Welding arc control method and system for gas shield welding

Abstract

The invention discloses a welding arc control method and system for gas shield welding. The welding arc control method comprises the steps that the wire feeding speed of a welding wire is controlled, welding is conducted on base metal, welding parameters in the welding process are set, welding current is applied to the welding wire, an arc and arc voltage are generated between the front end of the welding wire and the base metal, and a molten pool is formed in the base metal; when the welding wire is fed at the peak value of the wire feeding speed, the front end of the welding wire gradually goes deep into the molten pool to the bottom of the molten pool, the rotating radius of the arc at the front end of the welding wire is reduced along with the increase of the depth, and the arc voltage is reduced along with the increase of the depth; and when the welding wire is fed according to the wire feeding speed base value, the front end of the welding wire gradually moves towards the outside of the molten pool, the maximum radius of the arc at the front end of the welding wire is increased along with the reduction of the depth, and the arc voltage is increased along with the reduction of the depth. The arc stability of high-current welding of 400 A or above is improved, weld joint forming is improved, and the welding quality is improved.

Description

Technical Field

[0001] The invention relates to the technical field of arc welding, and in particular to a welding arc control method for metal-electrode gas shielded welding. Background Art

[0002] The statements in this section merely provide background information related to the present invention and do not necessarily constitute prior art.

[0003] Gas shielded welding is a type of metal arc welding. With its high efficiency and stable process, gas shielded welding occupies an important position in the metal structure manufacturing industry and is widely used in welding of various metal structures.

[0004] For the welding of medium and thick plates, the current gas shielded welding process faces certain limitations. The gas shielded welding in the prior art cannot achieve a single pass welding to completely connect two medium and thick plates at a time, so multi-layer multi-pass welding is required. Under normal circumstances, for general multi-layer multi-pass welding, the current is about 200A. This welding method has many layers, resulting in a long welding time, extended construction period, and increased production costs and time costs. In order to improve the welding deposition rate and shorten the welding time, increasing the welding current becomes an effective solution. However, when the welding current reaches 400A or even higher, new problems arise. As the welding current increases, the molten droplet transition form changes significantly, from a stable molten droplet transition to a rotating jet transition. This unstable transition form causes the arc stability to decrease, which in turn causes the quality of the weld formation to deteriorate, the spatter phenomenon is serious, and other problems, which have an extremely adverse effect on the welding quality and seriously restrict the wide application of high-current welding technology in actual production. In summary, there is currently no perfect solution to the problem of arc instability during high-current welding. Although some research is devoted to improving the welding process, in practical applications, it is still unable to effectively solve the problems caused by the rotating arc, such as large spatter and poor weld formation. Summary of the invention

[0005] In order to solve the above problems, the present invention proposes a welding arc control method and system for gas shielded welding, which realizes arc control by adjusting the wire feeding speed, can better control the behavior of the arc, achieve better welding effect, improve the arc stability of high current welding of 400A and above, improve weld formation, and improve welding quality.

[0006] In order to achieve the above object, the present invention adopts the following technical solution:

[0007] In a first aspect, the present invention provides a gas shielded welding arc control method for controlling the wire feeding speed of a welding wire to perform welding on a parent metal, comprising:

[0008] Setting welding parameters during welding, wherein the welding parameters include a peak value of a wire feeding speed of the welding wire and a base value of a wire feeding speed of the welding wire;

[0009] A welding current is applied to the welding wire, an arc and an arc voltage are generated between the front end of the welding wire and the base metal, and a molten pool is formed on the base metal; when the welding wire is fed at the peak value of the wire feeding speed, the front end of the welding wire gradually penetrates into the molten pool to the bottom of the molten pool, the rotation radius of the arc at the front end of the welding wire decreases with the increase of the penetration depth, the arc voltage decreases with the increase of the penetration depth, and the bottom of the molten pool is heated; when the welding wire is fed at the base value of the wire feeding speed, the front end of the welding wire gradually moves to the outside of the molten pool, the maximum radius of the arc at the front end of the welding wire increases with the decrease of the penetration depth, the arc voltage increases with the decrease of the penetration depth, the upper part of the molten pool is heated, and the base metal in front of the welding direction is preheated, thereby increasing the width of the molten pool.

