v is the velocity, t is the time, and r is the radius.

[0116] The heat source distribution function in the positive direction of the double ellipsoid along the x-axis is:

[0117] ;

[0118] The heat source distribution function in the negative direction of the double ellipsoid along the x-axis is:

[0119] .

[0120] in, is the heat source of the front hemisphere, the unit is W«m -3 ; is the heat source of the rear hemisphere, the unit is W«m -3 ; , , , is the shape parameter of the front and rear ellipsoids; Q is the welding heat power, in W; and It is the ratio of the front and back parts to the total input.

[0121] Based on the initial information, motion information, and spatial information obtained above, the heat source continuously moves and transfers heat in each welding layer. The temperature of the weld area increases, and the temperature of the heat-affected zone contacting the weld area increases and then decreases, undergoing different thermal cycle processes. Taking this position point in the weld cross section as an example, you can refer to Figure 8 and Figure 9 . Figure 8 This is an example diagram of a weld cross section for a punched thermocouple installation according to an embodiment of the present invention. Figure 9 This is an example diagram of a thermal cycle curve provided by an embodiment of the present invention. In the experiment, a thermocouple can measure the thermal cycle curve of the point, and the simulation obtains the thermal cycle curve of the same point. The experiment and simulation are compared and verified.

[0122] S204: Define the basic thermophysical parameters of the meshed three-dimensional pipeline model, set the heat transfer coefficient of the heat transfer method, determine the boundary conditions and initial conditions, and import the welding heat source model to obtain a preliminary pipeline girth weld finite element model.

[0123] Specifically, at a specific moment, a high-input heat source moves at a constant velocity from the initial position of each weld layer. As the heat source moves across the weld, heat transfer between the weld and the surrounding environment occurs primarily through convection and radiation, satisfying Newton's cooling equation and Boltzmann's law. Energy is primarily exchanged within the welded component through conduction, satisfying Fourier's heat conduction equation. The weld area, in contact with the heat source, receives heat and continuously heats up, transferring heat to other areas through conduction. The heated temperature of the weldment constantly changes, and the temperature distribution at each point in the weldment is described as a temperature field. During multi-layer, multi-pass welding, the welding temperature changes dramatically with the heat source input, resulting in a continuous change in temperature at each node in the circumferential weld region. Due to the multi-pass, multi-pass welding process, the weldment undergoes cyclical temperature fluctuations. The nonlinear relationship between the temperature and the thermophysical properties of the welding process makes welding a nonlinear transient heat transfer problem, satisfying the law of conservation of energy. In the simulation software, the basic thermophysical parameters of the meshed three-dimensional pipeline model are defined, the heat transfer coefficients of the three heat transfer modes are set, the boundary conditions and initial conditions are determined, and then the welding heat source model is imported to obtain a preliminary finite element model of the pipeline girth weld.

[0124] S205: Based on the thermo-solid coupling, energy conservation and heat transfer equations, the preliminary pipeline girth weld finite element model is calculated for welding heat transfer to obtain the temperature field distribution in each region and simulate the weld morphology. The regions are the weld zone, heat-affected zone and base material zone.

[0125] Specifically, the initial pipeline girth weld finite element model was used to calculate welding heat transfer based on thermo-solid coupling, the law of conservation of energy, and the heat transfer equation. The temperature field distribution and variation patterns of the weld zone, heat-affected zone, and parent metal zone were obtained. At the end of the welding simulation, the simulated weld morphology was obtained. The welding heat transfer of each weld layer in the pipeline girth weld was calculated using the birth-death unit technique. During the actual welding process, the weld layers are accumulated layer by layer from the root to the top. To accurately reflect the actual engineering process, each weld layer is set as a different regional unit and associated with an analysis step. The activation and deactivation time of each weld layer unit is reasonably set according to the welding process parameters. In the pipeline girth weld finite element model, the unwelded weld layer units are set as "dead units" so that they do not participate in the heat transfer response during the calculation. As the welding process progresses, these units are activated in sequence according to the actual welding sequence, transforming them into "live units" and assigning corresponding material properties and heat source loading, thereby accurately simulating the physical process of the weld layer from scratch to the accumulation.

