Vertical and overhead mixed penetration welding method for diamond-shaped cross-section steel tower corner welds

Abstract

The present invention relates to a vertical and overhead mixed penetration welding method for the corner welds of a steel tower with a diamond-shaped cross section. The cross section of the steel tower in this project is an octagonal design with unequal sides, presenting an irregular diamond-shaped cross section. The design requires that the connecting edges are connected by penetration welding. Due to the irregular cross section, the groove is not neat, the cross-sectional profile of the steel tower is large, and it is assembled vertically, which makes it impossible to turn over and weld. Therefore, the present invention is used, i.e., a vertical and overhead mixed penetration welding method for the corner welds of a steel tower with a diamond-shaped cross section. After the steel tower is assembled, the welding is first performed by positioning welding with an arc welding rod. In the second step, solid wire CO2 gas shielded welding is used to complete the climbing side weld. The purpose is to obtain a larger penetration depth and improve welding efficiency. In the third step, air gouging is used on the reverse side, i.e., the overhead-vertical side, to ensure the weld is fully penetrated. In the fourth step, flux-cored wire CO2 gas shielded welding is used to complete the welding of the overhead-vertical side welds. The construction efficiency of the present invention is greatly improved, and the one-time flaw detection pass rate exceeds 98%.

Description

Technical Field

[0001] The invention relates to a vertical and horizontal mixed penetration welding method for diamond-shaped cross-section steel tower corner welds, which can effectively avoid turning over of corner welded tower segments and avoid structural deformation during the turning over process. Background Art

[0002] The existing bridge steel tower design cross-sections can be divided into regular quadrilaterals and regular octagons. They have common characteristics for the corner welds. They can be adjusted when designing the welding grooves, and the welding process can be turned over. The efficiency and quality of the corner welds are easy to ensure. The diamond-shaped cross-section steel tower has an irregular structure, and the design of the corner weld grooves is difficult to adjust. The conventional process needs to solve the following problems: (1) The tower cross-section is an irregular octagon, diamond-shaped, and has a large cross-sectional profile. The flat welding of the corner weld tower segment cannot be turned over. That is, the diamond-shaped cross-section steel tower has an irregular structure and the design of the groove is difficult to adjust. More importantly, the corner welding process is difficult to turn over. If it is necessary to turn over, more equipment needs to be invested, the cost is high, and the safety risk is high. After turning over, when the conventional steel tower corner weld welding process is used, only two welds can be welded each time, the welding efficiency is low, and the deformation caused by the turning process will affect the outline size and welding quality; (2) The deformation caused by the turning process will affect the outline size. Therefore, the existing welding technology can no longer provide technical support for the welding of diamond-shaped cross-section corner welds. Summary of the Invention

[0003] Design purpose: To avoid the shortcomings of the background technology, a vertical and horizontal mixed penetration welding method for the corner welds of diamond-shaped steel towers is designed, which can effectively avoid the overturning of the tower segments during the corner weld welding and avoid structural deformation caused by the overturning process.

[0004] Design Solution: To achieve the above design objectives, the present invention has designed and developed a vertical and horizontal mixed penetration welding method for diamond-shaped steel tower corner welds to overcome the shortcomings of traditional technologies and achieve high efficiency and practicality. That is, while ensuring the welding quality of steel tower corner welds, it also improves welding efficiency and avoids the safety risks caused by turning over.

[0005] The present invention first uses a computer to simulate the actual bridge posture of the tower segment and designs the welding groove. When assembling the tower segments, positioning welding is completed on the climbing welding side to ensure the structural size. In order to improve welding efficiency, the climbing welding side is completed by solid welding wire CO2 gas shielded welding. After the vertical and overhead sides are cleaned by arc air gouging, flux-cored wire CO2 gas shielded welding is used to complete the welding. After passing the non-destructive testing, the welding of the corner weld is completed.

[0006] (1) Design of welding groove for tower segment in simulation of actual bridge: Based on the vertical and horizontal welding conditions of tower segment in the actual bridge state, a double-sided "V" type welding groove is designed ( Figure 3), ensure that the weld is fully melted and that the weld and the wood have equal strength connection;

[0007] (2) Tower segment assembly: When assembling the steel tower segment, arc welding is used to position the segment to ensure the geometric dimensions of the steel tower segment. Generally, the positioning welding is completed with a current of 150±15A. The climbing side positioning ( Figure 2 ), the tack weld length is 50~100mm, and the interval is 400~600mm to avoid the tack weld tearing causing the geometric dimensions of the steel tower segment to change and affect the manufacturing accuracy;

[0008] (3) Tower segment climbing welding side welding: In order to ensure a greater penetration depth during the welding process and improve welding efficiency, solid wire CO2 gas shielded welding is used to complete the climbing welding side weld, see Figure 3 Since the steel tower segments have a diamond-shaped cross-section, the sides are similar to parallelograms, and the cross-section is large, turning over is difficult, so the corner welds can only be welded at the climbing position. Solid wire CO2 gas shielded welding is used to complete the climbing side welds. Generally, 240±20A current and 26±2V voltage are used to complete the climbing side welds. This takes advantage of the high efficiency of solid wire CO2 gas shielded welding.