[0010] A further technical solution is that when the welding wire is fed at a peak wire feeding speed, the speed at which the arc melts the welding wire is less than the peak wire feeding speed; when the welding wire is fed at a base wire feeding speed, the speed at which the arc melts the welding wire is greater than the base wire feeding speed.

[0011] According to a further technical solution, the welding parameters also include a transition time between a wire feeding speed peak value and a wire feeding speed base value, a proportion of a wire feeding speed peak value, and a cycle frequency.

[0012] In a further technical solution, the peak value of the wire feeding speed accounts for: Among them, α is the proportion of the wire feeding speed peak, T1 is the time of one cycle, and T2 is the proportion of the wire feeding speed peak time; the cycle frequency is:

[0013] A further technical solution, the welding arc control method also includes: according to the difference between the wire feeding speed peak value and the wire feeding speed base value, by adjusting the proportion of the wire feeding speed peak value and the cycle frequency, the welding wire is periodically switched between the wire feeding speed peak value and the wire feeding speed base value, so as to ensure that the droplet transition remains stable.

[0014] A further technical solution is that if the welding wire is fed at the peak value of the wire feeding speed, the front end of the welding wire penetrates deep into the molten pool. When it reaches the bottom of the molten pool, the radius of the arc at the front end of the welding wire is the smallest and the arc voltage is the smallest. At this time, the wire feeding speed of the welding wire is switched to the base value of the wire feeding speed.

[0015] A further technical solution is that if the welding wire is fed at the base wire feeding speed, the front end of the welding wire moves toward the outside of the molten pool. When the front end of the welding wire reaches the outer surface of the base metal, the radius of the arc at the front end of the welding wire is the largest, and the arc voltage is the largest. In order to reduce the uncontrollable time of the arc, the wire feeding speed of the welding wire is switched to the peak wire feeding speed at this time.

[0016] In a second aspect, the present invention provides a gas shielded welding arc control system, comprising:

[0017] The welding parameter setting module is configured to: set welding parameters during welding, wherein the welding parameters include a peak value of a wire feeding speed of the welding wire and a base value of a wire feeding speed of the welding wire;

[0018] The welding control module is configured to: apply welding current to the welding wire, generate an arc and arc voltage between the front end of the welding wire and the base metal, and form a molten pool on the base metal; when the welding wire is fed at the peak value of the wire feeding speed, the front end of the welding wire gradually penetrates into the molten pool to the bottom of the molten pool, the maximum radius of the arc at the front end of the welding wire decreases with the increase of the penetration depth, the arc voltage decreases with the increase of the penetration depth, and the bottom of the molten pool is heated; when the welding wire is fed at the base value of the wire feeding speed, the front end of the welding wire gradually moves to the outside of the molten pool, the maximum radius of the arc at the front end of the welding wire increases with the decrease of the penetration depth, the arc voltage increases with the decrease of the penetration depth, the upper part of the molten pool is heated, and the base metal in front of the welding direction is preheated to increase the width of the molten pool.

[0019] Compared with the prior art, the present invention has the following beneficial effects:

[0020] 1. The present invention effectively limits the rotation radius of the arc in the rotation transition form during high current welding by controlling the wire feeding speed (the peak value of the wire feeding speed of the welding wire and the base value of the wire feeding speed of the welding wire), so that the arc moves in a stable space, thereby significantly improving the stability of the arc. Compared with the traditional high current welding method, the present invention can effectively avoid welding defects caused by arc instability and provide a solid foundation for high quality welding.

[0021] 2. During the welding process, the present invention achieves precise adjustment of the molten pool depth and molten pool width by accurately controlling the wire feeding speed peak value and the wire feeding speed base value. When the wire feeding speed is taken as the wire feeding speed at the wire feeding speed peak value, a stable molten pool depth is ensured; when the wire feeding speed is taken as the wire feeding speed at the wire feeding speed base value, the molten pool width increases, and the stability of the molten pool width is ensured, so that the weld is formed more uniformly and beautifully, meeting the requirements of high-quality welding.

