Pipe welding execution method and testing machine in mountainous environment

Abstract

The application discloses a pipeline welding execution method and a testing machine in a mountainous environment and relates to the technical field of pipeline welding. The pipeline welding execution method in the mountainous environment comprises a testing machine, the testing machine is provided with a pendulum, the pendulum is provided with a force sensor, and the pipeline welding execution method further comprises the following methods: test piece preparation, testing machine preparation, starting test and selecting a welding mode. The testing machine comprises a test main body, the test main body is provided with a protractor, a test table and a protection frame, the pendulum is provided with the force sensor for recording an impact dynamic process, the pendulum is connected with the test main body, the test table is placed with a pipeline test piece aligned with the pendulum, the pendulum comprises a swing arm and a U-shaped hammer head connected with each other, the U-shaped hammer head is provided with a pair of detachable counterweights on the front face and the back face, and the U-shaped hammer head is provided with a striker for impacting the test main body in a groove. The pipeline welding execution method and the testing machine in the mountainous environment have the beneficial effects that a correct welding mode is adopted, and the service life of the pipeline is longer.

Description

Technical Field

[0001] This invention relates to the field of pipeline welding technology, specifically to a pipeline welding execution method and testing machine in mountainous environments. Background Technology

[0002] In mountainous environments, natural gas pipeline welding is prone to embrittlement. The welding process and pipeline service are subject to complex stresses, often under stress. Under the combined effect of complex stresses and embrittlement, the potential risk of brittle failure of the pipeline increases.

[0003] The degree of automation in the construction of pipelines in mountainous areas affects welding efficiency and the stability of welding quality. Based on a scientific evaluation of the energy consumption process of weld fracture in mountainous environments, the selection of automated welding combinations for mountainous pipelines directly impacts the construction and service safety of pipelines in these environments. Currently, welding procedure qualification primarily uses conventional impact testing to assess weld toughness, using the impact energy at final fracture as the evaluation standard. This method is insufficient to accurately reflect the fracture process of welds in mountainous environments, resulting in inaccurate descriptions of welding failures in mountainous pipelines. Furthermore, it fails to guide the selection of welding methods for mountainous pipelines, and incorrect welding methods can easily affect the service life of subsequent pipelines.

[0004] Therefore, existing technologies need to be improved. Summary of the Invention

[0005] The technical problem to be solved by this invention is that it is difficult to choose a suitable welding method in the prior art, which affects the use of subsequent pipelines. The purpose is to provide a pipeline welding execution method and testing machine in mountainous environments. By adopting the corresponding technical solution, it has the beneficial effect of using the correct welding method and extending the service life of the pipeline.

[0006] This invention is achieved through the following technical solution:

[0007] In a first aspect, the present invention provides a method for performing pipeline welding in mountainous environments, comprising a testing machine equipped with a pendulum, the pendulum being equipped with a force sensor.

[0008] It also includes the following methods,

[0009] S1 Specimen Preparation: Machine impact notches into the pipe specimens, and then install the pipe specimens on the test bench.

[0010] Prepare the S2 testing machine, adjust the weight of the pendulum according to the test requirements, and fix the pendulum to the appropriate release height;

[0011] The test begins with S3, releasing the pendulum, which then strikes the pipe specimen. At the moment the pendulum strikes the pipe specimen, the force sensor records the entire dynamic impact process, and the computer plots the characteristic impact curve based on the feedback from the force sensor.

[0012] S4 selects the welding method, and determines the maximum load displacement, yield load displacement, and crack initiation energy based on the characteristic impact curve. It then selects one of three welding methods: manual welding, combined automatic welding, or fully automatic welding.

[0013] In S4, the welding method is selected using the following formula.

[0014] If the maximum load displacement / yield load displacement is ≥6 and the crack initiation energy is ≥70J, manual welding should be selected.

[0015] 6≥Maximum load displacement / Yield load displacement≥2, 70J≥Crack initiation energy≥50J, Select combined automatic welding execution.

[0016] 2≥Maximum load displacement / Yield load displacement, 50J≥Crack initiation energy, select fully automatic welding execution.

