Mountainous area different slope under pipeline automatic welding technology adaptability evaluation method and angle conversion equipment

Abstract

The application discloses a mountainous pipeline automatic welding technology adaptability evaluation method and an angle conversion device, and relates to the technical field of pipeline automatic welding technology adaptability evaluation. The mountainous pipeline automatic welding technology adaptability evaluation method comprises the following steps: selecting a welding opening material; welding and obtaining a sample; sample detection and analysis; structure organization analysis; mechanical property analysis; and adaptability evaluation. The angle conversion device is used in the mountainous pipeline automatic welding technology adaptability evaluation method. Through analysis and comparison, an adaptive welding mode is provided for pipeline welding under different slopes, and the adaptability of automatic welding technology is evaluated. Furthermore, in combination with theoretical knowledge and working experience of workers, a conclusion is given through S400 for reference and selection of others, which is helpful to improve the efficiency and quality of mountainous pipeline welding. The angle conversion device is used to adjust the angle, so that different slopes are simulated to complete welding work under different slopes.

Description

Technical Field

[0001] This invention relates to the field of welding technology, specifically to a method for evaluating the adaptability of automatic pipeline welding technology under different slopes in mountainous areas and an angle transformation device. Background Technology

[0002] Currently, weldability evaluation mainly focuses on the ease with which a material can obtain a high-quality weld joint under specific welding process conditions, as well as the reliability of that weld joint under service conditions. Evaluation is primarily conducted using the carbon equivalent method and the highest hardness test (HAZ) method. The carbon equivalent method assesses the tendency for cracking and hardening during welding by calculating the equivalent of a certain amount of carbon content in the alloying elements in the steel. The highest hardness test (HAZ) method assesses the cold cracking resistance of the material by measuring the highest hardness value in the weld heat-affected zone (HAZ).

[0003] In practical applications, various welding techniques are employed. For instance, in mountainous pipeline welding, techniques such as internal welding machine + dual-torch external welding machine, combined automatic welding, single-torch automatic welding, and gas-shielded semi-automatic welding are commonly used. Existing welding adaptability evaluation methods struggle to differentiate the merits of different welding methods in mountainous pipeline welding. The quality of mountainous pipeline welding relies heavily on the experience of the workers, making it difficult to guarantee its quality. Summary of the Invention

[0004] The technical problem to be solved by this invention is that existing welding adaptability evaluation methods are difficult to distinguish the advantages and disadvantages of different welding methods in mountainous pipeline welding. The purpose is to provide an automatic welding technology adaptability evaluation method and angle transformation device for pipelines under different slopes in mountainous areas to solve the above-mentioned problems.

[0005] This invention is achieved through the following technical solution:

[0006] In a first aspect, the present invention provides a method for evaluating the adaptability of automatic pipeline welding technology under different slopes in mountainous areas, comprising the following steps:

[0007] S100 Select weld material;

[0008] S200 welding and obtaining samples: setting different welding slopes; welding with different welding methods; obtaining weld samples;

[0009] S300 Specimen Testing and Analysis: Structural Analysis; Mechanical Property Analysis;

[0010] S400 evaluates adaptability.

[0011] In one possible design, in step S200, the welding slope is between 0° and 90°, and multiple welding groups with different slopes are set up respectively.

[0012] Welding methods include internal welding machine + double welding torch external welding machine, combined automatic welding, single welding torch automatic welding, internal welding machine single welding torch automatic welding and gas shielded semi-automatic welding.

[0013] In one possible design, in step S300, the structural analysis includes macroscopic morphology analysis, metallographic sample preparation and observation (OM), weld joint and fracture surface SEM microstructure detection, and constituent phase sample preparation and XRD detection (XRD).

[0014] Mechanical property analysis includes microhardness distribution testing, oscilloscope impact testing, DIC tensile testing, and slow strain tensile testing.

[0015] In one possible design, the macroscopic morphology analysis includes the following steps: selecting multiple samples; grinding with sandpaper of grades 240#, 400#, 800#, 1000#, 2000#, 3000#, and 5000# respectively; fine polishing with a polishing machine, a velvet-type polishing cloth, and a diamond polishing compound with a particle size of 1.5μm; metallographic etching of the samples with 4% nitric acid alcohol for 14-16 seconds; and macroscopic morphology observation using a stereomicroscope.

[0016] Metallographic sample preparation and observation include the following steps: selecting samples for macroscopic morphology analysis; cleaning with acetone, wiping with alcohol, and drying; grinding with 60#, 100#, 240#, 600#, 800#, 1000#, 1500#, 2000#, and 2500# sandpaper respectively; fine polishing with a polishing machine, velvet-type polishing cloth, and diamond polishing agent with a particle size of 1.5μm, continuously rinsing with water during the polishing process until the scratches disappear; metallographic etching of the sample with 4% nitric acid alcohol for 14-16 seconds; and observation using a metallographic microscope.

[0017] The SEM microstructure examination of weld joints and fracture surfaces includes the following steps:

[0018] Select the metallographic sample preparation OM and the specimen for observation; re-prepare the specimen according to the metallographic sample preparation OM and observation steps; or, cut the specimen from the impact fracture point of the oscilloscope impact test; ultrasonically clean with acetone; clean the acetone with alcohol.

[0019] The scanning observation was performed using a tungsten filament scanning electron microscope with EDS function;

[0020] The sample preparation and XRD testing of the constituent phases include the following steps: selecting the sample; testing the weld joint using an X-ray diffractometer; wherein, the sample includes only the base material and only the weld joint and heat-affected zone, and the X-ray scanning angle is 30°-70°.

[0021] In one possible design, the microhardness distribution test includes the following steps: setting the loading force, loading time, and loading location; conducting the test using a digital microhardness tester; performing three tests at each test point and taking the average value as the test result.

