Method of manufacturing a seamless flux-cored wire

Abstract

The application discloses a manufacturing method of seamless flux-cored wire, comprising the following steps: providing a metal strip, rolling the metal strip into a strip structure with a groove; adding flux powder to the groove of the metal strip; rolling the metal strip into a tubular structure with a water-drop-shaped cross section, and the joint position is located at the tip of the water-drop-shaped tubular structure; conveying the metal strip to a welding workbench, and positioning the metal strip by using positioning wheels, wherein the positioning wheels comprise upper and lower positioning wheels, the wheel surface of the upper positioning wheel is provided with a groove matched with the tip and clamping the tip of the metal strip, and the wheel surface of the lower positioning wheel is provided with a groove matched with the thick part of the water-drop-shaped tubular structure and abutting against the thick part of the metal strip; welding the joint position; and rounding, rolling and drawing to manufacture the welding wire with a preset size. The manufacturing method of the seamless flux-cored wire can effectively reduce welding defects of the seamless flux-cored wire in the manufacturing process and improve the stability of the welding wire.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of welding wire manufacturing, in particular to a manufacturing method of seamless flux-cored wire. BACKGROUND

[0002] Flux-cored wire is widely used in the field of welding, not only plays an important role in surfacing and thermal spraying, but also is increasingly used in the manufacture of steel structures such as ships, automobiles and aviation, and additive manufacturing. Flux-cored wire is divided into two types according to the cross-sectional form, namely seamless flux-cored wire and flux-cored wire with a seam. Figure 1 The figure shows the cross-sectional photo of the seamless flux-cored wire, the outer skin is a tubular structure wrapped around the core, and the cross-section is a closed ring structure. Figure 2 The figures show the cross-sectional photos of two types of flux-cored wire with a seam. In the flux-cored wire with a seam, the cross-section of the tubular outer skin wrapped around the core has an opening.

[0003] The opening of the flux-cored wire with a seam retains impurities such as lubricating powder during the wire manufacturing process, and also makes the internal powder more prone to moisture absorption during storage and use, which makes the wire surface more prone to rust, reduces the weldability of the wire, causes more spatter and smoke, and also increases the oxygen and hydrogen content in the weld layer, which reduces the mechanical properties of the weld layer.

[0004] Making the flux-cored wire seamless not only avoids the drawbacks of the flux-cored wire with a seam, but also reduces the wear of the welding gun electrode, which is very suitable for welding situations with higher performance requirements, such as aerospace.

[0005] There are generally two ways to manufacture seamless flux-cored wire. In the first way, a U-shaped metal strip such as a stainless steel strip is provided, the flux powder is filled into the groove of the U-shaped metal strip, then the U-shaped metal strip is rolled tightly and folded, then the opening or gap at the folded part is welded, and then drawn to form the required specification of seamless flux-cored wire. In the second way, a metal tube is provided, the flux powder is filled into the metal tube, and then the metal tube is drawn to obtain the required specification of seamless flux-cored wire.

[0006] The second way has low processing efficiency, short wire length, high cost, and the powder is prone to form gaps and layers in the tube. The first way has high processing efficiency, theoretically the wire length can be infinite, the cost is low, the powder filling is stable, and it is suitable for mass production. Therefore, the first way is more commonly used in the industry to prepare seamless flux-cored wire.

[0007] But the length of the metal strip for manufacturing welding wire is long in the processing process, up to hundreds to thousands of meters, and it is difficult to ensure that the long welding seam has no defects when the opening or gap of the strip at the closing position is welded closed in the processing process using the second method. Especially, the cross section of the strip after closing and pressing is nearly circular or elliptical tube shape, the opening of the strip of this shape is easy to deflect, which is not conducive to the subsequent welding of the opening, and welding defects are easy to occur, thereby affecting the stability of the welding wire performance.

[0008] Therefore, it is necessary to provide a seamless flux-cored wire manufacturing method which reduces welding defects and improves the stability of the welding wire. SUMMARY

[0009] The technical problem solved by the present application is to provide a seamless flux-cored wire manufacturing method which can effectively reduce welding defects of the seamless flux-cored wire in the manufacturing process and improve the stability of the welding wire.

