Slag blowing pipe welding tool and welding method thereof

Abstract

The present invention provides a slag blowing pipe welding tool and a welding method thereof. The slag blowing pipe welding tool comprises: two symmetrically arranged clamps that clamp the ends of a steel pipe; and a plurality of support blocks, whose heights decrease from the center to the sides, for supporting the steel pipe so that it bends upward. The steel pipe is first fixed to bend downward, and then a nozzle is welded to the upper end of the steel pipe. After the steel pipe is released, the deformation direction caused by welding is opposite to the bending direction before welding, and the deformation caused by welding just compensates for the bending before welding, so that the steel pipe is in a straight state after welding. The present invention eliminates the straightening process, not only improving efficiency but also preventing weld cracking.

Description

Technical Field

[0001] The invention relates to the technical field, in particular to a slag blowing pipe welding tool and a welding method thereof. Background Art

[0002] After being heated in a heating furnace, the steel billet enters the rolling process. Rolling typically involves multiple rolling mills, which pass through them sequentially to achieve final shape. The rolling mills emit yellow smoke, which impacts the environment. The rolling process also causes the oxidized iron scale to flake off. The oxidized iron belts that feed the rollers during rolling can affect rolling quality, causing surface defects such as pits. Therefore, slag blowers are installed between the rolling mills. These blowers spray high-pressure water to flush the billet surface, removing the yellow smoke and oxidized iron scale.

[0003] like Figure 6 As shown, the slag blowing pipe consists of a steel pipe with multiple evenly spaced nozzles welded onto it. During the welding process, the pipe body will be heated unevenly, causing the steel pipe to bend towards the nozzle after the nozzle and the steel pipe are welded. Therefore, straightening is required after welding. This process not only prolongs the processing time and increases the processing cost, but also repeatedly pressurizes the steel pipe during straightening, which reduces its load-bearing capacity and affects its performance. Furthermore, because the nozzle and the steel pipe are made of different materials (carbon steel for the steel pipe and stainless steel for the nozzle), the weld is prone to cracking under pressure during straightening, resulting in the workpiece being scrapped.

[0004] Therefore, how to overcome the above-mentioned defects has become a problem that needs to be solved urgently by those skilled in the art. Summary of the Invention

[0005] In order to solve the technical problems in the background technology, the present invention discloses a slag blowing pipe welding tool and a welding method thereof.

[0006] The present invention provides a slag blowing pipe welding tool, comprising:

[0007] Two symmetrically arranged clamps fix the two ends of the steel pipe by clamping;

[0008] A plurality of support blocks, the height of which decreases from the middle to both sides, are used to support the steel pipe so that the steel pipe bends upward.

[0009] First, the steel pipe is fixed so that it bends downward, and then the nozzle is welded to the upper end of the steel pipe. After the steel pipe is loosened, the deformation direction caused by welding is opposite to the bending direction before welding, and the deformation amount caused by welding just compensates for the bending amount before welding, so that the steel pipe is in a straight state after welding is completed. The present invention eliminates the straightening process, which not only improves efficiency but also does not cause weld cracking.

[0010] The specific structure of the clamping seat is as follows: the clamping seat is provided with a slot, and the steel pipe is inserted into the slot;

[0011] A pressure plate is provided on the upper side of the slot, which is tightened by a tightening bolt connected by threads to compress the steel pipe.

[0012] When the pressure plate applies pressure to the steel pipe, it is easy to crush the steel pipe. Based on this, a further design is that pipe plugs are inserted at both ends of the steel pipe. The pipe plugs support the steel pipe and prevent it from being crushed.

[0013] When the steel pipe bends downward, its end will form an angle with the work surface, so the opening direction of the slot also needs to form an angle with the work surface. This will increase the difficulty of processing the slot, so further improvements are made to solve this problem. Specifically, the lower end of the clamp is also connected to a triangular pad, so that the inner end of the clamp is tilted upward.

[0014] If the bending angles of the steel pipe are different, different pads need to be matched, which will increase the cost of the pads. Therefore, further improvements are made to solve this problem. Specifically, the pads are located on both sides of the axial direction of the steel pipe and are threadedly connected with adjusting bolts. By adjusting the length of the protruding threaded end of the adjusting bolt from the lower end face of the pad, the inclination angle of the upper end face of the pad can be adjusted.