[0017] Furthermore, in this invention, the above-mentioned combined automatic welding configuration consists of tungsten inert gas welding root welding / thermal welding and flux-cored wire gas shielded arc welding filler welding.

[0018] Furthermore, in this invention, the above-mentioned fully automatic welding configuration is a single-torch, metal arc electrode, and welding wire fully automatic welding.

[0019] Secondly, the present invention also provides a testing machine used in a pipeline welding execution method in a mountainous environment. The testing machine includes a testing body, which is equipped with an angle disk, a testing platform and a protective frame. The pendulum is equipped with a force sensor for recording the dynamic impact process. The pendulum is connected to the testing body. The testing platform holds a pipeline specimen aligned with the pendulum. The pendulum includes a pendulum arm and a U-shaped hammer head that are connected to each other. The U-shaped hammer head is equipped with a pair of detachable counterweights on the front and back. The groove of the U-shaped hammer head is provided with a striker for impacting the testing body.

[0020] Furthermore, in this invention, the U-shaped hammer head is provided with a locking device, and the counterweight is provided with a plug that cooperates with the locking device. The locking device includes an L-shaped plate fixed to the front or back of the U-shaped hammer head, and the plug includes a U-shaped plate fixedly connected to the counterweight.

[0021] Furthermore, in this invention, a reinforcing plate is provided in the middle part of the L-shaped plate, the reinforcing plate is connected to the U-shaped hammer head, and an insertion port adapted to the reinforcing plate is provided in the middle part of the U-shaped plate.

[0022] Furthermore, in this invention, the aforementioned swing arm is threadedly connected to a sleeve, and a stop bar for resisting the counterweight is provided at the bottom of the sleeve, the width of which does not exceed the width of the U-shaped hammer.

[0023] Furthermore, in this invention, the counterweights on both sides are provided with clamping strips, the clamping strips are provided with wedges, and the surface of the counterweights is provided with slots for the wedges to be inserted.

[0024] Furthermore, in this invention, the aforementioned striking pin is provided with a base, which is connected to the bottom screw of the U-shaped hammer head.

[0025] Furthermore, in this invention, the protective frame is provided with a protective net, and a stopper is provided on the rear side of the test bench.

[0026] Compared with the prior art, the present invention has the following advantages and beneficial effects:

[0027] This invention provides a method for pipe welding in mountainous environments. A testing machine is used to test pipe specimens, and a force sensor records the dynamic impact process. A computer plots characteristic impact curves based on the force sensor feedback. These curves determine the maximum load displacement, yield load displacement, and crack initiation energy. A suitable welding method is selected from three options: manual welding, combined automatic welding, and fully automatic welding. Choosing the correct welding method will give the pipe weld better resistance to crack propagation, thus resulting in a longer service life.

[0028] This invention also provides a testing machine that can be used in pipeline welding operations in mountainous environments. The machine tests pipeline specimens, relying on force sensors to record the dynamic impact process, allowing selection of a suitable welding method from three options: manual welding, combined automatic welding, and fully automatic welding. Different pipeline specimens or different test conditions require U-shaped hammers of varying weights. This invention features detachable counterweights on the front and back of the U-shaped hammer, symmetrically installed to ensure the impact pin remains at the center of pressure during impact, thus ensuring more accurate test results. Accurate test results lead to more accurate selection of the welding method. Attached Figure Description

[0029] 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:

[0030] Figure 1 This is a schematic diagram of the testing machine of the present invention;

[0031] Figure 2 This is a schematic diagram of the pendulum structure of the present invention;

[0032] Figure 3 This is a schematic diagram of the U-shaped hammer and counterweight of the present invention;

[0033] Figure 4This is a top view of the U-shaped hammer and counterweight of the present invention;

[0034] Figure 5 This is a schematic diagram of the U-shaped hammer and counterweight with locking mechanism of the present invention;

[0035] Figure 6 This is a top view of the U-shaped hammer and counterweight of the present invention.

[0036] Figure 7 To impact the typical curve chart.

