Method and device for locating impact initiation source of submerged arc multi-pass weld metal

Abstract

The application provides a submerged arc multi-pass welding weld metal impact crack source positioning method and device, which comprises the following steps: based on the target temperature field simulation result generated by welding simulation on the submerged arc multi-pass welding weld metal, heat history subarea identifiers are given to a plurality of grid units contained in the submerged arc multi-pass welding weld metal; according to the impact test sampling position information corresponding to the submerged arc multi-pass welding weld metal, the heat history subarea identifiers matched with the impact fracture surface of the submerged arc multi-pass welding weld metal are mapped to the impact fracture surface to obtain a heat history subarea projection map; and based on the heat history subarea projection map, the weld metal heat history subarea corresponding to the impact crack source in the impact fracture surface is identified. The application can realize positioning of the weld metal heat history subarea corresponding to the impact crack source.

Description

Technical Field

[0001] This invention relates to the field of welding technology, and in particular to a method and apparatus for locating the impact crack initiation source of submerged arc multi-pass welding weld metal. Background Technology

[0002] Submerged arc welding (SAW) is characterized by high efficiency, large deposition rate, and stable process, and is commonly used in the manufacture of thick-plate structural components, pressure vessels, and high-temperature pressure-bearing components. Thick-walled components typically employ multi-layer, multi-pass welding, where the initially formed weld metal is repeatedly reheated by subsequent weld passes, thus creating different thermal history sub-regions within the weld metal. These different thermal history sub-regions differ in peak temperature, number of thermal cycles, and reheat sequence, thereby affecting local microstructure and impact behavior. However, these sub-regions usually lack clear macroscopic boundaries within the weld metal and are difficult to accurately delineate solely through metallographic analysis.

[0003] Existing temperature field simulation methods can obtain the temperature field of the welding process, or extract the characteristic thermal cycle and material properties of the heat-affected zone based on the peak temperature; fracture analysis methods can identify the crack initiation location from the fracture morphology. However, it is difficult to determine the multi-pass weld heat history sub-region corresponding to the actual crack initiation source by using only temperature field simulation or fracture analysis. Summary of the Invention

[0004] In view of this, the purpose of the present invention is to provide a method and apparatus for locating the impact crack initiation source of weld metal in submerged arc multi-pass welding, which can realize the location of the thermal history sub-region of weld metal corresponding to the impact crack initiation source.

[0005] In a first aspect, the present invention provides a method for locating the impact crack initiation source of submerged arc multi-pass weld metal, comprising: Based on the target temperature field simulation results generated by welding simulation of submerged arc multi-pass weld metal, thermal history sub-region identifiers are assigned to multiple mesh elements contained in the submerged arc multi-pass weld metal. Based on the impact test sampling location information corresponding to the weld metal of submerged arc multi-pass welding, the thermal history sub-region identifier that matches the impact fracture surface of the weld metal of submerged arc multi-pass welding is mapped onto the impact fracture surface to obtain the thermal history sub-region projection map. Based on the thermal history sub-region projection map, the thermal history sub-region of weld metal corresponding to the impact crack initiation source on the impact fracture surface is identified.

[0006] In one embodiment, based on the impact test sampling location information corresponding to the submerged arc multi-pass weld metal, the thermal history sub-region identifier matching the impact fracture surface of the submerged arc multi-pass weld metal is mapped onto the impact fracture surface to obtain a thermal history sub-region projection map, including: Based on the sampling location information of the impact test corresponding to the weld metal of submerged arc multi-pass welding, the sampling space range corresponding to the impact specimen and the model fracture plane corresponding to the impact fracture surface of the impact specimen are determined in the target temperature field simulation results. Based on the sampling space range, establish the spatial mapping relationship between the temperature field coordinate system and the impact specimen coordinate system; Extract the thermal history sub-region identifiers that match the fracture plane of the model, and use spatial mapping relationships to map the thermal history sub-region identifiers that match the fracture plane of the model to the impact fracture surface to obtain the thermal history sub-region projection map.

[0007] In one implementation, extracting thermal history sub-region identifiers that match the fracture plane of the model includes: From the multiple mesh elements contained in the weld metal of submerged arc multi-pass welding, the target mesh element that intersects with the fracture plane of the model is extracted, and its corresponding thermal history sub-region identifier is used as the thermal history sub-region identifier for matching the fracture plane of the model.

[0008] In one implementation, based on the target temperature field simulation results generated by welding simulation of the submerged arc multi-pass weld metal, multiple mesh elements contained in the submerged arc multi-pass weld metal are assigned thermal history sub-region identifiers, including: Welding simulation was performed on the weld metal of submerged arc multi-pass welding to generate simulation results of the target temperature field. Based on the target temperature field simulation results and the preset critical temperature threshold of the steel grade, the thermal history feature regions and their thermal history sub-region identifiers corresponding to the effective thermal cycle events experienced by multiple grid units contained in the submerged arc multi-pass weld metal are identified. The thermal history feature regions include a single coarse-grained heat-affected zone thermal cycle region, a single fine-grained heat-affected zone thermal cycle region, a single critical heat-affected zone thermal cycle region, and multiple thermal cycle regions formed by combining at least two of the coarse-grained temperature range, fine-grained temperature range, and critical temperature range in the order of effective thermal cycle events. The thermal history sub-region identifier is used to mark the thermal history feature regions corresponding to the effective thermal cycle events experienced by the mesh element.

