CN111360380B - A high-speed rotary submerged arc welding method for thin plates - Google Patents

Abstract

The invention discloses a rotating submerged arc high-speed welding method for a thin plate, which comprises the following steps: the assembled thin plates to be welded are pressed on a welding backing plate along the welding direction, then welding flux and welding wires matched with the thin plates to be welded are selected according to the materials of the thin plates to be welded, a rotary submerged-arc welding method and technological parameters are set according to the plate thickness and the groove form of the thin plates to be welded, finally the welding flux is laid along the welding direction at the welding starting position, welding electric arcs are ignited, a rotary submerged-arc welding torch is controlled to drive the welding electric arcs to rotate at a constant speed in the welding flux according to the set rotating speed and direction, and meanwhile, a dragging mechanism drives the whole rotary submerged-arc welding torch to move towards the front of welding, so that the rotary submerged-arc high-speed welding of the thin plates is realized. The invention has low implementation cost, can obviously improve the welding speed of single-welding-wire electric arc and reduce the welding assembly requirement, and is particularly suitable for thin plate welding occasions.

Description

A high-speed rotary submerged arc welding method for thin plates

technical field

The invention relates to the technical field of welding, in particular to a rotary submerged arc high-speed welding method for thin plates.

Background technique

Aiming at the thin plate welding widely used in locomotives, ships and other thin-walled parts, the commonly used automatic welding methods include melting electrode (or non-melting electrode) gas shielded welding, laser welding, friction stir welding, etc. Among them, conventional melting electrode (or non-melting electrode) gas shielded welding has low implementation cost, but requires high welding heat input control; laser welding has fast welding speed, but high assembly requirements, complex welding system and high price; friction stir welding The welding position is limited, the material of the stirring needle is special, and the performance requirements are high.

The Chinese invention patent number is "ZL201310387751.9" and the name is "laser welding method and fixture for fillet weld of stainless steel sheet" discloses a copper fixture with an included angle of 90° and the action of 4-way coaxial shielding gas The laser welding connection of 0.7mm thick stainless steel fillet weld is realized under the laser, the laser output power is 1000~2000W, the welding speed is 2~6m/min, the protective gas flow rate is 5~10L/min, and the defocus amount is +15~+25mm. Although this technology realizes high-speed welding of stainless steel sheets, the fixtures used in the implementation process are complex, and CCD sensors need to be used to teach positioning at the welding start and end positions, and the welding parameters need to be strictly controlled according to the laser spot position. The method is complex in system, high in cost and inconvenient to implement.

The Chinese invention patent number is "ZL20131073066.6" and the name is "Arcless rapid welding method of stainless steel sheet" discloses a method of using 1.2mm thin welding wire and granular alkaline sintering flux to realize the welding of 4-6mm thick austenite Arcless welding method of stainless steel sheet, the welding voltage is 34-36V, the welding current is 190-260A, the welding speed is 660-840mm/min, and the welding heat input is 4.6-8.5kJ/cm. This technology is only suitable for 4-6mm thick austenitic stainless steel sheet, and the scope of application is small; it needs to use special flux and strictly clean the welding workpiece, so its practicability is not strong; compared with the laser welding method, the welding speed of this method is much lower, so Applications are subject to certain restrictions.

The Chinese invention patent number is "201511017320.9" and the title is "a method for improving the performance of thin-plate friction stir welded joints", which discloses a method of preparing butt welding plates and auxiliary plates by machining methods, and strictly assembling and fixing them before welding. The appropriate size stirring head realizes the friction stir welding connection of 2-6mm thick butt welding plates. The rotation speed of the stirring head is 500-3000r/min, the lowering speed is 5-50mm/min, and the depth of the shaft shoulder pressing into the workpiece is 0.1-0.8mm , Welding speed 200 ~ 1000mm/min. This technology solves the problem of low load-carrying capacity of the stir-plate friction welding joint, and also improves the welding tooling to a certain extent. However, in general, the implementation process of this method is complicated, the requirements for the preparation of the welding plate, the pre-welding assembly, the material and size of the stirring head are high, and the welding speed is relatively slow.

