Large gap gas electric horizontal welding automatic welding method

Abstract

The application discloses a kind of big gap gas electric transverse welding automatic welding methods, comprising the following steps: S1, complete welding preparation work;S2, select reasonable welding process parameters, complete big gap gas electric transverse welding single-sided welding double-sided forming welding of layer coverage;S3, lane cleaning, complete welding preparation work again;S4, select reasonable welding process parameters, complete big gap gas electric transverse welding single-sided welding double-sided forming welding of filling layer;S5, relevant detection is carried out to weld seam.The application makes up the defect that gas electric transverse welding is only suitable for the welding of small assembly gap width, reduces the labor intensity of big gap welding, improves the efficiency and welding quality of big gap welding, and reduces the assembly difficulty of large welding structure.

Description

Technical Field

[0001] This invention relates to the field of ship hull joint welding technology, and in particular to an automatic welding method for large-gap gas-electric horizontal welding. Background Technology

[0002] Gas-electric vertical welding is a highly efficient automatic welding technology with stable quality. For example, Chinese patent CN112453650A discloses a gas-electric welding process for transverse butt joints in ship hulls, used to weld workpieces with assembly gaps of 6-7mm. However, in actual shipbuilding processes, it's inevitable that semi-automatic cutting tools will not correct beveling and section precision control will not meet welding process requirements, resulting in large gaps, such as root gaps greater than 10mm. Existing gas-electric vertical welding processes cannot handle these large gaps. Currently, the only way to solve large root gap welding tasks on-site is through CO2 semi-automatic welding to allow the weld to "grow" before welding. This method is affected by the welder's skill level, often resulting in defects such as incomplete penetration and lack of fusion, making it difficult to guarantee weld quality, and also leading to low welding efficiency and high labor intensity. Summary of the Invention

[0003] In view of the deficiencies in the existing technology, this application provides an automatic welding method for large-gap gas-electric horizontal welding to solve the technical problems of poor welding quality, low welding efficiency and high labor intensity in the existing large-gap welding methods.

[0004] To achieve the above-mentioned objectives, the present invention provides the following technical solution:

[0005] An automated method for large-gap gas-electric horizontal welding includes the following steps:

[0006] S1. Complete the pre-welding preparation work according to the process construction technical indicators;

[0007] S2. Select appropriate welding process parameters to complete the single-sided welding and double-sided forming welding of the large gap gas-electric horizontal welding cladding layer. The specific process parameters for cladding layer welding are: welding current of 300-330A, welding voltage of 37-40V, welding speed of 15-20cm / min, welding torch oscillation amplitude of 8-10mm, front dwell time of 1s-1.5s, root dwell time of 1s-1.5s, and start the welding machine to complete the welding of the cladding layer.

[0008] S3, interpass cleaning, complete the pre-welding preparation work again;

[0009] S4. Select reasonable welding process parameters to complete the single-sided welding and double-sided forming welding of the large gap gas-electric horizontal welding filler layer.

[0010] S5, Perform relevant inspections on the weld.

[0011] In one embodiment, the specific process parameters of the cladding layer in S4 are as follows: set the welding current to 300 - 330 A, the welding voltage to 37 - 40 V, the welding speed to 15 - 20 cm / min, the swing amplitude of the welding torch to 8 - 10 mm, the front dwell time to 1 - 1.5 s, the root dwell time to 1 - 1.5 s, and turn on the welding machine to complete the welding of the cladding layer.

[0012] In one embodiment, S1 further includes the following steps:

[0013] S11) Select the workpiece to be welded;

[0014] S12) Groove assembly;

[0015] S13) Installation of the arc starting and extinguishing plates;

[0016] S14) Lining pasting;

[0017] S15) Preparation of the electro - gas horizontal welding device.

[0018] In one embodiment, for the S12 groove assembly: the groove form is single - side V - type, the upper groove angle is 35° and the lower groove angle is 0°, without blunt edge and the blunt edge error L is controlled within 0 - 2 mm, the groove root gap range is 11 mm < GAP ≤ 14 mm, and when assembling the groove, attention should be paid to the flatness of the plate surface, and the misalignment amount on the back of the weld is less than 1.5 mm.

[0019] In one embodiment, the specific steps of S15 are as follows: select an electro - gas horizontal welding slider with a forming groove width of 24 mm according to the groove width, install the slider at the center position of the weld, make the slider fit tightly with the groove, ensure that the air vent of the slider is clean and unobstructed, and at the same time adjust the angle and height of the welding torch.