[0022] The oscilloscope impact test includes the following steps: cutting the specimen; metallographic corrosion; selecting impact points at the weld joint and heat-affected zone respectively; impact test; plotting the load-displacement curve of the specimen;

[0023] The DIC tensile test includes the following steps: one outer surface of the specimen is painted and dried; random speckle patterns are applied to the outer surface; the specimen is stretched and the tensile fracture process is recorded by a high-speed camera; strain data of at least one point is extracted from three regions: the fractured part, the necked part, and the region far from the fractured part, and strain curves of each point over time are obtained.

[0024] In one possible design, the slow strain tensile test includes the following steps: selecting and fixing the specimen; stretching the specimen at a constant slow speed using a tensile machine; and determining the specimen's SCC susceptibility after the specimen breaks.

[0025] Wherein, the sample elongation L can be replaced by the corresponding displacement of the clamp head:

[0026]

[0027] In the formula, ε—engineering strain; L0—gauge length of the specimen; —Strain rate; ΔL / Δt —Clip displacement velocity;

[0028] The SCC sensitivity of the sample is:

[0029]

[0030] CGR=D max / t f

[0031] In the formula, RA is the reduction of area; A0 is the original cross-sectional area of ​​the gauge length portion of the tensile specimen; A is the minimum cross-sectional area of ​​the fracture surface after tensile fracture; CGR is the crack propagation rate; D is the crack length. max - Maximum depth of SCC crack propagation at the fracture site; t f - Fracture time.

[0032] In one possible design, in step S400:

[0033] For flat areas with a slope of less than 15°, use an internal welding machine + a double-torch external welding machine, a combination of automatic welding or a single-torch automatic welding.

[0034] For gentle slopes with a gradient between 15° and 30°, use either combined automatic welding or internal welding machine with single welding torch automatic welding.

[0035] For steep slopes with a gradient between 30° and 45°, use either combined automatic welding or single-torch automatic welding.

[0036] For steep slopes with an angle between 45° and 90°, use combined automatic welding, single-torch automatic welding, or gas-shielded semi-automatic welding.

[0037] Secondly, the present invention provides an angle transformation device for the adaptive evaluation method of automatic pipeline welding technology under different slopes in mountainous areas, comprising a base, a welding plate, an angle transformation module and a lifting module;

[0038] The base includes an upper plate and a lower plate that are spaced apart and opposite to each other. The upper plate has a through first groove. The welding plate is rotatably mounted on the first groove, with one end of the welding plate being a connecting end and the other end being a free end.

[0039] An angle transformation module is slidably mounted on the first groove and connected to the welding plate. The angle transformation module is used to drive the welding plate to swing back and forth around the connection end so as to change the slope of the welding plate.

[0040] The lifting module is fixed on the lower plate, and its working end extends upward and is connected to the angle transformation module. The lifting module is used to drive the angle transformation module to lift and lower so that the welding plate is flush with the upper plate.

[0041] In one possible design, the angle transformation module includes a base plate, a connector, a pull cord, and a cord winder;

[0042] The substrate is located in the first groove and is connected to the working end of the lifting module.

[0043] The connector includes a seat body slidably disposed on the top surface of the substrate, an intermediate shaft rotatably disposed on the seat body, and a slide plate for connecting the soldering plate. The seat body is provided with a second groove, the intermediate shaft is located on the second groove, one side of the slide plate is connected to the intermediate shaft through a detachable fixed seat, and the other end of the slide plate is slidably connected to the soldering plate.

[0044] The middle part of the slide is connected to the intermediate shaft. Correspondingly, the depth of the second groove on the seat is greater than half the length of the slide. The outer surface of the seat facing the welding plate connection end is constructed as a vertical plane.

[0045] Two rope winders are provided and fixed at both ends of the base plate respectively. The two rope winders are connected to the connecting seat by a pull rope. Accordingly, the two rope winders control the sliding and fixing of the connecting seat on the base plate by winding and unwinding the pull rope.

[0046] In one possible design, the lifting module is selected from lifting equipment;

[0047] The upper plate is equipped with a detachable bracket, which includes a base plate, a base cylinder, a sliding rod, and a support plate. One end of the base plate is rotatably connected to the support plate, and the other end of the base plate is provided with several base cylinders at intervals. Each base cylinder is connected to a sliding rod through an elastic element. One end of the sliding rod is located inside the base cylinder, and the other end of the sliding rod is connected to the support plate. Both the base cylinder and the sliding rod are arc-shaped.

[0048] Compared with the prior art, the present invention has the following advantages and beneficial effects:

[0049] 1. Through analysis and comparison, suitable welding methods are provided for pipeline welding under different slopes, thus evaluating the adaptability of automatic welding technology. Furthermore, combining theoretical knowledge with the work experience of personnel, conclusions are drawn using S400 for others to reference and select, contributing to improving the efficiency and quality of pipeline welding in mountainous areas.

[0050] 2. The angle is adjusted using the aforementioned angle transformation device to simulate different slopes, thereby enabling welding operations on varying slopes. This facilitates simulation experiments for staff and improves experimental efficiency. Attached Figure Description

[0051] To more clearly illustrate the technical solutions of the exemplary embodiments of the present invention, the accompanying drawings used in the embodiments will be briefly described below. It should be understood that the following drawings only show some embodiments of the present invention and should not be considered as a limitation of the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort. In the drawings:

[0052] Figure 1 This is a flowchart illustrating an adaptive evaluation method for automated pipeline welding technology under different slopes in mountainous terrain.

[0053] Figures 2-4 This is a schematic diagram of an angle transformation device for different slopes.

[0054] Figure 5 This is a schematic diagram of the base structure.