Rotary arc welding is a welding method in which the ignited welding arc rotates at a certain frequency and high speed around the axis of the welding torch by mechanical or electromagnetic drive. It was first developed by Japanese experts for fillet welding and thick plate narrow gap welding. After the arc rotates, its thermal action range becomes wider, thereby reducing the requirements for the workpiece assembly gap, and at the same time, it can also increase the melting speed of the welding wire and stir the molten metal in the molten pool to promote grain refinement. At present, most of the conventional rotating arcs are MIG/MAG welding, which has strong arc radiation, high welding wire current density, and is easily affected by the environmental wind speed, and the speed of single-wire rotating arc welding is limited. In addition, the existing submerged arc welding mostly uses welding wires with a diameter larger than 3 mm, which has large welding heat input and high deposition efficiency, but for thin plate workpieces, welding penetration defects are prone to occur during the implementation of this method. To sum up, the prior art fails to achieve low-cost, high-speed welding of thin plates.

SUMMARY OF THE INVENTION

The purpose of the present invention is to solve the problems of low welding efficiency, complicated welding method and expensive welding equipment, and comprehensively utilize the low requirements for groove assembly of rotating arc welding and the deposition efficiency of submerged arc welding, aiming at the current welding technology that is difficult to meet the requirements of high-speed welding of thin plates. A high-speed rotary submerged arc welding method for thin plates is proposed. The method has low implementation cost, good applicability and fast welding speed.

In order to achieve the above object, the technical scheme proposed by the present invention is:

A high-speed rotary submerged arc welding method for thin plates, comprising the following specific steps:

Step 1. Press the two assembled sheets 6 on the welding backing plate 7 along the welding direction, and place the rotary submerged arc welding torch 1 above the groove of the sheet 6 to be welded, and set the torch height _h1 is 15～25mm;

Step 2. Select the matching flux and welding wire 2 with a diameter of 1.2 to 1.6 mm according to the material of the thin plate 6 to be welded, and set the rotary submerged arc high-speed welding method and Process parameters, which process parameters include: welding current I is 350-500A, arc voltage is 32-38V, arc rotation speed n is 3000-7200r/min, arc rotation radius _r is 2-4mm, welding speed Vw is 1000- 3000mm/min;

Step 3. After the welding flux 3 is laid along the welding direction and the welding arc 4 is ignited at the welding position of the sheet 6 to be welded, the rotating submerged arc welding torch 1 is controlled to drive the welding arc 4 to rotate at a constant speed in the flux 3 according to the set rotation speed and direction, At the same time, the drag mechanism drives the rotary submerged arc welding torch 1 to move toward the welding front at the welding speed _Vw as a whole, so as to realize the high-speed rotary submerged arc welding of the thin plate 6 to be welded.

Further preferably, in step 1, when the two thin plates 6 to be welded are assembled in pairs in the form of butt grooves, the assembly gap G ₁ is 0-2.5 mm, and the misalignment amount C ₁ is 0-1 mm; When the thin plates 6 to be welded are assembled in pairs in the form of lap joints, corner joints or T-shaped grooves, the assembly gap _G1 is 0-2 mm.

Further preferably, in step 1, when the grooves of the two assembled sheets 6 to be welded are butt grooves, the welding backing plate 7 is a copper backing plate, which is provided with a width along the welding direction. G ₂ is a forming groove 7-1 with a depth of 0 to 5 mm and a depth of h ₂ of 0 to 1.5 mm. After the welding pressure plate is pressed, the two thin plates 6 to be welded are in close contact with the copper backing plate, and the center of the butt groove is all located in the forming groove. In the groove 7-1; when the grooves of the two assembled thin plates 6 to be welded are overlapping grooves, the welding backing plate 7 includes a steel fixing backing plate 7-4, a lifting backing plate 7-2 and at least one lifting platform 7-3, of which the lifting pad 7-2 is placed flat on the lifting platform 7-3, and the lifting platform 7-3 is adjusted before welding to control the height of the lifting pad 7-2 and the height of the lifting pad 7-2. The surface level is so that the two thin plates 6 to be welded are in close contact with the lifting pad 7-2 and the steel fixed pad 7-4 respectively after the welding pressure plate is pressed; When the groove form of 6 is a corner joint or a T-shaped groove, the welding backing plate 7 is a copper backing plate, and its corners along the welding direction are provided with a width G of ₀ to 3 mm and a depth of h of ₀ to 1.5 mm. mm forming groove 7-1, after the welding pressure plate is pressed, the two thin plates 6 to be welded are in close contact with the copper backing plate, and the center of the fillet or T-shaped groove is all located in the forming groove 7-1.

