CN110977114A

CN110977114A - Steel bridge welding process and device thereof

Info

Publication number: CN110977114A
Application number: CN201911380708.3A
Authority: CN
Inventors: 谈翔; 袁飞; 刘瑾; 俞卫松; 林正伯; 周炎
Original assignee: Shanghai Greenland Construction Steel Structure Co ltd; Shanghai Greenland Construction Group Co Ltd
Current assignee: Shanghai Greenland Construction Steel Structure Co ltd; Shanghai Greenland Construction Group Co Ltd
Priority date: 2019-12-27
Filing date: 2019-12-27
Publication date: 2020-04-10

Abstract

The invention discloses a steel bridge welding process, which relates to the technical field of inert gas shielded welding and comprises the following steps of S1, cleaning two sides of a welding seam to reach the light quality of metal; s2, splicing steel plates to be welded on the horizontal platform, and controlling the gap of a welding seam; s3, drying and cleaning the welding wires; s4, welding the steel plate in a gas shielded welding mode; the gas is a mixed gas of nitrogen and hydrogen under a high pressure state. Aiming at the problem that the rust-proof layer on the surface of the steel is damaged by high-temperature welding in the prior art, the invention enhances the rust-proof performance of the welding joint on the premise of ensuring the normal welding quality.

Description

Steel bridge welding process and device thereof

Technical Field

The invention relates to the technical field of inert gas shielded welding, in particular to a steel bridge welding process and a steel bridge welding device.

Background

Inert gas arc welding is arc welding in which an inert gas is used as a shield medium, and an arc burned between a fusible welding wire and a welding wire workpiece is continuously fed as a heat source. The welding quality of the inert gas shielded welding is stable and reliable, and the inert gas shielded welding is most suitable for welding nonferrous metal medium plates such as aluminum, copper, titanium and alloys thereof, and is also suitable for welding stainless steel, heat-resistant steel, low alloy steel and the like.

For the existing gas shielded welding process, for example, chinese patent with patent publication No. CN102126089B, it discloses a novel welding process combining submerged arc welding and CO2 gas shielded welding, and adopts the welding power supply, control box and welding carriage of submerged arc welding, and the welding carriage is equipped with the welding gun of CO2 gas shielded welding, but does not use CO2 gas; the welding wire of the gas shielded welding passes through a wire feeder and a welding gun of the CO2 gas shielded welding, and the welding flux of the submerged arc welding is used for welding two layers of the backing welding layer and the cover welding layer on the welding seam of the workpiece.

When the steel is welded by adopting the above patent, the surface of the finished steel can be subjected to rust prevention treatment, a rust prevention layer is formed on the surface of the finished steel, and after high-temperature welding treatment, particularly in the field of welding of steel structures and bridges, the steel at the welding joint is subjected to high-temperature treatment, the rust prevention layer on the surface of the joint is easily damaged, and then in the subsequent use process, the steel welding joint is exposed to the outside and is easily rusted, so that the attractiveness and the safety are influenced.

Disclosure of Invention

Aiming at the problem that the rust-proof layer on the surface of steel is damaged by high-temperature welding in the prior art, the invention aims to provide a steel bridge welding process and a steel bridge welding device, which can enhance the rust-proof performance of a welding joint on the premise of ensuring the normal welding quality.

The above object of the present invention is achieved by the following technical solutions:

a steel bridge welding process comprises the following steps,

s1, cleaning the two sides of the welding seam to reach the light quality of the metal;

s2, splicing steel plates to be welded on the horizontal platform, and controlling the gap of a welding seam;

s3, drying and cleaning the welding wires;

s4, welding the steel plate in a gas shielded welding mode; the gas is a mixed gas of nitrogen and hydrogen under a high pressure state.