[0126] S206: Adjust the process parameters based on the temperature information in the welding experiment and the temperature field distribution obtained by simulation, and adjust the welding heat source shape parameters based on the actual weldment morphology and the simulated weldment morphology to obtain a pipeline girth weld finite element model that is consistent with the experiment, and use the simulation forming result corresponding to the pipeline girth weld finite element model as the simulated formed part.

[0127] Based on the heat transfer simulation calculation results, the thermal cycle curves of the heat-affected zone and the same punching position in the experiment are extracted and compared with the experimental results. If the error is within the range, the pre-set process parameters can be adjusted in a small range to make the simulation results more consistent with the expected conditions. If the error between the two is large and not within the error range, it is necessary to analyze based on the existing simulation results and adjust the process parameters to meet reasonable welding requirements. The actual weld morphology of the experimental results is compared with the simulated weld morphology, and the welding heat source shape parameters are adjusted according to the difference to obtain reasonable weld layer weld bead forming requirements. The purpose of the above steps is to obtain a finite element model of the pipeline girth weld that is consistent with the experiment, and use its corresponding simulation forming results as the simulated forming part.

[0128] Once a finite element model of the pipe girth weld is obtained that matches the experiment, the temperature field distribution and heat transfer patterns of the weld zone, heat-affected zone, and parent material under different process parameters can be analyzed based on thermo-solid coupling calculations. Specifically, when the heat source moves, it carries high energy and acts on the local area of ​​the weld. When the heat source moves to the material to be welded, the high heat input energy of the heat source is transferred to the interior of the material in the form of heat conduction, forming a temperature gradient between the weld zone, heat-affected zone, and parent material. When the heat source continues to move along the weld direction to the next area, the temperature of this area will drop rapidly. The heat transfer caused by the contact of the heat source at each point on the weld will cause the temperature distribution to change at a certain moment. Under the influence of the uneven temperature field caused by the welding process, the internal microstructure and mechanical properties of the weld material will change. Therefore, the temperature field distribution and heat transfer patterns of the weld zone, heat-affected zone, and parent material can be analyzed based on thermo-solid coupling calculations.

[0129] The method in the above embodiment decomposes the welding velocity of the heat source along the motion plane in three dimensions at a macroscopic scale, decomposing the heat source motion into two-dimensional uniform circular motion around the center of the pipe and one-dimensional periodic oscillation of a point along the axial direction during the circling process. This systematic study, using a double ellipsoid as a heat source at a macroscopic scale, examines the contact heat transfer between the heat source and the weld zone during welding, where the temperature in the weld zone continuously changes. This method accurately describes the different thermal cycle histories experienced by the heat-affected zone during welding, providing a solid theoretical foundation for determining the heat-affected zone and extracting temperature data. Based on the determined temperature data, heat-affected zone parameter information can be extracted, and relevant prediction formulas can be proposed, providing a theoretical basis for actual welding processes in engineering.

[0130] In some embodiments of the present application, the welding speed of the heat source is decomposed two-dimensionally along the center plane of the weld on a macroscopic scale. The heat source performs uniform circular motion around the weld center with a certain heat input. Different welding positions lead to differences in the difficulty of the welding operation, molten pool control, and slag removal. Therefore, different welding process parameters are used for flat welding, vertical welding, and overhead welding in pipeline welding. These parameters also need to be adjusted accordingly in numerical simulations based on welding experiments. Flat welding (12 o'clock to 2 o'clock) has a smaller welding angle and is less difficult than vertical welding (2 o'clock to 4 o'clock), while overhead welding (4 o'clock to 6 o'clock) is more difficult. All three welding methods require adjustments to the welding current, welding voltage, and welding speed to achieve the appropriate welding effect. After verifying the accuracy of the finite element model of the pipeline girth weld at the same welding position, the welding process parameters are varied, and the heat input is then varied to observe the effects of different heat inputs on the weldment temperature field and heat-affected zone parameters.