[0055] Figure 6 This is a schematic diagram of the skateboard's structure.

[0056] Figure 7 This is a schematic diagram of the support structure.

[0057] Figure 8 This is a schematic diagram of the base structure.

[0058] The attached diagram shows the markings and corresponding component names:

[0059] 1. Base; 101. Upper plate; 102. Lower plate; 103. First groove; 104. Support column; 2. Welding plate; 3. Angle transformation module; 301. Base plate; 302. Connecting seat; 303. Pull rope; 304. Rope winder; 305. Seat; 306. Intermediate shaft; 307. Slide plate; 308. Second groove; 309. Fixed seat; 310. Limiting strip; 311. Rotary hole; 4. Lifting module; 5. Bracket; 501. Base plate; 502. Base cylinder; 503. Sliding rod; 504. Support plate. Detailed Implementation

[0060] To make the objectives, technical solutions, and advantages of the present invention clearer, the present invention will be further described in detail below with reference to the embodiments and accompanying drawings. The illustrative embodiments and descriptions of the present invention are only used to explain the present invention and are not intended to limit the present invention.

[0061] In the following description, numerous specific details are set forth in order to provide a thorough understanding of the invention. However, it will be apparent to those skilled in the art that these specific details are not necessary to practice the invention. In other embodiments, well-known structures, circuits, materials, or methods have not been specifically described in order to avoid obscuring the invention.

[0062] Throughout this specification, references to "an embodiment," "an example," or "an example" mean that a particular feature, structure, or characteristic described in connection with that embodiment or example is included in at least one embodiment of the invention. Therefore, the phrases "an embodiment," "an example," "an example," or "an example" appearing in various places throughout the specification do not necessarily refer to the same embodiment or example. Furthermore, specific features, structures, or characteristics can be combined in one or more embodiments or examples in any suitable combination and / or sub-combination. Moreover, those skilled in the art will understand that the illustrations provided herein are for illustrative purposes and are not necessarily drawn to scale. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0063] In the description of this invention, the terms "front", "rear", "left", "right", "up", "down", "vertical", "horizontal", "high", "low", "inner", and "outer" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limiting the scope of protection of this invention.

[0064] Example 1:

[0065] like Figure 1As shown, a method for evaluating the adaptability of automated pipeline welding technology under different slopes in mountainous areas includes the following steps:

[0066] S100 Select weld material;

[0067] S200 welding and obtaining samples: setting different welding slopes; welding with different welding methods; obtaining weld samples;

[0068] S300 Specimen Testing and Analysis: Structural Analysis; Mechanical Property Analysis;

[0069] S400 evaluates adaptability.

[0070] The aforementioned method for evaluating the adaptability of automated pipeline welding technology under different mountain slopes selects and combines welding slope and welding method through S200 to obtain a variety of weld samples. The weld samples are then tested and analyzed through S300. This method can analyze the metallographic structure, inclusions, second phase, and elemental distribution of welds under different welding slopes. Combined with theoretical knowledge, it can form the microstructure formation mechanism of welds obtained by combined automated welding processes under different slopes. Furthermore, it can make horizontal comparisons and integrate and summarize the influence of welding slope on the microstructure and mechanical properties of welds.

[0071] Therefore, through analysis and comparison, suitable welding methods are provided for pipeline welding under different slopes, thus evaluating the adaptability of automatic welding technology. Furthermore, combining theoretical knowledge with the work experience of personnel, conclusions are drawn using S400 for others to reference and select, contributing to improving the efficiency and quality of pipeline welding in mountainous areas.

[0072] Specifically, in S100, a suitable weld material is selected based on the target mountain pipeline. It is easy to understand that those skilled in the art can choose any suitable existing weld material, and the present invention does not impose any restrictions on this.

[0073] In step S200, the welding slope is between 0° and 90°, and multiple welding groups with different slopes are set up respectively;

[0074] Welding methods include internal welding machine + double welding torch external welding machine, combined automatic welding, single welding torch automatic welding, internal welding machine single welding torch automatic welding and gas shielded semi-automatic welding.

[0075] For welding slope, multiple welding groups are set up to enrich the sample size and ensure the accuracy of the test results. In a single test, the slope can be divided into segments according to existing theories, and multiple slopes can be set for each segment to reduce the sample size and thus improve the efficiency of the test; subsequent tests can then be corrected based on the results of the previous test. If the test is for a specific slope, that slope can be selected and welding can be performed using different welding methods.

[0076] Each welding method has its own advantages and disadvantages, specifically:

[0077] Internal welding machine + dual-torch external welding machine: High efficiency, fast welding speed; high weld quality, high first-pass yield; high degree of automation, reducing manual operation. However, this method has high equipment costs, requires highly skilled operators, and necessitates good site conditions.

[0078] Combined automatic welding combines the advantages of internal and external welding, resulting in high-quality welds; it also boasts a high degree of automation, reducing manual intervention; and is suitable for welding large-diameter, high-grade steel pipes. However, this method involves complex equipment and operation, requires professional technical support, and has high maintenance costs.

[0079] Single-torch automatic welding: This method can improve welding efficiency, being more than 30% faster than semi-automatic welding; the weld formation is aesthetically pleasing and has good density; and the labor intensity of welders is low. However, this method requires a large investment in equipment and systems, and has certain requirements regarding environmental conditions (such as wind power).

[0080] Gas-shielded semi-automatic welding: The equipment is simple, easy to operate and maintain, and applicable to welding various materials and thicknesses, with relatively low cost. However, this method has relatively low welding efficiency, weld quality is greatly affected by the operator's skill, involves high labor intensity, and may have an impact on the operator's health.

