A pulse submerged arc welding method applied to a power transmission line tower pole

Abstract

The application discloses a pulse submerged-arc welding method applied to a power transmission line tower pole, which comprises the following steps: groove processing, parallel face root cleaning, assembly preparation, pre-fixing, welding preparation, upper surface welding, edge turning treatment and bottom surface welding. The welding method is characterized in that the groove is designed as a Y type after combination, the upper and lower V grooves are connected through parallel channels, and the upper and lower solder accumulation V grooves are not on the same vertical line, so that the pressure strength is higher than that of a V type or X type groove. In the welding process, the parallel channels are connected by using spot welding first, and then in the subsequent pulse submerged-arc welding process, the welding liquid can flow obliquely, fill the parallel channels and the flow channels arranged obliquely, so that the flow rate is reduced, the welding liquid is caused to be wall-hung in the parallel channels and finally fills the whole channels, so that the overall welding surface between the two steel plates is improved, and the problems of a large welding amount, low welding strength and a large welding proportion in the traditional V type large groove welding are avoided.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of submerged arc welding, in particular to a pulse submerged arc welding method applied to a power transmission line tower. BACKGROUND

[0002] Submerged arc welding (including submerged arc surfacing and electroslag surfacing, etc.) is a method of welding with an electric arc burning under a layer of flux. Its inherent advantages of stable welding quality, high welding productivity, no arc light, and little smoke make it the main welding method for important steel structure manufacturing such as pressure vessels, pipe sections, box beams, and columns.

[0003] In the welding process of a power transmission line tower, in order to ensure the strength of the structure, a more efficient welding method is needed to improve the welding strength. Currently, when welding thick structures (20mm or more in thickness), V-shaped welds and I-shaped welds are mostly used.

[0004] Among them, V-shaped welds are widely used, but the disadvantages of V-shaped welds are that the welding amount is large, the welding cycle is long, and the welding strength is low, especially for thick plates.

[0005] Therefore, to improve the welding strength of thick plates and reduce the welding amount, the present application proposes a pulse submerged arc welding method applied to a power transmission line tower. SUMMARY

[0006] The purpose of the present application is to solve the shortcomings in the prior art and propose a pulse submerged arc welding method applied to a power transmission line tower.

[0007] In order to achieve the above-mentioned purpose, the present application adopts the following technical solutions:

[0008] A pulse submerged arc welding method applied to a power transmission line tower, comprising:

[0009] S1, groove machining: two steel plates to be welded are combined after machining and design to form a Y-shaped groove, and the upper and lower surfaces are both Y-shaped grooves, and the longest sides of the upper and lower grooves form a parallel channel in common;

[0010] S2, parallel surface root cleaning: the parallel surfaces of the grooves of the two steel plates are cleaned;

[0011] S3, assembly preparation: the two steel plates are combined, and the gap is adjusted to a specific assembly gap;

[0012] S4, pre-fixing: spot welding, filling the groove gap parallel channel, and the welding point spacing is 5-10cm;

[0013] S5, welding preparation: setting triangular welding backing plate inside bottom V groove, and performing cleaning treatment on inner wall of upper V groove; adjusting submerged arc welding trolley track, and aligning welding wire center with groove center;

[0014] S6, upper welding procedure: performing front submerged arc welding operation;

[0015] S7, flanging treatment: turning over the steel plate after welding cooling, removing welding backing plate, and performing upper V groove cleaning operation;

[0016] S8, bottom welding procedure: performing bottom submerged arc welding operation.

[0017] Preferably, the steel plate thickness is not less than 20 mm, the groove short side cutting angle a1 is 36°, the groove long side cutting angle a2 is 26°, the Y-shaped section internal horizontal passage vertical height P is at least half of the steel plate thickness H, the upper and bottom V groove maximum width W is at least half of the steel plate thickness H, and the gap V between the parallel faces of the two steel plates in the step S3 assembly preparation is one fourth of the steel plate thickness H.

[0018] Preferably, the upper welding procedure and the bottom welding procedure are both automatic submerged arc welding using ultra-low frequency pulse submerged arc welding, and the total welding amount is based on filling the upper and bottom V grooves.