Further preferably, in step 2, when the plate thickness δ of the two described thin plates 6 to be welded is not greater than 5mm, the rotary submerged arc high-speed welding method is a single-layer single-pass rotary submerged arc high-speed welding method; When the thickness δ of the two thin plates 6 to be welded is greater than 5 mm, the rotary submerged arc high-speed welding method is a multi-layer multi-pass rotary submerged arc high-speed welding method.

Further preferably, in step 2, the welding wire 2 is either a solid welding wire or a flux-cored welding wire.

Further preferably, in step 2, when the groove form of the two assembled sheets 6 to be welded is lap joint or fillet joint or T-shaped groove, the set rotary submerged arc high-speed welding process parameters. It also includes: the torch inclination angle α ₁ is 0-60°, the upper offset distance C ₂ is 0-2.5 mm, and the right offset distance C ₃ is 0-2.5 mm.

Further preferably, when laying the flux 3 in step 3, the laying thickness of the flux 3 is greater than the height h ₁ of the welding torch, and the laying width is greater than three times the arc rotation radius r.

Further preferably, the method for laying the flux 3 described in step 3 is to lay the flux 3 on the entire groove at one time before welding, or lay the flux 3 in real time during the welding process. The flux 3 with a length of L ₁ is pre-laid from the starting point to the welding front. After starting the welding, it moves with the rotating submerged arc welding torch 1, and the real-time laying length is L ₂ from the position of the advanced welding arc 4 to the welding front to the end of the welding. of flux 3.

Further preferably, the pre-laying length L ₁ is greater than 100 mm, and the real-time laying length L ₂ is greater than 100 mm.

Compared with the prior art, the rotary submerged arc high-speed welding method for thin plates of the present invention has the following advantages:

(1) Combine the technical advantages of both the rotary arc welding and the submerged arc welding method, and adjust the welding current, arc voltage, arc rotation speed and radius, torch height and inclination angle by selecting the flux and welding wire that match the base metal. and offset distance, it can realize single-layer single-pass single-wire rotary submerged arc high-speed welding of steel sheets with a maximum thickness of 5mm under different assembly clearance conditions, with a wide range of applications and strong practicability.

(2) Compared with the existing thin plate welding method, the welding speed of the present invention is much higher than that of MIG welding and friction stir welding, and reaches the speed level of laser welding, but the pre-welding preparation requirements are low, the welding process is simple, and the implementation The cost is low, it has significant economic advantages, and it is easy to realize engineering promotion.

(3) In the existing rotary arc welding method, when the arc rotation speed is greater than 3000 r/min and the welding speed is greater than 400 mm/min, the stability of the welding process and the quality of the welding seam will deteriorate sharply. In contrast, the present invention can still obtain good weld formation when the arc rotation speed is as high as 3000-7200 r/min and the welding speed is as fast as 1000-3000 mm/min, and at the same time, there is no welding arc radiation and less welding fume.

(4) Compared with the traditional submerged arc welding method, the diameter of the welding wire used in the present invention is small, and the welding heat input is low, which can effectively prevent the welding penetration defect in the submerged arc welding of the thin plate.

Description of drawings

FIG. 1 is a schematic diagram of the high-speed rotary submerged arc welding method for thin plates according to the present invention (taking a butt groove as an example).

Figure 2 is a schematic diagram of the arc rotation of the present invention.

3 is a schematic diagram of the butt welding assembly of the thin plate workpiece of the present invention.

4 is a schematic diagram of the lap joint assembly and arc rotation of the thin plate workpiece of the present invention.

5 is a schematic diagram of the fillet welding assembly of the thin plate workpiece of the present invention.

6 is a schematic diagram of the T-shaped groove welding assembly of the thin plate workpiece of the present invention.

Fig. 7 is a schematic diagram of laying flux of the present invention, wherein Fig. 7(a) is a schematic diagram of pre-laying before welding, and Fig. 7(b) is a schematic diagram of pre-laying of flux after starting welding.

Figure 8 is a photo of the front and back weld formation after high-speed butt welding of 2mm plate thickness rotary submerged arc, wherein, Figure 8 (a) and Figure 8 (b) are the assembly gap G ₁ is 1mm, and the misalignment C ₁ is 0.5. Figure 8(c) and Figure 8(d) are the photos of the front and back weld formation when the assembly gap G ₁ is 0 mm and the misalignment C ₁ is 0.2 mm, respectively.