[0081] In step S300, the structural analysis includes macroscopic morphology analysis, metallographic sample preparation and observation using OM (Optical Microscope), weld and fracture surface SEM (Scanning Electron Microscope) microstructure detection, and compositional phase sample preparation and detection using XRD (X-Ray Diffractometer).

[0082] Mechanical property analysis includes microhardness distribution testing, oscilloscope impact testing, DIC (Digital Image Correlation) tensile testing, and slow strain tensile testing.

[0083] Based on the above design scheme, theoretically, if the structural organization analysis and mechanical performance analysis are sampled separately, there is no strict order requirement between the various test items. Staff can make flexible adjustments to make the implementation of S300 more convenient and efficient.

[0084] Specifically, when obtaining samples, sampling should be carried out in accordance with the provisions of GB / T 31032-2014 "Welding and Acceptance of Steel Pipelines". During sampling, a wire cutting machine should be used to cut the entire weld joint. The cut sample includes three parts: the weld joint, the heat-affected zone, and the base material. The required sample size is 50mm × 10mm, and the thickness is the full thickness of the sample.

[0085] In one possible implementation, the macroscopic morphology analysis includes the following steps: selecting multiple samples; grinding with sandpaper of grades 240#, 400#, 800#, 1000#, 2000#, 3000#, and 5000# respectively; fine polishing with a polishing machine, a velvet-type polishing cloth, and a diamond polishing compound with a particle size of 1.5μm; metallographic etching of the samples with 4% nitric acid alcohol for 14-16s; and macroscopic morphology observation using a stereomicroscope.

[0086] Based on the above design scheme, when obtaining samples, sampling should be carried out in accordance with the provisions of GB / T 31032-2014 "Welding and Acceptance of Steel Pipelines". During sampling, a wire EDM machine should be used to cut the entire weld joint, including the weld joint, heat-affected zone, and base material. The sample size should be 50mm × 10mm, with a thickness equal to the full thickness of the sample. The sample should then undergo surface treatment through grinding, polishing, and metallographic etching.

[0087] Defects in the weld include cracks, voids, solid impurities, lack of fusion and penetration, shape defects, and other defects. A stereomicroscope is used to observe the weld, which consists of the weld area, heat-affected zone, and base material. The appearance of the joint is evaluated, and the crystallization direction and characteristics are analyzed using macroscopic joint photographs.

[0088] In one possible implementation, metallographic sample preparation and observation include the following steps: selecting samples for macroscopic morphology analysis; cleaning with acetone, wiping with alcohol, and drying; grinding with sandpaper of grades 60#, 100#, 240#, 600#, 800#, 1000#, 1500#, 2000#, and 2500# respectively; fine polishing with a polishing machine, velvet-type polishing cloth, and diamond polishing agent with a particle size of 1.5μm, with continuous rinsing with water during the polishing process until the scratches disappear; metallographic etching of the sample with 4% nitric acid alcohol for 14-16 seconds; and observation using a metallographic microscope.

[0089] Based on the above design scheme, samples for macroscopic morphology analysis were selected to reduce the number of sample cuttings and lower the experimental difficulty. The samples were then re-grinded, polished, and etched to remove oxide films, scratches, etc., that may occur during macroscopic morphology analysis, thereby improving the accuracy of metallographic sample preparation and observation.

[0090] Preferably, since the macroscopic morphology analysis and metallographic sample preparation and observation steps are similar, the two can be performed sequentially to improve the efficiency of the experiment and reduce the number of sample cuttings.

[0091] In one possible implementation, SEM microstructure inspection of the weld and fracture surface includes the following steps:

[0092] Select the metallographic sample preparation OM and the specimen for observation; re-prepare the specimen according to the metallographic sample preparation OM and observation steps; or, cut the specimen from the impact fracture point of the oscilloscope impact test; ultrasonically clean with acetone; clean the acetone with alcohol.

[0093] The scanning observation was performed using a tungsten filament scanning electron microscope with EDS function.

[0094] Based on the above design scheme, the preparation process differs for different types of samples. Specifically, for weld joint microstructure, after metallographic sample preparation (OM) and observation, the sample is re-prepared according to the standard metallographic preparation to eliminate any possible oxide film and scratches that may have appeared during metallographic observation. For impact samples, sampling and preparation are carried out after the oscilloscope impact test is completed, and finally, the samples are scanned and observed using a tungsten filament scanning electron microscope with EDS function.

[0095] The morphology and elemental composition of the cover weld, weld center, and root weld were examined using SEM microstructure analysis of the weld joint and fracture surface. Elemental analysis of defects and precipitates in different areas was performed using an equipped EDS (Energy Dispersive Spectroscopy) instrument. Simultaneously, the impact fracture surface of the weld joint was scanned and observed to analyze its morphology and establish the fracture mechanism of the weld joint.

[0096] In one possible implementation, the preparation and XRD analysis of the constituent phases include the following steps: selecting a sample; testing the weld joint using an X-ray diffractometer; wherein the sample includes only the base material and only the weld joint and heat-affected zone, and the X-ray scanning angle is 30°-70°.

[0097] Based on the above design scheme, during sampling, samples are taken from the weld joint by wire cutting, and the sample size requirement is 10mm×10mm×2mm. The samples are divided into two categories: base material only and weld joint and heat-affected zone only, so that they are scanned separately. By performing X-ray scanning, the grain size, crystal structure and grain orientation are analyzed, and the specific microstructure of the weld joint is determined by combining the weld joint and fracture surface SEM microstructure detection and other tests.

[0098] In one possible implementation, the microhardness distribution test includes the following steps: setting the loading force, loading time, and loading location; conducting the test using a digital microhardness tester; performing three tests at each test point and taking the average value as the test result.

