Automatic welding method for large-gap electro-gas horizontal position welding

Abstract

The invention discloses an automatic welding method for large-gap electro-gas horizontal position welding. The automatic welding method comprises the following steps that S1, pre-welding preparation work is completed; s2, reasonable welding process parameters are selected, and single-face welding and double-face forming welding of the large-gap electro-gas horizontal position welding stack covering layer is completed; s3, interpass cleaning is conducted, and the pre-welding preparation work is completed again; s4, reasonable welding process parameters are selected, and single-face welding and double-face forming welding of the large-gap electro-gas horizontal position welding filling and covering layer is completed; and S5, carrying out related detection on the welding seam. The defect that electro-gas horizontal position welding is only suitable for welding with the small assembly gap width is overcome, the labor intensity of large-gap welding is reduced, the efficiency and the welding quality of large-gap welding are improved, and the assembly difficulty of a large welding structure is reduced.

Description

Technical Field

[0001] The invention relates to the technical field of hull seam welding, in particular to a large-gap gas-electric horizontal welding automatic welding method. Background Art

[0002] Gas-electric vertical welding is an efficient automatic welding technology with stable quality. For example, Chinese patent CN112453650A discloses a gas-electric welding process for transverse butt seams of hulls, which is used to weld workpieces with a gap width of 6-7mm. In the actual shipbuilding process, it is inevitable that the semi-automatic cutting knife will correct the groove and the segmented precision control will not meet the welding process requirements. For example, large gaps greater than 10mm will appear at the root, and the existing gas-electric vertical welding process cannot complete the large gap welding task. At present, the only way to solve the root large gap welding task on site is to use CO2 semi-automatic welding "growing meat" and then welding. This method is affected by the welder's skills, and often has defects such as incomplete penetration and incomplete fusion. It is difficult to ensure the quality of the weld, and the welding efficiency is low and the labor intensity is high. Summary of the invention

[0003] In view of the defects existing in the prior art, the present application provides a large-gap gas-electric horizontal welding automatic welding method to solve the technical problems existing in the prior art of large-gap welding methods such as poor welding quality, low welding efficiency, and high labor intensity.

[0004] In order to achieve the purpose of the above invention, the technical solution provided by the present invention is as follows:

[0005] A large gap gas-electric horizontal welding automatic welding method comprises the following steps:

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

[0007] S2, select reasonable 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 of the cladding layer welding are: welding current is 300-330A, welding voltage is 37-40V, welding speed is 15-20cm / min, welding gun swing 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;

[0008] S3, interpass cleaning, completing 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 filling 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: the welding current is set to 300 - 330 A, the welding voltage is 37 - 40 V, the welding speed is 15 - 20 cm / min, the oscillation amplitude of the welding torch is 8 - 10 mm, the front dwell time is 1 - 1.5 s, the root dwell time is 1 - 1.5 s, and the welding machine is turned on 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 striking 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 a 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 during groove assembly, the flatness of the plate surface needs to be noted, 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 welding torch angle and the welding torch height.

[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 welded overlay layer weld and the welding wire slag on the deposited layer, move the electro - gas welding device to the arc - striking 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 macro - structure inspection.

[0023] In one embodiment, the electro - gas horizontal welding uses an SC - EGH fine welding 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 the present invention makes up for the defect that the gas-electric horizontal welding in the prior art is only suitable for welding with a smaller assembly gap width, reduces the labor intensity of large-gap welding, and improves the efficiency of large-gap welding; the gas-electric horizontal welding automatic welding can automatically control the filling amount of welding wire by the welding machine. The present invention applies the gas-electric horizontal welding automatic welding to large-gap welding, avoiding the influence of welder skills on weld quality; when the method of the present invention is used for horizontal large-gap groove welding, first a deposition layer is welded on the lower groove, and then the deposition layer and the upper groove weld are welded single-sided and double-sided, which can greatly reduce the assembly difficulty of related large-scale welding structures. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 This is a schematic diagram of the groove form in the embodiment of the present application;

[0027] Figure 2 It is a schematic diagram of the arrangement of weld seams and weld passes in an embodiment of the present application;

[0028] Figure 3 is a distribution diagram of hardness measurement points of welding specimens in the embodiment of the present application;

[0029] Figure 4 It is a schematic diagram of macroscopic detection of welds in an embodiment of the present application.

