One-time forming submerged-arc welding method for butt joint of marine steel thin plates

Abstract

The invention discloses a one-time forming submerged-arc welding method for butt joint of marine steel thin plates, which comprises the following steps of: flatly laying the thin plates needing to be in butt joint on a welding platform, and adjusting a butt gap between the thin plates needing to be in butt joint; welding and fixing run-on plates at the two ends of the weld bead, not forming grooves in the four sides of each run-on plate, and keeping the plate thickness and the material consistent with the base material; a liner is fixed to the back face of the welding bead, the liner is a ceramic liner, a groove is formed in the middle of the ceramic liner in the length direction and located below a welding seam of the steel plate to be welded, and the ceramic liner on the two sides of the groove is tightly attached to the thin plates on the two sides of the welding bead; a submerged arc welding machine walking trolley track is laid on one side of the welding bead, and one end of the welding bead is welded through a welding machine; after welding is completed, welding coatings on the welding front face are removed, ceramic gaskets on the welding back face are removed, and air cooling is conducted for natural temperature; wherein the thickness of the marine steel thin plate is 6-12mm. According to the method, electric arcs are dispersed, heat input is reduced, thermal deformation is reduced, and a welding seam is formed at one time.

Description

Technical Field

[0001] The invention belongs to the technical field of steel plate welding, and in particular relates to a one-step forming submerged arc welding method for butting ship steel thin plates. Background Art

[0002] Submerged arc welding is a welding method in which an electric arc burns under a flux layer. Its inherent advantages, such as stable welding quality, high welding productivity, no arc light and very little smoke, make it the main welding method in the production of important steel structures such as pressure vessels, pipe section manufacturing, box beams and columns.

[0003] With the continuous updating of energy-saving concepts in the international shipbuilding industry, the selection of ship steel plate thickness is increasingly inclined to meet the minimum plate thickness under strength, especially in the construction of car roll-on / roll-off ships, where a large number of 6-10mm thin plates are used in more than a dozen decks. Therefore, the effective control of thin plate welding deformation is a problem that has been troubling domestic peers. The traditional submerged arc welding method for butt joint of steel plates adopts a two-sided welding method. The weld must receive two welding heat inputs, which is prone to large longitudinal deformation of the weld. After the thin plate is deformed, it is difficult to correct it. At the same time, the whole plate needs to be turned over, which is inefficient. In addition, the single-wire submerged arc welding has concentrated arc heat, large welding heat input, and is also prone to thermal deformation. Summary of the invention

[0004] In order to solve the problems existing in the background technology, the purpose of the present invention is to provide a data preprocessing method and system based on the random forest algorithm, which can effectively reduce the dimensionality of high-dimensional data sets by introducing a random contamination matrix, and is particularly suitable for online diagnostic data of power supply equipment with a high proportion of Boolean quantities;

[0005] The present invention adopts the following technical solutions to realize the present invention:

[0006] The one-step submerged arc welding method for butting ship steel thin plates comprises the following steps:

[0007] Lay the thin plates to be butted flat on the welding platform and adjust the gap between the thin plates to be butted;

[0008] The arc-starting plates are welded and fixed at both ends of the weld bead. The four sides of the arc-starting plates are not grooved, and the plate thickness and material are consistent with the parent material;

[0009] A liner is fixed on the back of the weld bead. The liner is a ceramic liner. A groove is provided in the middle of the ceramic liner along the length direction. The groove is located below the weld seam of the steel plate to be welded, and the ceramic liners on both sides of the groove are closely attached to the thin plates on both sides of the weld bead.

[0010] A submerged arc welding machine trolley track is laid on one side of the weld bead, and welding is carried out by the welding machine at one end of the weld bead;

[0011] After welding is completed, remove the welding coating on the front side of the welding, remove the ceramic liner on the back side of the welding, and air cool to natural temperature;

[0012] Among them, the thickness of marine steel sheets is 6 to 12 mm;

[0013] The welding machine adopts double-wire submerged arc welding equipment, selects welding wire with a diameter of 1.6, and controls the welding current within the range of 700-950A.

[0014] Furthermore, before welding and fixing the arc-starting plates at both ends of the weld, the thin plates to be butted against each other need to be fixed.

[0015] Furthermore, when the thin plates to be butted are fixed, manual welding is used to implement electric welding fixation, and the fixing interval is to set a fixing point every 150-200 mm.