[0037] The attached diagram shows the markings and corresponding component names: 1-Test body, 2-Pendulum, 201-Pendulum arm, 202-U-shaped hammer head, 203-Counterweight, 2031-Slot, 204-Striker, 2041-Base, 205-Sleeve, 206-Stop bar, 207-Clamping bar, Wedge block 2071, 3-Test bench, 301-Suppressing component, 4-Angle disc, 5-Pipe specimen, 6-Protective frame, 601-Protective net, 7-Clamping component, 701-L-shaped plate one, 702-Reinforcing plate, 8-Plug-in, 801-Socket. Detailed Implementation

[0038] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to embodiments and accompanying drawings. The illustrative embodiments and descriptions of this invention are for explanation only and are not intended to limit the invention. The following detailed description of the embodiments of the invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of this invention without inventive effort are within the scope of protection of this invention.

[0039] It should be noted that similar reference numerals and letters in the following figures indicate similar items. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures. In the description of the embodiments of the present invention, it should also be noted that, unless otherwise explicitly specified and limited, the terms "set," "install," and "connect" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0040] In existing technologies, in mountainous environments, macroscopically, as the welding slope increases, the inclination angle of the weld reinforcement gradually decreases, the degree of molten metal exceeding the pipe surface decreases, and the degree of base metal melting also decreases. Microscopically, this change does not alter the weld microstructure type, but rather alters the size and content of the microstructure. Specifically, the width of the fusion zone changes with increasing welding slope: in lower sections, the fusion zone narrows significantly; while in higher sections, it gradually expands. Relatively speaking, the microstructure composition of the heat-affected zone (HAZ) does not change significantly, mainly consisting of blocky ferrite and granular bainite. As the welding slope increases, the grain size of the HAZ gradually increases, and the coarse-grained zone also widens accordingly. Microhardness testing results show that in the root weld layer, the hardness distribution is stable with small variations, exhibiting a trend of decreasing hardness with increasing welding slope. However, in the weld capping layer, the hardness of both the HAZ and the weld zone shows an increasing trend with increasing welding slope. The area with the highest hardness is the weld zone, followed by the heat-affected zone on the lower side, and then the heat-affected zone on the higher side.

[0041] Welding in a steep slope environment directly affects the macroscopic morphology of the weld joint. As the weld slope increases, the degree of melting of the base material on the lower slope side increases, leading to a larger weld reinforcement. This, in turn, affects the formation of the weld microstructure. As the weld slope increases, the microstructure of the weld gradually enlarges and becomes more heterogeneous. The fusion zone width increases on the lower slope side and decreases on the higher slope side. In the heat-affected zone (HAZ), the coarse-grained region of the HAZ widens and the grain size increases on the higher slope side, while the coarse-grained region shrinks and the grain size decreases on the lower slope side. These changes in microstructure often lead to changes in properties. As the weld slope increases, the weld joint exhibits decreased ductility and toughness, increased brittleness, increased strength, and a slight decrease in resistance to crack propagation due to the combined effects of grain size, fusion zone width, and HAZ grain size and width.

[0042] Fully automated welding boasts a high degree of automation, enabling continuous and efficient welding processes, reducing human interference, and thus improving welding efficiency. While welding in steep slope environments directly affects the macroscopic morphology of the weld joint, the microstructure and phase types remain unchanged, with only variations in grain size. As the welding slope increases, changes in grain size, fusion zone width, and heat-affected zone grain size and width lead to decreased weld toughness, increased brittleness, increased strength, and a slight decrease in resistance to crack propagation.

[0043] The general characteristics of manual welding are simple equipment and flexible operation, but the welding process is unstable, the labor intensity of workers is high, and the efficiency is low. The hardness of the weld joint fluctuates greatly, with the weld seam having the highest hardness. The heat-affected zone decreases rapidly and then increases again, resulting in uneven microstructure of the weld joint. However, the cover weld has the lowest deviation and the quality is good.

[0044] Combined automatic welding produces the highest toughness welds. It is recommended to use combined automatic welding when the weld performance has high toughness requirements, moderate hardness, and the cap weld is centered. The construction environment should be a mountainous backside with little wind and sand. Wind protection measures should also be taken during welding, especially for the safety of welding operators.

[0045] Therefore, choosing the appropriate welding method is beneficial to the stable use of pipelines.