By adopting the technical scheme, the temperature of the welding pool is highest, wherein the temperature of the stainless steel welding pool is 1520-1570 ℃, the temperature of the carbon steel is 1450-1480 ℃, and the temperature of the peripheral side of the welding pool is slightly lower than that of the welding pool; the mixed gas of nitrogen and hydrogen under the high pressure state is adopted as the protective gas to implement gas shielded welding, the high-temperature environment of the welding position is matched, the reduction heat treatment is implemented on the welding position, on the premise of ensuring the normal welding quality, an antirust protective layer is formed on the surface of the welding position, the welding connection position is prevented from being easily oxidized, and therefore the purpose of rust prevention is achieved.

The present invention in a preferred example may be further configured to: the ratio of the volume of hydrogen to the volume of nitrogen is 0.03 to 0.1.

By adopting the technical scheme, the proportion of the volume of hydrogen to the volume of nitrogen is reasonably controlled, and anaerobic heat treatment is carried out on the welding position while the construction safety is ensured.

The present invention in a preferred example may be further configured to: the specific operation of step S3 is: and (3) drying the welding wire for 2 hours in an environment of 250-300 ℃, and then preserving heat in an environment of 100-150 ℃.

By adopting the technical scheme, the welding wire is cleaned and dried, and the normal use of the welding wire is ensured.

The utility model provides a steel bridge welding set, includes the nozzle, coaxial fixed with current-conducting nozzle in the nozzle, run through in the current-conducting nozzle and seted up the welding wire hole, current-conducting nozzle with circumference is provided with airflow channel between the nozzle, still be connected with on the nozzle with the air supply pipe of airflow channel intercommunication, the air supply pipe is kept away from the one end of nozzle is connected with nitrogen cylinder and hydrogen cylinder.

By adopting the technical scheme, the mixed gas of nitrogen and hydrogen is used as the protective gas to implement gas shielded welding under the high-pressure state, the purpose of implementing anaerobic heat treatment on the welding position is achieved by matching the high-temperature environment of the welding position, the antirust protective layer is formed on the surface of the welding position, the welding connection position is prevented from being easily oxidized, and the purpose of rust prevention is achieved.

The present invention in a preferred example may be further configured to: be provided with the tubule along its extending direction in the air feed pipe, the one end of tubule is located in the air feed pipe, the other end extends the air feed pipe is connected with the hydrogen cylinder.

By adopting the technical scheme, the hydrogen is supplied to the nitrogen in the gas supply pipe by utilizing the thin pipe, and the proportion between the nitrogen and the hydrogen is effectively controlled.

The present invention in a preferred example may be further configured to: the tubule is located one end tip in the air feed pipe seals the setting, the tubule is located a plurality of thin through-holes have been seted up along its length direction to one end lateral wall in the air feed pipe.

By adopting the technical scheme, the hydrogen and nitrogen are effectively enhanced and the mixing uniformity is improved.

The present invention in a preferred example may be further configured to: the coaxial backing sheet that is fixed with in the air feed pipe, the perforation has been seted up to coaxial running through on the backing sheet, the tubule is located one end in the air feed pipe passes a plurality ofly in proper order the perforation.

Through adopting above-mentioned technical scheme, utilize the backing sheet with tubule coaxial support in the air feed pipe, ensure that the perforation smoothly supplies hydrogen.

The present invention in a preferred example may be further configured to: the contact tube is close to the one end of the nozzle opening is arranged to be round platform-shaped, the inner diameter of the nozzle is gradually reduced along the direction close to the opening of the nozzle, and the opening of the nozzle is flush with the end part of the contact tube.

By adopting the technical scheme, the device is used for intensively supplying the mixed gas to the welding generation point, so that the mixed gas can be impacted to the welding generation position, the mixed gas is heated at high temperature, and the mixed gas is fully contacted with the welding position; secondly, the mixed gas impact is also beneficial to welding wire feeding and drawing of the welding wire.

The present invention in a preferred example may be further configured to: the cross-section of the air flow channel is gradually reduced along the direction close to the opening of the air flow channel.

