Railway vehicle stainless steel sheet wide gap welding process based on arc breaking and rewelding

Abstract

The application discloses a kind of based on arc breaking back-off stainless steel sheet wide gap welding process method of rail vehicle, including S1, stainless steel sheet group interval control, and the stainless steel sheet of welding joint side is carried out and is opened groove treatment and blunt edge treatment;S2, the welding parameter adjustment of gas shielded welding;S3, stainless steel sheet is welded using arc breaking back-off welding.The welding process method of the application can solve the problem of directly completing welding when encountering the case that the thickness of stainless steel sheet is 3-4mm group interval is large, flat welding position, i.e. European standard is PA position;American welding standard is 1G (F) position, solve the problem of waste caused by re-feeding when welding joint appears group interval is large in prior art, and the problem of cycle extension and workload increase caused by lengthening material piece on-site research and development.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of stainless steel sheet welding of rail vehicles, and particularly relates to a rail vehicle stainless steel sheet wide gap welding process method based on arc breaking and rewelding. BACKGROUND

[0002] In the body and each major component of a stainless steel rail vehicle, especially the major component of the underframe, many structures adopt 3-4mm stainless steel sheets. In the process of assembling and butt welding of the material pieces, in order to ensure the overall size of the body and the major component, the gap between the welding joints of the assembled material pieces often exceeds the standard gap. The main method to solve this problem is to lengthen the material pieces, re-feed, or lengthen the material pieces in advance, and cut and adjust the gap between the welding joints on site during the construction process. Such a welding process not only wastes materials, but also increases the labor intensity.

[0003] Therefore, based on the above technical problems, the technical personnel in the field urgently need to develop a rail vehicle stainless steel sheet wide gap welding process method based on arc breaking and rewelding. SUMMARY

[0004] The purpose of the present application is to provide a rail vehicle stainless steel sheet wide gap welding process method based on arc breaking and rewelding, which mainly solves the problem that the welding can be directly completed when the gap between the assembled stainless steel 3-4mm sheets is large.

[0005] In order to achieve the above purpose, the present application provides the following technical scheme:

[0006] The rail vehicle stainless steel sheet wide gap welding process method based on arc breaking and rewelding mainly includes the following steps:

[0007] S1, control the gap between the assembled stainless steel sheets, and perform opening groove processing and edge blunting processing on one side of the stainless steel sheet of the welding joint;

[0008] S2, adjust the welding parameters of the gas shielded welding;

[0009] S3, use arc breaking and rewelding to weld the stainless steel sheet.

[0010] Further, in the step S1, the thickness of the stainless steel sheet is 3-4mm;

[0011] The control of the gap between the assembled stainless steel sheets is 4-6mm;

[0012] The plate on one side of the welding joint is provided with a half V-shaped groove, and the opening angle of the groove is 45°. The bottom of the plate provided with the half V-shaped groove is provided with an edge, and the width of the edge is 0.5-1mm.

[0013] Furthermore, the misalignment between the two stainless steel sheet assemblies shall not exceed 0.5mm.

[0014] Furthermore, in step S2, the control of welding parameters for gas shielded welding mainly includes:

[0015] The welding environment temperature for the stainless steel sheet assembly is not lower than 5°C, and there is no draft at the welding site.

[0016] The gas shielded welding uses a welding current of 200~220A, a welding voltage of 20~25V, a welding speed of 40~50cm / min, and adopts a DC reverse polarity method, jet transfer and non-pulse current.

[0017] The shielding gas for the gas shielded welding consists of 97% Ar and 3% O2, with a gas flow rate of 18 L / min.

[0018] The welding wire used in the gas shielded welding is made of 309LSi and has a diameter of 1.0 mm.

[0019] Furthermore, the gas-shielded welding torch is angled at 80° to the weld bead for welding stainless steel sheets.

[0020] Furthermore, the welding sequence in step S3 mainly includes:

[0021] S301. First, the arc is started on the side of the stainless steel sheet without a blunt edge, and the arc is pulled laterally to the side of the half-V bevel. After the molten pool of deposited metal is formed, the welding gun is lifted to cut off the arc.