[0019] Preferably, the pulse frequency in the steps S6 and S8 welding is 360-370 Hz, the base current is 100 A, the pulse time is 1.7-1.8 ms, the average welding current is 590±10 A, and the pulse peak current is 720 A.

[0020] Preferably, the welding wire diameter in the steps S6 and S8 is 3 mm, the welding flux particle size is 12-60 mesh, the welding is performed in a multi-layer and multi-pass fast welding manner, the interlayer temperature is controlled at 130-140℃, the welding line energy is controlled at 20-24 KJ / cm, and the welding speed is 125-135 cm / min.

[0021] Preferably, in the step S5, the cleaning operation is simultaneously performed on the area within 10-15 cm range around the bottom V groove, and the metal luster is exposed as the reference.

[0022] Preferably, in the step S7, the cleaning operation is simultaneously performed on the area within 5-10 cm range around the upper V groove, and the metal luster is exposed as the reference.

[0023] Preferably, the welding backing plate is made of high-temperature resistant ceramic, is used for plugging the lower V groove, and has a flat upper surface, and the top of the welding backing plate does not enter the parallel gap between the two steel plates, but only plugs the parallel gap from the bottom.

[0024] Beneficial effects: the pulse submerged arc welding method applied to the power transmission line tower rod provided by the application, by designing the groove as a combination of Y type, the upper and lower two V grooves are connected through parallel channels, and the upper and lower two solder accumulation V grooves are not on the same vertical line, the welding point after forming has strong impact resistance, and the pressure strength is higher than that of V type or X type groove, meanwhile, in the welding process, the parallel channels are connected by using spot welding first, and in the subsequent pulse submerged arc welding process, the welding liquid can flow obliquely, fill the parallel channels, the obliquely arranged flow channels can reduce the flow rate, promote the welding liquid to hang on the wall inside the parallel channels, and finally fill the entire channel, so that the overall welding surface between the two steel plates is improved, and the phenomenon of more welding amount, low welding strength and more welding proportion in traditional V type large groove welding is eliminated. BRIEF DESCRIPTION OF DRAWINGS

[0025] Figure 1 It is a welding display diagram of two steel plates in the application.

[0026] Figure 2 It is a steel plate cross-sectional structure schematic diagram in the welding process.

[0027] In the figure: a1, groove short side cutting angle; a2, groove long side cutting angle; H, steel plate thickness; P, vertical height of Y type cross-section internal horizontal channel; W, maximum width of V type groove; V, gap between parallel faces of two steel plates. DETAILED DESCRIPTION

[0028] The technical solutions in the embodiments of the application will be clearly and completely described below with reference to the drawings in the embodiments of the application. Obviously, the described embodiments are only part of the embodiments of the application, not all embodiments of the application.

[0029] In the description of the application, it should be understood that the terms "upper", "lower", "front", "rear", "left", "right", "top", "bottom", "inner", "outer" and the like indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the application and simplifying the description, and do not indicate or imply that the devices or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, therefore it cannot be understood as a limitation on the application.

[0030] Embodiment 1

[0031] A pulse submerged arc welding method applied to a power transmission line tower rod

[0032] S1, groove processing: two steel plates to be welded are processed and designed to form a Y type groove, and the upper and lower surfaces are Y grooves, and the Y type longest edges of the upper and lower grooves are connected to form parallel channels;

[0033] S2, parallel face root cleaning: the parallel faces of the bevels of the two steel plates are root cleaned;

[0034] S3, assembly preparation: the two steel plates are combined, and the gap is adjusted to a specific assembly gap;

[0035] S4, pre-fixing: spot welding, filling the bevel gap parallel channel, and the welding point spacing is 6 cm;

[0036] S5, welding preparation: a triangular welding backing plate is arranged inside the bottom V groove, and the upper V groove inner wall is root cleaned; the submerged arc welding trolley track is adjusted, and the welding wire center is aligned with the bevel center;

[0037] S6, upper welding process: front submerged arc welding operation is performed;

[0038] S7, flanging treatment: the steel plate is turned over after welding cooling, the welding backing plate is removed, and the upper V groove root cleaning operation is performed;