In Figures 1 to 7: 1—rotating submerged arc welding torch; 2—welding wire; 3—flux; 4—arc; 5—welding power source; 6—plate to be welded; 7—welding backing plate; 7-1—forming groove ;7-2—Lifting pad; 7-3—Lifting platform; 7-4—Fixing pad; 8—Arc rotation track; 9—Conducting tip; n—Arc rotation speed; I—Welding current; _Vw —Welding Speed; h ₁ - torch height; r - arc rotation radius; O ₁ - arc rotation track center; δ - thin plate thickness; G ₁ - assembly gap; G ₂ - forming groove width; h ₂ - forming groove depth; C ₁ - misalignment; C ₂ - upper offset distance; C ₃ - right offset distance; α ₁ - torch inclination angle; L ₁ - pre-laying length; L ₂ - laying length.

Detailed ways

In order to make the purpose, technical solutions and advantages of the present invention clearer, the present invention will be described in further detail below with reference to the accompanying drawings and specific embodiments. However, the protection scope of the present invention is not limited to the following examples. The technical solutions obtained by the transformation are all within the protection scope of the present invention.

The technical principle of the rotating submerged arc high-speed welding method for thin plates of the present invention is: for the two thin plates 6 to be welded that are assembled and pressed on the welding backing plate 7, the arc rotation technology is adopted and the submerged arc welding method is used. The advantage of high deposition efficiency is that a rotating arc 4 is generated inside the submerged arc flux 3 laid in the grooves of the two sheets 6 to be welded, and the rotating speed n and the rotating radius r of the welding arc 4 at the end of the welding wire 2 are sent out by adjusting the contact tip 9 , the arc heat is evenly transmitted to both sides of the groove and promotes the transfer of molten droplets and the stirring of the molten pool. A thin-plate welded joint with good penetration, no defects and excellent mechanical properties is obtained.

As shown in FIG. 1 , it is a schematic diagram of the high-speed rotary submerged arc welding method for thin plates according to the present invention (taking the butt groove as an example). Before welding, firstly, two sheets 6 to be welded are assembled into a butt groove workpiece with the assembly gap G ₁ of 0-2.5mm and the misalignment amount C ₁ of 0-1mm, and the two assembled pieces are assembled by welding pressure plate. The sheet 6 to be welded is pressed against the welding backing plate 7 . At this time, the welding pad 7 used in the present invention is a copper pad, which is provided with a forming groove 7-1 (see FIG. 3 ) with a width G ₂ of 0-5 mm and a depth h ₂ of 0-1.5 mm along the welding direction. Before welding, after the two thin plates 6 to be welded are pressed by the welding pressure plate, the two thin plates 6 to be welded are in close contact with the copper backing plate, and the centers of the butt grooves are all located in the forming groove 7-1. Then, according to the thickness δ of the two thin plates 6 to be welded, the assembly gap G ₁ and the misalignment amount C ₁ , the arc rotation radius r is set in the range of 2-4 mm (see FIGS. 2 and 3 ). Next, place the rotary submerged arc welding torch 1 vertically above the center of the butt groove of the two thin plates 6 to be welded, set the torch height h ₁ to 15-25 mm (see Figure 2), and set the rotary submerged arc welding torch 1 and the sheet to be welded 6 are respectively connected with two welding cables of the welding power source 5 .

As shown in FIG. 4 , when two thin plates 6 to be welded are assembled into overlapping workpieces with an assembly gap G ₁ of 0 to 2 mm, the welding pad 7 used in the present invention includes a steel fixing pad 7-4, a lifting pad The board 7-2 and at least one lifting platform 7-3, wherein the lifting pad 7-2 is placed flat on the lifting platform 7-3. Before welding, firstly press the two lapped and assembled sheets 6 to be welded together on the steel fixed backing plate 7-4 through the welding pressure plate, and make one of the thin sheets to be welded 6 and the steel fixed backing plate 7-4. Close contact; then adjust the lifting platform 7-3 to control the height of the lifting pad 7-2 and the levelness of its upper surface, so that another sheet 6 to be welded is in close contact with the lifting pad 7-2 after the welding pressure plate is pressed. At this time, the preferred number of lifting platforms 7-3 in the welding pad 7 is greater than 1, so as to adjust the levelness of the upper surface of the lifting pad 7-2. Next, according to the thickness δ of the overlapped sheet 6 to be welded and the size of the lap joint, the arc rotation radius r is set to a range of 2 to 4 mm, and the rotary submerged arc welding torch 1 is placed on the overlap of the two sheets to be welded 6. Above the groove, set the torch height h ₁ to 15-25mm, and set the torch inclination α ₁ to 0-60°, the upper offset distance C ₂ to be 0-2.5mm, and the right offset distance C ₃ to be 0- Adjust the posture and position of the rotary submerged arc welding torch 1 within a range of 2.5 mm, and then connect the rotary submerged arc welding torch 1 and the thin plate 6 to be welded to the two welding cables of the welding power source 5 respectively.