[0131] In some embodiments of the present application, the heat source contacts the weld area, and the weld area is continuously heated and the temperature changes during the heat transfer process. The heat source has a certain heat input and contacts the weld area during the movement. The temperature of the weld area receives heat and changes, and the heat is transferred to the surrounding area in the form of heat conduction, which can accurately reflect the temperature change law of the weld during the actual welding process. Specifically, when the heat source contacts the weld area in each weld layer, the heat diffuses to the weld area, the heat-affected zone, and the parent material area in the form of heat conduction, forming a significant temperature field distribution; the heat source continuously moves in each weld layer according to the process requirements and welding information, simulating the heat transfer law and temperature field distribution of the weld layer in each weld layer during the actual welding process; inside the weld, the temperature of each point changes continuously with time, satisfying the energy conservation equation, and the heat-affected zone undergoes different welding thermal cycles, and the structure and performance change significantly; first, the method for extracting the width data of the simulated forming heat-affected zone is determined based on the actual situation of the weld joint (i.e., the experimental weld joint), and then the peak temperature and cooling time t are determined. 8 / 5 Based on this extraction method, the heat affected zone parameter data is extracted.

[0132] In some embodiments of the present application, based on the determination of the heat-affected zone parameter data extraction method, the heat-affected zone parameters are extracted and calculated according to the determined temperature data, and by analyzing the parameter change law under different welding heat inputs, a prediction formula for the heat-affected zone parameters with respect to the welding heat input is proposed, which can provide certain theoretical support for the actual welding process in the engineering, including: after obtaining the temperature field data of the girth weld formed part after multi-pass weld forming work, the heat-affected zone parameters can be extracted based on the numerical value of the welding temperature field of the heat-affected zone at a certain instant and fixed position, and the microstructure can be observed in combination with the CCT (Continuous Cooling Transformation Diagram) diagram to achieve welding micro-quality control.

[0133] The following is an introduction to the pipeline girth weld heat affected zone parameter determination device provided by an embodiment of the present invention. The pipeline girth weld heat affected zone parameter determination device described below and the pipeline girth weld heat affected zone parameter determination method described above can be referenced to each other.

[0134] Please refer to Figure 10 , Figure 10 A schematic structural diagram of a device for determining parameters of a heat-affected zone of a pipe girth weld provided in an embodiment of the present invention may include:

[0135] An acquisition module 100 is used to obtain an experimental welded joint and a simulated formed part of the annular pipeline to be tested under the same working conditions;

[0136] The experimental weld joint heat-affected zone width determination module 200 is configured to determine the heat-affected zone width at the center line of the cross section of each weld layer in the experimental weld joint based on the heat-affected zone range of each weld layer in the experimental weld joint; each weld layer includes a hot weld layer, an intermediate filler weld layer, and a final filler weld layer; the cross section is a cross section along the radial direction of the pipeline; and the cross section center line is the geometric center line of the cross section of a single weld layer in the experimental weld joint, i.e., a straight line perpendicular to the thickness direction of the weld layer and located at the center of the weld layer;

[0137] A temperature range determination module 300 is configured to determine a temperature range of a heat-affected zone of a simulated formed part based on a width of the heat-affected zone at a center line of a cross section of each weld layer in the experiment; the temperature range of the heat-affected zone includes an upper temperature limit of the heat-affected zone and a lower temperature limit of the heat-affected zone;

[0138] A module 400 for determining the width of a heat-affected zone of a simulated formed part is used to determine the width of the heat-affected zone according to the upper limit temperature of the heat-affected zone and the lower limit temperature of the heat-affected zone;

[0139] A peak temperature determination module 500 is configured to extract a peak temperature based on thermal cycle data of a target region with the width of the heat-affected zone as the target region;

[0140] The cooling time determination module 600 is used to calculate the cooling time t according to the thermal cycle data on the two isotherms. 8 / 5 ; The cooling time t 8 / 5 It is the time required for the temperature to cool from 800°C to 500°C; the two isotherms are two isotherms formed by the upper limit temperature of the heat affected zone and the lower limit temperature of the heat affected zone.

[0141] Based on the above embodiment, the device for determining parameters of the heat-affected zone of a pipeline girth weld may further include:

[0142] The simulation result acquisition module is used to set different process parameters for the finite element model of the pipeline girth weld that matches the experiment to obtain simulation results under different process parameters, including the width of the heat affected zone, peak temperature and cooling time t 8 / 5 The pipeline girth weld finite element model is a model of the simulated formed part without welding heat transfer calculation;

[0143] The prediction formula determination module is used to analyze the simulation results under different process parameters to obtain the heat affected zone width, peak temperature and cooling time t 8 / 5 The prediction formula between and heat input.