[0010] To solve the above technical problems, the present application provides a seamless flux-cored wire manufacturing method, comprising the following steps:

[0011] Providing a metal strip, rolling and deforming the metal strip into a strip structure having a groove extending along the length direction thereof;

[0012] Adding flux powder into the groove of the metal strip;

[0013] Rolling and closing the metal strip into a tubular structure with a water droplet-shaped cross section, and the closing position is located at the tip of the water droplet-shaped tubular structure;

[0014] Transporting the rolled and closed metal strip to a welding workbench and positioning the metal strip using positioning wheels, wherein the positioning wheels comprise an upper positioning wheel and a lower positioning wheel, the wheel surface of the upper positioning wheel has a groove matched with the tip of the water droplet-shaped tubular structure, the wheel surface of the lower positioning wheel has a groove matched with the thick part of the water droplet-shaped tubular structure, the tip of the metal strip is clamped by the upper positioning wheel, and the thick part of the metal strip is attached to the lower positioning wheel;

[0015] Welding the closing position of the metal strip;

[0016] Performing roundness rolling on the metal strip;

[0017] Performing drawing on the metal strip to manufacture a welding wire with a preset specification size.

[0018] The present application has the following beneficial effects: In the present application, the metal strip is processed into a tubular structure with a water droplet-shaped cross section before being welded seamlessly, and the positioning wheels matched with the water droplet-shaped structure are used to clamp the metal strip during welding and closing, thereby improving the stability of the welding area position during welding and improving the welding quality. BRIEF DESCRIPTION OF DRAWINGS

[0019] Figure 1 A cross-sectional view of a prior art seamless flux-cored wire.

[0020] Figure 2 A cross-sectional view of a prior art flux-cored wire with a seam.

[0021] Figure 3 A schematic view of the structure of the metal strip after rolling in an embodiment of the present application.

[0022] Figure 4 A schematic view of the structure of the metal strip after filling the flux core in an embodiment of the present application.

[0023] Figure 5 A schematic view of the structure of the metal strip after rolling and folding in an embodiment of the present application.

[0024] Figure 6 A schematic view of the structure of the metal strip after rolling and folding in another embodiment of the present application.

[0025] Figure 7 A schematic view of the structure of the wheel surface of the first folding wheel in the rolling and folding step in an embodiment of the present application.

[0026] Figure 8 A schematic view of the structure of the wheel surface of the second folding wheel in the rolling and folding step in an embodiment of the present application.

[0027] Figure 9 A schematic view of the arrangement of the positioning wheel in the welding step in an embodiment of the present application.

[0028] Figure 10 A schematic view of the structure of the positioning wheel in an embodiment of the present application.

[0029] Figure 11 A schematic view of the structure of the positioning wheel in another embodiment of the present application. DETAILED DESCRIPTION

[0030] The preferred embodiments of the present application will be described in detail below with reference to the accompanying drawings, so that the advantages and features of the present application can be more easily understood by those skilled in the art, and the scope of protection of the present application can be more clearly defined.

[0031] The manufacturing method of the seamless flux-cored wire in an embodiment of the present application comprises the following steps:

[0032] S1, providing a metal strip, and rolling and deforming the metal strip into a strip structure having a groove extending along the length direction thereof;

[0033] S2, adding flux powder into the groove of the metal strip;

[0034] S3, rolling the metal strip into a tubular structure with a cross-section in the shape of a water droplet, and the joint position is located at the tip of the water droplet-shaped tubular structure;

[0035] S4, conveying the rolled metal strip to a welding workbench and positioning the metal strip using positioning wheels, wherein the positioning wheels include an upper positioning wheel and a lower positioning wheel, the wheel surface of the upper positioning wheel has a groove matched with the tip of the water droplet-shaped tubular structure, and the wheel surface of the lower positioning wheel has a groove matched with the thick part of the water droplet-shaped tubular structure, the upper positioning wheel engages the tip of the metal strip, and the lower positioning wheel abuts the thick part of the metal strip;

[0036] S5, welding the joint position of the metal strip;

[0037] S6, performing rounding rolling on the metal strip to roll the metal strip into a circular pipe shape;

[0038] S7, performing drawing on the metal strip to manufacture a welding wire with a preset specification and size.