[0009] In one implementation, based on the target temperature field simulation results and a preset critical temperature threshold for the steel grade, the thermal history feature regions and their thermal history sub-region identifiers corresponding to the effective thermal cycling events experienced by multiple grid units contained in the submerged arc multi-pass weld metal are identified, including: For any grid cell contained in the weld metal of submerged arc multi-pass welding, perform the following operations: determine the temperature range to which the peak temperature in the effective thermal cycle events experienced by the grid cell belongs, determine the thermal history feature region corresponding to the grid cell in combination with the order of the effective thermal cycle events, and assign the grid cell the thermal history sub-region identifier corresponding to the thermal history feature region. After identifying the thermal history feature regions and their thermal history sub-region identifiers corresponding to the effective thermal cycling events experienced by multiple mesh elements contained in the submerged arc multi-pass weld metal, based on the target temperature field simulation results and the preset critical temperature threshold for the steel grade, the method further includes: Multiple spatially continuous grid cells with the same thermal history subregion identifier are merged into a thermal history subregion, forming a three-dimensional spatial distribution result carrying the thermal history subregion identifier.

[0010] In one implementation, welding simulation is performed on the weld metal of submerged arc multi-pass welding to generate simulation results of the target temperature field, including: Based on the current weld simulation parameters, welding simulation is performed on the submerged arc multi-pass weld metal to generate the current temperature field simulation results. Based on the current temperature field simulation results, identify the simulated weld boundary, simulated weld morphology, and simulated thermal zone influence area boundary; Determine whether one or more of the simulated weld boundary, simulated weld morphology, and simulated thermal zone influence area boundary meet the preset conditions. If the result is negative, continue to simulate the welding of the submerged arc multi-pass weld metal according to the updated weld simulation parameters until the result is positive and the target temperature field simulation result is obtained.

[0011] In one embodiment, based on the thermal history sub-region projection map, identifying the weld metal thermal history sub-region corresponding to the impact crack initiation site on the impact fracture surface includes: Obtain the position coordinates of the impact crack initiation site on the impact fracture surface; Based on the location coordinates of the impact-induced crack initiation site and the corresponding thermal history sub-region identifier in the thermal history sub-region projection diagram, the thermal history sub-region of the weld metal corresponding to the impact-induced crack initiation site is determined.

[0012] Secondly, the present invention also provides a device for locating the impact crack initiation source of submerged arc multi-pass weld metal, comprising: The identifier assignment module is used to assign thermal history sub-region identifiers to multiple mesh cells contained in the submerged arc multi-pass weld metal based on the target temperature field simulation results generated by welding simulation of the weld metal. The projection map generation module is used to map the thermal history sub-region identifier that matches the impact fracture surface of the submerged arc multi-pass weld metal to the impact fracture surface based on the impact test sampling location information corresponding to the weld metal of the submerged arc multi-pass weld, so as to obtain the thermal history sub-region projection map. The crack initiation source identification module is used to identify the weld metal thermal history sub-region corresponding to the impact crack initiation source on the surface of the impact fracture based on the thermal history sub-region projection map.

[0013] Thirdly, the present invention also provides an electronic device, including a processor and a memory, wherein the memory stores computer-executable instructions that can be executed by the processor, and the processor executes the computer-executable instructions to implement the submerged arc multi-pass welding weld metal impact crack initiation source location method provided in the first aspect.

[0014] Fourthly, the present invention also provides a computer-readable storage medium storing computer-executable instructions. When the computer-executable instructions are invoked and executed by a processor, the computer-executable instructions cause the processor to implement the submerged arc multi-pass welding weld metal impact crack initiation location method provided in the first aspect.

[0015] This invention provides a method and apparatus for locating the impact crack initiation source in submerged arc multi-pass weld metal. By using a temperature field model obtained from welding simulation, multiple grid cells contained in the submerged arc multi-pass weld metal are assigned thermal history sub-region identifiers. These identifiers are then associated with the sampling location of the impact specimen and mapped onto the actual impact fracture surface to form a thermal history sub-region projection map. Furthermore, by combining the position of the impact crack initiation source on the impact fracture surface, the thermal history sub-region of the weld metal corresponding to the impact crack initiation source is determined. This invention can accurately identify the weld metal thermal history sub-region from which the impact crack initiation source originates, even when there is no clear macroscopic boundary of the thermal history sub-region.

[0016] Other features and advantages of the invention will be set forth in the following description, and will be apparent in part from the description, or may be learned by practicing the invention. The objects and other advantages of the invention are realized and obtained through the structures particularly pointed out in the description and the drawings.

[0017] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, preferred embodiments are described below in detail with reference to the accompanying drawings. Attached Figure Description

[0018] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0019] Figure 1 A flowchart illustrating a method for locating the impact crack initiation source in submerged arc multi-pass welding weld metal according to an embodiment of the present invention; Figure 2 A schematic diagram of a temperature field model of submerged arc multi-pass weld metal provided in an embodiment of the present invention; Figure 3A schematic diagram of the spatial division and partial magnification of thermal history subregions based on peak temperature, number of thermal cycles and reheat sequence is provided for an embodiment of the present invention. Figure 4 This is a schematic diagram illustrating the sampling location and spatial coordinate system establishment of an impact specimen, provided by an embodiment of the present invention. Figure 5 A schematic diagram illustrating the mapping of a three-dimensional spatial distribution result of a thermal history subregion onto the actual impact fracture surface, as provided in an embodiment of the present invention; Figure 6 This is a schematic diagram of a submerged arc multi-pass welding weld metal impact crack initiation source positioning device provided in an embodiment of the present invention; Figure 7 This is a schematic diagram of the structure of an electronic device provided in an embodiment of the present invention. Detailed Implementation

[0020] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the present invention will be clearly and completely described below in conjunction with the embodiments. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0021] Currently, existing methods do not encode the multiple thermal cycles sequentially experienced by each spatial location in a multi-pass weld metal as ordered thermal history features, nor do they establish a coordinate transformation relationship between the model fracture plane with thermal history sub-region identifiers and the actual impact fracture surface image. Therefore, it is difficult to determine the multi-pass weld thermal history sub-region corresponding to the actual crack initiation site using only temperature field simulation or fracture surface analysis.