[0099] Optionally, a loading force of 500 gf and a loading time of T = 10 s are used, with loading positions set at the weld joint, heat-affected zone, and base material. The hardness of the weld joint is tested using microhardness distribution testing to determine the overall hardness variation of the weld joint. The hardness of inclusions can also be tested, increasing the richness and amount of data in the experiment.

[0100] In one possible implementation, the oscilloscope impact test includes the following steps: cutting the specimen; metallographic corrosion; selecting impact points at the weld joint and heat-affected zone respectively; impact test; and plotting the load-displacement curve of the specimen.

[0101] Based on the above design, the oscilloscope impact test uses a unique angle sensor and a force sensor mounted on the hammer to sample the specimen at the instant the hammer impacts it, recording the entire dynamic impact process and thus plotting the material's characteristic impact curve, which reflects the material's dynamic tearing process. Oscilloscope impact tests are performed on weld joints to analyze the deformation process and crack propagation mode of weld joints and heat-affected zones under different slopes under load.

[0102] Optionally, the impact notches are located at the center of the weld and the heat-affected zone, respectively. First, the cut sample is subjected to metallographic etching treatment. After the weld and heat-affected zone are clearly visible to the naked eye, three oscilloscope impact points are taken on the outer and inner sides of the weld and three oscilloscope impact points on the heat-affected zone, respectively. The processed sample is then subjected to an impact test using an oscilloscope impact testing machine.

[0103] In one possible implementation, the DIC tensile test includes the following steps: painting and drying an outer surface of the specimen; randomly speckling spots on the outer surface; stretching and recording the tensile fracture process using a high-speed camera; taking three regions—the fractured part, the necked part, and the region far from the fractured part—and extracting strain data from at least one point in each region to obtain strain curves for each point over time.

[0104] Based on the above design, the DIC tensile test uses the randomly distributed speckle pattern on the surface of the test sample as a carrier of deformation information. A digital camera records the speckle pattern before and after deformation, referred to as the reference image and the deformed image, respectively. According to statistical principles, the randomly distributed speckle pattern ensures that any sub-region containing a sufficient number of pixels in the image is unique in its grayscale distribution. Based on this, the strain curve of the sample is obtained, enabling the detection of the strain rate of the sample.

[0105] During the experiment, fine, randomly distributed black and white speckles were sprayed onto the surface of the test object beforehand to ensure that the grayscale characteristics of each location on the surface were unique, thereby improving the correlation matching accuracy of the images before and after loading. Simultaneously, three regions—the fractured portion, the necked portion, and the region far from the fractured portion—were selected to facilitate the study of the specific changes in these regions under tension.

[0106] In one possible implementation, the slow strain tensile test includes the following steps: selecting and fixing the specimen; stretching the specimen at a constant slow speed using a tensile machine; and determining the specimen's SCC (Stress Corrosion Cracking) susceptibility after the specimen breaks.

[0107] Wherein, the sample elongation L can be replaced by the corresponding displacement of the clamp head:

[0108]

[0109] In the formula, ε—engineering strain; L0—gauge length of the specimen; —Strain rate; ΔL / Δt —Clip displacement velocity;

[0110] The SCC sensitivity of the sample is:

[0111]

[0112] CGR=D max / t f

[0113] In the formula, RA is the reduction of area; A0 is the original cross-sectional area of ​​the gauge length portion of the tensile specimen; A is the minimum cross-sectional area of ​​the fracture surface after tensile fracture; CGR is the crack propagation rate; D is the crack length. max - Maximum depth of SCC crack propagation at the fracture site; t f - Fracture time.

[0114] Based on the above design scheme, when stretching the specimen, tensile stress is applied to the specimen at a constant and relatively slow strain rate. By strengthening the strain state, the stress generation and development process is accelerated, causing the specimen to fracture in a very short time, thereby evaluating the deformation and fracture process of the specimen.

[0115] In step S400:

[0116] For flat areas with a slope of less than 15°, use an internal welding machine + a double-torch external welding machine, a combination of automatic welding or a single-torch automatic welding.

[0117] For gentle slopes with a gradient between 15° and 30°, use either combined automatic welding or internal welding machine with single welding torch automatic welding.

[0118] For steep slopes with a gradient between 30° and 45°, use either combined automatic welding or single-torch automatic welding.

[0119] For steep slopes with an angle between 45° and 90°, use combined automatic welding, single-torch automatic welding, or gas-shielded semi-automatic welding.

[0120] Based on the above design scheme, and according to the test data obtained in S300, analysis and horizontal comparison were carried out. Combining theoretical knowledge with the practical experience of the staff, the welding adaptability of different welding methods under different slopes was determined, and the slope was also segmented to facilitate the staff to quickly select the appropriate welding method for welding.

[0121] Preferably, 2-3 welding methods are provided for each section, allowing workers to choose according to their own circumstances, which further improves flexibility and convenience, and also helps to further improve the quality of welding.

[0122] Example 2:

[0123] This embodiment, based on Embodiment 1, provides an angle transformation device for the aforementioned method of evaluating the adaptability of automatic pipeline welding technology under different slopes in mountainous terrain, such as... Figures 2-8 As shown, the angle conversion device includes a base 1, a welding plate 2, an angle conversion module 3, and a lifting module 4;

[0124] The base 1 includes an upper plate 101 and a lower plate 102 that are spaced apart and opposite to each other. The upper plate 101 is provided with a through first groove 103. The welding plate 2 is rotatably mounted on the first groove 103, and one end of the welding plate 2 is a connecting end and the other end is a free end.

[0125] Angle transformation module 3 is slidably mounted on the first groove 103 and connected to the welding plate 2. Angle transformation module 3 is used to drive the welding plate 2 to swing back and forth around the connection end so as to change the slope of the welding plate 2.