[0030] The specific description of the reference numerals is as follows:

[0031] 1: Overlay layer, 2: Filling layer, 3: Workpiece to be welded, 4: Backing. DETAILED DESCRIPTION

[0032] In order to make the purpose, technical scheme and advantages of the present invention clearer, the present invention is described below by the specific embodiments shown in the accompanying drawings. However, it should be understood that these descriptions are only exemplary and are not intended to limit the scope of the present invention. In addition, in the following description, the description of well-known structures and technologies is omitted to avoid unnecessary confusion of the concept of the present invention.

[0033] The terms used in this disclosure are for the purpose of describing specific embodiments only and are not intended to limit the disclosure. The singular forms of "a", "said" and "the" used in this disclosure and the appended claims are also intended to include plural forms unless the context clearly indicates otherwise. It should also be understood that the term "and / or" used herein refers to and includes any or all possible combinations of one or more 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 a determination".

[0035] In the description of the present invention, unless otherwise specified and defined, 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 gas-electric 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 both-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 large joint horizontal welding of the hull can be guaranteed, and welding defects such as porosity, undercut, slag inclusion, and lack of fusion that are easily caused by manual or semi-automatic welding can be avoided, effectively ensuring the one-time radiographic pass rate and product acceptance rate, and providing further guarantee for the realization of ship automation.

[0037] 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 gas-electric 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-class 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 leaving a root face and the root face error L is controlled within 0-2 mm. The groove root gap range is 11 mm < GAP ≤ 14 mm, and when assembling the groove, the flatness of the plate surface needs to be noted, and the misalignment amount on the back of the weld must be less than 1.5 mm;

[0043] S13) Installation of arc-initiating and arc-extinguishing plates: Arc-initiating and arc-extinguishing plates are installed at both ends of the weld to prevent defects such as pores, slag inclusions, and lack of fusion from easily appearing at both ends of the weld during process welding;

[0044] S14)Pad installation: Figure 1 As shown, a liner 4 is pasted at the root of the groove on the back of the steel plate.

[0045] Special attention should be paid to ensure that the backing of the gasket and the back of the steel plate are tightly bonded, and that the joints between the gaskets are pushed against each other without any gaps, so as to prevent the welds at the joints between the gaskets from being penetrated 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 groove width, install the slider to the center of the weld, make the slider fit tightly against the groove, and ensure that the slider vent is clean and unobstructed. At the same time, adjust the welding gun angle and welding gun height so that the angle between the welding gun and the horizontal plane is 10°, and the vertical distance between the top of the welding gun and the bottom edge of the slider protective gas outlet is controlled at 25mm.

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

[0048] The specific process parameters of the overlay layer welding are: welding current is 300-330A, welding voltage is 37-40V, welding speed is 15-20cm / min, welding gun swing 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 overlay layer.

[0049] S3, inter-pass cleaning, re-completing the pre-welding preparation work, inter-pass cleaning refers to cleaning the spatter generated during the welding process of the welding overlay weld and the welding wire slag on the overlay, re-completing the pre-welding preparation work means moving the gas-electric welding device to the arc-starting plate position, measuring the root groove gap and replacing a new gasket 4.

[0050] 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 filling layer.

[0051] The specific process parameters of the filling layer are: set the welding current to 300-330A, the welding voltage to 37-40V, the welding speed to 15-20cm / min, the welding gun swing amplitude to 8-10mm, the front dwell time to 1-1.5s, the root dwell time to 1-1.5s, and start the welding machine to complete the welding of the filling layer.

[0052] S5, perform relevant tests on the weld, including non-destructive testing and destructive testing. Non-destructive testing includes magnetic particle testing and radiographic testing, and destructive testing includes tensile testing, bending testing, hardness testing and macroscopic structural testing. The test results are shown in Tables 1 and 2.