[0022] Based on this, the present invention provides a method and apparatus for locating the impact crack initiation source of weld metal in submerged arc multi-pass welding. By jointly characterizing the peak temperature and occurrence sequence of each thermal cycle of multi-pass welding, a three-dimensional distribution of the thermal history sub-regions of weld metal is formed, and the sub-region markers on the fracture plane of the model are mapped to the actual impact fracture surface, thereby realizing the location of the thermal history sub-region of weld metal corresponding to the impact crack initiation source.

[0023] To facilitate understanding of this embodiment, a detailed description of the method for locating the impact crack initiation site of submerged arc multi-pass weld metal disclosed in this embodiment of the invention will be provided first. (See [link to relevant documentation]). Figure 1 The diagram shows a method for locating the impact crack initiation source in submerged arc multi-pass welding weld metal. The method mainly includes the following steps S102 to S106: Step S102: Based on the target temperature field simulation results generated by welding simulation of submerged arc multi-pass weld metal, assign thermal history sub-region identifiers to multiple mesh units contained in the submerged arc multi-pass weld metal.

[0024] Submerged arc multi-pass welding (SAW) refers to the entire filler metal region of a thick plate structure formed by a multi-layer, multi-pass SAW process. Welding simulation includes transient heat conduction analysis and cooling analysis based on a heat source model. Target temperature field simulation results refer to the validated welding simulation output, containing the complete temperature-time curve (i.e., complete thermal cycle data) for each node or integration point within the weld metal throughout the entire welding-cooling process. Thermal history sub-region identifiers are used to mark the thermal history feature regions corresponding to the effective thermal cycle events experienced by the mesh elements. These feature regions include single coarse-grained heat-affected zone (HAZ) thermal cycle regions, single fine-grained HAZ thermal cycle regions, single critical HAZ thermal cycle regions, and multiple thermal cycle regions formed by combining at least two of the coarse-grained temperature range, fine-grained temperature range, and critical temperature range in the order of the effective thermal cycle events.

[0025] In one embodiment, welding parameters, weld bead layout parameters, and impact sample sampling location information of the submerged arc multi-pass weld metal are obtained; a temperature field model of the submerged arc multi-pass weld metal is established based on the welding parameters and weld bead layout parameters; the corresponding weld bead filling units are activated sequentially according to the weld bead sequence; and a moving heat source model is applied along the corresponding welding path to obtain the thermal cycle data of each spatial position in the weld metal in each weld bead analysis step, which is the target temperature field simulation result.

[0026] Step S104: Based on the impact test sampling location information corresponding to the submerged arc multi-pass weld metal, the thermal history sub-region identifier that matches the impact fracture surface of the submerged arc multi-pass weld metal is mapped onto the impact fracture surface to obtain the thermal history sub-region projection map.

[0027] The impact test sampling location information refers to the spatial positioning parameters used to prepare Charpy impact test specimens on the actual welded joint. The impact fracture surface refers to the actual macroscopic fracture plane exposed after the impact specimen fractures; its geometry is determined by the crack propagation path, is usually approximately perpendicular to the impact load direction, and includes morphological features such as herringbone patterns and radial zones. The thermal history sub-region projection image is a superimposed image with the same size, orientation, and scale as the actual impact fracture surface image, where each pixel region is labeled with the thermal history sub-region identifier of the weld metal mesh unit it covers.

[0028] In one embodiment, based on the temperature threshold corresponding to the steel to be welded, the peak temperature of each spatial location in each effective thermal cycle is divided into corresponding temperature ranges, and thermal history feature regions are formed according to the thermal cycle occurrence sequence. Based on the preset correspondence between thermal history feature regions and thermal history sub-region identifiers, thermal history sub-region identifiers are assigned to each spatial location within the weld metal to obtain a three-dimensional spatial distribution result with thermal history sub-region identifiers. Based on the sampling location information of the impact specimen, the sampling spatial range of the impact specimen in the temperature field model and the model fracture plane are determined, and a spatial mapping relationship is established between the temperature field model, the spatial coordinate system of the impact specimen, and the pixel coordinates of the fracture image. The mesh cells intersecting with the model fracture plane and their thermal history sub-region identifiers are extracted, and the thermal history sub-region identifiers are mapped to the impact fracture surface after actual fracture according to the spatial mapping relationship to obtain a thermal history sub-region projection map.

[0029] Step S106: Based on the thermal history sub-region projection map, identify the weld metal thermal history sub-region corresponding to the impact crack initiation source on the impact fracture surface.

[0030] The thermal history subregion of weld metal refers to the thermal history subregion identifier carried by the color block / region covering the location coordinates of the impact-induced crack initiation point and the three-dimensional spatial entity it represents in the thermal history subregion projection map.

[0031] In one embodiment, the coordinates of the crack initiation location on the impact fracture surface are determined based on the overall image of the impact fracture surface and the scanning electron microscope image; the thermal history sub-region corresponding to the impact crack initiation location is determined based on the thermal history sub-region identifier corresponding to the thermal history sub-region projection map.

[0032] This invention provides a method for locating the impact crack initiation source in submerged arc multi-pass weld metal. By using a temperature field model obtained from welding simulation, multiple grid cells contained in the submerged arc multi-pass weld metal are assigned thermal history sub-region identifiers. These identifiers are then associated with the sampling location of the impact specimen and mapped onto the actual impact fracture surface to form a thermal history sub-region projection map. Furthermore, by combining the position of the impact crack initiation source on the impact fracture surface, the thermal history sub-region of the weld metal corresponding to the impact crack initiation source is determined. This invention can accurately identify the weld metal thermal history sub-region from which the impact crack initiation source originates, even when there are no clear macroscopic boundaries in the thermal history sub-region.