[0020] In one embodiment, in S15, the angle between the welding torch and the horizontal plane is 10°, and the vertical distance between the top of the welding torch and the lower edge of the shielding gas outlet of the slider is controlled within 25 mm.

[0021] In one embodiment, the specific steps of S3 are as follows: clean the spatter generated during the welding of the welding overlay layer weld and the welding slag of the wire on the deposited layer, move the electro - gas welding device to the arc starting plate position, measure the root groove gap and replace the new lining.

[0022] In one embodiment, the relevant inspections include non - destructive inspection and destructive inspection. Non - destructive inspection includes magnetic particle inspection and radiographic inspection. Destructive inspection includes tensile test, bending test, hardness test and macroscopic structure inspection.

[0023] In one embodiment, the electro - gas horizontal welding uses a SC - EGH fine wire with a diameter of 1.4 mm to weld the transverse joint.

[0024] Compared with the prior art, this application has at least the following beneficial effects:

[0025] The large-gap gas-electric horizontal welding automatic welding method of this invention overcomes the shortcomings of existing technologies where gas-electric horizontal welding is only suitable for welding with small assembly gaps, reducing the labor intensity of large-gap welding and improving its efficiency. Automatic gas-electric horizontal welding can automatically control the amount of welding wire filled by the welding machine. This invention applies automatic gas-electric horizontal welding to large-gap welding, avoiding the influence of welder skills on weld quality. When welding large-gap bevels in horizontal positions, this invention first welds a layer of deposit on the lower bevel, then completes the welding of the deposit layer and the upper bevel weld with single-sided welding and double-sided forming, which can significantly reduce the assembly difficulty of related large welded structures. Attached Figure Description

[0026] Figure 1 This is a schematic diagram of the bevel form in the embodiments of this application;

[0027] Figure 2 This is a schematic diagram of the weld bead arrangement in an embodiment of this application;

[0028] Figure 3 This is a distribution diagram of hardness measurement points of the welded specimens in the embodiments of this application;

[0029] Figure 4 This is a schematic diagram of macroscopic inspection of weld seams in an embodiment of this application.

[0030] The specific explanations of the reference numerals in the attached figures are as follows:

[0031] 1: Overlay layer, 2: Filler layer, 3: Workpiece to be welded, 4: Gasket. Detailed Implementation

[0032] To make the objectives, technical solutions, and advantages of this invention clearer, the invention is described below with reference to specific embodiments shown in the accompanying drawings. However, it should be understood that these descriptions are merely exemplary and not intended to limit the scope of the invention. Furthermore, descriptions of well-known structures and technologies are omitted in the following description to avoid unnecessarily obscuring the concept of the invention.

[0033] The terminology used in this disclosure is for the purpose of describing particular embodiments only and is not intended to be limiting of the disclosure. The singular forms “a,” “the,” and “the” as used in this disclosure and the appended claims are also intended to include the plural forms unless the context clearly indicates otherwise. It should also be understood that the term “and / or” as used herein refers to and includes any and all possible combinations of one or more of the associated listed items.

[0034] It should be understood that although the terms first, second, third, etc. may be used in this disclosure to describe various information, such information should not be limited to these terms and should not be construed as indicating or implying relative importance. These terms are only used to distinguish information of the same type from each other. For example, without departing from the scope of this disclosure, the first information may also be referred to as the second information, and similarly, the second information may also be referred to as the first information. Depending on the context, the word "if" as used herein may be interpreted as "when" or "while" or "in response to determining".

[0035] In the description of the present invention, unless otherwise specified and limited, it should be noted that the terms "installation", "connection", and "coupling" should be understood in a broad sense. For example, it may be a mechanical connection, or it may be the communication inside two components. It may be directly connected, or it may be indirectly connected through an intermediate medium. For those of ordinary skill in the art, the specific meanings of the above terms can be understood according to specific circumstances.

[0036] The present invention provides a welding method for large-gap electro-gas horizontal welding. A SC-EGH fine wire with a diameter of 1.4 mm is used to weld the transverse joint. First, a surfacing layer is welded on the downhill groove, and then the surfacing layer and the uphill groove weld are welded with one-side welding and double-side forming. During welding, by selecting reasonable welding process parameters, the performance such as joint forming, tensile bending stress, impact toughness, and hardness of the horizontal welding of the large joint of the hull can be ensured, and welding defects such as porosity, bead edge, slag inclusion, and lack of fusion that are easily caused by manual or semi-automatic welding can be avoided, effectively ensuring the passing rate of the first radiographic inspection and the product acceptance rate, and providing further guarantee for the realization of ship automation.