[0022] S302. Observe the color of the molten pool. When the molten iron changes from dark red to dark red, start arc welding at the rear 1 / 3 of the previous deposited metal. Cut off the arc after the deposited metal forms a molten pool.

[0023] S303. Repeat steps S301 and S302 until the welding of the entire weld joint is completed.

[0024] In the above technical solution, the present invention provides a wide-gap welding process for stainless steel thin plates for rail vehicles based on arc-interrupted back welding, which has the following beneficial effects:

[0025] The welding process of this invention can solve the problem of directly completing welding when encountering stainless steel thin plates with a thickness of 3-4mm and a large gap between the assembly parts. It also solves the problems in the prior art where the gap between the assembly parts is large and exceeds the standard gap, resulting in waste caused by re-feeding materials and increased workload due to the extension of the cycle caused by on-site preparation of longer materials. Attached Figure Description

[0026] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in this invention. For those skilled in the art, other drawings can be obtained based on these drawings.

[0027] Figure 1 This is a schematic diagram of the assembly structure of stainless steel sheet in a wide-gap welding process for stainless steel sheet of rail vehicles based on arc-breaking back welding, as disclosed in an embodiment of the present invention.

[0028] Figure 2 This is a schematic diagram of the welding sequence of the arc-breaking back welding method for wide-gap welding of stainless steel thin plates for rail vehicles, as disclosed in an embodiment of the present invention.

[0029] Explanation of reference numerals in the attached figures:

[0030] 1. Stainless steel sheet; 2. Weld bead;

[0031] 101. Half-V bevel; 102. Obtuse edge. Detailed Implementation

[0032] To enable those skilled in the art to better understand the technical solution of the present invention, the present invention will be further described in detail below with reference to the accompanying drawings.

[0033] See Figures 1-2 As shown;

[0034] This embodiment presents a wide-gap welding process for stainless steel thin plates used in rail vehicles based on arc-interrupted back-welding. The welding process mainly includes the following steps:

[0035] S1. Stainless steel sheet 1 is used for gap control, and the stainless steel sheet 1 on the welded joint side is beveled and blunted 102.

[0036] S2. Adjustment of welding parameters for gas shielded welding;

[0037] S3. Weld the stainless steel sheet 1 using intermittent arc back welding.

[0038] Specifically, this embodiment discloses a welding process for wide gaps in stainless steel thin plates for rail vehicles based on arc-breaking back welding. It mainly includes controlling the gap of stainless steel thin plate 1 group, and beveling and blunt edge 102 treatment on one side of the stainless steel thin plate 1; secondly, controlling the welding parameters of gas shielded welding; and finally, performing arc-breaking back welding treatment on stainless steel thin plate 1.

[0039] Preferably, in step S1 of this embodiment, the thickness of the stainless steel sheet 1 is 3-4 mm;

[0040] The assembly gap of stainless steel sheet 1 is controlled to be 4-6mm;

[0041] The plate on one side of the welded joint has a semi-V-shaped groove 101 with an opening angle of 45°. The bottom of the plate with the semi-V-shaped groove 101 has a blunt edge 102 with a width of 0.5~1mm.

[0042] In step S1 of this embodiment, the misalignment of the two stainless steel sheets in group 1 does not exceed 0.5mm.

[0043] Preferably, in step S2 of this embodiment, the control of welding parameters for gas shielded welding mainly includes:

[0044] The welding environment temperature for welding one group of stainless steel sheets shall not be lower than 5℃, and there shall be no draft in the welding site.

[0045] The welding current for gas shielded welding is 200~220A, the welding voltage is 20~25V, the welding speed is 40~50cm / min, and a DC reverse polarity method is used, with jet transfer and non-pulsed current.

[0046] The shielding gas for gas shielded welding consists of 97% Ar and 3% O2, with a gas flow rate of 18 L / min.

[0047] The welding wire material for gas shielded welding is 309LSi, and the diameter of the welding wire is 1.0mm.

[0048] See Figure 2 As shown, in this embodiment, the gas shielded welding torch is at an 80° angle to the weld bead for welding the stainless steel sheet 1.