[0033] For ease of understanding, this invention provides a specific implementation of a method for locating the impact crack initiation source in submerged arc multi-pass weld metal, including: Step 1: Obtain the welding parameters, weld bead layout parameters, and impact test sample location information for the submerged arc multi-pass weld metal.

[0034] The welding parameters may include one or more of the following: welding current, welding voltage, welding speed, heat input, welding efficiency, preheating temperature, interpass temperature, and welding path; the weld bead arrangement parameters may include one or more of the following: number of weld beads, weld bead sequence, weld bead size, weld bead spatial position, bevel size, and number of filler layers; the impact specimen sampling location information may include the cut location, notch location, specimen direction, specimen thickness direction, and the plane location of the actual fracture.

[0035] The sampling location information is used to determine the three-dimensional spatial range of the impact specimen in the temperature field model and to establish the spatial mapping relationship between the temperature field model and the actual impact fracture surface.

[0036] Step 2: Based on the welding parameters and weld bead layout parameters, establish a temperature field model for the weld metal of submerged arc multi-pass welding. Activate the corresponding weld bead filling units in sequence according to the weld bead order, and apply a moving heat source along the corresponding welding path to obtain the thermal cycle data of each spatial position in the weld metal during each weld bead analysis step.

[0037] In one specific implementation: Step 2.1: Establish a three-dimensional finite element model including the base material and the weld metal filling region of each weld bead, and mesh the weld and its adjacent areas. For example... Figure 2 The diagram shows a temperature field model of submerged arc multi-pass welding weld metal. The left diagram is a schematic diagram of the weld bead arrangement of the model, and the right diagram is a schematic diagram of the model mesh division. Figure 2 Taking a three-pass weld as an example, the model weld bead layout and mesh generation are shown. The actual number of weld beads is determined by the weld bead layout parameters.

[0038] Step 2.2: Based on the current weld simulation parameters, perform welding simulation on the submerged arc multi-pass weld metal to generate the current temperature field simulation results. The weld simulation parameters may include at least one of the following: heat source shape parameters, heat source energy distribution parameters, heat source application location, and welding heat input parameters.

[0039] Specifically: Before the first weld bead is welded, the base material unit is in an active state, while all unfilled weld bead filling units are in an inactive state.

[0040] For the i-th weld bead, the corresponding filler unit is activated at the start of the i-th weld analysis step; after the analysis step ends, the filler unit remains activated in subsequent weld and cooling analysis steps. Thus, the filler is completed sequentially according to the weld bead order.

[0041] Before model calculations, thermal properties such as thermal conductivity, specific heat capacity, density, and latent heat, which vary with temperature, are assigned to the base material and weld metal. After the weld filler element is activated, the thermal properties corresponding to the weld metal are used in the transient heat conduction calculation.

[0042] For the i-th weld pass, the composite heat source parameters are set based on the current, voltage, welding speed, thermal efficiency, and weld pass size. The heat source model includes a composite heat source model consisting of a surface heat source and a spherical heat source. The surface heat source is applied to the upper surface of the currently active weld pass, and the volume heat source is applied to the currently active weld pass and its adjacent area. The surface heat source is a Gaussian surface heat source, and the volume heat source is a double ellipsoidal heat source. Both move synchronously along the i-th weld pass path according to the preset welding speed. The welding path is determined by the weld pass start point, end point, and direction of movement before the start of the i-th weld pass analysis step.

[0043] After completing the i-th welding analysis step, a cooling analysis step is set according to the actual interpass process; then, the (i+1)-th welding analysis step is entered. During the calculation, the temperature-time data of all nodes or integration points in each welding analysis step and cooling analysis step are recorded. After completing all weld passes and the final cooling analysis, the data from each analysis step are stitched together in chronological order to obtain the current temperature field simulation result.

[0044] Step 2.3: Identify the simulated weld boundary, simulated weld morphology, and simulated thermal zone influence area boundary based on the current temperature field simulation results.

[0045] In one embodiment, the unit boundary that reaches the preset melting temperature in the current temperature field simulation results is determined as the simulated weld boundary, and the unit boundary that reaches the preset phase transformation temperature in the current temperature field simulation results is determined as the simulated heat-affected zone boundary.

[0046] Step 2.4: Determine whether one or more of the simulated weld boundary, simulated weld morphology, and simulated hot zone influence area boundary meet the preset conditions.

[0047] In one embodiment, the simulated weld boundary, simulated weld morphology, and simulated thermal zone influence area boundary are compared with the actual weld boundary, actual weld morphology, and actual thermal zone influence area boundary characterized by the macroscopic cross-section of the actual joint to determine the similarity. If the similarity reaches a preset similarity threshold, it is determined that the preset condition is met; otherwise, it is determined that the preset condition is not met.

[0048] Step 2.5: If the judgment result is negative, continue to perform welding simulation on the submerged arc multi-pass weld metal according to the updated weld simulation parameters, repeating steps 2.2 to 2.4 until the judgment result is positive. Then, take the current temperature field simulation result obtained at this time as the target temperature field simulation result (i.e., thermal cycle data).

[0049] Step 3: Based on the simulation results of the target temperature field, extract the peak temperature of each spatial location in the weld metal under different welding thermal cycles.

[0050] For any node or mesh element, the target temperature field simulation results are divided according to the weld analysis step, and the local maximum temperature is determined in each weld analysis step and its subsequent cooling stage as the peak temperature of the thermal cycle; at the same time, the weld number and occurrence time corresponding to the peak temperature are recorded to preserve the order of each thermal cycle.