[0046] Example 1

[0047] A method for performing pipeline welding in mountainous environments includes a testing machine equipped with a pendulum 2 and a force sensor.

[0048] It also includes the following methods,

[0049] S1 Specimen preparation: Machine an impact notch into pipe specimen 5, and then install pipe specimen 5 on test bench 3;

[0050] Prepare the S2 testing machine, adjust the weight of the pendulum 2 according to the test requirements, and fix the pendulum 2 to the appropriate release height;

[0051] S3 starts the test, releases pendulum 2, and then pendulum 2 hits pipe specimen 5. At the moment pendulum 2 hits pipe specimen 5, the force sensor records the entire impact dynamic process, and the computer draws the characteristic impact curve based on the feedback from the force sensor.

[0052] Combination Figure 7 As shown, according to GB / T 19748—2019, the load-displacement curve of the characteristic impact curve is summarized as follows: Figure 7 The six types, A through F, represent six typical curve morphologies of materials ranging from brittle fracture to ductile fracture.

[0053] Figure 7 In the test, Type A indicates the absence of yield force before the maximum load, with only unstable crack propagation; Type B indicates a small amount of stable crack propagation; based on the different proportions of stable and unstable crack propagation, it is further divided into Types C, D, and E, indicating the presence of plastic deformation before the maximum load, followed by both stable and unstable crack propagation; Type F indicates the presence of plastic deformation before the maximum load, followed by only stable crack propagation. The test includes the following indicators:

[0054] Yield force Fgy: The force corresponding to the intersection of the sharply rising portion of the second peak on the force-displacement curve and the fitted curve.

[0055] Maximum load Fm: The maximum force passing through the fitted curve of the oscillation curve. The abscissa of this point is the maximum load displacement Sm. Under the load-displacement curve, the area from S=0 to S=Sm is the energy Wm at the maximum force.

[0056] Unstable crack propagation initiation force (initiation force) Fiu: The force corresponding to the intersection of the fitted curve and the point where the curve begins its sharp decline after the maximum load. The x-axis of this point is the displacement Sid corresponding to the crack initiation. Under the load-displacement curve, the area from S=0 to S=Sid is the unstable crack propagation initiation energy Wiu.

[0057] The unsteady crack propagation termination force (crack arresting force) Fa: The force corresponding to the intersection of the load-displacement curve at the point where the downward curve terminates and the subsequent load-displacement fitted curve. The abscissa of this point is the displacement Sa corresponding to the crack arrest. The area under the load-displacement curve from S=0 to S=Sa is the unsteady crack propagation termination energy Wa.

[0058] Based on the test results, the load-displacement curve of pipe specimen 5 was plotted (representing the characteristic impact curve).

[0059] S4 selects the welding method, and determines the maximum load displacement, yield load displacement, and crack initiation energy based on the characteristic impact curve. It then selects one of three welding methods: manual welding, combined automatic welding, or fully automatic welding.

[0060] In S4, the welding method is selected using the following formula.

[0061] If the maximum load displacement / yield load displacement is ≥6 and the crack initiation energy is ≥70J, manual welding should be selected.

[0062] 6≥Maximum load displacement / Yield load displacement≥2, 70J≥Crack initiation energy≥50J, Select combined automatic welding execution.

[0063] 2≥Maximum load displacement / Yield load displacement, 50J≥Crack initiation energy, select fully automatic welding execution.

[0064] The above-mentioned automatic welding configuration includes tungsten inert gas (TIG) root welding / hot welding and flux-cored wire gas shielded arc welding filler welding.

[0065] The above-mentioned fully automatic welding configuration is a single welding torch, metal electrode, and welding wire fully automatic welding.

[0066] For example, consider a mountainous environment with the following characteristics: slope angle (21-30)°, slope length approximately 3000m, on-site humidity 82%, base material L485M grade pipeline steel (X70), pipeline steel diameter Φ = 1219mm, and straight pipe wall thickness T = 26.8m. Based on the construction plan design documents and pre-welding process qualification plan, welding samples were prepared simulating the characteristics of this mountainous environment. The combined automatic welding process used GTAW+FCAW-G (tungsten inert gas welding for root / hot welding + flux-cored wire gas shielded arc welding for filling and capping), and the fully automatic welding process used GMAW (single-torch consumable electrode wire fully automatic welding), with the welding wire being (Φ1.2mm) ER70S-G. The shielding gas was a mixture of 80% Ar + 20% CO2.