As shown in FIGS. 5 and 6 , when the two thin plates 6 to be welded are assembled into a fillet or T-bevel workpiece with an assembly gap G ₁ of 0 to 2 mm, the welding pad 7 used in the present invention is a copper pad. The edges and corners of the plate are provided with forming grooves 7-1 with a width G ₂ of 0-3 mm and a depth h ₂ of 0-1.5 mm along the welding direction. At this time, it is preferable to set forming grooves 7-1 at multiple corners of the copper backing plate, so as to facilitate the repeated use of the copper backing plate. Before welding, when the grooves of the assembled two thin plates 6 to be welded are in the form of fillet grooves, press the assembled two thin plates 6 to be welded on the copper backing plate through the welding pressure plate. , and the centers of the fillet grooves of the two sheets to be welded 6 are all located in the forming groove 7-1; when the grooves of the two sheets 6 to be welded that have been assembled are T-shaped The assembled two thin plates 6 to be welded are pressed on the copper backing plate and the welding table respectively, and the centers of the T-shaped grooves of the two thin plates 6 to be welded are all located in the forming groove 7-1. Then, according to the plate thickness δ of the two thin plates 6 to be welded, the assembly gap G ₁ , and the size requirements of the fillet or T-joint, the arc rotation radius r is set in the range of 2 to 4 mm, and the rotating submerged arc welding torch 1 is placed at the same time. Set the welding torch height h ₁ to 15-25mm, and set the torch inclination angle α ₁ to 0-60° and the upper offset distance C ₂ to 0-2.5mm above the 6-corner joint or T-shaped groove of the sheet to be welded. Adjust the posture and position of the rotating submerged arc welding torch ₁ within the range of 0-2.5mm from the right offset distance C3, and then connect the rotating submerged arc welding torch 1 and the sheet to be welded 6 with the two welding cables of the welding power source 5 respectively. connected.

After the above-mentioned pre-welding preparations are completed, according to the material of the two thin plates 6 to be welded, select the matching flux 3 and the solid or flux-cored welding wire 2 with a diameter of 1.2 to 1.6 mm, according to the thickness of the two thin plates 6 to be welded. and groove form, other process parameters set for high-speed rotary submerged arc welding, including: welding current I is 350-500A, arc voltage is _32-38V , welding speed Vw is 1000-3000mm/min, arc rotation speed n is 3000 to 7200 r/min and the rotation direction. Then, the flux ₃ of length L1 is pre-laid along the welding direction at the starting welding position. The preferred pre-laying length L1 before welding is greater _than 100mm (see Figure 7a), and the laying height is greater than the height of the welding torch _h1 (see Figure 7a). The width is greater than three times the arc rotation radius r.

After igniting the welding arc 4, control the rotating submerged arc welding torch 1 to drive the welding arc 4 to rotate at a constant speed with the point O ₁ as the center of the rotation track 8 inside the flux 3 according to the set rotation speed n, direction and rotation radius r, while dragging. The mechanism drives the rotary submerged arc welding torch 1 to move toward the welding front at the welding speed _Vw as a whole, so as to realize high-speed rotary submerged arc welding of two thin plates 6 to be welded. During the welding process, at the position L2 of the advanced welding arc ₄ , the flux 3 is laid in the groove to be welded in real time according to the set laying height and width, until the end of welding, and the preferred advanced laying length L2 is greater _than 100mm (see Fig. 7b). In addition, it is also possible to lay flux 3 on the entire groove at one time before welding. As the rotary submerged arc welding torch 1 moves to the front of the welding, the flux 3 provides effective protection for the arc 4 and the welding pool that are about to move here along the welding direction at the front of the welding. High-speed welded joints for thin plates.

When the thickness δ of the two thin plates 6 to be welded is not greater than 5 mm, the high-speed rotary submerged arc welding method for thin plates of the present invention can realize single-layer and single-pass rotary submerged arc high-speed welding. When the thickness δ of the two thin plates 6 to be welded is greater than 5 mm, the high-speed rotary submerged arc welding method for thin plates of the present invention can realize multi-layer and multi-pass rotary submerged arc high-speed welding.