[0051] When the peak temperature of a thermal cycle is lower than the preset effective reheat temperature, the thermal cycle can be marked as a low-temperature reheat or excluded from the subsequent thermal history feature area, as determined by the preset division rules.

[0052] Step 4: Spatial division of different thermal history sub-regions within the weld metal.

[0053] Step 4.1: Based on the phase transformation temperature, thermal simulation results, microstructure observation results, or process data of the steel to be welded, pre-set the coarse grain temperature range, fine grain temperature range, and critical temperature range, and establish the correspondence between the thermal history characteristic regions and the thermal history sub-region identifiers.

[0054] Step 4.2: Based on the target temperature field simulation results and the preset critical temperature threshold of the steel grade, identify the thermal history feature regions and their thermal history sub-region identifiers corresponding to the effective thermal cycle events experienced by multiple grid units contained in the submerged arc multi-pass weld metal.

[0055] In one implementation, for any grid cell contained in the weld metal of a submerged arc multi-pass weld, the following operations are performed: determining the temperature range to which the peak temperature in the effective thermal cycle events experienced by the grid cell belongs; determining the thermal history feature region corresponding to the grid cell based on the chronological order of the effective thermal cycle events; and assigning the grid cell a thermal history sub-region identifier corresponding to the thermal history feature region. Multiple grid cells with the same thermal history sub-region identifier and spatial contiguousness are merged into a thermal history sub-region, forming a three-dimensional spatial distribution result carrying thermal history sub-region identifiers.

[0056] Specifically, for each node or grid cell, the peak temperatures of each effective thermal cycle extracted in step 3 are sequentially assigned to the corresponding temperature range, and ordered thermal history feature regions are formed according to the order in which the thermal cycles occur. For example, a single entry into the temperature range of the coarse-grained heat-affected zone forms a coarse-grained region; entering the temperature range of the coarse-grained heat-affected zone first and then the critical heat-affected zone forms a coarse-grained critical region; entering the temperature range of the critical heat-affected zone twice forms a critical region.

[0057] Based on a pre-defined correspondence, each node or mesh cell is assigned a thermal history sub-region identifier, and nodes or mesh cells with the same identifier and spatial contiguousness are merged into the same thermal history sub-region. This yields... Figure 3The diagram shows a spatial division and local magnification of thermal history sub-regions based on peak temperature, number of thermal cycles, and reheat sequence. The identifiers are not only used to indicate the sub-region type, but are also extracted along with the mesh elements on the fracture plane of the model in step 6 to generate a thermal history sub-region projection map of the fracture surface.

[0058] Step 5: Based on the sampling location information of the impact specimen, establish the spatial mapping relationship between the temperature field model and the actual impact fracture surface. Based on the spatial mapping relationship, map the spatial distribution results of the thermal history sub-region to the actual impact fracture surface to obtain the thermal history sub-region projection map.

[0059] In one embodiment, based on the sampling location information of the submerged arc multi-pass weld metal corresponding to the impact test, the sampling space range corresponding to the impact specimen and the model fracture plane corresponding to the impact fracture surface of the impact specimen are determined in the target temperature field simulation results; based on the sampling space range, a spatial mapping relationship between the temperature field coordinate system and the impact specimen coordinate system is established; thermal history sub-region identifiers matching the model fracture plane are extracted, and the thermal history sub-region identifiers matching the model fracture plane are mapped to the impact fracture surface using the spatial mapping relationship to obtain a thermal history sub-region projection map.

[0060] Specifically: like Figure 4 The diagram illustrates the sampling location and spatial coordinate system establishment for an impact specimen. Based on the sampling location, specimen size, and notch location of the impact specimen in the actual welded joint, a three-dimensional spatial range corresponding to the impact specimen is extracted in the temperature field model. The boundaries of the three-dimensional spatial range correspond to the length, width, and height boundaries of the actual impact specimen, respectively.

[0061] A spatial coordinate system for the impact specimen is established with the center of the notch root as the origin, the length direction of the impact specimen as the X-axis, the width direction of the impact specimen as the Y-axis, and the height direction of the impact specimen as the Z-axis. The actual impact fracture surface corresponds to the YZ plane perpendicular to the X-axis and passing through the actual fracture location.

[0062] In the temperature field model, the model position corresponding to the center of the notch root is used as the model mapping reference point, and the direction transformation relationship is determined according to the correspondence between the length, width and height of the impact specimen in the model and the X-axis, Y-axis and Z-axis; the translation amount is determined according to the position difference between the model reference point and the coordinate origin.

[0063] Furthermore, the proportional relationship between the model coordinates and the physical coordinates of the specimen is determined based on the unit size of the temperature field model and the actual size of the impact specimen; the proportional relationship between the physical coordinates of the specimen and the pixel coordinates of the fracture image is determined based on the pixel width, pixel height, and actual fracture size of the overall impact fracture image. Thus, a continuous transformation relationship is established between the temperature field model coordinates, the physical coordinates of the impact specimen, and the pixel coordinates of the impact fracture image.

[0064] like Figure 5 The diagram illustrates the mapping of the three-dimensional spatial distribution of thermal history subregions to the actual impact fracture surface. Based on the notch location and the actual fracture location, a model fracture plane corresponding to the actual impact fracture surface is determined within the sampling space of the temperature field model. Target mesh elements intersecting with the model fracture plane are extracted from multiple mesh elements contained in the submerged arc multi-pass weld metal, and their corresponding thermal history subregion identifiers are used as the thermal history subregion identifiers for matching the model fracture plane.