[0016] Furthermore, the welding machine adopts a double-wire submerged arc welding machine with a welding wire diameter of 1.6 mm.

[0017] Furthermore, after laying the thin plates to be butt-jointed on the welding platform, it is necessary to check whether the joints meet the welding requirements. If not, re-grinding is required.

[0018] Furthermore, when adjusting the butt gap between the thin plates to be butted, the gap amount is controlled between 1.5 and 2 mm.

[0019] The beneficial technical effects of the present invention are:

[0020] The welding method of the present invention utilizes double-wire submerged arc welding equipment, selects welding wire with a diameter of 1.6, and controls the welding current within the range of 700 to 950A. This not only solves the problem of arc heat concentration, but also improves the problem of large welding heat input and reduces the restraint stress generated by welding. At the same time, the method of attaching a ceramic liner on the back also solves the problems of welding deformation and welding stress caused by two weldings. The welding method disperses the arc, reduces heat input, reduces thermal deformation, and allows the weld to be formed in one step. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 A schematic diagram of laying steel plates on a welding platform and adjusting the gap provided by an embodiment of the present invention;

[0022] Figure 2 A schematic diagram of a fixed welding bead provided by an embodiment of the present invention;

[0023] Figure 3 A schematic diagram of fixing an arc-starting plate provided in an embodiment of the present invention;

[0024] Figure 4 A schematic diagram of placing a ceramic liner provided in an embodiment of the present invention;

[0025] Figure 5 for Figure 4 AA cross-sectional diagram of ;

[0026] Figure 6 A schematic diagram of a submerged arc welding device provided by an embodiment of the present invention during welding with a welding gun;

[0027] Figure 7 for Figure 6 AA cross-sectional diagram of ;

[0028] Figure 8 Schematic diagram of welding wire position provided by the embodiment of the present invention;

[0029] Fig. 9 A schematic diagram of a welded marine steel sheet provided in an embodiment of the present invention. DETAILED DESCRIPTION

[0030] The invention discloses a one-step forming submerged arc welding method for butting ship steel thin plates. Figures 1 to 8 As shown, the specific operation steps of welding the steel plate 1 are as follows:

[0031] First, Figure 1 As shown, first lay the steel plate 1 to be butted flat on the welding platform to check whether the joint meets the welding requirements. If not, it needs to be re-grinded; specifically, it is necessary to check whether the joint is flat and straight, and if necessary, re-grind;

[0032] Setting the gap: According to the actual plate thickness, adjust the butt gap 6 between the steel plates 1 to be butted to form a weld bead 9, and the gap amount is controlled between 1.5 and 2 mm.

[0033] Electric welding fixation: according to Figure 2 As shown, the weld 9 is manually welded to form the positioning weld 7, and the positioning welding spacing is 150 to 200 mm;

[0034] Apply arc-starting plate: Figure 3 As shown, the arc-starting plate 3 is welded and fixed at both ends of the weld 9. The width and length of the arc-starting plate 3 are required to be 300mm×300mm, and the thickness is the same as the thickness of the welding base material. A groove with a width of 10 to 15mm, a length of 100mm, and a thickness of 50% of the plate thickness is opened on the arc-starting plate near the weld end.

[0035] Fixed pad: As Figure 4 , 5 As shown, a ceramic liner 2 is fixed on the back of the weld 9: the ceramic liner 2 is centered and pressed against both sides of the weld, and the liner is pressed hard at the pasting position to fix it on the steel plate; it should be noted that a groove is provided in the middle of the ceramic liner along the length direction, the groove is below the weld seam of the steel plate to be welded, and the ceramic liners on both sides of the groove are pressed against the thin plates on both sides of the weld;

[0036] Welding: Figure 6 , 7 As shown, a submerged arc welding machine trolley track is laid on one side of the weld bead 9. The welding machine adopts a double-wire submerged arc welding device, and a double-wire submerged arc welding machine 4 with a welding wire diameter of 1.6 mm is adopted. The welding current is controlled within the range of 700 to 950 A, and the welding gun 5 is extended into the weld bead 9. According to the actual situation of the gap of the weld bead 9, the position of the welding wire 8 is adjusted up and down, left and right, and the flux is piled up and adjusted to the appropriate specification, as shown in Table 1, and welding is carried out from one end of the weld bead 9;

[0037] Welding process adjustment: such as Figure 8 As shown, according to the movement of the welding machine 4, the transmission of the welding wire 8, and the feeding of the flux during the welding process, the wire feeding speed, welding current and voltage are adjusted in time;

[0038] Post-weld treatment: After welding is completed, remove the welding coating on the front side of the weld, remove the ceramic liner 2 on the back side of the weld, and air cool to natural temperature.