[0037] In order to better understand the technical solution of the present invention, the present invention will be described in detail below with reference to the accompanying drawings.

[0038] This embodiment provides a welding method for large-gap electro-gas horizontal welding, including the following steps:

[0039] S1. According to the process construction technical indicators, complete the pre-welding preparation work.

[0040] The pre-welding preparation is as follows:

[0041] S11) Select the workpiece to be welded 1: Cut two A-grade steel plates with a length × width × thickness of 1000 × 200 × 15 as the workpiece to be welded 1;

[0042] S12) Groove assembly: The groove form is a single-sided V shape, the uphill groove is 35° and the downhill groove is 0°, without a root face and the root face error L is controlled within 0 - 2 mm. The range of the groove root gap is 11 mm < GAP ≤ 14 mm, and during groove assembly, attention should be paid to the flatness of the plate surface, and the misalignment amount on the back of the weld must be less than 1.5 mm;

[0043] S13) Installation of arc-starting and arc-extinguishing plates: Arc-starting and arc-extinguishing plates are installed at both ends of the weld to prevent defects such as porosity, slag inclusion, and lack of fusion from easily occurring at the beginning and end of the weld during process welding.

[0044] S14) Padding: such as Figure 1 As shown, padding 4 is affixed at the root of the bevel on the back of the steel plate.

[0045] Special attention should be paid to ensuring that the back of the gasket and the steel plate are tightly bonded, and that the joints between the gaskets are pushed together without gaps, to prevent burn-through at the weld joints of the gaskets during the welding process.

[0046] S15) Preparation of gas-electric horizontal welding device: Select a gas-electric horizontal welding slider with a forming groove width of 24mm according to the bevel width. Install the slider at the center of the weld, ensuring that the slider fits tightly with the bevel and that the air vent of the slider is clean and unobstructed. At the same time, adjust the angle and height of the welding torch so that the angle between the welding torch and the horizontal plane is 10°. Control the vertical distance between the top of the welding torch and the lower edge of the protective gas outlet of the slider to 25mm.

[0047] S2. Select appropriate welding process parameters to complete the single-sided welding and double-sided forming welding of the large gap gas-electric horizontal welding cladding layer.

[0048] The specific process parameters for welding the cladding layer are as follows: welding current is 300-330A, welding voltage is 37-40V, welding speed is 15-20cm / min, welding torch oscillation amplitude is 8-10mm, front dwell time is 1s-1.5s, root dwell time is 1s-1.5s, and the welding machine is turned on to complete the welding of the cladding layer.

[0049] S3, Interpass cleaning, completing the pre-welding preparation work again. Interpass cleaning refers to cleaning the spatter generated during the welding process of the weld overlay and the welding wire slag on the overlay. Completing the pre-welding preparation work again refers to moving the gas electric welding device to the arc-starting plate position, measuring the root bevel gap and replacing the new backing 4.

[0050] S4. Select appropriate welding process parameters to complete the single-sided welding and double-sided forming welding of the large gap gas-electric horizontal welding filler layer.

[0051] The specific process parameters for the filler layer are as follows: set the welding current to 300-330A, the welding voltage to 37-40V, the welding speed to 15-20cm / min, the welding torch oscillation amplitude to 8-10mm, the dwell time on the front side to 1-1.5s, the dwell time on the root side to 1-1.5s, and then turn on the welding machine to complete the welding of the filler layer.

[0052] S5. Relevant inspections were performed on the weld, including non-destructive testing (NDT) and destructive testing. NDT included magnetic particle testing and radiographic testing, while destructive testing included tensile testing, bending testing, hardness testing, and macrostructure analysis. The inspection results are shown in Tables 1 and 2.

[0053] Table 1 Mechanical data of 15mm Grade A steel plate

[0054]

[0055] Table 2 Hardness data for 15mm Grade A steel plates

[0056]

[0057] 1) Radiographic testing revealed no defects inside the weld;

[0058] 2) Magnetic particle testing showed no defects on the weld surface;

[0059] 3) According to classification society standards, the transverse tensile strength of the weld is 434 N / mm². 2 and 438N / mm 2 All are higher than the standard value of 400 N / mm 2 It meets the requirements.

[0060] 4) The bending test consisted of four side bending tests, all of which met the requirements.