[0039] S8, bottom welding process: bottom submerged arc welding operation is performed;

[0040] The thickness of the steel plate is 30 mm, the bevel short side cut angle a1 is 36°, the bevel long side cut angle a2 is 26°, the Y-shaped cross-section internal horizontal channel vertical height P is half of the steel plate thickness H, the upper and bottom V-shaped groove maximum width W is half of the steel plate thickness H, and the parallel face gap V of the two steel plates in step S3 assembly preparation is one fourth of the steel plate thickness H;

[0041] Both the upper welding process and the bottom welding process are automatic submerged arc welding using ultra-low frequency pulse submerged arc welding, and the total welding amount is based on filling the upper and bottom V grooves.

[0042] In the above welding process, the welding pulse frequency is 360 Hz, the base current is 100 A, the pulse time is 1.7 ms, the average welding current is 580 A, the pulse peak current is 720 A, the welding wire diameter is 3 mm, the welding flux particle size is 40 mesh, and the welding is performed in a multi-layer and multi-pass fast welding manner, the interlayer temperature is controlled at 130°C, the welding line energy is controlled at 24 KJ / cm, and the welding speed is 125 / min.

[0043] In step S5, the area within a range of 15 cm around the bottom V groove is root cleaned at the same time, and the metal luster is exposed as a reference, and in step S7, the area within a range of 10 cm around the upper V groove is root cleaned at the same time, and the metal luster is exposed as a reference.

[0044] Example 2

[0045] A pulse submerged arc welding method applied to a power transmission line tower pole

[0046] S1, groove processing: two pieces of steel plate to be welded are processed and designed to form a Y-shaped groove, and the upper and lower surfaces are Y-shaped grooves, and the Y-shaped longest edges of the upper and lower grooves are commonly formed into parallel channels;

[0047] S2, parallel surface root cleaning: the parallel surfaces of the grooves of the two steel plates are cleaned;

[0048] S3, assembly preparation: the two steel plates are combined, and the gap is adjusted to a specific assembly gap;

[0049] S4, pre-fixing: spot welding, filling the gap of the groove parallel channel, the welding point spacing is 8 cm;

[0050] S5, welding preparation: a triangular welding backing plate is arranged inside the bottom V groove, and the upper V groove inner wall is cleaned; the submerged arc welding trolley track is adjusted, and the welding wire center is aligned with the groove center;

[0051] S6, upper welding process: front submerged arc welding operation is performed;

[0052] S7, flanging treatment: after the steel plate is cooled after welding, the welding backing plate is removed, and the upper V groove is cleaned;

[0053] S8, bottom welding process: bottom submerged arc welding operation is performed;

[0054] The thickness of the steel plate is 35 mm, the groove short edge cutting angle a1 is 36°, the groove long edge cutting angle a2 is 26°, and the vertical height P of the Y-shaped cross-section internal horizontal channel is half of the thickness H of the steel plate. The maximum width W of the upper and lower V grooves is half of the thickness H of the steel plate. In step S3, the parallel surface gap V of the two steel plates is one fourth of the thickness H of the steel plate.

[0055] Both the upper welding process and the bottom welding process are automatic submerged arc welding using ultra-low frequency pulse submerged arc welding, and the total welding amount is based on filling the upper and lower V grooves.

[0056] In the above welding process, the welding pulse frequency is 370 Hz, the base current is 100 A, the pulse time is 1.8 ms, the average welding current is 590 A, the pulse peak current is 720 A, the welding wire diameter is 3 mm, the welding flux particle size is 40 mesh, and the welding is performed in a multi-layer and multi-pass fast welding manner. The interlayer temperature is controlled at 130°C, the welding line energy is controlled at 23 KJ / cm, and the welding speed is 130 / min.

[0057] In step S5, the area within 10 cm of the bottom V groove is cleaned, and the metal luster is exposed as a reference. In step S7, the area within 10 cm of the upper V groove is cleaned, and the metal luster is exposed as a reference.