[0039] Weld seam forming: Fig. 9 As shown, the weld is straight, smooth, and has a metallic luster. The weld is beautifully formed and has good weld quality, which solves the quality problems of difficult to control welding deformation, excessive weld excess height, and excessive weld width caused by large heat output during double-sided welding with large diameter welding wire.

[0040] The one-step submerged arc welding method for butting ship steel thin plates in this embodiment has the following specific welding operation methods and parameters:

[0041] 1. Connector type: Type I

[0042] 2. Welding method: SAW (automatic submerged arc welding)

[0043] 3. Parent material

[0044] Material grade: Marine Grade A plate

[0045] Material specification: 1000mmX300mmX6mmX2

[0046] 4. Filler Metal

[0047] Filler metal grade: H10Mn2

[0048] Filler metal specification: φ=1.6mm

[0049] 5. Flux protection

[0050] Flux brand: SJ101

[0051] 6. Ceramic liner: TC-1

[0052] 7. Welding type: flat butt

[0053] 8. Single-sided welding or double-sided welding: Single-sided welding

[0054] 9. Is the back cleaned: No

[0055] 10. Welding position: flat welding

[0056] 11. Preheating: No preheating required

[0057] 12. Single or multiple channels: Single channel

[0058] Specific welding parameters are shown in the following table:

[0059]

[0060]

[0061] So far, the technical solutions of the present invention have been described in conjunction with the preferred embodiments shown in the accompanying drawings. However, it is easy for those skilled in the art to understand that the protection scope of the present invention is obviously not limited to these specific embodiments. Without departing from the principle of the present invention, those skilled in the art can make equivalent changes or substitutions to the relevant technical features, and the technical solutions after these changes or substitutions will fall within the protection scope of the present invention.

Claims

1. A one-step submerged arc welding method for butting ship steel sheets, characterized in that: The steps include: Lay the thin plates to be butted flat on the welding platform and adjust the gap between the thin plates to be butted; The arc-starting plates are welded and fixed at both ends of the weld bead. The four sides of the arc-starting plates are not grooved, and the plate thickness and material are consistent with the parent material; A liner is fixed on the back of the weld bead. The liner is a ceramic liner. A groove is provided in the middle of the ceramic liner along the length direction. The groove is located below the weld seam of the steel plate to be welded, and the ceramic liners on both sides of the groove are closely attached to the thin plates on both sides of the weld bead. A submerged arc welding machine trolley track is laid on one side of the weld bead, and welding is carried out by the welding machine at one end of the weld bead; After welding is completed, remove the welding coating on the front side of the welding, remove the ceramic liner on the back side of the welding, and air cool to natural temperature; Among them, the thickness of marine steel sheets is 6 to 12 mm; The welding machine adopts double-wire submerged arc welding equipment, selects welding wire with a diameter of 1.6, and controls the welding current within the range of 700-950A.

2. The one-step submerged arc welding method for butting ship steel sheets according to claim 1 is characterized in that: Before welding and fixing the arc-starting plates at both ends of the weld, the thin plates to be butt-jointed need to be fixed.

3. The one-step submerged arc welding method for butting ship steel sheets according to claim 2 is characterized in that: When fixing the thin plates to be butt-jointed, manual welding is used for electric welding, and the fixing spacing is to set a fixing point every 150-200mm.

4. The one-step submerged arc welding method for butting ship steel sheets according to claim 1 is characterized in that: The welding machine adopts a double-wire submerged arc welding machine with a welding wire diameter of 1.6 mm.

5. The one-step submerged arc welding method for butting ship steel sheets according to claim 1 is characterized in that: After laying the thin plates to be joined flat on the welding platform, it is necessary to check whether the joints meet the welding requirements. If not, they need to be reground.

6. The one-step submerged arc welding method for butting ship steel sheets according to claim 1 is characterized in that: When adjusting the gap between the thin plates to be butt-jointed, the gap should be controlled between 1.5 and 2 mm.

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