[0015] The present invention also provides a slag blowing pipe welding method, which uses a slag blowing pipe welding tool to fix the steel pipe, including the following steps:

[0016] S1. Spot weld the nozzles onto the steel pipe in sequence, with the outlet facing upwards;

[0017] S2. Set a natural number n and weld the 2n+1th nozzle. The weld is set as the first weld. The first weld is semi-annular and located on the same axial side of the steel pipe.

[0018] S3, welding the 2n+2nd nozzle, wherein the weld seam is set as the second weld seam, the second weld seam is semi-annular and arranged opposite to the first weld seam;

[0019] S4. Welding the 2n+1th nozzle, wherein the weld is set as the third weld, the third weld is semi-annular, and forms a closed ring with the first weld;

[0020] S5. Welding the 2n+2nd nozzle is performed, and the weld seam thereof is set as the fourth weld seam. The fourth weld seam is semi-annular and forms a closed ring with the second weld seam.

[0021] The above welding method can effectively disperse the welding heat, reduce the temperature difference between the two ends of the weld, avoid or reduce the thermal expansion deformation caused by welding, thereby improving production efficiency and reducing the cost of weld repair.

[0022] Since the nozzle is placed on the steel pipe, there is point contact, and the gap between the nozzle and the steel pipe increases from the contact point to both sides. It is difficult to weld linearly around the connection point, so further improvements are made to solve this problem. Specifically, the first weld, the second weld, the third weld and the fourth weld have the same structure, are all fillet welds, and the welding method adopts swing welding.

[0023] In order to improve the connection strength between the steel pipe and the nozzle, a further design is: the first weld, the second weld, the third weld and the fourth weld are welded in two layers, and the welding of each layer adopts steps S2-S5; the width of the second layer weld is 2 / 3 wider than the width of the first layer weld.

[0024] The welding rod is generally moved at a constant speed for welding. When it moves to the connection between the steel pipe and the nozzle, the fusion is relatively poor, which will affect the connection strength. Therefore, further improvements are made to solve this problem. Specifically, when the welding rod is welded to the connection between the steel pipe and the nozzle, it pauses for 0.5-1 second.

[0025] The choice of welding rod directly affects weld quality and the strength of the connection between the steel pipe and the nozzle. Based on this, the following design is further developed: the maximum width of the gap between the steel pipe and the nozzle is set to s, and the diameter of the welding rod is set to d. During the first weld, 0.6s>d>0.5s; during the second weld, s≤d≤s+1. When the welding rod is positioned at the angle between the steel pipe and the nozzle, a triangular gap is formed. Adjusting the welding rod diameter can reduce the size of this gap, allowing the melted welding rod to quickly fill the gap, thereby improving the strength of the connection between the steel pipe and the nozzle. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] The present invention will be further described below with reference to the accompanying drawings and examples.

[0027] Figure 1 It is a structural schematic diagram of the present invention;

[0028] Figure 2-Figure 5 It is a schematic diagram of the welding sequence;

[0029] Figure 6 This is a structural diagram of the slag blowing pipe;

[0030] In the figure: 1. Clamp; 2. Steel pipe; 3. Support block; 4. Pressure plate; 5. Tightening bolt; 6. Pipe plug; 7. Spacer; 8. Adjusting bolt; 9. Work table; 10. Nozzle; 11. First weld; 12. Second weld; 13. Third weld; 14. Fourth weld; 15. Slot. DETAILED DESCRIPTION

[0031] The present invention will now be described in further detail with reference to the accompanying drawings, which are simplified schematic diagrams that illustrate the basic structure of the present invention in a schematic manner.

[0032] Example 1:

[0033] like Figure 1 As shown, the present invention discloses a slag blowing pipe welding tool, which includes two symmetrically arranged clamping seats 1, which are installed on a work surface 9 and are locked and fixed by bolts.

[0034] The clamping base 1 is provided with slots 15, which are arranged opposite each other, and the steel pipe 2 is inserted into the slots 15. The upper end of the clamping base 1 is provided with multiple threaded tightening bolts 5, and the upper side of the slots 15 is provided with a pressure plate 4. The threaded ends of the tightening bolts 5 abut against the pressure plate 4, and drive the pressure plate 4 to compress the steel pipe 2.