[0144] Based on the above embodiment, the acquisition module 100 may include:

[0145] A pipeline three-dimensional model determination unit is used to obtain temperature information and actual weldment morphology of the annular pipeline to be tested during the welding experiment;

[0146] a pipeline three-dimensional model division unit, configured to construct a pipeline three-dimensional model based on the structural information of the annular pipeline to be measured, and to perform mesh division on the pipeline three-dimensional model to obtain a meshed pipeline three-dimensional model;

[0147] A welding heat source model building unit, configured to build a welding heat source model based on the process requirements and welding information of the annular pipeline to be tested;

[0148] a pipeline girth weld finite element model acquisition unit, configured to define basic thermophysical parameters of the meshed three-dimensional pipeline model, set the heat transfer coefficient of the heat transfer mode, determine boundary conditions and initial conditions, and import the welding heat source model to obtain a preliminary pipeline girth weld finite element model;

[0149] a simulation data acquisition unit for performing welding heat transfer calculations on the preliminary pipeline girth weld finite element model based on thermo-solid coupling, energy conservation, and heat transfer equations to obtain temperature field distributions in various regions and simulated weldment morphology; the various regions being the weld zone, heat-affected zone, and base metal zone;

[0150] An adjustment unit is used to adjust the process parameters based on the temperature information in the welding experiment and the temperature field distribution obtained by the simulation, and to adjust the welding heat source shape parameters based on the actual weldment morphology and the simulated weldment morphology to obtain a pipeline girth weld finite element model that is consistent with the experiment, and to use the simulation forming result corresponding to the pipeline girth weld finite element model as the simulated formed part.

[0151] Based on the above embodiment, the experimental weld joint heat-affected zone width determination module 200 may include:

[0152] a change acquisition unit, configured to prepare metallographic samples of each weld layer in the experimental weld joint and obtain changes in the material microstructure; the changes in the material microstructure include differences in grain morphology, precipitate phase distribution, and structural transformation characteristics between the base material region, the heat-affected zone, and the weld region;

[0153] a boundary position determining unit, configured to determine a first boundary position between the heat-affected zone and the base material zone and a second boundary position between the heat-affected zone and the weld zone according to the material structure change;

[0154] The experimental heat-affected zone width determination unit is used to take the vertical distance between the first boundary position and the second boundary position as a width value, and determine the heat-affected zone width at the center line of the cross section of each welding layer in the experiment according to the width value.

[0155] Based on the above embodiment, the temperature range determination module 300 may include:

[0156] an upper limit temperature determination unit, configured to use the temperature corresponding to the liquidus line of the material of the annular pipe to be tested as the upper limit temperature of the heat-affected zone, wherein the upper limit temperature of the heat-affected zone is the starting point temperature of the heat-affected zone at the center line of the cross section of each weld layer of the simulated formed part;

[0157] an end point temperature determining unit for determining, based on the same spatial coordinate positioning principle and the width of the heat affected zone at the center line of the cross section of each weld layer of the experimental part, the end point temperature of the heat affected zone at the center line of the cross section of each weld layer of the simulated formed part based on the starting point temperature;

[0158] The lower limit temperature determination unit is used to take the average value of the end point temperature of the heat affected zone at the center line of the cross section of each welding layer of the simulated formed part as the lower limit temperature of the heat affected zone.

[0159] Based on the above embodiment, the welding heat source model building unit may include:

[0160] The process requirement acquisition subunit is used to obtain the process requirements of the welding experiment; the process requirements include welding methods and process parameters;

[0161] The welding information acquisition subunit is used to obtain welding information of the welding experiment; the welding information at least includes the number of welding guns, the spacing between welding guns, the starting time and starting position of the welding guns in each welding layer;

[0162] A construction subunit is used to construct the welding heat source model based on the process requirements and the welding information.

[0163] It should be noted that the order of the modules and units in the above-mentioned device for determining parameters of the heat-affected zone of a pipeline girth weld can be changed without affecting the logic.