During the implementation of the rotary submerged arc high-speed welding method for thin plates of the present invention, when the thickness δ and groove form of the thin plates 6 to be welded are changed, the selected welding parameters have a mutual matching relationship. In practical application, in order to ensure the formation of the weld, it is necessary to set the welding process parameters according to the thickness δ of the thin plate 6 to be welded and the groove form, so as to realize the high-speed rotary submerged arc welding. The selection principle of the specific rotary submerged arc high-speed welding process parameters is as follows: the larger the thickness δ of the thin plate 6 to be welded, the slower the selected welding speed _Vw ; the smaller the thickness δ of the thin plate 6 to be welded, the selected welding speed V The faster _w is; when the plate thickness δ is constant, the larger the welding current I and arc voltage are, the faster the arc rotation speed n and the welding speed V _w are; when the plate thickness is constant, the welding current I and arc voltage are smaller, the selected The slower the arc rotation speed n and the welding speed _Vw ; the larger the assembly gap _G1 of the two sheets 6 to be welded, the larger the selected welding current I and arc voltage, the faster the arc rotation speed n, and the slower the welding speed _Vw . , the larger the arc rotation radius r; the smaller the assembly gap _G1 of the two thin plates 6 to be welded, the smaller the selected welding current I and arc voltage, the slower the arc rotation speed n, the faster the welding speed _Vw , and the arc rotation radius. The smaller r is; the larger the size requirements of lap joint or corner joint or T-joint are, the selected welding current I, arc voltage, welding torch inclination angle α ₁ , upper offset distance C ₂ , right offset distance C ₃ and arc rotation radius The larger the _r is, the slower the welding speed Vw is; the smaller the size of the lap joint or the angle joint or the T-joint is, the selected welding current I, arc voltage, welding torch inclination angle α ₁ , upper offset distance C ₂ , right offset _The smaller the distance C3 and the arc rotation radius _r , the faster the welding speed Vw; compared with the flux-cored welding wire, when the welding wire 2 uses a solid welding wire, the corresponding welding speed _Vw is faster.

Four embodiments of the high-speed rotary submerged arc welding method for thin plates of the present invention are provided below to specifically describe the parameter selection of the high-speed rotary submerged arc welding method when 6 different pairs of two thin plates to be welded are assembled. In all the embodiments, the thin plate 6 to be welded is made of carbon steel, and is realized on the premise that the height h ₁ of the welding torch is 18 mm, the diameter of the welding wire 2 is 1.2 mm, and the flux 3 is Lincoln 781 flux. When the material of the two thin plates 6 to be welded changes, it is only necessary to select the matching welding wire 2 and flux 3, and a rotating submerged arc high-speed welding joint with good performance can also be obtained.

Example 1

Figure 8 shows the photos of the front and back welding seam forming of two thin plates 6 to be welded with a plate thickness δ of 2 mm after high-speed butt welding by rotating submerged arc. Among them, Figure 8(a) and Figure 8(b) are the photos of the front and back welding seam forming when the assembly gap G ₁ is 1 mm and the misalignment amount C ₁ is 0.5 mm, respectively. The forming of the copper backing plate 7 used at this time _The width G2 of the slot 7-1 is 3mm, the depth _h2 is 1mm, the set welding current I is 370A, the arc voltage is 35V, the arc rotation speed n is 4500r/min, the arc rotation radius _r is 2mm, and the welding speed Vw is 2300mm/min. Figures 8(c) and 8(d) are the photos of the front and back weld formation when the assembly gap G ₁ is 0 mm and the misalignment amount C ₁ is 0.2 mm, respectively. The forming groove 7 of the copper backing plate 7 used at this time is _{-1 The} width G2 is 4mm, the depth h2 is 1mm, the set welding current I is 440A, the arc voltage is 36V, the arc rotation speed n is 6000r/min, the arc rotation radius _r is 3mm, and the welding speed Vw is 2700mm /min.

As can be seen from Figure 8, for the grooves of the butt-welded sheet 6 with different assembly gaps G ₁ and misalignment C ₁ , by adjusting the technical parameters of the high-speed butt welding of the rotating submerged arc, the welding arc energy and its distribution are changed. The rotating submerged arc high-speed welding method used for thin plates can obtain thin plate weld formation with good penetration and no weld penetration defects, and the welding speed is much higher than the welding speed of conventional MIG and friction stir welding. The speed level of laser welding can be achieved under the condition of implementation cost.