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

[0054]

[0055] Table 2 15mm A-grade steel plate hardness data

[0056]

[0057] 1) There are no defects inside the weld after radiographic inspection;

[0058] 2) There are no defects on the weld surface after magnetic particle inspection;

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

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

[0061] 5) The sampling positions for the impact test are respectively at the center of the weld, the fusion line, +2mm outside the fusion line, and +5mm outside the fusion line. The impact energy of the grade A steel plate with a thickness of 15mm is higher than the standard value of 34J, which meets the requirements.

[0062] 6) The hardness test is performed using a Vickers hardness tester, usually applying a force of 98N. Figure 3 The test points shown in the figure show that the hardness values ​​of the 15mm thick plate are all lower than 350HV10, which meets the requirements.

[0063] 7) The macroscopic inspection results show that no welding defects such as cracks, pores, slag inclusions, and 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 solution of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the preferred embodiments, ordinary technicians in the field should understand that the specific implementation methods of the invention can still be modified or some technical features can be replaced by equivalents without departing from the spirit of the technical solution of the present invention, which should be included in the scope of the technical solution for protection of the present invention.

Claims

1. A large gap gas-electric horizontal welding automatic welding method, characterized in that: It includes the following steps: S1. Complete the pre-welding preparation work according to the process construction technical indicators; S2. Select reasonable welding process parameters to complete the single-sided welding with double-sided forming of the surfacing layer by large-gap gas-electric horizontal welding. The specific process parameters for surfacing layer welding are as follows: welding current is 300 - 330A, welding voltage is 37 - 40V, welding speed is 15 - 20 cm / min, the swing amplitude of the welding torch is 8 - 10 mm, the front stay time is 1 s - 1.5 s, the root stay time is 1 s - 1.5 s, and turn on the welding machine to complete the welding of the surfacing layer; S3. Clean between passes and complete the pre-welding preparation work again; S4. Select reasonable welding process parameters to complete the single-sided welding with double-sided forming of the filling layer by large-gap gas-electric horizontal welding; S5. Conduct relevant inspections on the weld.

2. The large gap gas-electric horizontal welding automatic welding method according to claim 1 is characterized in that: The specific process parameters of the filling layer in S4 are as follows: set the welding current to 300 - 330A, welding voltage to 37 - 40V, welding speed to 15 - 20 cm / min, the swing amplitude of the welding torch to 8 - 10 mm, the front stay time to 1 - 1.5 s, the root stay time to 1 - 1.5 s, and turn on the welding machine to complete the welding of the filling layer.

3. The large gap gas-electric horizontal welding automatic welding method according to claim 1 is characterized in that: S1 further includes the following steps: S11) Select the workpiece to be welded; S12) Groove assembly; S13) Installation of the arc starting and extinguishing plates; S14) Lining pasting; S15) Preparation of the gas-electric horizontal welding device.

4. The large gap gas-electric horizontal welding automatic welding method according to claim 3 is characterized in that: The groove assembly in S12: The groove form is single-sided V-shaped, the upper groove is 35° and the lower groove 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, the flatness of the plate surface needs to be noted, and the misalignment amount on the back of the weld is less than 1.5 mm.

5. The large gap gas-electric horizontal welding automatic welding method according to claim 4 is characterized in that: The specific steps of S15 are as follows: Select a gas-electric 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 welding torch angle and the height of the welding torch.

6. The large gap gas-electric horizontal welding automatic welding method according to claim 5 is characterized in that: 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 at 25 mm.

7. The large gap gas-electric horizontal welding automatic welding method according to claim 1 is characterized in that: The specific steps of S3 are as follows: Clean the spatter generated during the welding of the welding surfacing layer weld and the welding wire slag on the surfacing layer, move the gas-electric welding device to the arc starting plate position, measure the root groove gap and replace the new lining.

8. The large gap gas-electric horizontal welding automatic welding method according to claim 1 is characterized in that: 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 macrostructure inspection.

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

Images