[0022] 3. The present invention controls the arc radius and arc voltage by adjusting the wire feeding speed, thereby effectively reducing the generation of spatter. This not only improves the safety of the welding process and reduces the pollution to the surrounding environment, but also reduces the cleaning workload after welding and improves production efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] The accompanying drawings in the specification, which constitute a part of the present invention, are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute improper limitations on the present invention.

[0024] Figure 1 A schematic diagram of adjusting the wire feeding speed in the welding arc control method of the present invention;

[0025] Figure 2 A schematic diagram of wire feeding speed and arc voltage under constant current state in the welding arc control method of the present invention;

[0026] Figure 3 It is a schematic diagram of the welding process of the present invention;

[0027] Among them, 11. base metal; 12. molten pool; 13. front end of welding wire; 14. welding wire; 15. wire feeding device. DETAILED DESCRIPTION

[0028] The present invention will be further described below in conjunction with the accompanying drawings and embodiments.

[0029] It should be noted that the following detailed descriptions are exemplary and are intended to provide further explanation of the present invention. Unless otherwise specified, all technical and scientific terms used herein have the same meanings as those commonly understood by those of ordinary skill in the art to which the present invention belongs. In the absence of conflict, the embodiments of the present invention and the features in the embodiments may be combined with each other.

[0030] Embodiment 1

[0031] This embodiment provides a method for controlling a gas shielded welding arc. Figure 3 As shown, the welding arc control method is used to control the wire feeding speed of the welding wire 14 on the wire feeding device 15 to perform welding on the parent metal 11. The specific method is as follows:

[0032] Welding preparation:

[0033] Ensure that the wire feeding device 15 is correctly installed on the welding equipment and is smoothly connected to the welding wire 14 so that the wire can be fed accurately at the set speed; clean the surface of the parent metal 11 to be welded and remove impurities such as oil and rust to ensure the welding quality; connect the welding power supply to the wire feeding device, parent metal, etc., set the welding current to more than 400A (such as 500A), and ensure that the power output is stable.

[0034] Parameter settings:

[0035] The welding parameters during the welding process are set, and the welding parameters include the peak value of the wire feeding speed of the welding wire, the base value of the wire feeding speed of the welding wire, the transition time between the peak value of the wire feeding speed and the base value of the wire feeding speed, the proportion of the peak value of the wire feeding speed, and the cycle frequency. Specifically: according to the welding current of 400A or more (such as 500A) and the required welding effect, the difference range between the peak value of the wire feeding speed of the welding wire and the base value of the wire feeding speed of the welding wire is set to 2-50m / min. For example, when the welding current is 500A, the peak value of the wire feeding speed is set to 40m / min, and the base value of the wire feeding speed is set to 25m / min, and the difference between the two is 15m / min. The transition time between the peak value of the wire feeding speed and the base value of the wire feeding speed is 0s-2s. In this embodiment, the transition time is 0s, that is, in this embodiment, it is considered that the wire feeding speed can be switched between the peak value of the wire feeding speed and the base value of the wire feeding speed instantly. In this embodiment, the proportion α of the peak value of the wire feeding speed is set between 10% and 90%. In this embodiment, the proportion α of the peak value of the wire feeding speed is set to 50%. Specifically, the proportion of the peak value of the wire feeding speed is: Among them, α is the proportion of the wire feeding speed peak value, T1 is the time of one cycle, and T2 is the proportion of the wire feeding speed peak value time. The cycle frequency is set between 5 and 100 Hz. In this embodiment, the cycle frequency is set to 10 Hz. Specifically: The cycle frequency is:

[0036]

[0037] Welding process control:

[0038] The welding power source is turned on, and the wire feeding device starts to control the welding wire to weld on the parent metal 11 according to the set welding parameters. Specifically: Figure 2 As shown, a welding current is applied to the welding wire, an arc and an arc voltage are generated between the front end of the welding wire and the base metal, and a molten pool is formed on the base metal; Figure 1 As shown, when the welding wire is fed at the peak value of the wire feeding speed, the front end of the welding wire gradually penetrates into the molten pool to the bottom of the molten pool, the rotation radius of the arc at the front end of the welding wire decreases with the increase of the penetration depth, the arc voltage decreases with the increase of the penetration depth, and the bottom of the molten pool is heated; wherein, when the welding wire is fed at the peak value of the wire feeding speed, the speed at which the arc melts the welding wire is less than the peak value of the wire feeding speed. When the welding wire is fed at the base value of the wire feeding speed, the front end of the welding wire gradually moves to the outside of the molten pool, the maximum radius of the arc at the front end of the welding wire increases with the decrease of the penetration depth, the arc voltage increases with the decrease of the penetration depth, and the upper part of the molten pool is heated and the parent metal in front of the welding direction is preheated to increase the width of the molten pool, wherein, when the welding wire is fed at the base value of the wire feeding speed, the speed at which the arc melts the welding wire is greater than the base value of the wire feeding speed.