[0164] The pipeline girth weld heat-affected zone parameter determination device provided by the embodiment of the present invention is used to obtain the experimental welding joint and the simulated formed part of the annular pipeline to be tested under the same working conditions through the acquisition module 100; the experimental welding joint heat-affected zone width determination module 200 is used to determine the heat-affected zone width of each experimental welding layer at the center line of the cross section according to the heat-affected zone range of each welding layer in the experimental welding joint; each welding layer includes a hot welding layer, an intermediate filling welding layer and a final filling welding layer; the cross section is a cross section along the radial direction of the pipeline; the cross section center line is the geometric center line of the cross section of a single welding layer of the experimental welding joint, that is, a straight line perpendicular to the thickness direction of the welding layer and located at the center of the welding layer ; A temperature range determination module 300 is used to determine the temperature range of the heat-affected zone of the simulated formed part according to the width of the heat-affected zone at the center line of the cross section of each weld layer in the experiment; the temperature range of the heat-affected zone includes the upper limit temperature of the heat-affected zone and the lower limit temperature of the heat-affected zone; a heat-affected zone width determination module 400 is used to determine the width of the heat-affected zone according to the upper limit temperature of the heat-affected zone and the lower limit temperature of the heat-affected zone; a peak temperature determination module 500 is used to take the range of the width of the heat-affected zone as the target area and extract the peak temperature according to the thermal cycle data of the target area; a cooling time determination module 600 is used to calculate the cooling time t according to the thermal cycle data on two isotherms. 8 / 5 ; The cooling time t 8 / 5 It is the time required for the temperature to cool from 800°C to 500°C; the two isotherms are two isotherms formed by the upper limit temperature of the heat-affected zone and the lower limit temperature of the heat-affected zone. The present invention provides a device for quantitatively determining the parameters of the heat-affected zone of a pipeline girth weld, by which the temperature range of the width of the heat-affected zone of any welding process or welding material can be determined with high accuracy. The present invention determines a quantitative extraction method for the parameters of the heat-affected zone of a pipeline girth weld through numerical simulation and experimental calibration, and can be applied to simulations of different process parameters, which greatly saves time and economic costs; the simulation results under different process parameters are analyzed to obtain the changing laws of the heat-affected zone parameters under different process parameters, providing certain guidance for further optimizing process parameters and improving welding quality. The present invention provides a new idea for extracting the width of the heat-affected zone. The traditional method requires a large amount of destructive sample preparation, while the present application combines numerical simulation with experimental calibration to reduce the number of experiments and reduce costs.

[0165] The following introduces a device for determining parameters of a heat-affected zone of a pipe girth weld provided by an embodiment of the present invention. The device for determining parameters of a heat-affected zone of a pipe girth weld described below and the method for determining parameters of a heat-affected zone of a pipe girth weld described above can refer to each other.

[0166] Please refer to Figure 11 , Figure 11A schematic structural diagram of a device for determining parameters of a heat-affected zone of a pipe girth weld provided in an embodiment of the present invention may include:

[0167] Memory 10, for storing computer programs;

[0168] The processor 20 is configured to execute a computer program to implement the above-mentioned method for determining parameters of the heat-affected zone of a pipeline girth weld.

[0169] The memory 10 , the processor 20 , and the communication interface 31 all communicate with each other via the communication bus 32 .

[0170] In the embodiment of the present invention, the memory 10 is used to store one or more programs. The program may include program code, and the program code includes computer operation instructions. In the embodiment of the present invention, the memory 10 may store programs for implementing the following functions:

[0171] Obtain the experimental welded joint and simulated formed part of the annular pipe to be tested under the same working conditions;

[0172] The width of the heat-affected zone at the center line of the cross section of each weld layer in the experimental weld joint is determined based on the range of the heat-affected zone of each weld layer in the experimental weld joint; each weld layer includes a hot weld layer, an intermediate filler weld layer, and a final filler weld layer; the cross section is a section along the radial direction of the pipeline; the center line of the cross section is the geometric center line of the cross section of a single weld layer in the experimental weld joint, that is, a straight line perpendicular to the thickness direction of the weld layer and located at the center of the weld layer;

[0173] The temperature range of the heat-affected zone of the simulated formed part is determined according to the width of the heat-affected zone at the center line of the cross section of each weld layer in the experiment; the temperature range of the heat-affected zone includes the upper limit temperature of the heat-affected zone and the lower limit temperature of the heat-affected zone;

[0174] Determine the width of the heat affected zone according to the upper and lower temperature limits of the heat affected zone;

[0175] The width of the heat-affected zone is taken as the target area, and the peak temperature is extracted based on the thermal cycle data of the target area;

[0176] The cooling time t is calculated based on the thermal cycle data on the two isotherms. 8 / 5 ; Cooling time t 8 / 5 It is the time required for the temperature to cool from 800°C to 500°C; the two isotherms are two isotherms formed by the upper limit temperature of the heat affected zone and the lower limit temperature of the heat affected zone.