[0067] The welding process and parameters for the welded specimens are shown in the table below:

[0068]

[0069] Based on the welding procedure qualification standards and specifications, the corresponding qualification tests and quantities were completed, and the evaluation was conducted according to the standards. The conclusions are shown in the table below.

[0070]

[0071]

[0072] The testing machine in this embodiment was used to conduct an impact test on the processed pipe specimen 5. The test results are shown in the table below.

[0073]

[0074] In summary, according to the execution method of this embodiment of the present invention, the welding process qualification of both fully automatic welding and combined automatic welding is qualified. Based on the impact test results, the 2≦Sm / Sgy≦6 and 50≦Wi≦70 of fully automatic welding and combined automatic welding meet the principle of selecting combined automatic welding. Therefore, combined automatic welding is given priority in the mountain welding construction of this section.

[0075] Example 2

[0076] Combination Figures 1 to 6 As shown in the figure, this embodiment 2 provides a testing machine for performing pipeline welding in mountainous environments. The specific structure and principle are described below.

[0077] In some implementations of this embodiment, combined with Figure 1As shown, the testing machine consists of six parts: a test body 1, a pendulum 2, a test platform 3, an angle disc 4, a pipe specimen 5, and a protective frame 6. The bottom of the test body 1 is fixed to the laboratory floor with bolts to ensure stable impact testing. The pendulum 2 is rotatably connected to the test body 1 and impacts the pipe specimen 5 after being lowered. The test platform 3 is used to fix the pipe specimen 5. The angle disc 4 is used to detect the angle of rotation of the pendulum 2, thereby determining the height of the pendulum 2. The protective frame 6 limits the range of motion of the pendulum 2 and improves the protection effect. A protective net 601 is installed on the protective frame 6, providing better protection and preventing debris from splashing during impact and causing safety accidents. A force sensor is installed on the pendulum 2 to detect the impact force generated by the pendulum 2 on the pipe specimen 5.

[0078] Furthermore, in combination Figure 1 and Figure 2 As shown, the pendulum 2 mainly consists of two parts: a pendulum arm 201 and a U-shaped hammer head 202. The pendulum arm 201 is a cylindrical metal rod. One end of the pendulum arm 201 is fixedly connected to the U-shaped hammer head 202, and the other end of the pendulum arm 201 is rotatably connected to the test body 1. The pendulum arm 201 and the U-shaped hammer head 202 can rotate freely.

[0079] Furthermore, combining Figure 1 As shown, the test bench 3 is a platform for fixing the pipe specimen 5. The test bench 3 is fixed on the bottom plate of the test body 1 and will not displace when subjected to impact. In order to increase the stability of the test bench 3, a triangular stop 301 is fixed on the bottom plate of the test body 1. The stop 301 is fixedly connected to the rear side of the test bench 3 (the side facing away from the impact of the U-shaped hammer head 202).

[0080] Combination Figure 2 As shown, the U-shaped hammer head 202 can be made of stainless steel or cast iron. A groove is provided on the forward-facing side of the U-shaped hammer head 202, making its shape approximately U-shaped. The striking pin 204 is a metal block, fixedly installed within the groove of the U-shaped hammer head 202. After the U-shaped hammer head 202 swings downwards, the striking pin 204 impacts the pipe specimen 5 to conduct the test.

[0081] It should be noted that, as Figure 2 As shown, a base 2041 is fixed to the firing pin 204. The base 2041 and the firing pin 204 are integrally formed. Screws are installed on the top and bottom of the base 2041 to fix and connect to the bottom of the groove of the U-shaped hammer head 202, which facilitates the disassembly of the firing pin 204 during maintenance or replacement. The structure is simple and the design is reasonable.