[0039] According to the difference between the peak value of the wire feeding speed and the base value of the wire feeding speed, by adjusting the proportion of the peak value of the wire feeding speed and the periodic frequency, the welding wire is periodically switched between the peak value of the wire feeding speed and the base value of the wire feeding speed to ensure that the droplet transition remains stable. The periodic switching is specifically as follows: if the welding wire is fed at the peak value of the wire feeding speed, the front end of the welding wire penetrates deep into the molten pool. When it reaches the bottom of the molten pool, the radius of the arc at the front end of the welding wire is the smallest, and the arc voltage is the smallest. At this time, the wire feeding speed of the welding wire is switched to the base value of the wire feeding speed; if the welding wire is fed at the base value of the wire feeding speed, the front end of the welding wire moves outside the molten pool. When the front end of the welding wire reaches the outer surface of the parent metal, the radius of the arc at the front end of the welding wire is the largest, and the arc voltage is the largest. In order to reduce the uncontrollable time of the arc, the wire feeding speed of the welding wire is switched to the peak value of the wire feeding speed.

[0040] Embodiment 2

[0041] This embodiment discloses a gas shielded welding arc control system, including:

[0042] The welding parameter setting module is configured to: set welding parameters during welding, wherein the welding parameters include a peak value of a wire feeding speed of the welding wire and a base value of a wire feeding speed of the welding wire;

[0043] The welding control module is configured to: apply welding current to the welding wire, generate an arc and arc voltage between the front end of the welding wire and the base metal, and form a molten pool on the base metal; when the welding wire is fed at the peak value of the wire feeding speed, the front end of the welding wire gradually penetrates into the molten pool to the bottom of the molten pool, the rotation radius of the arc at the front end of the welding wire decreases with the increase of the penetration depth, the arc voltage decreases with the increase of the penetration depth, and the bottom of the molten pool is heated; when the welding wire is fed at the base value of the wire feeding speed, the front end of the welding wire gradually moves to the outside of the molten pool, the maximum radius of the arc at the front end of the welding wire increases with the decrease of the penetration depth, the arc voltage increases with the decrease of the penetration depth, the upper part of the molten pool is heated, and the base metal in front of the welding direction is preheated to increase the width of the molten pool.

[0044] Embodiment 3

[0045] This embodiment provides a computer-readable storage medium on which a program is stored. When the program is executed by a processor, the steps in the gas shielded welding arc control method as described in the above-mentioned embodiment 1 are implemented.

[0046] Embodiment 4

[0047] An electronic device comprises a memory, a processor and a program stored in the memory and executable on the processor, wherein when the processor executes the program, the steps of a gas shielded welding arc control method described in the first embodiment are implemented.

[0048] It should be noted here that each module in this embodiment corresponds one-to-one to the method in Embodiment 1, and the specific implementation process is the same, which will not be repeated here.

[0049] The above are only preferred embodiments of the present invention and are not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

[0050] Although the above describes the specific implementation mode of the present invention in conjunction with the accompanying drawings, it is not intended to limit the scope of protection of the present invention. Those skilled in the art should understand that various modifications or variations that can be made by those skilled in the art on the basis of the technical solution of the present invention without creative work are still within the scope of protection of the present invention.