[0065] For each intersecting mesh element, calculate its intersection line or cross-sectional region with the fracture plane of the model, and use the direction transformation relationship and translation to transform the intersection line or cross-sectional region to the YZ plane of the impact specimen spatial coordinate system.

[0066] Then, based on the proportional relationship between the model coordinates and the physical coordinates of the specimen, and between the physical coordinates of the specimen and the pixel coordinates of the fracture image, the cross-sectional regions in the YZ plane are transformed into the actual impact fracture image. During the transformation process, the thermal history sub-region identifiers corresponding to each cross-sectional region are retained, thereby generating a thermal history sub-region projection map that is consistent with the surface scale and orientation of the actual impact fracture.

[0067] When the coordinates of the crack initiation source are located within a certain marked area, the marked area serves as the thermal history sub-region identifier corresponding to the crack initiation source. When the crack initiation source is located near the boundary between two marked areas, the corresponding thermal history sub-region can be determined based on the marked area with the largest proportion within the crack initiation source positioning error range.

[0068] Step 6: Obtain the position coordinates of the impact crack initiation source on the impact fracture surface.

[0069] like Figure 5 As shown, after the impact specimen fractures, the notch direction and specimen orientation remain unchanged, and a full-view image of the impact fracture surface including the entire fracture surface and scale is obtained, so that the horizontal and vertical directions of the full-view image are aligned with the Y-axis and Z-axis, respectively.

[0070] Based on the herringbone pattern, radial cracks, and macroscopic crack propagation morphology in the overall image, the crack propagation direction is traced backward to the texture convergence area, which is then identified as a candidate crack initiation area. For cases where the fracture morphology is discontinuous, the overlapping area of ​​multiple backward extension lines can be used as a candidate area.

[0071] Subsequently, the candidate areas were observed at low magnification under a scanning electron microscope. The field of view was moved along the reverse convergence direction of the cleavage steps or river patterns, and the magnification was gradually increased. When multiple cleavage steps or river patterns were observed to converge at the same location, that location was taken as the crack initiation point. When cracks were observed to diverge outward from around the inclusions, the initial cracking location at or around the interface between the inclusions and the matrix was taken as the crack initiation point.

[0072] To transform the crack initiation location in the scanning electron microscope (SEM) image into a full fracture view image, geometric feature points are selected in the image. These geometric feature points can be fracture boundary inflection points, notch edges, significant dimples, or intersections of characteristic cracks. Image translation, rotation, and scale transformation relationships are established based on common geometric feature points, and the pixel coordinates of the crack initiation location in the SEM image are transformed into the full fracture view image.

[0073] Finally, based on the scale of the overall fracture image, the center pixel coordinates of the notch root, and the Y and Z axis directions, the crack initiation pixel coordinates are converted into physical coordinates in the YZ plane of the impact fracture surface.

[0074] Step 7: Determine the weld metal thermal history sub-region corresponding to the impact crack initiation site based on the coordinates of the crack initiation location and the thermal history sub-region identifier mapped to the impact fracture surface.

[0075] Convert the YZ coordinates of the crack initiation site to pixel coordinates of the fracture image, or directly overlay them with the thermal history sub-region projection map. Read the thermal history sub-region identifiers retained in the cross-sectional area corresponding to the crack initiation site, and query the corresponding thermal history feature region and thermal history sub-region type based on the identifiers.

[0076] Therefore, it is possible to output the coordinates of the fracture initiation location, the thermal history sub-region identifier corresponding to the fracture initiation, the thermal history feature region, and the thermal history sub-region projection map with the fracture initiation mark.

[0077] Using the above method, the ordered thermal cycle information of each spatial location of the multi-pass weld, the sub-region markings on the fracture plane of the model, and the actual fracture initiation location can be continuously correlated to determine the weld metal thermal history sub-region corresponding to the impact initiation source.

[0078] In summary, the method provided by the embodiments of the present invention has at least the following characteristics: In this embodiment of the invention, the complete thermal cycle of each spatial position is obtained according to the weld sequence. The peak temperature range of each effective thermal cycle and its sequence are combined into a thermal history feature region. The grid unit is assigned a thermal history sub-region identifier through a preset correspondence, so that the thermal history sub-regions that are difficult to be directly identified in the weld metal of multi-pass welds are represented in a three-dimensional identifier distribution form.

[0079] In this embodiment of the invention, the sampling space range and fracture plane of the model are determined according to the actual sampling location, the transformation relationship between model coordinates, physical coordinates of the sample and pixel coordinates of the fracture image is established, and the thermal history sub-region identifier on the fracture plane of the model is mapped to the actual impact fracture surface.

[0080] In this embodiment of the invention, the physical coordinates of the crack initiation site are obtained by hierarchical positioning and coordinate calibration of macroscopic fracture surface and scanning electron microscope images, and the thermal history sub-region identifier at the coordinates is read, thereby determining the multi-pass weld thermal history sub-region corresponding to the impact crack initiation site.

[0081] Based on the foregoing embodiments, this invention provides a device for locating the impact crack initiation source of submerged arc multi-pass weld metal. (See also...) Figure 6 The diagram shows a structural schematic of a submerged arc multi-pass weld metal impact crack initiation location device, which mainly includes the following parts: The identifier assignment module 602 is used to assign thermal history sub-region identifiers to multiple mesh cells contained in the submerged arc multi-pass weld metal based on the target temperature field simulation results generated by welding simulation of the weld metal. The projection map generation module 604 is used to map the thermal history sub-region identifier that matches the impact fracture surface of the submerged arc multi-pass weld metal to the impact fracture surface based on the impact test sampling location information corresponding to the weld metal of the submerged arc multi-pass weld, so as to obtain the thermal history sub-region projection map. The crack initiation source identification module 606 is used to identify the weld metal thermal history sub-region corresponding to the impact crack initiation source on the surface of the impact fracture based on the thermal history sub-region projection map.