[0082] In some implementations of this embodiment, combined with Figure 2 and Figure 3As shown, the front and back of the U-shaped hammer head 202 are detachably connected to a counterweight 203. The counterweight 203 and the U-shaped hammer head 202 are connected by the cooperation of the clip 7 and the plug 8.

[0083] Combination Figure 2 and Figure 4 As shown, the clip 7 comprises two parts: an L-shaped plate 701 and a reinforcing plate 702. The L-shaped plate 701 is fixedly connected to the front or back of the U-shaped hammer head 202, and the side plate of the L-shaped plate 701 is parallel to the front or back of the U-shaped hammer head 202. The thickness of the reinforcing plate 702 is the same as the distance between the side plate of the L-shaped plate 701 and the front or back of the U-shaped hammer head 202. One side of the reinforcing plate 702 is fixedly connected to the side plate of the L-shaped plate 701, and the other side of the reinforcing plate 702 is fixedly connected to the front or back of the U-shaped hammer head 202.

[0084] Furthermore, refer to Figure 2 and Figure 4 As shown, a plug-in 8 is fixedly installed on the side of the counterweight 203 facing the U-shaped hammer head 202. The plug-in 8 is U-shaped, and the side plate of the U-shaped plate is fixedly connected to the counterweight 203. In order for the plug-in 8 to be smoothly inserted into the clip 7, a slot 801 is provided in the middle of the plug-in 8. The width of the slot 801 is the same as that of the reinforcing plate 702.

[0085] It should be noted that, in combination Figure 2 and Figure 4 As shown, when the counterweight 203 and the U-shaped hammer 202 are connected, the plug 8 is inserted from above the clip 7. The side plate of the plug 8 is inserted between the front or back of the L-shaped plate 701 and the U-shaped hammer 202. The side plate of the L-shaped plate 701 is inserted into the surface of the plug 8 and the counterweight 203 to achieve a fixed connection and increase the impact force of the U-shaped hammer 202 test.

[0086] Furthermore, the bottom plate of the L-shaped plate 701 restricts the bottom of the plug-in 8 to prevent the counterweight 203 from moving downwards, combined with... Figure 2 and Figure 3 As shown, a stop bar 206 is used to restrict the top of the counterweight 203, preventing it from moving upwards. A sleeve 205 is fitted onto the swing arm 201 and threadedly connected to it. The stop bar 206 and the bottom of the sleeve 205 are fixedly connected. Rotating the sleeve 205 allows control to position the stop bar 206 parallel or perpendicular to the U-shaped hammer head 202, as shown. Figure 2 As shown, when the stop bar 206 is parallel to the U-shaped hammer head 202, it facilitates the removal or insertion of the counterweight 203, such as... Figure 3 As shown, when the stop bar 206 is perpendicular to the U-shaped hammer head 202, it restricts the top of the counterweight 203 and prevents the counterweight 203 from falling off.

[0087] It should be noted that the width of the stop bar 206 does not exceed the width of the U-shaped hammer head 202. When the stop bar 206 is rotated to be parallel to the U-shaped hammer head 202, the stop bar 206 does not affect the insertion or removal of the counterweight 203. The shape of the counterweight 203 is the same as that of the U-shaped hammer head 202. Multiple sets of counterweights 203 with different thicknesses can be prepared to meet various test requirements.

[0088] Combination Figure 5 and Figure 6 As shown, to enhance fixation and prevent the counterweight 203 and U-shaped hammer head 202 from loosening, a clamping strip 207 is installed. The clamping strip 207 is concave, and a wedge block 2071 is installed on the inner side of the clamping strip 207. A corresponding groove 2031 is formed on the surface of the counterweight 203, and the shape of the groove 2031 is the same as that of the counterweight 203. During installation, the clamping strip 207 is clamped onto the two sides of the counterweight 203, and then the clamping strip 207 is gently tapped in with a hammer until the wedge block 2071 is inserted into the groove 2031, thus achieving a fixed connection.

[0089] In summary, this invention provides a method for performing pipeline welding in mountainous environments, comprising a testing machine equipped with a pendulum 2, the pendulum 2 being equipped with a force sensor, and further comprising the following methods.