[0039] In step S1, please refer to Figure 3 The metal strip 30 can be a stainless steel strip or a nickel alloy strip. The metal strip 30 is rolled by a rolling mill to have a groove 31 extending along the length direction of the strip. The cross-section of the rolled metal strip can be designed to be U-shaped, and the groove is a U-shaped groove.

[0040] In step S2, please refer to Figure 4 The flux powder 32 is filled into the groove 31 of the metal strip 30. The flux powder 32 can include conventional flux components such as deoxidizers, alloy powders, and slag formers.

[0041] In step S3, please refer to Figure 5 The metal strip 30 filled with the flux powder 32 is rolled and closed into a tubular structure with a cross-section in the shape of a water droplet. The upper part of the cross-section of the rolled and closed metal strip 30 is a tip 35 in an inverted V-shaped structure, and the lower part of the cross-section of the metal strip 30 is a thick part 36 in a semicircular arc structure. After the metal strip 30 is rolled and closed, its cross-section forms an approximately closed structure, but the rolling process cannot guarantee that the joint position is completely closed. To avoid the adverse effects of the small gaps on the performance of the subsequent welding wire, further welding technology is needed to close the gaps.

[0042] In the specific embodiments of the present application, the rolling and closing step can also be provided to include two steps. The first step rolls and closes the metal strip 30 filled with the flux powder into a tubular structure with a cross-section in the shape of a water droplet. Please refer to Figure 6, the second section of the step further rolls the joint of the tip 35 of the metal strip 30 to have the outwardly protruding hem 33, and the hems 33 of the two sides of the metal strip 30 to be jointed are mutually adhered.

[0043] Please refer to Figure 7 In the first section of the step of the rolling jointing step, the metal strip 30 is jointed by using the first jointing wheel 40. The first jointing wheel 40 comprises a first upper jointing wheel 41 and a first lower jointing wheel 42. The wheel surface of the first upper jointing wheel 41 has a V-shaped groove 410 along the radial section thereof. The wheel surface of the first lower jointing wheel 42 has a U-shaped groove 420 along the radial section thereof. The first upper jointing wheel 41 and the first lower jointing wheel 42 cooperate to joint and roll the metal strip 30 to have a water-drop-shaped structure in the cross section.

[0044] Please refer to Figure 8 In the second section of the step of the rolling jointing step, the metal strip 30 is jointed by using the second jointing wheel 50. The second jointing wheel 50 comprises a second upper jointing wheel 51 and a second lower jointing wheel 52. The wheel surface of the second upper jointing wheel 51 has a V-shaped groove 510 along the radial section thereof. The V-shaped groove 510 of the second upper jointing wheel 51 is provided with an opening 511 at the groove bottom, and the opening 511 is used to roll the hem 33 of the metal strip 30 in the second section of the jointing step. The second lower jointing wheel 52 has the same structure as the first lower jointing wheel 42, and the wheel surface of the second lower jointing wheel 52 has a U-shaped groove 520 along the radial section thereof. The second upper jointing wheel 51 and the second lower jointing wheel 52 cooperate to further joint and roll the metal strip 30 at the joint position thereof to have the hem 33.

[0045] In step S4, the jointed and rolled metal strip 30 is transported to a welding workbench. Please refer to Figure 9 and Figure 10 The welding workbench (not shown in the figure) is provided with two sets of positioning wheels 60 and a welding device 70 in sequence along the conveying direction. The two sets of positioning wheels 60 are distributed before and after the welding point of the welding device 70. Each set of positioning wheels comprises an upper positioning wheel 61 and a lower positioning wheel 62. The wheel surface of the upper positioning wheel 61 has a V-shaped groove along the radial section thereof, and the wheel surface of the lower positioning wheel 62 has a U-shaped groove along the radial section thereof. The V-shaped groove of the upper positioning wheel 61 engages the joint position of the tip 35 of the metal strip 30, so as to limit the deflection of the metal strip 30. The U-shaped groove of the lower positioning wheel 62 adheres to the thick part 36 of the metal strip 30, so as to facilitate the rotation of the metal strip 30 and improve the correction effect. Please refer to Figure 11 When the joint position of the metal strip 30 has the hem 33, the groove bottom of the V-shaped groove on the wheel surface of the upper positioning wheel 61 is provided with an opening 63, and the opening 63 engages the hem 33 of the metal strip 30.