[0082] This invention provides a device for locating the impact crack initiation source of submerged arc multi-pass weld metal. By using a temperature field model obtained from welding simulation, multiple grid cells contained in the submerged arc multi-pass weld metal are assigned thermal history sub-region identifiers. These identifiers are then associated with the sampling location of the impact sample and mapped onto the actual impact fracture surface to form a thermal history sub-region projection map. Furthermore, by combining the position of the impact crack initiation source on the impact fracture surface, the thermal history sub-region of the weld metal corresponding to the impact crack initiation source is determined. This invention can accurately identify the weld metal thermal history sub-region from which the impact crack initiation source originates, even when there is no clear macroscopic boundary of the thermal history sub-region.

[0083] The device provided in this embodiment of the invention has the same implementation principle and technical effect as the aforementioned method embodiment. For the sake of brevity, any parts not mentioned in the device embodiment can be referred to the corresponding content in the aforementioned method embodiment.

[0084] This invention provides an electronic device, specifically, the electronic device includes a processor and a memory; the memory stores a computer program, which, when run by the processor, executes the method described in any of the above embodiments.

[0085] Figure 7The present invention provides a schematic diagram of the structure of an electronic device 100, which includes a processor 70, a memory 71, a bus 72 and a communication interface 73. The processor 70, the communication interface 73 and the memory 71 are connected through the bus 72. The processor 70 is used to execute executable modules, such as computer programs, stored in the memory 71.

[0086] The memory 71 may include high-speed random access memory (RAM) or non-volatile memory, such as at least one disk storage device. Communication between this system network element and at least one other network element is achieved through at least one communication interface 73 (which can be wired or wireless), such as the Internet, wide area network, local area network, metropolitan area network, etc.

[0087] Bus 72 can be an ISA bus, PCI bus, or EISA bus, etc. The bus can be divided into address bus, data bus, control bus, etc. For ease of representation, Figure 7 The symbol is represented by a single double-headed arrow, but this does not mean that there is only one bus or one type of bus.

[0088] The memory 71 is used to store programs. After receiving an execution instruction, the processor 70 executes the programs. The method executed by the device for defining the flow process disclosed in any of the foregoing embodiments of the present invention can be applied to the processor 70 or implemented by the processor 70.

[0089] The processor 70 may be an integrated circuit chip with signal processing capabilities. In implementation, each step of the above method can be completed by the integrated logic circuitry in the hardware of the processor 70 or by instructions in software form. The processor 70 may be a general-purpose processor, including a Central Processing Unit (CPU), a Network Processor (NP), etc.; it may also be a Digital Signal Processor (DSP), an Application Specific Integrated Circuit (ASIC), a Field-Programmable Gate Array (FPGA), or other programmable logic devices, discrete gate or transistor logic devices, or discrete hardware components. It can implement or execute the methods, steps, and logic block diagrams disclosed in the embodiments of this invention. The general-purpose processor may be a microprocessor or any conventional processor. The steps of the methods disclosed in the embodiments of this invention can be directly embodied in the execution of a hardware decoding processor, or executed by a combination of hardware and software modules in the decoding processor. The software modules may reside in random access memory, flash memory, read-only memory, programmable read-only memory, electrically erasable programmable memory, registers, or other mature storage media in the art. The storage medium is located in memory 71. Processor 70 reads the information in memory 71 and, in conjunction with its hardware, completes the steps of the above method.

[0090] The computer program product of the readable storage medium provided in the embodiments of the present invention includes a computer-readable storage medium storing program code. The instructions included in the program code can be used to execute the methods described in the foregoing method embodiments. For specific implementation, please refer to the foregoing method embodiments, which will not be repeated here.

[0091] If the aforementioned functions are implemented as software functional units and sold or used as independent products, they can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present invention, or the part that contributes to the prior art, or a portion of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods described in the various embodiments of the present invention. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, portable hard drives, read-only memory (ROM), random access memory (RAM), magnetic disks, or optical disks.

[0092] Finally, it should be noted that the above-described embodiments are merely specific implementations of the present invention, used to illustrate the technical solutions of the present invention, and not to limit it. The scope of protection of the present invention is not limited thereto. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that any person skilled in the art can still modify or easily conceive of changes to the technical solutions described in the foregoing embodiments within the technical scope disclosed in the present invention, or make equivalent substitutions for some of the technical features; and these modifications, changes, or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention, and should all be covered within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. A method for locating the impact crack initiation site in submerged arc multi-pass weld metal, characterized in that, include: Based on the target temperature field simulation results generated by welding simulation of the submerged arc multi-pass weld metal, thermal history sub-region identifiers are assigned to multiple mesh units contained in the submerged arc multi-pass weld metal. Based on the impact test sampling location information corresponding to the submerged arc multi-pass weld metal, the thermal history sub-region identifier that matches the impact fracture surface of the submerged arc multi-pass weld metal is mapped onto the impact fracture surface to obtain a thermal history sub-region projection map. Based on the thermal history sub-region projection map, the thermal history sub-region of weld metal corresponding to the impact crack initiation source in the impact fracture surface is identified.

2. The method for locating the impact crack initiation source of submerged arc multi-pass weld metal according to claim 1, characterized in that, Based on the impact test sampling location information corresponding to the submerged arc multi-pass weld metal, the thermal history sub-region identifier matching the impact fracture surface of the submerged arc multi-pass weld metal is mapped onto the impact fracture surface to obtain a thermal history sub-region projection map, including: Based on the impact test sampling location information corresponding to the submerged arc multi-pass weld metal, the sampling space range corresponding to the impact specimen and the model fracture plane corresponding to the impact fracture surface of the impact specimen are determined in the target temperature field simulation results. Based on the sampling space range, a spatial mapping relationship between the temperature field coordinate system and the impact sample coordinate system is established; Extract the thermal history sub-region identifiers that match the fracture plane of the model, and use the spatial mapping relationship to map the thermal history sub-region identifiers that match the fracture plane of the model onto the impact fracture surface to obtain a thermal history sub-region projection map.