[0061] 5) The sampling locations for the impact test were the weld center, the fusion line, +2mm outside the fusion line, and +5mm outside the fusion line. The impact energy of the 15mm thick Grade A steel plate was higher than the standard value of 34J, which met the requirements.

[0062] 6) The hardness test is performed using a Vickers hardness tester, typically applying a force of 98 N along the direction of the test. Figure 3 The test points shown were measured. The hardness values ​​of the 15mm thick plate were all below 350HV10, which meets the requirements.

[0063] 7) Macroscopic inspection results show that no welding defects such as cracks, porosity, slag inclusions, or lack of fusion were found in the weld, interface, and heat-affected zone of the sample. Figure 4 As shown, it meets the requirements.

[0064] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit them; although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications can still be made to the specific implementation of the invention or equivalent substitutions can be made to some technical features without departing from the spirit of the technical solutions of the present invention, and all such modifications and substitutions should be covered within the scope of the technical solutions claimed in the present invention.

Claims

1. An automatic welding method for large-gap gas-electric horizontal welding, characterized in that, Includes the following steps: S1. According to the technical specifications of the process construction, complete the pre-welding preparation work. The bevel form is a single-sided V-shape, without leaving a blunt edge and the blunt edge error L is controlled within 0-2mm. The gap GAP at the root of the bevel is 11mm < GAP ≤ 14mm. The upper bevel is 35° and the lower bevel is 0°. When assembling the bevel, attention should be paid to the horizontality of the plate surface. The misalignment on the back of the weld is less than 1.5mm. S2. Select appropriate welding process parameters to complete the welding of the large gap gas-electric horizontal welding cladding layer. The specific process parameters for welding the cladding layer are: welding current of 300-330A, welding voltage of 37-40V, welding speed of 15-20cm / min, welding torch oscillation amplitude of 8-10mm, front dwell time of 1s-1.5s, root dwell time of 1s-1.5s, turn on the welding machine to complete the welding of the cladding layer, and weld a cladding layer on the lower bevel. The upper surface of the cladding layer is at a certain distance from the upper bevel. S3, interpass cleaning, complete the pre-welding preparation work again; S4. Select appropriate welding process parameters to complete the single-sided welding and double-sided forming welding of the large gap gas-electric horizontal welding filler layer. The specific process parameters for the filler layer welding are: welding current of 300-330A, welding voltage of 37-40V, welding speed of 15-20cm / min, welding torch oscillation amplitude of 8-10mm, front dwell time of 1-1.5s, root dwell time of 1-1.5s, and start the welding machine to complete the welding of the filler layer. S5, Perform relevant inspections on the weld.

2. The automatic welding method for large-gap gas-electric horizontal welding according to claim 1, characterized in that, S1 further includes the following steps: S11) Select the workpiece to be welded; S12) Bevel assembly; S13) Installation of the arc extinguishing plate; S14) Gasket mounting; S15) Preparation of gas-electric horizontal welding equipment.

3. The automatic welding method for large-gap gas-electric horizontal welding according to claim 2, characterized in that, Step S15 specifically involves: selecting a gas-electric horizontal welding slider with a forming groove width of 24mm based on the bevel width, installing the slider at the center of the weld, ensuring the slider fits tightly against the bevel, and ensuring the air vent of the slider is clean and unobstructed, while adjusting the welding torch angle and welding torch height.

4. The automatic welding method for large-gap gas-electric horizontal welding according to claim 3, characterized in that, In step S15, the angle between the welding torch and the horizontal plane is 10°, and the vertical distance between the top of the welding torch and the lower edge of the protective gas outlet of the slider is controlled at 25mm.

5. The automatic welding method for large-gap gas-electric horizontal welding according to claim 2, characterized in that, The specific steps of S3 are as follows: cleaning the spatter generated during the welding process of the weld overlay and the welding wire slag on the overlay, moving the gas-electric horizontal welding device to the position of the arc-starting plate, measuring the root bevel gap and replacing the new backing.

6. The automatic welding method for large-gap gas-electric horizontal welding according to claim 1, characterized in that, The relevant tests include non-destructive testing and destructive testing. Non-destructive testing includes magnetic particle testing and radiographic testing, while destructive testing includes tensile testing, bending testing, hardness testing, and macrostructure testing.

7. The automatic welding method for large-gap gas-electric horizontal welding according to claim 1, characterized in that, The gas-electric horizontal welding uses SC-EGH fine welding wire with a diameter of 1.4mm to weld the transverse joint.

Images