Claims

1. A gas shielded welding arc control method for controlling the wire feeding speed of a welding wire to perform welding on a parent metal, characterized in that: include: Setting welding parameters during welding, wherein the welding parameters include a peak value of a wire feeding speed of the welding wire and a base value of a wire feeding speed of the welding wire; A welding current is applied to the welding wire, an arc and an arc voltage are generated between the front end of the welding wire and the base metal, and a molten pool is formed on the base metal; when the welding wire is fed at the peak value of the wire feeding speed, the front end of the welding wire gradually penetrates into the molten pool to the bottom of the molten pool, the rotation radius of the arc at the front end of the welding wire decreases with the increase of the penetration depth, the arc voltage decreases with the increase of the penetration depth, and the bottom of the molten pool is heated; when the welding wire is fed at the base value of the wire feeding speed, the front end of the welding wire gradually moves to the outside of the molten pool, the maximum radius of the arc at the front end of the welding wire increases with the decrease of the penetration depth, the arc voltage increases with the decrease of the penetration depth, the upper part of the molten pool is heated, and the base metal in front of the welding direction is preheated, thereby increasing the width of the molten pool.

2. A gas shielded welding arc control method as claimed in claim 1, characterized in that: When the welding wire is fed at a peak wire feeding speed, the speed at which the arc melts the welding wire is less than the peak wire feeding speed; when the welding wire is fed at a base wire feeding speed, the speed at which the arc melts the welding wire is greater than the base wire feeding speed.

3. A gas shielded welding arc control method as claimed in claim 1, characterized in that: The welding parameters also include a transition time between a wire feeding speed peak value and a wire feeding speed base value, a proportion of a wire feeding speed peak value, and a cycle frequency.

4. A gas shielded welding arc control method as claimed in claim 3, characterized in that: Place The time of the cycle, T2 is the peak time of wire feeding speed; the cycle frequency is:

5. A gas shielded welding arc control method as claimed in claim 3, characterized in that: The welding arc control method also includes: according to the difference between the wire feeding speed peak value and the wire feeding speed base value, by adjusting the proportion of the wire feeding speed peak value and the cycle frequency, the welding wire is periodically switched between the wire feeding speed peak value and the wire feeding speed base value to ensure that the droplet transition remains stable.

6. A gas shielded welding arc control method as claimed in claim 1, characterized in that: If the welding wire is fed at the peak wire feeding speed, the front end of the welding wire penetrates deep into the molten pool. When it reaches the bottom of the molten pool, the radius of the arc at the front end of the welding wire is the smallest and the arc voltage is the smallest. At this time, the wire feeding speed is switched to the base wire feeding speed.

7. A gas shielded welding arc control method as claimed in claim 1, characterized in that: If the welding wire is fed at the base wire feeding speed, the front end of the welding wire moves toward the outside of the molten pool. When the front end of the welding wire reaches the outer surface of the base metal, the radius of the arc at the front end of the welding wire is the largest and the arc voltage is the largest. In order to reduce the uncontrollable time of the arc, the wire feeding speed is switched to the peak wire feeding speed at this time.

8. A gas shielded welding arc control system, characterized in that: include: The welding parameter setting module is configured to: set welding parameters during welding, wherein the welding parameters include a peak value of a wire feeding speed of the welding wire and a base value of a wire feeding speed of the welding wire; The welding control module is configured to: apply welding current to the welding wire, generate an arc and arc voltage between the front end of the welding wire and the base metal, and form a molten pool on the base metal; when the welding wire is fed at the peak value of the wire feeding speed, the front end of the welding wire gradually penetrates into the molten pool to the bottom of the molten pool, the rotation radius of the arc at the front end of the welding wire decreases with the increase of the penetration depth, the arc voltage decreases with the increase of the penetration depth, and the bottom of the molten pool is heated; when the welding wire is fed at the base value of the wire feeding speed, the front end of the welding wire gradually moves to the outside of the molten pool, the maximum radius of the arc at the front end of the welding wire increases with the decrease of the penetration depth, the arc voltage increases with the decrease of the penetration depth, the upper part of the molten pool is heated, and the base metal in front of the welding direction is preheated to increase the width of the molten pool.

9. A computer-readable storage medium having a program stored thereon, characterized in that: When the program is executed by a processor, the steps in the gas shielded welding arc control method as described in any one of claims 1 to 7 are implemented.

10. An electronic device comprising a memory, a processor, and a program stored in the memory and executable on the processor, characterized in that: When the processor executes the program, the steps in the gas shielded welding arc control method as described in any one of claims 1-7 are implemented.

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