[0009] (4) Arc gouging of vertical and upward side welds: After the climbing side weld is completed, the weld root will have a phenomenon of unfused weld and blunt edge. In order to ensure the overall penetration of the weld, the focus is on controlling the penetration of the blunt edge of the groove. Therefore, the arc gouging of the vertical and upward side welds is used. Figure 4 );

[0010] (5) Welding of the vertical and horizontal sides of the tower segment: In order to ensure the appearance quality of the weld seam outside the box, the vertical and horizontal side welds are completed by flux-cored CO2 gas shielded welding. This is mainly due to the advantages of flux-cored CO2 gas shielded welding itself in terms of welding processability. The current of 200±20A and the voltage of 24±2V are used, which also improves the welding efficiency. Figure 5 .

[0011] Technical solution: A method for vertical and overhead mixed penetration welding of diamond-shaped cross-section steel tower corner welds, (1) design of welding grooves for tower segment real bridge simulation: design welding grooves based on the vertical and overhead welding conditions of the tower segment in the real steel tower bridge state; (2) tower segment assembly: arc welding is used for climbing welding, side welding, and positioning welds during the assembly of steel tower segments; (3) tower segment climbing welding and side welding: solid wire CO2 gas shielded welding is used to complete the climbing welding side welds; (4) arc gouging of vertical and overhead side welds: arc gouging of vertical and overhead side welds is used to ensure full penetration welding; (5) tower segment vertical and overhead side welding: flux-cored wire CO2 gas shielded welding is used to complete the vertical and overhead side welds.

[0012] Compared with the background technology, the present invention, first, solves the problems that the traditional technology cannot solve; second, it avoids the turning over of the tower segment due to the welding of sharp corner welds, and avoids the structural deformation caused by the turning over process; third, the present invention has the advantage of welding eight sharp corner welds of the tower segment at the same time; fourth, the present invention does not require additional investment, is simple and easy to operate; fifth, the construction efficiency of the present invention is greatly improved and the one-time flaw detection pass rate exceeds 98%. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 It is a schematic diagram of welding groove.

[0014] Figure 2 It is a schematic diagram of tack weld welding.

[0015] Figure 3 This is a schematic diagram of the climbing side weld using solid wire CO2 gas shielded welding.

[0016] Figure 4 It is a schematic diagram of the vertical and overhead side welds of arc gouging.

[0017] Figure 5 It is a schematic diagram of the vertical and overhead side welds using flux-cored CO2 gas shielded welding.

[0018] Figure 6 This is a schematic diagram of the tower segment wall panel connection welds.

[0019] Figure 7 This is a workflow diagram of the vertical and overhead mixed penetration welding method for the corner welds of a diamond-shaped cross-section steel tower. DETAILED DESCRIPTION

[0020] Example 1: Refer to the attached Figure 1-7 1) Design the welding groove according to the vertical and horizontal welding conditions of the tower segments on the actual bridge posture of the tower column;

[0021] 2) After the steel beams are assembled, they are first positioned by arc welding to ensure the structural dimensions of the tower segments;

[0022] 3) Use solid wire CO2 gas shielded welding to complete the slope welding side weld in order to obtain greater penetration and improve welding efficiency;

[0023] 4) Use air gouging on the vertical and horizontal sides to ensure full penetration of the weld;

[0024] 5) Use flux-cored wire CO2 gas shielded welding to complete the welding of the vertical and overhead side welds.

[0025] It should be understood that although the above embodiments provide a relatively detailed textual description of the design ideas of the present invention, these textual descriptions are only simple textual descriptions of the design ideas of the present invention, rather than limitations on the design ideas of the present invention. Any combination, addition or modification that does not exceed the design ideas of the present invention shall fall within the scope of protection of the present invention.

Claims

1. A method for vertical and horizontal mixed penetration welding of diamond-shaped cross-section steel tower corner welds, characterized by: (1) Design of welding grooves for tower segments based on actual bridge simulation: Based on the vertical and horizontal welding conditions of the tower segments under the actual steel tower bridge state, a double-sided "V"-shaped welding groove is designed; (2) Tower segment assembly: When assembling the steel tower segments, arc welding is used to position them to ensure the geometric dimensions of the steel tower segments. Positioning welding is completed with a current of 150±15A. Positioning is done on the climbing side. The positioning welding length is 50~100mm and the interval is 400~600mm. (3) Tower segment climbing welding side welding: Use solid wire CO2 gas shielded welding and use 240±20A current and 26±2V voltage to complete the climbing welding side weld; (4) Arc gouging of vertical and overhead side welds: After the climbing side weld is completed, the weld root will have a phenomenon of unfused weld and blunt edge. In order to ensure the overall penetration of the weld, the focus is on controlling the penetration of the blunt edge of the groove. Therefore, arc gouging is used to control the blunt edge of the vertical and overhead side welds. (5) Welding of the vertical and horizontal sides of the tower segment: The vertical and horizontal side welds are completed by flux-cored CO2 gas shielded welding, using a current of 200±20A and a voltage of 24±2V, which improves the welding efficiency.

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