[0090] S1 Specimen preparation: Machine an impact notch into pipe specimen 5, and then install pipe specimen 5 on test bench 3;

[0091] Prepare the S2 testing machine, adjust the weight of the pendulum 2 according to the test requirements, and fix the pendulum 2 to the appropriate release height;

[0092] S3 starts the test, releases pendulum 2, and then pendulum 2 hits pipe specimen 5. At the moment pendulum 2 hits pipe specimen 5, the force sensor records the entire impact dynamic process, and the computer draws the characteristic impact curve based on the feedback from the force sensor.

[0093] S4 selects the welding method, and determines the maximum load displacement, yield load displacement, and crack initiation energy based on the characteristic impact curve. It then selects one of three welding methods: manual welding, combined automatic welding, or fully automatic welding.

[0094] In S4, the welding method is selected using the following formula.

[0095] If the maximum load displacement / yield load displacement is ≥6 and the crack initiation energy is ≥70J, manual welding should be selected.

[0096] 6≥Maximum load displacement / Yield load displacement≥2, 70J≥Crack initiation energy≥50J, Select combined automatic welding execution.

[0097] 2≥Maximum load displacement / Yield load displacement, 50J≥Crack initiation energy, select fully automatic welding execution.

[0098] Furthermore, in this invention, the above-mentioned combined automatic welding configuration consists of tungsten inert gas welding root welding / thermal welding and flux-cored wire gas shielded arc welding filler welding.

[0099] Furthermore, in this invention, the above-mentioned fully automatic welding configuration is a single-torch, metal arc electrode, and welding wire fully automatic welding.

[0100] This invention also provides a testing machine for use in a pipeline welding method in mountainous environments. The testing machine includes a testing body 1, which is equipped with an angle disk 4, a testing platform 3, and a protective frame 6. A pendulum 2 is equipped with a force sensor for recording the dynamic impact process. The pendulum 2 is connected to the testing body 1. A pipeline specimen 5 aligned with the pendulum 2 is placed on the testing platform 3. The pendulum 2 includes a pendulum arm 201 and a U-shaped hammer head 202 connected to each other. The U-shaped hammer head 202 is equipped with a pair of detachable counterweights 203 on the front and back. A striker 204 for impacting the testing body 1 is disposed in the groove of the U-shaped hammer head 202. The U-shaped hammer head 202 is equipped with a locking piece 7, and the counterweight 203 is equipped with a plug 8 that cooperates with the locking piece 7. The locking piece 7 includes an L-shaped plate 701 fixed to the front or back of the U-shaped hammer head 202, and the plug 8 includes a U-shaped plate fixedly connected to the counterweight 203. A reinforcing plate 702 is provided in the middle of the L-shaped plate 701. The reinforcing plate 702 is connected to the U-shaped hammer head 202. An insertion slot 801 for the reinforcing plate 702 is provided in the middle of the U-shaped plate. A sleeve 205 is threadedly connected to the swing arm 201. A stop bar 206 for resisting the counterweight 203 is provided at the bottom of the sleeve 205. The width of the stop bar 206 does not exceed the width of the U-shaped hammer head 202. The striking pin 204 is provided with a base 2041, which is connected to the bottom screw of the groove of the U-shaped hammer head 202. A protective net 601 is provided on the protective frame 6. A stopper 301 is provided on the rear side of the test bench 3.

[0101] The pipeline welding method in mountainous environments employs a testing machine to test pipeline specimens 5. Force sensors record the dynamic impact process, and a computer plots characteristic impact curves based on the sensor feedback. These curves determine the maximum load displacement, yield load displacement, and crack initiation energy, allowing for the selection of a suitable welding method from three options: manual welding, combined automatic welding, and fully automatic welding. Choosing the correct welding method improves the weld's resistance to crack propagation, resulting in a longer service life. The testing machine, usable in mountainous environments, allows for testing of pipeline specimens 5 using force sensors to record the dynamic impact process. Different pipeline specimens 5 or different test conditions require U-shaped hammers 202 of varying weights. This invention features detachable counterweights 203 mounted in pairs on the front and back of the U-shaped hammers 202. These counterweights 203 are symmetrically installed to ensure the impact pin 204 remains at the pressure center during impact, ensuring more accurate test results. The accuracy of the test results allows for a more accurate selection of welding methods.