[0177] In one possible implementation, the memory 10 may include a program storage area and a data storage area, wherein the program storage area may store an operating system and applications required for at least one function, etc.; the data storage area may store data created during use.

[0178] In addition, the memory 10 may include a read-only memory and a random access memory, and provides instructions and data to the processor. A portion of the memory may also include NVRAM. The memory stores an operating system and operating instructions, executable modules or data structures, or a subset or an extended set thereof. The operating instructions may include various operating instructions for implementing various operations. The operating system may include various system programs for implementing various basic tasks and processing hardware-based tasks.

[0179] The processor 20 may be a central processing unit (CPU), an application-specific integrated circuit, a digital signal processor, a field programmable gate array, or other programmable logic device. The processor 20 may be a microprocessor or any conventional processor. The processor 20 may call a program stored in the memory 10 .

[0180] The communication interface 31 may be an interface of a communication module, used for connecting to other devices or systems.

[0181] Of course, it needs to be explained that Figure 11 The structure shown does not constitute a limitation on the device for determining parameters of the heat-affected zone of a pipe girth weld in the embodiment of the present invention. In actual applications, the device for determining parameters of the heat-affected zone of a pipe girth weld may include: Figure 11 More or fewer components than shown, or combinations of certain components.

[0182] The computer-readable storage medium provided by an embodiment of the present invention is introduced below. The computer-readable storage medium described below and the method for determining parameters of the heat-affected zone of a pipeline girth weld described above can be referenced to each other.

[0183] The present invention also provides a computer-readable storage medium having a computer program stored thereon. When the computer program is executed by a processor, the steps of the above-mentioned method for determining the parameters of the heat-affected zone of a pipeline girth weld are implemented.

[0184] The computer-readable storage medium may include: a USB flash drive, a mobile hard disk, a read-only memory (ROM), a random access memory (RAM), a magnetic disk, or an optical disk, etc., which can store program codes.

[0185] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on its differences from the other embodiments. Reference can be made to the descriptions of the identical or similar parts between the various embodiments. For the devices disclosed in the embodiments, since they correspond to the methods disclosed in the embodiments, the descriptions are relatively simple, and the relevant parts can be referred to the descriptions of the methods.

[0186] Professionals may further appreciate that the units and algorithm steps of each example described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, computer software, or a combination of the two. In order to clearly illustrate the interchangeability of hardware and software, the above description has generally described the components and steps of each example according to their functions. Whether these functions are performed in hardware or software depends on the specific application and design constraints of the technical solution. Professionals and technicians may use different methods to implement the described functions for each specific application, but such implementation should not be considered to be beyond the scope of the present invention.

[0187] Finally, it should be noted that, in this document, relationships such as first and second, etc., are used solely to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations. Moreover, the terms "comprises," "comprising," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that includes a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus.

[0188] The above is a detailed introduction to the method, device, equipment and medium for determining the heat-affected zone parameters of a pipe girth weld provided by the present invention. Specific examples are used herein to illustrate the principles and implementation methods of the present invention. The description of the above embodiments is only used to help understand the method of the present invention and its core ideas. At the same time, for those skilled in the art, according to the ideas of the present invention, there may be changes in the specific implementation methods and application scopes. In summary, the contents of this specification should not be understood as limiting the present invention.