[0035] The work surface 9 is provided with a plurality of support blocks 3, the height of which decreases from the middle to the sides, for supporting the steel pipe 2 so that the steel pipe 2 is bent upward. The upper end of the support block 3 is provided with a V-shaped groove, and the steel pipe 2 is placed in the V-shaped groove to improve stability.

[0036] First, the steel pipe 2 is fixed so that it bends downward, and then the nozzle 10 is welded to the upper end of the steel pipe 2. After the steel pipe 2 is released, the deformation caused by welding is in the opposite direction of the bending direction before welding, and the amount of deformation caused by welding just compensates for the bending before welding, so that the steel pipe 2 is in a straight state after welding. This invention eliminates the straightening process, not only improving efficiency but also preventing weld cracking.

[0037] Example 2:

[0038] Compared with the first embodiment, the difference is that pipe plugs 6 are inserted at both ends of the steel pipe 2. The pipe plugs 6 support the ends of the steel pipe 2 to prevent them from being crushed.

[0039] Example 3:

[0040] Compared with Example 1, the difference is that when the steel pipe 2 is bent downward, its end will form an angle with the work surface 9, so the opening direction of the slot 15 also needs to form an angle with the work surface 9, which will increase the processing difficulty of the slot 15. Therefore, the lower end of the clamp 1 is also connected to a triangular pad 7, so that the inner end of the clamp 1 is tilted upward.

[0041] Example 4:

[0042] Compared with Example 3, the difference is: if the bending angle of the steel pipe 2 is different, different pads 7 need to be matched, which will increase the cost of the pads 7. Therefore, the following design is made: the pads 7 are located on both axial sides of the steel pipe 2 and are threadedly connected with adjusting bolts 8. By adjusting the length of the threaded end of the adjusting bolt 8 protruding from the lower end face of the pad 7, the inclination angle of the upper end face of the pad 7 is adjusted, so that the tooling can be suitable for steel pipes 2 with different bending angles, saving costs.

[0043] Embodiment 5:

[0044] The present invention further discloses a slag blowing pipe welding method, which uses any one of the slag blowing pipe welding tools of embodiments 1 to 4 to fix the steel pipe 2, comprising the following steps:

[0045] S1. Spot weld the nozzles 10 onto the steel pipe 2 in sequence, with the outlet facing upwards;

[0046] S2. Set a natural number n, such as Figure 2 As shown, the 2n+1th nozzle 10 is welded, and its weld is set as the first weld 11. The first weld 11 is semi-annular and located on the same axial side of the steel pipe 2. After the welding is completed, the root is cleaned;

[0047] S3, such as Figure 3 As shown, the 2n+2nd nozzle 10 is welded, and its weld is set as the second weld 12, the second weld 12 is semi-annular and arranged opposite to the first weld 11; after the welding is completed, the root is cleaned;

[0048] S4, such as Figure 4 As shown, the 2n+1th nozzle 10 is welded, and its weld is set as the third weld 13. The third weld 13 is semi-annular and forms a closed ring with the first weld 11. After the welding is completed, the root is cleaned;

[0049] S5, such as Figure 5 As shown, the 2n+2nd nozzle 10 is welded, and its weld is set as the fourth weld 14. The fourth weld 14 is semi-annular and forms a closed ring with the second weld 12. After welding is completed, the root is cleaned;

[0050] S6, repeating the operations S2-S5 to weld the second layer of weld seams, wherein the width of the second layer of weld seams is 2 / 3 wider than the width of the first layer of weld seams. In this way, the connection strength between the steel pipe 2 and the nozzle 10 can be improved.

[0051] Since the nozzle 10 is placed on the steel pipe 2, there is point contact, and the gap between the nozzle 10 and the steel pipe 2 increases from the contact point to both sides, and linear welding around the connection is difficult. Therefore, the first weld 11, the second weld 12, the third weld 13 and the fourth weld 14 have the same structure, are all fillet welds, and the welding method adopts swing welding.