[0058] In the present application, by designing the groove as a combination of Y type, the upper and lower V grooves are connected through parallel channels, and the upper and lower solder accumulation V grooves are not on the same vertical line, the formed welding point has strong impact resistance, and the pressure strength is higher than that of V type or X type groove, meanwhile, in the welding process, the parallel channels are first connected by spot welding, and then in the subsequent pulse type submerged arc welding process, the welding liquid can flow obliquely, fill the parallel channels, the obliquely arranged flow channel can reduce the flow rate, promote the welding liquid to hang on the wall inside the parallel channel, and finally fill the entire channel, so as to improve the overall welding surface between the two steel plates, and also eliminate the phenomenon of more welding amount, low welding strength and more welding proportion in the traditional V type large groove welding.

[0059] The above is only the preferred specific embodiment of the present application, but the protection scope of the present application is not limited to this, any skilled person in the art can make equivalent replacement or change according to the technical scheme and the inventive concept of the present application within the technical range disclosed by the present application, which should be covered in the protection scope of the present application.

Claims

1. A method of pulsed submerged arc welding applied to a tower pole of a power transmission line, characterized by, Comprise: S1, groove machining: two pieces of steel plate to be welded are processed and designed to form a Y-shaped groove, and the upper and lower surfaces are Y-shaped grooves, and the longest edges of the upper and lower grooves are commonly formed into parallel channels; S2, parallel surface root cleaning: the parallel surfaces of the grooves of the two steel plates are cleaned; S3, assembly preparation: the two steel plates are combined, and the gap is adjusted to a specific assembly gap; S4, pre-fixing: spot welding, filling the parallel channel gap, and the welding point spacing is 5-10 cm; S5, welding preparation: a triangular welding backing plate is arranged inside the bottom V groove, and the upper V groove inner wall is cleaned; the submerged arc welding trolley track is adjusted, and the welding wire center is aligned with the groove center; S6, upper welding process: front submerged arc welding operation is performed; S7, flanging treatment: the steel plate is turned over after welding and cooling, the welding backing plate is removed, and the upper V groove is cleaned; S8, bottom welding process: bottom submerged arc welding operation is performed; The thickness of the steel plate is not less than 20 mm, the groove short edge angle (a1) is 36°, the groove long edge angle (a2) is 26°, and the vertical height (P) of the Y-shaped groove inside the horizontal channel is at least half of the thickness (H) of the steel plate. The maximum width (W) of the upper and lower V grooves is at least half of the thickness (H) of the steel plate. In the step S3, the parallel gap (V) between the two steel plates is one-fourth of the thickness (H) of the steel plate. The upper and bottom welding processes are both automatic submerged arc welding using ultra-low frequency pulse submerged arc welding. The total welding amount is based on filling the upper and bottom V grooves. The welding backing plate is used to block the lower V groove, and the upper surface of the welding backing plate is flat. The top of the welding backing plate does not enter the parallel gap (V) between the two steel plates, but only blocks the parallel gap (V) from the bottom.

2. A method of pulsed submerged arc welding for use in the construction of a tower for a power transmission line according to claim 1, characterized in that: The pulse frequency in steps S6 and S8 is 360-370 Hz, the base current is 100 A, the pulse time is 1.7-1.8 ms, the average welding current is 590±10 A, and the pulse peak current is 720 A.

3. The method for pulsed submerged arc welding of a tower pole for a power transmission line according to claim 1, characterized in that: In steps S6 and S8, the welding wire diameter is 3 mm, the welding agent particle size is 12-60 mesh, and the welding is performed in a multi-layer and multi-pass fast welding manner. The interlayer temperature is controlled at 130-140℃, the welding line energy is controlled at 20-24 KJ / cm, and the welding speed is 125-135 cm / min.

4. The method for pulsed submerged arc welding of a tower pole for a power transmission line according to claim 1, characterized in that: In step S5, the area within 10-15 cm of the bottom V groove is cleaned to expose the metal luster.

5. The method of pulse submerged arc welding of a tower pole of a power transmission line according to claim 1, characterized in that: In step S7, the area within 5-10 cm of the upper V groove is cleaned to expose the metal luster.

6. The method of pulsed submerged arc welding of a tower pole for a power transmission line according to claim 1, characterized in that: The material of the welding backing plate can be a high-temperature resistant ceramic backing plate.

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