Claims

1. A method for determining parameters of the heat-affected zone of a pipeline girth weld, characterized in that: include: Obtain the experimental welded joint and simulated formed part of the annular pipe to be tested under the same working conditions; The width of the heat-affected zone at the center line of the cross section of each weld layer in the experimental weld joint is determined based on the range of the heat-affected zone of each weld layer in the experimental weld joint; each weld layer includes a hot weld layer, an intermediate filler weld layer, and a final filler weld layer; the cross section is a cross section along the radial direction of the pipeline; the center line of the cross section is the geometric center line of the cross section of a single weld layer in the experimental weld joint, that is, a straight line perpendicular to the thickness direction of the weld layer and located at the center of the weld layer; Determine the temperature range of the heat-affected zone of the simulated formed part according to the width of the heat-affected zone at the center line of the cross section of each weld layer in the experiment; the temperature range of the heat-affected zone includes an upper limit temperature of the heat-affected zone and a lower limit temperature of the heat-affected zone; Determine the width of the heat-affected zone according to the upper limit temperature of the heat-affected zone and the lower limit temperature of the heat-affected zone; Taking the width of the heat-affected zone as a target area, extracting the peak temperature based on the thermal cycle data of the target area; The cooling time t is calculated based on the thermal cycle data on the two isotherms. 8 / 5 ; The cooling time t 8 / 5 It is the time required for the temperature to cool from 800°C to 500°C; the two isotherms are two isotherms formed by the upper limit temperature of the heat affected zone and the lower limit temperature of the heat affected zone.

2. The method for determining heat-affected zone parameters of a pipeline girth weld according to claim 1, characterized in that: The cooling time t is calculated based on the thermal cycle data on the two isotherms. 8 / 5 After that, it also includes: Different process parameters are set for the finite element model of the pipeline girth weld that is consistent with the experiment to obtain simulation results under different process parameters, including the width of the heat affected zone, peak temperature and cooling time t 8 / 5 The pipeline girth weld finite element model is a model of the simulated formed part without welding heat transfer calculation; Based on the simulation results under different process parameters, the width of the heat affected zone, peak temperature and cooling time t are obtained. 8 / 5 The prediction formula between and heat input.

3. The method for determining parameters of the heat-affected zone of a pipeline girth weld according to claim 1, characterized in that: Obtain the experimental welded joint and simulated formed parts of the annular pipeline to be tested under the same working conditions, including: Obtaining temperature information and actual weld morphology of the annular pipe to be tested during the welding experiment; Constructing a three-dimensional pipeline model based on the structural information of the annular pipeline to be measured, and performing meshing on the three-dimensional pipeline model to obtain a meshed three-dimensional pipeline model; Constructing a welding heat source model based on the process requirements and welding information of the annular pipeline to be tested; Defining basic thermophysical parameters of the meshed three-dimensional pipeline model, setting the heat transfer coefficient of the heat transfer mode, and determining boundary conditions and initial conditions, and importing the welding heat source model to obtain a preliminary pipeline girth weld finite element model; Based on thermo-solid coupling, energy conservation, and heat transfer equations, welding heat transfer calculations are performed on the preliminary pipeline girth weld finite element model to obtain the temperature field distribution in each region and the simulated weldment morphology; the regions are the weld zone, heat-affected zone, and base metal zone; The process parameters are adjusted based on the temperature information in the welding experiment and the temperature field distribution obtained by the simulation, and the welding heat source shape parameters are adjusted based on the actual weldment morphology and the simulated weldment morphology to obtain a pipeline girth weld finite element model that is consistent with the experiment, and the simulation forming result corresponding to the pipeline girth weld finite element model is used as the simulated formed part.

4. The method for determining parameters of the heat-affected zone of a pipeline girth weld according to claim 1, wherein: Determining the width of the heat-affected zone at the center line of the cross section of each weld layer in the experimental weld joint according to the range of the heat-affected zone of each weld layer in the experimental weld joint includes: Performing metallographic sampling of each weld layer in the experimental weld joint and obtaining material microstructural changes; the material microstructural changes include differences in grain morphology, precipitate phase distribution, and structural transformation characteristics between the base material region, heat-affected zone, and weld region; Determine a first boundary position between the heat-affected zone and the base material zone and a second boundary position between the heat-affected zone and the weld zone according to the material structure change; The vertical distance between the first boundary position and the second boundary position is used as the width value, and the width of the heat-affected zone at the center line of the cross section of each welding layer in the experiment is determined according to the width value.