By adopting the technical scheme, the loss of the gas pressure of the mixed gas is reduced, the mixed gas is ensured to be sufficient with a welding part in a high-temperature and high-pressure state, and reduction heat treatment is carried out.

The present invention in a preferred example may be further configured to: the opening part cover of nozzle is equipped with loudspeaker form transparent safety cover.

Through adopting above-mentioned technical scheme to avoid the outside air to get into, be favorable to the abundant reaction of mist and welding department simultaneously.

In summary, the invention includes at least one of the following beneficial technical effects:

(1) the mixed gas of nitrogen and hydrogen under high pressure is used as protective gas to carry out gas shielded welding, and reduction heat treatment is carried out on the welding position in cooperation with the high-temperature environment of the welding position, so that an anti-rust protective layer is formed on the surface of the welding position, the welding position is prevented from being easily oxidized, and the anti-rust performance of the welding position is enhanced;

(2) furthermore, the mixed gas is intensively supplied to the welding generation point, so that the mixed gas is favorably impacted to the welding generation position, the mixed gas is heated at high temperature, and the mixed gas is fully contacted with the welding position; secondly, the mixed gas impact is also beneficial to welding wire supply and drawing of welding wires;

(3) furthermore, the thin tube is coaxially erected in the gas supply tube, so that the hydrogen and the nitrogen are effectively enhanced and the uniform mixing degree is effectively enhanced.

Drawings

FIG. 1 is a block flow diagram of a steel bridge welding process;

FIG. 2 is a schematic structural diagram of a steel bridge welding device;

fig. 3 is a partially enlarged view of a portion a in fig. 2.

In the figure: 1. a nozzle; 2. a contact tip; 3. a wire hole; 4. an air flow channel; 5. a gas supply pipe; 6. a nitrogen gas cylinder; 7. a hydrogen gas cylinder; 8. a thin tube; 9. a thin through hole; 10. a support sheet; 11. perforating; 12. a horn-shaped transparent protective cover; 13. a wire feeder; 14. a wire reel feeding mechanism; 15. a hose.

Detailed Description

The present invention will be described in further detail with reference to the accompanying drawings.

Referring to fig. 1, a steel bridge welding process includes the steps of,

s1, removing oil stain, rust, moisture, burrs and other impurities in the range of 25mm on both sides of the welding line by adopting a pneumatic steel wire brush to achieve the light quality of the metal;

s2, splicing steel plates to be welded on a horizontal platform, controlling the gap of a welding seam, carrying out electric welding splicing at a distance of 300mm, and welding an arc striking plate and an arc extinguishing plate at two ends of the welding seam, wherein the thickness of the arc striking plate and the arc extinguishing plate is the same as that of the steel plates;

s3, drying and cleaning the welding wire: and (3) drying the welding wires in an environment of 250-300 ℃ for 2 hours, then placing the welding wires in a heat preservation box of 100-150 ℃ for heat preservation and storage, and taking the welding wires out of the heat preservation box for more than 4 hours to be dried again.

And S4, performing gas shielded welding by using a mixed gas of nitrogen and hydrogen under a high pressure as a shielding gas, wherein the ratio of the volume of the hydrogen to the volume of the nitrogen is 0.03-0.1.

And S5, detecting the flaw by using ultrasonic waves and rays.

In a common welding process, the temperature of a welding pool is highest, wherein the temperature of the stainless steel welding pool is 1520-1570 ℃, the temperature of carbon steel is 1450-1480 ℃, and the temperature of the periphery of the welding pool is slightly lower than that of the welding pool; the mixed gas of nitrogen and hydrogen under high pressure is used as protective gas to implement gas shielded welding, and the high-temperature environment of the welding position is matched to achieve the purpose of implementing anaerobic heat treatment on the welding position and avoid the easy oxidation of the welding position, thereby achieving the purpose of rust prevention.