[0052] The maximum width of the gap between the steel pipe 2 and the nozzle 10 is set to s, and the diameter of the welding rod is set to d. During the first weld, 0.6s > d > 0.5s; during the second weld, s ≤ d ≤ s + 1. When the welding rod is positioned at the angle between the steel pipe 2 and the nozzle 10, a triangular gap is formed. Adjusting the welding rod diameter can reduce the size of the gap, allowing the melted welding rod to quickly fill the gap, thereby improving the connection strength between the steel pipe 2 and the nozzle 10.

[0053] The above welding method can effectively disperse the welding heat, reduce the temperature difference between the two ends of the weld, avoid or reduce the thermal expansion deformation caused by welding, thereby improving production efficiency and reducing the cost of weld repair.

[0054] Example 6:

[0055] Compared with Example 5, the difference is that the welding rod generally moves at a constant speed during welding. When it reaches the connection between the steel pipe 2 and the nozzle 10, the fusion is relatively poor, which affects the connection strength. Therefore, when the welding rod welds to the connection between the steel pipe 2 and the nozzle 10, it pauses for 0.5-1 second.

[0056] With the above-described preferred embodiments of the present invention as a guide, and with reference to the above description, relevant personnel are fully capable of making various changes and modifications without departing from the technical scope of this invention. The technical scope of this invention is not limited to the contents of the specification and must be determined according to the scope of the claims.

Claims

1. A welding method for a slag blowing pipe, characterized in that: Use a slag blowing pipe welding tool to fix the steel pipe (2); The slag blowing pipe welding tool comprises: Two symmetrically arranged clamping seats (1) fix the two ends of the steel pipe (2) by clamping; A plurality of support blocks (3), the height of which decreases from the middle to both sides, for supporting the steel pipe (2) so that the steel pipe (2) bends upward; The clamping seat (1) is provided with a slot (15), and the steel pipe (2) is inserted into the slot (15); A pressure plate (4) is provided on the upper side of the slot (15), which is tightened by a tightening bolt (5) connected by thread, thereby pressing the steel pipe (2); Pipe plugs (6) are inserted at both ends of the steel pipe (2); The lower end of the clamp seat (1) is also connected to a triangular pad (7), so that the inner end of the clamp seat (1) is tilted upward; The pad (7) is located on both axial sides of the steel pipe (2) and is threadedly connected to an adjusting bolt (8). By adjusting the distance between the threaded end of the adjusting bolt (8) and the work surface (9), the inclination angle of the upper end surface of the pad (7) is adjusted; The following steps are involved: S1. Spot-weld the nozzles (10) onto the steel pipe (2) in sequence, with the outlets facing upwards; S2, setting a natural number n, welding the 2n+1th nozzle (10), wherein the weld is set as a first weld (11), the first weld (11) is semi-annular and is located on the same axial side of the steel pipe (2); S3, welding the 2n+2th nozzle (10), wherein the weld is set as a second weld (12), the second weld (12) is semi-annular and arranged opposite to the first weld (11); S4, welding the 2n+1th nozzle (10), wherein the weld is set as a third weld (13), the third weld (13) is semi-annular and forms a closed ring with the first weld (11); S5. Welding the 2n+2th nozzle (10), wherein the weld is set as a fourth weld (14), the fourth weld (14) is semi-annular and forms a closed ring with the second weld (12).

2. The welding method for a slag blowing pipe according to claim 1, characterized in that: The first weld (11), the second weld (12), the third weld (13) and the fourth weld (14) have the same structure, are all fillet welds, and are welded by rocking welding.

3. The welding method for a slag blowing pipe according to claim 2, characterized in that: The first weld (11), the second weld (12), the third weld (13) and the fourth weld (14) are all welded in two layers, and the welding of each layer adopts steps S2-S5; the width of the weld of the second layer is 2 / 3 wider than the width of the weld of the first layer.

4. The welding method for a slag blowing pipe according to claim 3, characterized in that: When the welding rod is welded to the connection between the steel pipe (2) and the nozzle (10), a pause of 0.5-1 second is performed.

5. The welding method for a slag blowing pipe according to claim 3, characterized in that: The maximum width of the gap between the steel pipe (2) and the nozzle (10) is set to s, and the diameter of the welding rod is set to d; When welding the first layer of weld, 0.6s>d>0.5s; When welding the second layer of weld, s≤d≤s+1.

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