[0126] The lifting module 4 is fixed on the lower plate 102, and its working end extends upward and is connected to the angle transformation module 3. The lifting module 4 is used to drive the angle transformation module 3 to lift and lower so that the welding plate 2 is flush with the upper plate 101.

[0127] The angle is adjusted using the aforementioned angle transformation device to simulate different slopes, thereby enabling welding operations on varying slopes. This facilitates simulation experiments for staff and improves experimental efficiency.

[0128] Specifically, the pipe is mounted on welding plate 2, which is rotatably positioned on base 1. Angle transformation module 3 moves according to the required slope for the test, causing welding plate 2 to swing until it reaches the desired slope, at which point welding can be performed. This allows for stepless adjustment of the welding plate 2's angle, providing a wide and flexible adjustment range.

[0129] When the required slope for welding is small, the welding plate 2 is nearly flush with the substrate 301. Since both the welding plate 2 and the angle transformation module 3 are located within the first groove 103, the angle transformation module 3 is lowered a certain distance by the lifting module 4 to ensure that the welding plate 2 can be adjusted to a small angle, thus expanding the range of slope changes.

[0130] And such as Figures 2-4 As shown, the angle transformation module 3 and the lifting module 4 are located on the same side of the welding plate 2, while the pipe is fixed on the other side of the welding plate 2. The welding plate 2 achieves isolation so that there are no obstructions around the pipe, thus improving the convenience of welding.

[0131] It is easy to understand that the pipe is connected to the welding plate 2 by any suitable detachable connection method.

[0132] like Figure 8 As shown, the base 1 also includes several support columns 104, which connect the upper plate 101 and the lower plate 102 so that the components are integrated into one unit.

[0133] In one possible implementation, such as Figures 2-6 As shown, the angle transformation module 3 includes a base plate 301, a connecting seat 302, a pull rope 303, and a rope winder 304;

[0134] The substrate 301 is located inside the first groove 103 and is connected to the working end of the lifting module 4.

[0135] The connecting seat 302 includes a seat body 305 slidably disposed on the top surface of the substrate 301, an intermediate shaft 306 rotatably disposed on the seat body 305, and a sliding plate 307 for connecting the welding plate 2. The seat body 305 is provided with a second groove 308, the intermediate shaft 306 is located on the second groove 308, one side of the sliding plate 307 is connected to the intermediate shaft 306 through a detachable fixing seat 309, and the other end of the sliding plate 307 is slidably connected to the welding plate 2.

[0136] The middle part of the slide plate 307 is connected to the intermediate shaft 306. Correspondingly, the depth of the second groove 308 on the seat 305 is greater than half the length of the slide plate 307. The outer surface of the seat 305 facing the welding plate 2 connection end is constructed as a vertical plane.

[0137] Two rope winders 304 are provided and fixed at both ends of the base plate 301 respectively. The two rope winders 304 are connected to the connecting seat 302 by a pull rope 303. Accordingly, the two rope winders 304 control the sliding and fixing of the connecting seat 302 on the base plate 301 by winding and unwinding the pull rope 303.

[0138] Based on the above design, the connecting seat 302 is slidably connected to the substrate 301 via the seat body 305 and slidably connected to the welding plate 2 via the sliding plate 307, thereby achieving relative sliding and adjusting the angle of the welding plate 2. The sliding plate 307 can rotate relative to the seat body 305 to avoid jamming and improve the smoothness of the angle transformation module 3.

[0139] The rope winder 304 is connected to the connecting seat 302 via a pull rope 303. By winding or releasing the pull rope 303, the rope winder 304 provides force for the movement of the connecting seat 302. The two opposing rope winders 304 cooperate to realize the reciprocating movement of the connecting seat 302. Moreover, when it is necessary to fix the position of the connecting seat 302, both rope winders 304 can simultaneously wind up the pull rope 303, without the need for additional fixing equipment, which helps to simplify the structure.

[0140] Specifically, when adjusting the angle, one of the two rope winders 304 releases the pull rope 303, while the other winds it up, thus providing a unidirectional driving force for the sliding of the connecting seat 302, allowing the connecting seat 302 to slide in one direction. At this time, the seat body 305 slides along the base plate 301, the slide plate 307 rotates relative to the seat body 305 and slides relative to the welding plate 2, and the welding plate 2 rotates under the drive of the slide plate 307. After adjusting the welding plate 2 to the required angle, both rope winders 304 wind up the pull rope 303, and the connecting seat 302 remains relatively stationary under the action of two opposing forces. The tilt angle of the welding plate 2 is also fixed, so that the pipe is fixed on the required slope.

[0141] It is easy to understand that the pull rope 303 and the rope winder 304 can each be any suitable existing model, with a wide range of choices.

[0142] Optionally, when the tilt angle of the welding plate 2 is close to or equal to 90°, the depth of the second groove 308 on the base 305 is greater than half the length of the slide plate 307, allowing the slide plate 307 to be inserted into the second groove 308. Furthermore, the outer surface of the base 305 facing the connection end of the welding plate 2 is constructed as a vertical plane, allowing the outer surface of the welding plate 2 to be in contact with the vertical plane, thus ensuring the welding plate 2 remains vertical. This further expands the swing range of the welding plate 2 and the range of the welding angle.