Referring to fig. 2 and 3, the steel bridge welding device disclosed by the invention comprises a nozzle 1, a contact tip 2 is coaxially fixed in the nozzle 1, a welding wire hole 3 penetrates through the contact tip 2, one end, away from the opening of the nozzle 1, of the welding wire hole 3 is connected with a hose 15, one end, away from the contact tip 2, of the hose 15 is sequentially provided with a wire feeding mechanism 13 and a wire reel feeding mechanism 14, a power supply is electrically connected between the contact tip 2 and a welding object, an air flow channel 4 is circumferentially arranged between the contact tip 2 and the nozzle 1, the nozzle 1 is further connected with an air supply pipe 5 communicated with the air flow channel 4, and one end, away from the nozzle 1, of the air supply pipe 5 is connected with a nitrogen cylinder 6 and a hydrogen cylinder 7.

When the welding wire feeding device is used, welding wire raw materials are placed on the welding wire coil feeding mechanism 14 in a disc shape, the welding wires penetrate through the hose 15 and extend into the contact tip 2, the power supply is started, current at one end of the power supply is transmitted to the welding wires through the contact tip 2, and welding operation can be carried out after the welding wires are contacted with a welding object; in the welding process, high-pressure nitrogen and high-pressure hydrogen are stored in the nitrogen cylinder 6 and the hydrogen cylinder 7 respectively, the nitrogen and the hydrogen are sprayed to a welding place through the airflow channel 4 after being mixed in the air supply pipe 5, and then the metal is subjected to reduction treatment after the mixed gas of the high-pressure nitrogen and the hydrogen meets the high-temperature condition, so that the oxidation resistance of the surface of the metal is improved, and the antirust performance of the welding place is effectively enhanced.

The nitrogen cylinder 6 is directly communicated with the air supply pipe 5, and a flowmeter and a switch valve are arranged at the air outlet pipe of the nitrogen cylinder 6; be provided with tubule 8 along its extending direction in the air supply pipe 5, the one end of tubule 8 is sealed and is set up in air supply pipe 5, and a plurality of thin through-holes 9 have been seted up along its length direction to the one end lateral wall that tubule 8 is located air supply pipe 5, and the other end of tubule 8 extends air supply pipe 5 and is connected with hydrogen cylinder 7. Because the proportion of nitrogen in the mixed gas is far greater than that of hydrogen, the gas supply pipe 5 is directly communicated with the nitrogen cylinder 6, so that more nitrogen can be supplied conveniently; hydrogen occupies than less, adopts tubule 8 supply, is convenient for control hydrogen occupy than, in addition, adopts a plurality of thin through-holes 9 to supply hydrogen in the air supply pipe 5, can also be favorable to the mixture degree of consistency between hydrogen and the nitrogen gas.

A support piece 10 is coaxially fixed in the gas supply pipe 5, a through hole 11 is coaxially formed in the support piece 10 in a penetrating manner, one end of the thin pipe 8, which is positioned in the gas supply pipe 5, sequentially penetrates through the through holes 11, namely, the thin pipe 8 is coaxially supported by the support piece 10 and is arranged in the gas supply pipe 5, one end of the thin pipe 8 can prevent the thin pipe 8 from falling on the inner wall of the gas supply pipe 5 and blocking part of the thin through holes 9 to cause unsmooth hydrogen supply, and the other end of the thin pipe further promotes the mixing of hydrogen.

One end of the contact tube 2 close to the opening of the nozzle 1 is in a circular truncated cone shape, the inner diameter of the nozzle 1 is gradually reduced along the direction close to the opening, the opening of the nozzle 1 is flush with the end part of the contact tube 2, and then the mixed gas of hydrogen and nitrogen is guided by the gas flow channel 4 to be collected to the welding position below the contact tube 2, so that the impact of gas flow is enhanced, welding scraps generated in the welding process are blown away, and the mixed gas is in full contact with the welding position; the cross section of the gas flow channel 4 is gradually reduced in the direction close to the opening thereof to reduce the loss of the gas pressure of the mixed gas. The opening of the nozzle 1 is sleeved with a horn-shaped transparent protective cover 12 to prevent outside air from entering and simultaneously facilitate the full reaction of mixed gas and a welding part.