[0046] In step S5, the welding device is used to weld the joint position of the metal strip 30. The welding process selects laser welding technology, i.e., laser is selected as the welding heat source, because laser welding has small heat input, large energy density, stable laser capacity, and can work for a long time, and is suitable for high-speed welding. In addition, laser welding does not need to connect the wire to the power supply, which can reduce the complexity of the equipment. In order to improve the quality of laser welding, the roll surface of the roller is redesigned.

[0047] The welding device comprises a speed monitoring module, a visual image monitoring module, a human-computer interaction module, a central processing unit, a control module, a water cooling module, a laser generator, a laser deflection module, a protective gas module, a memory and a display.

[0048] The speed monitoring module is placed in front of the welding point, and measures the running speed of the metal strip 30 in real time, and transmits the value to the central processing unit, and displays it on the display and stores it in the memory. The running speed of the metal strip 30 reaches the set threshold range, which is a necessary condition for welding. When the running speed of the metal strip 30 is lower than the lower limit of the threshold, the welding is stopped.

[0049] The visual image monitoring module captures the image of the welding point in real time, and transmits the image to the central processing unit, and displays it on the display and stores it in the memory. The visual image monitoring module marks the spatial coordinates of the joint position of the metal strip 30 in real time. For the area where the joint position deviates from the preset welding position, the central processing unit combines the running speed of the metal strip 30 to make the laser deflect through the laser deflection module, adjust the position of the laser focal point in real time, and complete the welding of the joint of these areas. The joint position is within the allowable deviation range, and the laser focal point does not need to be moved. The deviation range of the joint position is within the set threshold range, which is a necessary condition for welding.

[0050] The human-computer interaction module inputs information to the central processing unit through the display to adjust or set the deviation threshold of the joint position and the start and stop of laser welding.

[0051] The control module manages the start and stop of the water cooling machine, the laser generator, the protective gas and the displacement amount of the laser deflection.

[0052] In step S6, the metal strip after welding is subjected to round rolling to roll the metal strip into a preset wire shape.

[0053] S7, the metal strip is drawn to make a welding wire with a preset specification size.

[0054] The manufacturing method of the seamless flux-cored wire of the embodiment of the present application adopts laser welding to butt the wire, so that the adaptability of the wire making equipment is improved, the component, thickness and running speed adjustment range of the strip are wide; the seamless wire can be manufactured after small-scale modification of the existing flux-cored wire equipment, and the popularization and application are strong. In the laser welding, the wire does not need to be connected with the power supply, and the overall safety of the equipment is high. At the same time, when the wire butt operation is performed, the butt position of the wire is greatly reduced through the folding wheel and the wire positioning wheel, and the welding stability is improved.

[0055] The above is only the embodiment of the present application, and does not limit the patent scope of the present application, and any equivalent structure or equivalent process transformation using the content of the specification and drawings of the present application, or direct or indirect application in other related technical fields, are also included in the patent protection scope of the present application.