5. The method for determining parameters of the heat-affected zone of a pipeline girth weld according to claim 1, wherein: The temperature range of the heat-affected zone of the simulated formed part is determined based on the width of the heat-affected zone at the center line of the cross section of each weld layer in the experiment, including: The temperature corresponding to the liquidus line of the material of the annular pipe to be tested is used as the upper limit temperature of the heat-affected zone, and the upper limit temperature of the heat-affected zone is the starting point temperature of the heat-affected zone at the center line of the cross section of each weld layer of the simulated formed part; According to the same spatial coordinate positioning principle and the width of the heat-affected zone at the center line of the cross section of each weld layer in the experiment, the end point temperature of the heat-affected zone at the center line of the cross section of each weld layer of the simulated formed part is determined based on the starting point temperature; The average value of the termination point temperature of the heat-affected zone at the center line of the cross section of each welding layer of the simulated formed part is used as the lower limit temperature of the heat-affected zone.

6. The method for determining parameters of the heat-affected zone of a pipeline girth weld according to claim 3, characterized in that: A welding heat source model is constructed based on the process requirements and welding information of the annular pipeline to be tested, including: Obtaining process requirements for welding experiments; the process requirements include welding methods and process parameters; Obtain welding information of the welding experiment; the welding information includes at least the number of welding guns, the spacing between welding guns, the starting time and starting position of the welding guns at each welding layer; The welding heat source model is constructed based on the process requirements and the welding information.

7. A device for determining parameters of heat-affected zone of pipeline girth weld, characterized in that: include: An acquisition module is used to obtain the experimental welded joint and simulated formed part of the annular pipeline to be tested under the same working conditions; A module for determining the width of the heat-affected zone of an experimental weld joint is configured to determine the width of the heat-affected zone at the center line of the cross section of each weld layer in the experimental weld joint based on the range of the heat-affected zone of each weld layer in the experimental weld joint; each weld layer includes a hot weld layer, an intermediate filler weld layer, and a final filler weld layer; the cross section is a cross section along the radial direction of the pipeline; and the center line of the cross section is the geometric center line of the cross section of a single weld layer in the experimental weld joint, i.e., a straight line perpendicular to the thickness direction of the weld layer and located at the center of the weld layer; a temperature range determination module, configured to determine a temperature range of a heat-affected zone of a simulated formed part according to a width of the heat-affected zone at a center line of a cross section of each weld layer in the experiment; the temperature range of the heat-affected zone includes an upper limit temperature of the heat-affected zone and a lower limit temperature of the heat-affected zone; A module for determining the width of a heat-affected zone of a simulated formed part, configured to determine the width of the heat-affected zone according to an upper limit temperature of the heat-affected zone and a lower limit temperature of the heat-affected zone; a peak temperature determination module, configured to take the width of the heat-affected zone as a target area and extract the peak temperature based on the thermal cycle data of the target area; The cooling time determination module is used to calculate the cooling time t based on the thermal cycle data on the two isotherms. 8 / 5 ; The cooling time t 8 / 5 It is the time required for the temperature to cool from 800°C to 500°C; the two isotherms are two isotherms formed by the upper limit temperature of the heat affected zone and the lower limit temperature of the heat affected zone.

8. The device for determining parameters of heat-affected zone of pipeline girth weld according to claim 7, characterized in that: Also includes: The simulation result acquisition module is used to set different process parameters for the finite element model of the pipeline girth weld that matches the experiment to obtain simulation results under different process parameters, including the width of the heat affected zone, peak temperature and cooling time t 8 / 5 The pipeline girth weld finite element model is a model of the simulated formed part without welding heat transfer calculation; The prediction formula determination module is used to analyze the simulation results under different process parameters to obtain the heat affected zone width, peak temperature and cooling time t 8 / 5 The prediction formula between and heat input.

9. A device for determining parameters of heat-affected zone of pipeline girth weld, characterized in that: include: memory for storing computer programs; A processor, configured to implement the method for determining parameters of a heat-affected zone of a pipeline girth weld as claimed in any one of claims 1 to 6 when executing the computer program.

10. A readable storage medium, characterized in that: The readable storage medium stores computer-executable instructions, and when the computer-executable instructions are loaded and executed by the processor, the method for determining the heat-affected zone parameters of a pipeline girth weld according to any one of claims 1 to 6 is implemented.

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