To sum up:

when the method is used, the mixed gas of nitrogen and hydrogen in a high-pressure state is used as the protective gas to carry out gas shielded welding, and reduction heat treatment is carried out on the welding position in cooperation with the high-temperature environment of the welding position, so that an anti-rust protective layer is formed on the surface of the welding position, and the welding position is prevented from being easily oxidized, and the anti-rust purpose is realized; the mixed gas is intensively supplied to the welding generation point, so that the mixed gas is favorably impacted to the welding generation position, the mixed gas is heated at high temperature, and the mixed gas is fully contacted with the welding position; secondly, the mixed gas impact is also beneficial to welding wire supply and drawing of welding wires; the proportion between the nitrogen and the hydrogen is effectively controlled by supplying the hydrogen into the nitrogen in the air supply pipe 5 through the thin pipe 8, and in addition, the thin pipe 8 is coaxially erected in the air supply pipe 5, so that the hydrogen and the nitrogen are effectively enhanced, and the mixing uniformity is improved.

The embodiments of the present invention are preferred embodiments of the present invention, and the scope of the present invention is not limited by these embodiments, so: all equivalent changes made according to the structure, shape and principle of the invention are covered by the protection scope of the invention.

Claims

1. A steel bridge welding process is characterized by comprising the following steps,

s3, drying and cleaning the welding wires;

2. A steel bridge welding process according to claim 1, wherein the ratio of the volume of hydrogen to the volume of nitrogen is 0.03 to 0.1.

3. The steel bridge welding process of claim 1, wherein the specific operation of the step S3 is as follows: and (3) drying the welding wire for 2 hours in an environment of 250-300 ℃, and then preserving heat in an environment of 100-150 ℃.

4. The utility model provides a steel bridge welding set, includes nozzle (1), coaxial fixed with contact tip (2) in nozzle (1), run through in contact tip (2) and seted up welding wire hole (3), its characterized in that, contact tip (2) with circumference is provided with air current passageway (4) between nozzle (1), still be connected with on nozzle (1) with air supply pipe (5) of air current passageway (4) intercommunication, air supply pipe (5) are kept away from the one end of nozzle (1) is connected with nitrogen cylinder (6) and hydrogen cylinder (7).

5. A steel bridge welding device according to claim 4, characterized in that a thin tube (8) is arranged in the gas supply pipe (5) along the extension direction thereof, one end of the thin tube (8) is positioned in the gas supply pipe (5), and the other end extends out of the gas supply pipe (5) and is connected with the hydrogen cylinder (7).

6. A steel bridge welding device according to claim 5, characterized in that the end of the thin tube (8) inside the gas supply pipe (5) is closed, and the side wall of the thin tube (8) at the end inside the gas supply pipe (5) is provided with a plurality of thin through holes (9) along the length direction.

7. A steel bridge welding device according to claim 6, characterized in that a support sheet (10) is coaxially fixed in the gas supply pipe (5), a through hole (11) is coaxially formed in the support sheet (10) in a penetrating manner, and one end of the thin pipe (8) in the gas supply pipe (5) sequentially penetrates through the through holes (11).

8. A steel bridge welding device according to claim 4, characterized in that the end of the contact tip (2) close to the opening of the nozzle (1) is arranged in a truncated cone shape, the inner diameter of the nozzle (1) is gradually reduced along the direction close to the opening of the nozzle, and the opening of the nozzle (1) is flush with the end of the contact tip (2).

9. A steel bridge welding device according to claim 7, wherein the cross-section of said gas flow channel (4) is gradually decreasing in a direction close to its opening.

10. A steel bridge welding device according to claim 4, characterized in that the opening of the nozzle (1) is sleeved with a trumpet-shaped transparent protective cover (12).