[0102] 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 performing pipeline welding in a mountainous environment, characterized in that, The test machine includes a pendulum (2) equipped with a force sensor. It also includes the following methods, S1 Specimen preparation: The pipe specimen (5) is machined with an impact notch, and then the pipe specimen (5) is installed on the test bench (3); S2 test machine preparation: adjust the weight of pendulum (2) according to the test requirements and fix pendulum (2) to a suitable release height; S3 starts the test, releases the pendulum (2), and then the pendulum (2) hits the pipe specimen (5). At the moment the pendulum (2) hits the pipe specimen (5), the force sensor records the entire impact dynamic process, and the computer draws the characteristic impact curve based on the feedback of the force sensor. S4 selects the welding method, and determines the maximum load displacement, yield load displacement, and crack initiation energy based on the characteristic impact curve. It then selects one of three welding methods: manual welding, combined automatic welding, or fully automatic welding. In S4, the welding method is selected using the following formula. If the maximum load displacement / yield load displacement is ≥6 and the crack initiation energy is ≥70J, manual welding should be selected. 6≥Maximum load displacement / Yield load displacement≥2, 70J≥Crack initiation energy≥50J, Select combined automatic welding execution. 2≥Maximum load displacement / Yield load displacement, 50J≥Crack initiation energy, select fully automatic welding execution.

2. The pipeline welding method in a mountainous environment according to claim 1, characterized in that, The combined automatic welding configuration consists of tungsten inert gas (TIG) root welding / hot welding and flux-cored wire gas shielded arc welding filler welding.

3. The pipeline welding method in a mountainous environment according to claim 2, characterized in that, The fully automatic welding configuration is a single welding torch, metal electrode, and welding wire fully automatic welding.

4. A testing machine used in the pipeline welding execution method in a mountainous environment as described in claim 1, characterized in that, The testing machine includes a testing body (1), which is equipped with an angle disk (4), a testing platform (3) and a protective frame (6). The pendulum (2) is equipped with a force sensor that records the dynamic impact process. The pendulum (2) is connected to the testing body (1). The testing platform (3) is equipped with a pipe specimen (5) aligned with the pendulum (2). The pendulum (2) includes a pendulum arm (201) and a U-shaped hammer head (202) connected to each other. The U-shaped hammer head (202) is equipped with a pair of detachable counterweights (203) on the front and back. The groove of the U-shaped hammer head (202) is equipped with a striker (204) that impacts the testing body (1).

5. The testing machine according to claim 4, characterized in that, The U-shaped hammer (202) is provided with a locking piece (7), and the counterweight (203) is provided with a plug-in (8) that cooperates with the locking piece (7). The locking piece (7) includes an L-shaped plate (701) fixed to the front or back of the U-shaped hammer (202), and the plug-in (8) includes a U-shaped plate fixedly connected to the counterweight (203).

6. The testing machine according to claim 5, characterized in that, A reinforcing plate (702) is provided in the middle part of the L-shaped plate (701), the reinforcing plate (702) is connected to the U-shaped hammer (202), and an insertion port (801) adapted to the reinforcing plate (702) is provided in the middle part of the U-shaped plate.

7. The testing machine according to claim 5, characterized in that, The swing arm (201) is threadedly connected to a sleeve (205), and the bottom of the sleeve (205) is provided with a stop bar (206) to block the counterweight (203). The width of the stop bar (206) does not exceed the width of the U-shaped hammer (202).

8. The testing machine according to claim 5, characterized in that, The counterweights (203) on both sides are provided with clamping strips (207), the clamping strips (207) are provided with wedges (2071), and the surface of the counterweights (203) is provided with slots (2031) for the wedges (2071) to be inserted.

9. The testing machine according to claim 4, characterized in that, The firing pin (204) is provided with a base (2041), and the base (2041) is connected to the bottom screw of the U-shaped hammer (202).

10. The testing machine according to claim 4, characterized in that, The protective frame (6) is provided with a protective net (601), and the test bench (3) is provided with a stop (301) on the rear side.

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