Example 2

As shown in Figure 4, two thin plates 6 to be welded with thickness δ of 3mm and 4mm are assembled into a lap groove form, the assembly gap G ₁ is 0.5mm, and a welding pressure plate is used to align the two well-lapped groups before welding. The sheet 6 to be welded is pressed on the lifting pad 7-2 and the steel fixing pad 7-4 respectively, and nine lifting platforms 7-2 are evenly placed in three rows below the lifting pad 7-2 along the welding direction. 3. Before welding, adjust the torch inclination α1 of the rotating submerged arc welding torch ₁ above the lap groove to be ₃₀ °, the upper offset distance _C2 to be 0mm, and the right offset distance C3 to be 0mm, and the set welding current I is 350A, the arc voltage is 32V, the arc rotation speed n is 3000r/min, the arc rotation radius _r is 2mm, and the welding speed Vw is 3000mm/min. After high-speed rotary submerged arc welding, thin-plate lap joints that are well formed and meet the requirements of use are obtained.

Example 3

As shown in Figure 5, two sheets 6 to be welded with a thickness δ of 5mm are assembled into a corner joint groove form, and the assembly gap G ₁ is 1mm. Before welding, a welding pressure plate is used to align the two sheets to be welded. 6 are respectively pressed on the copper backing plate, and its four corners are respectively provided with forming grooves 7-1 with a width G ₂ of 3 mm and a depth of h ₂ of 1.5 mm along the welding direction. Before welding, adjust the torch inclination α1 of the rotating submerged arc welding torch ₁ above the corner groove to be 60°, the upper offset distance _C2 to be 2.5mm, and the right offset distance _C3 to be 2.5mm, and the set welding current I is 500A, the arc voltage is 38V, the arc rotation speed n is 7200r/min, the arc rotation radius _r is 4mm, and the welding speed Vw is 1000mm/min. After high-speed rotary submerged arc welding, thin-plate fillet joints with good shape and meeting requirements are obtained.

Example 4

As shown in Figure 6, two thin plates 6 to be welded with thickness δ of 3mm and 5mm respectively are assembled into a T-shaped groove form, the assembly gap _G1 is 2mm, and the T-shaped groove group is aligned with a welding pressure plate before welding. The two thin plates 6 to be welded are respectively pressed against the copper backing plate, and four corners thereof are respectively provided with forming grooves 7-1 with a width G ₂ of 3 mm and a depth h ₂ of 1.5 mm along the welding direction. Before welding, adjust the torch inclination α1 of the rotary submerged arc welding torch ₁ above the T _- shaped groove to be 45°, the upper offset distance _C2 to be 1mm, and the right offset distance C3 to be 2mm, and the set welding current I The arc voltage was 400 A, the arc voltage was 35 V, the arc rotation speed n was 4500 r/min, the arc rotation radius r was 3 mm, and the welding speed V _w was 2400 mm/min. After high-speed rotary submerged arc welding, a thin-plate T-joint that is well formed and meets the requirements of use is obtained.

It can be seen from the above 4 examples that under the conditions of different groove forms and sizes, the thin plates with the plate thickness δ within 5 mm can obtain well-formed single-layer single-pass thin plates through the high-speed rotary submerged arc welding method of the present invention. Welded joints. When the plate thickness δ is greater than 5mm, it is only necessary to perform multi-layer multi-pass welding, and a well-formed rotary submerged arc high-speed welded joint can also be obtained. Because of the low pre-welding preparation requirements, simple welding process, easy maintenance of welding equipment and low welding cost implemented by the present invention, it is easy to realize engineering popularization and application.

Claims (5)