3. The method for locating the impact crack initiation source of submerged arc multi-pass weld metal according to claim 2, characterized in that, Extracting thermal history sub-region identifiers that match the fracture plane of the model, including: From the multiple mesh cells contained in the submerged arc multi-pass weld metal, the target mesh cell that intersects with the fracture plane of the model is extracted, and its corresponding thermal history sub-region identifier is used as the thermal history sub-region identifier that matches the fracture plane of the model.

4. The method for locating the impact crack initiation source of submerged arc multi-pass weld metal according to claim 1, characterized in that, Based on the target temperature field simulation results generated from welding simulation of submerged arc multi-pass weld metal, thermal history sub-region identifiers are assigned to multiple mesh elements contained in the submerged arc multi-pass weld metal, including: Welding simulation was performed on the weld metal of submerged arc multi-pass welding to generate simulation results of the target temperature field. Based on the target temperature field simulation results and the preset critical temperature threshold of the steel grade, identify the thermal history feature regions and their thermal history sub-region identifiers corresponding to the effective thermal cycling events experienced by the multiple grid units contained in the submerged arc multi-pass weld metal. The thermal history feature regions include a single coarse-grained heat-affected zone thermal cycle region, a single fine-grained heat-affected zone thermal cycle region, a single critical heat-affected zone thermal cycle region, and a multiple thermal cycle region formed by combining at least two of the coarse-grained temperature range, fine-grained temperature range, and critical temperature range in the order of effective thermal cycle events. The thermal history sub-region identifier is used to mark the thermal history feature regions corresponding to the effective thermal cycle events experienced by the mesh unit.

5. The method for locating the impact crack initiation source of submerged arc multi-pass weld metal according to claim 4, characterized in that, Based on the target temperature field simulation results and the preset critical temperature threshold for the steel grade, the thermal history feature regions and their thermal history sub-region identifiers corresponding to the effective thermal cycling events experienced by multiple grid units contained in the submerged arc multi-pass weld metal are identified, including: For any grid cell contained in the submerged arc multi-pass weld metal, the following operations are performed: determine the temperature range to which the peak temperature in the effective thermal cycle events experienced by the grid cell belongs, determine the thermal history feature region corresponding to the grid cell in combination with the order of the effective thermal cycle events, and assign the grid cell the thermal history sub-region identifier corresponding to the thermal history feature region. After identifying the thermal history feature regions and their thermal history sub-region identifiers corresponding to the effective thermal cycling events experienced by multiple grid units contained in the submerged arc multi-pass weld metal, based on the target temperature field simulation results and the preset critical temperature threshold for the steel grade, the method further includes: Multiple grid cells that have the same thermal history subregion identifier and are spatially continuous are merged into a thermal history subregion, forming a three-dimensional spatial distribution result carrying the thermal history subregion identifier.

6. The method for locating the impact crack initiation source of submerged arc multi-pass weld metal according to claim 4, characterized in that, Welding simulation was performed on the weld metal of submerged arc multi-pass welding to generate simulation results of the target temperature field, including: Based on the current weld simulation parameters, welding simulation is performed on the submerged arc multi-pass weld metal to generate the current temperature field simulation results. Based on the current temperature field simulation results, the simulated weld boundary, simulated weld morphology, and simulated thermal zone influence region boundary are identified. Determine whether one or more of the simulated weld boundary, the simulated weld morphology, and the simulated thermal zone influence region boundary meet preset conditions; If the result is negative, continue to simulate the welding of the submerged arc multi-pass weld metal according to the updated weld simulation parameters until the result is positive and the target temperature field simulation result is obtained.

7. The method for locating the impact crack initiation source of submerged arc multi-pass weld metal according to claim 1, characterized in that, Based on the thermal history sub-region projection map, the weld metal thermal history sub-region corresponding to the impact crack initiation site on the impact fracture surface is identified, including: Obtain the position coordinates of the impact crack initiation source on the surface of the impact fracture. Based on the location coordinates corresponding to the impact crack initiation source, the corresponding thermal history sub-region identifier in the thermal history sub-region projection diagram is used to determine the weld metal thermal history sub-region corresponding to the impact crack initiation source.

8. A device for locating the impact crack initiation source of submerged arc multi-pass weld metal, characterized in that, include: The identifier assignment module is used to assign thermal history sub-region identifiers to multiple mesh cells contained in the submerged arc multi-pass weld metal based on the target temperature field simulation results generated by welding simulation of the weld metal. The projection map generation module is used to map the thermal history sub-region identifier that matches the impact fracture surface of the submerged arc multi-pass weld metal to the impact fracture surface based on the impact test sampling location information corresponding to the submerged arc multi-pass weld metal, so as to obtain a thermal history sub-region projection map. The crack initiation source identification module is used to identify the weld metal thermal history sub-region corresponding to the impact crack initiation source on the impact fracture surface based on the thermal history sub-region projection map.

9. An electronic device, characterized in that, The method includes a processor and a memory, the memory storing computer-executable instructions that can be executed by the processor, the processor executing the computer-executable instructions to implement the submerged arc multi-pass welding weld metal impact crack initiation source location method of claim 1.

10. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores computer-executable instructions, which, when invoked and executed by a processor, cause the processor to implement the submerged arc multi-pass welding weld metal impact crack initiation source location method as described in claim 1.

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