Claims

1. A method of manufacturing a seamless flux-cored welding wire, characterized by, The method comprises the following steps: providing a metal strip, rolling the metal strip into a strip structure with grooves extending along the length direction of the strip structure; adding flux powder into the grooves of the metal strip; rolling the metal strip into a tubular structure with a cross section in the shape of a water drop, with the joint position located at the tip of the tubular structure; feeding the rolled metal strip to a welding station, and positioning the metal strip by using positioning wheels, wherein the positioning wheels comprise an upper positioning wheel and a lower positioning wheel, the wheel surface of the upper positioning wheel has grooves matching the tip of the tubular structure, the wheel surface of the lower positioning wheel has grooves matching the thick part of the tubular structure, the upper positioning wheel engages the tip of the metal strip, and the lower positioning wheel abuts against the thick part of the metal strip; welding the joint position of the metal strip; rounding the metal strip by rolling; drawing the metal strip to produce a welding wire with a preset size; the step of rolling the metal strip into a tubular structure with a cross section in the shape of a water drop comprises two steps: the first step of rolling the metal strip filled with flux powder into a tubular structure with a cross section in the shape of a water drop, and the second step of further rolling the joint position of the tip of the metal strip into a flange with an outward protrusion, with the flanges on the two sides of the metal strip to be rolled abutting against each other; the wheel surface of the upper positioning wheel of the positioning wheels has V-shaped grooves along the radial direction, the wheel surface of the lower positioning wheel of the positioning wheels has U-shaped grooves along the radial direction, the V-shaped grooves of the upper positioning wheel engage the joint position of the tip of the metal strip, and the U-shaped grooves of the lower positioning wheel abut against the thick part of the metal strip; the bottom of the V-shaped grooves of the upper positioning wheel is provided with an opening, and the opening engages the flange of the metal strip.

2. The method of manufacturing a seamless powder- cored welding wire according to claim 1, characterized in that: The metal strip is a stainless steel strip or a nickel alloy strip.

3. The method of manufacturing a seamless powder- cored welding wire according to claim 1, characterized in that: The flux powder comprises a deoxidizer, an alloy powder, and a slag former.

4. The method of manufacturing a seamless powder- cored welding wire according to claim 1, characterized in that: The upper part of the cross section of the rolled metal strip is the tip, which has an inverted V-shaped structure, and the lower part is the thick part, which has a semicircular arc structure.

5. The method of manufacturing a seamless powder- cored welding wire according to claim 1, characterized in that: The first rolling step is performed by using a first rolling wheel, which comprises a first upper rolling wheel and a first lower rolling wheel, the wheel surface of the first upper rolling wheel has V-shaped grooves along the radial direction, and the wheel surface of the first lower rolling wheel has U-shaped grooves along the radial direction; the first upper rolling wheel and the first lower rolling wheel cooperate to roll the metal strip into a tubular structure with a cross section in the shape of a water drop.

6. The method of making a seamless powder- cored welding wire of claim 5, wherein: The second rolling step is performed by using a second rolling wheel, which comprises a second upper rolling wheel and a second lower rolling wheel, the wheel surface of the second upper rolling wheel has V-shaped grooves along the radial direction, the bottom of the V-shaped grooves of the second upper rolling wheel is provided with an opening, the flange of the metal strip is formed by rolling through the opening in the second rolling step, and the second lower rolling wheel has the same structure as the first lower rolling wheel.

7. The method of making a seamless powder core wire of claim 1, wherein: Two groups of positioning wheels and welding devices are arranged in sequence along the feeding direction of the metal strip at the welding station.

8. The method of making a seamless powder core wire of claim 1, wherein: The welding method is laser welding.

9. The method of making a seamless powder core wire of claim 8, wherein: In the welding, the welding device used includes: speed monitoring module, visual image monitoring module, human-computer interaction module, central processing unit, control module, water cooling module, laser generator, laser deflection module, protective gas module, memory and display; the speed monitoring module is placed in front of the welding point, measures the running speed of the metal strip in real time, and transmits the value to the central processing unit, while displaying on the display and storing in the memory; the visual image monitoring module shoots the image of the welding point in real time, and transmits the image to the central processing unit, while displaying on the display and storing in the memory; the visual image monitoring module marks the spatial coordinates of the joint position of the metal strip in real time, for the area where the joint position deviates from the preset welding position, the central processing unit combines the running speed of the metal strip, makes the laser deflect through the laser deflection module, adjusts the laser focal point position in real time, and completes the welding of the joint of the area; the human-computer interaction module inputs information to the central processing unit through the display, adjusts or sets the deviation threshold of the joint position and the start and stop of the laser welding; the control module manages the start and stop of the water cooling machine, the laser generator, the protective gas and the laser deflection displacement amount.

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