[0049] Preferably, the welding sequence in step S3 of this embodiment mainly includes:

[0050] S301. First, the welding arc is started on the side of the stainless steel sheet 1 without the blunt edge, and the arc is pulled laterally to the side of the half-V groove 101. After the molten pool of deposited metal is formed, the welding gun is lifted to cut off the arc.

[0051] S302. Observe the color of the molten pool. When the molten iron changes from dark red to dark red, start arc welding at the rear 1 / 3 of the previous deposited metal. Cut off the arc after the deposited metal forms a molten pool.

[0052] S303. Repeat steps S301 and S302 until the welding of the entire weld joint is completed.

[0053] In the above technical solution, the present invention provides a wide-gap welding process for stainless steel thin plates for rail vehicles based on arc-interrupted back welding, which has the following beneficial effects:

[0054] The welding process of the present invention can solve the problem of directly completing welding when encountering stainless steel thin plates with a thickness of 3-4mm and a large gap between the assembly. It also solves the problems in the prior art where the gap between the assembly of the welded joint is large and exceeds the standard gap, resulting in waste caused by re-feeding materials and the problem of extending the cycle and increasing the workload caused by on-site preparation of lengthened materials.

[0055] The foregoing has only described certain exemplary embodiments of the present invention by way of illustration. Undoubtedly, those skilled in the art can modify the described embodiments in various ways without departing from the spirit and scope of the present invention. Therefore, the foregoing drawings and descriptions are illustrative in nature and should not be construed as limiting the scope of protection of the claims of the present invention.

Claims

1. A wide-gap welding process for thin stainless steel plates in rail vehicles based on arc-interrupted back-welding, characterized in that, The welding process includes the following steps: S1. Stainless steel sheet (1) assembly gap control, and beveling and blunt edge (102) treatment of stainless steel sheet (1) on the side of the welded joint. S2. Adjustment of welding parameters for gas shielded welding; S3. Welding of stainless steel sheet (1) using arc-breaking back welding; The welding sequence in step S3 includes: S301. First, the arc is started on the side of the stainless steel sheet (1) without the blunt edge, and the arc is pulled laterally to the side of the half-V groove (101). After the molten pool of deposited metal is formed, the welding gun is lifted to cut off the arc. S302. Observe the color of the molten pool. When the molten iron changes from dark red to dark red, start arc welding at the rear 1 / 3 of the previous deposited metal. Cut off the arc after the deposited metal forms a molten pool. S303. Repeat steps S301 and S302 until the welding of the entire weld joint is completed.

2. The wide-gap welding process for stainless steel thin plates in rail vehicles based on arc-interrupted back-welding as described in claim 1, characterized in that, In step S1, the thickness of the stainless steel sheet (1) is 3-4 mm; The assembly gap of the stainless steel sheet (1) is controlled to be 4-6 mm; The plate on one side of the welded joint has a semi-V-shaped bevel (101) with an opening angle of 45°. The bottom of the plate with the semi-V-shaped bevel (101) has a blunt edge (102) with a width of 0.5~1mm.

3. The wide-gap welding process for stainless steel thin plates in rail vehicles based on arc-interrupted back-welding as described in claim 2, characterized in that, The misalignment of the two stainless steel sheets (1) should not exceed 0.5mm.

4. The wide-gap welding process for stainless steel thin plates in rail vehicles based on arc-interrupted back-welding as described in claim 2, characterized in that, In step S2, the control of welding parameters for gas shielded welding includes: The welding environment temperature for the stainless steel sheet assembly is not lower than 5°C, and there is no draft at the welding site. The gas shielded welding current is 200~220A, the welding voltage is 20~25V, and the welding speed is 40~50cm / min; The shielding gas for the gas shielded welding consists of 97% Ar and 3% O2, with a gas flow rate of 18 L / min. The welding wire used in the gas shielded welding is made of 309LSi and has a diameter of 1.0 mm.

5. The wide-gap welding process for stainless steel thin plates in rail vehicles based on arc-interrupted back-welding as described in claim 4, characterized in that, The gas shielded welding torch is at an 80° angle to the weld bead for welding stainless steel sheet (1).

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