[0143] Optionally, such as Figure 6 As shown, the slide plate 307 has two opposing outer surfaces, one for connecting to the fixing seat 309 and the other for connecting to the fixing seat 309. Correspondingly, the welding plate 2 is provided with a groove adapted to the slide plate 307. One of the sidewalls of the groove and the slide plate 307 is provided with a concave limiting groove, and the other is provided with a convex limiting strip 310. Both the slide plate 307 and the fixing seat 309 are provided with inner grooves. When the fixing seat 309 is fixed on the slide plate 307, the two inner grooves are connected and form a rotating hole 311 adapted to the intermediate shaft 306. Based on this, the welding plate 2 and the connecting seat 302 can be disassembled and assembled through the cooperation of the slide plate 307 and the fixing seat 309, making installation and maintenance more convenient. At the same time, since the welding plate 2 has a large swing range, the combination of the limiting strip 310 and the limiting groove prevents the welding plate 2 from separating from the slide plate 307 and prevents external force disturbance from causing the angle of the welding plate 2 to change.

[0144] In one possible implementation, the lifting module 4 is a lifting device. Based on the above design, the lifting module 4 can be any suitable existing lifting device, offering a wide range of choices and good practicality.

[0145] In one possible implementation, the upper plate 101 is provided with a detachable bracket 5. The bracket 5 includes a base plate 501, a base cylinder 502, a sliding rod 503, and a support plate 504. One end of the base plate 501 is rotatably connected to the support plate 504, and the other end of the base plate 501 is provided with a plurality of base cylinders 502 at intervals. Each base cylinder 502 is connected to a sliding rod 503 by an elastic element. One end of the sliding rod 503 is located inside the base cylinder 502, and the other end of the sliding rod 503 is connected to the support plate 504. Both the base cylinder 502 and the sliding rod 503 are arc-shaped.

[0146] Based on the above design scheme, such as Figures 2-4 As shown, the welding plate 2 and the connecting seat 302 form a lever structure with the fulcrum located at the connecting end of the welding plate 2. The force applied during welding is transmitted to the connecting seat 302. The closer the welding plate 2 is to the vertical direction, the closer the connecting seat 302 is to the connecting end of the welding plate 2. At this time, according to the lever principle, the distance between the connecting seat 302 and the fulcrum decreases, and the force it experiences increases. Therefore, to prevent damage to the connecting seat 302, a detachable bracket 5 is provided on the upper plate 101 to distribute the force.

[0147] Specifically, the support 5 is connected to the upper plate 101 via the base plate 501, and the base cylinder 502 is connected to the sliding rod 503 via an elastic element. The sliding rod 503 can slide against the base cylinder 502 to adapt to different tilt angles of the welding plate 2. The support plate 504 abuts against the welding plate 2 to increase the contact area and avoid stress concentration.

[0148] During operation, if the tilt angle of the welding plate 2 is large, a bracket 5 should be placed on each side of the welding plate 2. Specifically, the support plate 504 is pressed down to retract the sliding rod 503, and then the bracket 5 is placed under the welding plate 2; then the support plate 504 is released, and under the action of the elastic element, the sliding rod 503 slides outward from the base cylinder 502 until the support plate 504 abuts against the welding plate 2. When welding pipes on the welding plate 2, the elastic force of the elastic element will offset part of the force to reduce the force on the connecting seat 302, so that the bracket 5 protects the connecting seat 302.

[0149] The specific embodiments described above further illustrate the purpose, technical solution, and beneficial effects of the present invention. It should be understood that the above description is only a specific embodiment of the present invention and is not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A method for evaluating the adaptability of automatic pipeline welding technology under different slopes in mountainous areas, characterized in that, Includes the following steps: S100 Select weld material; S200 welding and obtaining samples: setting different welding slopes; welding with different welding methods; obtaining weld samples; S300 Specimen Testing and Analysis: Structural Analysis; Mechanical Property Analysis; S400 evaluates adaptability.

2. The method for evaluating the adaptability of automatic pipeline welding technology under different slopes in mountainous areas according to claim 1, characterized in that, In step S200, the welding slope is between 0° and 90°, and multiple welding groups with different slopes are set up respectively; Welding methods include internal welding machine + double welding torch external welding machine, combined automatic welding, single welding torch automatic welding, internal welding machine single welding torch automatic welding and gas shielded semi-automatic welding.

3. The method for evaluating the adaptability of automatic pipeline welding technology under different slopes in mountainous areas according to claim 1, characterized in that, In step S300, the structural analysis includes macroscopic morphology analysis, metallographic sample preparation and observation, weld joint and fracture surface SEM microstructure detection, and compositional phase sample preparation and XRD detection. Mechanical property analysis includes microhardness distribution testing, oscilloscope impact testing, DIC tensile testing, and slow strain tensile testing.

4. The method for evaluating the adaptability of automatic pipeline welding technology under different slopes in mountainous areas according to claim 3, characterized in that, The macroscopic morphology analysis includes the following steps: selecting multiple samples; grinding with sandpaper of grades 240#, 400#, 800#, 1000#, 2000#, 3000#, and 5000# respectively; fine polishing with a polishing machine, velvet-type polishing cloth, and diamond polishing agent with a particle size of 1.5μm; metallographic etching of the samples with 4% nitric acid alcohol for 14-16s; and macroscopic morphology observation using a stereomicroscope. Metallographic sample preparation and observation include the following steps: selecting samples for macroscopic morphology analysis; cleaning with acetone, wiping with alcohol, and drying; grinding with 60#, 100#, 240#, 600#, 800#, 1000#, 1500#, 2000#, and 2500# sandpaper respectively; fine polishing with a polishing machine, velvet-type polishing cloth, and diamond polishing agent with a particle size of 1.5μm, continuously rinsing with water during the polishing process until the scratches disappear; metallographic etching of the sample with 4% nitric acid alcohol for 14-16 seconds; and observation using a metallographic microscope. The SEM microstructure examination of weld joints and fracture surfaces includes the following steps: Select the metallographic sample preparation OM and the specimen for observation; re-prepare the specimen according to the metallographic sample preparation OM and observation steps; or, cut the specimen from the impact fracture point of the oscilloscope impact test; ultrasonically clean with acetone; clean the acetone with alcohol. The scanning observation was performed using a tungsten filament scanning electron microscope with EDS function; The sample preparation and XRD testing of the constituent phases include the following steps: selecting the sample; testing the weld joint using an X-ray diffractometer; wherein, the sample includes only the base material and only the weld joint and heat-affected zone, and the X-ray scanning angle is 30°-70°.