1. a rotary submerged arc high-speed welding method for thin plate, is characterized in that: comprise the following concrete steps: Step 1. Press the two assembled sheets (6) to be welded on the welding backing plate (7) along the welding direction, and place the rotary submerged arc welding torch (1) on the slope of the sheet (6) to be welded. Above the mouth, set the torch height h ₁ to 15-25mm; Step 2. Select the matching flux and welding wire (2) with a diameter of 1.2 to 1.6 mm according to the material of the sheet to be welded (6), and set the rotation according to the thickness and groove form of the sheet to be welded (6). Submerged arc high-speed welding method and process parameters, wherein the process parameters include: welding current I is 350-500A, arc voltage is 32-38V, arc rotation speed n is 3000-7200r/min, arc rotation radius r is 2-4mm, welding Speed V _w is 1000～3000mm/min; Step 3. After the welding flux (3) is laid along the welding direction and the welding arc (4) is ignited at the welding start position of the sheet to be welded (6), the rotating submerged arc welding torch (1) is controlled to drive the welding arc (4) in the flux (3). ) internally rotates at a constant speed according to the set rotation speed and direction, and at the same time, the driving mechanism drives the rotating submerged arc welding torch (1) to move toward the welding front at the welding speed _Vw as a whole, so as to realize the rotating submerged arc high-speed welding of the thin plate (6) to be welded; Wherein, in step 1, when the two sheets (6) to be welded are assembled in pairs in the form of butt grooves, the assembly gap G ₁ is 0-2.5 mm, and the misalignment amount C ₁ is 0-1 mm; When the thin plates (6) to be welded are assembled in pairs in the form of lap joint or corner joint or T-shaped groove, the assembly gap _G1 is 0-2 mm, and the welding position of the corner joint groove is located outside the right angle; When the grooves of the two assembled sheets (6) to be welded are butt grooves, the welding backing plate ( ₇ ) is a copper backing plate, and it is provided with a width G2 along the welding direction. The forming groove (7-1) with a depth of 0 to 5 mm and a depth of h ₂ of 0 to 1.5 mm, after the welding pressure plate is pressed, the two thin plates to be welded (6) are in close contact with the copper backing plate, and the centers of the butt grooves are all located at In the forming groove (7-1); when the grooves of the two assembled pairs of sheets (6) to be welded are overlapping grooves, the welding backing plate (7) includes a steel fixing backing plate (7-4), a lifting pad (7-2) and at least one lifting platform (7-3), wherein the lifting pad (7-2) is placed flat on the lifting platform (7-3) and adjusted before welding The lift table (7-3) controls the height of the lift pad (7-2) and the levelness of its upper surface, so that the two thin plates (6) to be welded are respectively pressed against the lift pad (7-2) after the welding pressure plate is pressed. It is in close contact with the steel fixed backing plate (7-4); when the grooves of the two assembled sheets (6) to be welded are fillet joints or T-shaped grooves, the welding backing plate (7-4) 7) It is a copper backing plate, and its corners along the welding direction are provided with forming grooves (7-1) with a width G ₂ of 0 to 3 mm and a depth of h ₂ of 0 to 1.5 mm. The welding sheet (6) is in close contact with the copper backing plate, and the center of the fillet or T-shaped groove is all located in the forming groove (7-1); In step 2, when the thickness δ of the two thin plates (6) to be welded is not greater than 5 mm, the rotary submerged arc high-speed welding method is a single-layer and single-pass rotary submerged arc high-speed welding method; When the thickness δ of the thin plate (6) to be welded is greater than 5 mm, the rotary submerged arc high-speed welding method is a multi-layer multi-pass rotary submerged arc high-speed welding method; When the groove forms of the two assembled sheets (6) to be welded are lap joints, fillet joints or T-shaped grooves, the set process parameters for the high-speed rotary submerged arc welding further include: a welding torch The inclination angle α ₁ is 0 to 60°, the upper offset distance C ₂ is 0 to 2.5 mm, and the right offset distance C ₃ is 0 to 2.5 mm. 2. The high-speed rotary submerged arc welding method for thin plates according to claim 1, wherein in step 2, the welding wire (2) is any one of solid welding wire or flux-cored welding wire. 3. The high-speed rotary submerged arc welding method for thin plates according to claim 1, characterized in that: when laying flux (3) in step 3, the laying thickness of the flux (3) is greater than the height h of the welding torch ₁ , the laying width is greater than three times the arc rotation radius r. 4. The high-speed rotary submerged arc welding method for thin plate according to claim 1, characterized in that: the method for laying flux (3) described in step 3 is to lay flux (3) on the entire groove at one time before welding. ), or real-time laying of the flux (3) during the welding process, when using the real-time laying of the flux (3) during the welding process, the flux (3) of length L ₁ is pre-laid from the starting point to the welding front before welding, and the starting point is After welding, along with the rotating submerged arc welding torch (1), a flux (3) with a length of L ₂ is laid in real time from the position of the leading welding arc (4) to the front of the welding to the end of the welding. 5 . The high-speed rotary submerged arc welding method for thin plates according to claim 4 , wherein the pre-laying length L1 is greater than ₁₀₀ mm, and the real-time laying length L2 is greater than 100 mm. 6 .

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