5. The method for evaluating the adaptability of automatic pipeline welding technology under different slopes in mountainous areas according to claim 4, characterized in that, The microhardness distribution test includes the following steps: setting the loading force, loading time and loading location; conducting the test using a digital microhardness tester; performing three tests at each test point and taking the average value as the test result. The oscilloscope impact test includes the following steps: cutting the specimen; metallographic corrosion; selecting impact points at the weld joint and heat-affected zone respectively; impact test; plotting the load-displacement curve of the specimen; The DIC tensile test includes the following steps: one outer surface of the specimen is painted and dried; random speckle patterns are applied to the outer surface; the specimen is stretched and the tensile fracture process is recorded by a high-speed camera; strain data of at least one point is extracted from three regions: the fractured part, the necked part, and the region far from the fractured part, and strain curves of each point over time are obtained.

6. The method for evaluating the adaptability of automatic pipeline welding technology under different slopes in mountainous areas according to claim 5, characterized in that, The slow strain tensile test includes the following steps: selecting and fixing the specimen; stretching the specimen at a constant slow speed using a tensile machine; and determining the specimen's SCC susceptibility after the specimen breaks. Wherein, the sample elongation L can be replaced by the corresponding displacement of the clamp head: In the formula, ε—engineering strain; L0—gauge length of the specimen; —Strain rate; ΔL / Δt —Clip displacement velocity; The SCC sensitivity of the sample is: CGR=D max / t f In the formula, RA is the reduction of area; A0 is the original cross-sectional area of ​​the gauge length portion of the tensile specimen; A is the minimum cross-sectional area of ​​the fracture surface after tensile fracture; CGR is the crack propagation rate; D is the crack length. max - Maximum depth of SCC crack propagation at the fracture site; t f - Fracture time.

7. The method for evaluating the adaptability of automatic pipeline welding technology under different slopes in mountainous terrain according to any one of claims 1-6, characterized in that, In step S400: For flat areas with a slope of less than 15°, use an internal welding machine + a double-torch external welding machine, a combination of automatic welding or a single-torch automatic welding. For gentle slopes with a gradient between 15° and 30°, use either combined automatic welding or internal welding machine with single welding torch automatic welding. For steep slopes with a gradient between 30° and 45°, use either combined automatic welding or single-torch automatic welding. For steep slopes with an angle between 45° and 90°, use combined automatic welding, single-torch automatic welding, or gas-shielded semi-automatic welding.

8. An angle transformation device for evaluating the adaptability of automatic pipeline welding technology under different slopes in mountainous terrain as described in any one of claims 1-7, characterized in that, It includes a base (1), a welding plate (2), an angle transformation module (3), and a lifting module (4); The base (1) includes an upper plate (101) and a lower plate (102) that are spaced apart and opposite to each other. The upper plate (101) is provided with a through first groove (103). The welding plate (2) is rotatably mounted on the first groove (103), and one end of the welding plate (2) is a connecting end and the other end is a free end. Angle transformation module (3) is slidably set on the first groove (103) and connected to the welding plate (2). Angle transformation module (3) is used to drive the welding plate (2) to swing back and forth around the connection end so that the slope of the welding plate (2) changes. The lifting module (4) is fixed on the lower plate (102), and its working end extends upward and is connected to the angle transformation module (3). The lifting module (4) is used to drive the angle transformation module (3) to lift so that the welding plate (2) is flush with the upper plate (101).

9. The angle transformation device according to claim 8, characterized in that, The angle transformation module (3) includes a base plate (301), a connector (302), a pull rope (303), and a rope winder (304); The substrate (301) is located in the first groove (103) and connected to the working end of the lifting module (4); The connecting seat (302) includes a seat (305) slidably disposed on the top surface of the substrate (301), an intermediate shaft (306) rotatably disposed on the seat (305), and a sliding plate (307) for connecting the solder plate (2). The seat (305) is provided with a second groove (308), the intermediate shaft (306) is located on the second groove (308), one side of the sliding plate (307) is connected to the intermediate shaft (306) through a detachable fixing seat (309), and the other end of the sliding plate (307) is slidably connected to the solder plate (2). The middle part of the slide plate (307) is connected to the intermediate shaft (306). Correspondingly, the depth of the second groove (308) on the seat (305) is greater than half the length of the slide plate (307). The outer surface of the seat (305) facing the welding plate (2) is constructed as a vertical plane. Two rope winders (304) are provided and fixed at both ends of the base plate (301). The two rope winders (304) are connected to the connecting seat (302) by a pull rope (303). Accordingly, the two rope winders (304) control the sliding and fixing of the connecting seat (302) on the base plate (301) by winding and unwinding the pull rope (303).

10. The angle transformation device according to claim 9, characterized in that, The lifting module (4) uses a lifting device; The upper plate (101) is provided with a detachable bracket (5). The bracket (5) includes a base plate (501), a base cylinder (502), a sliding rod (503), and a support plate (504). One end of the base plate (501) is rotatably connected to the support plate (504). The other end of the base plate (501) is provided with several base cylinders (502) at intervals. Each base cylinder (502) is connected to a sliding rod (503) through an elastic element. One end of the sliding rod (503) is located inside the base cylinder (502), and the other end of the sliding rod (503) is connected to the support plate (504). Both the base cylinder (502) and the sliding rod (503) are arc-shaped.

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