Melted pole twisting arc magnetic spin control welding method

Abstract

A kind of method for melting pole twisted wire arc magnetic spin control welding.The prior art twisted wire welding is prone to produce blowhole in weld inside when large current welding, and excessive heat input will cause changes in structure and performance in joint area, such as problems of weld zone grain growth, joint plasticity, toughness and other mechanical properties decline, etc.The present application comprises: twisted wire welding electrode arc welding point, a coaxial coil is arranged around the twisted wire welding electrode arc welding point, direct current is passed into the coaxial coil to form longitudinal magnetic field, the force direction of longitudinal magnetic field on twisted wire welding arc should be consistent with the self-rotating direction of twisted wire welding arc, and opposite to the twisting direction of twisted wire, the direction of longitudinal magnetic field is controlled by the direction of direct current, while twisted wire melts to form its own twist angle release, the twist angle release is affected by Lorentz force to make the rotational angular velocity of twisted wire welding arc rapidly increase, to realize high-speed directional rotation of twisted wire welding arc.The present application is used for melting pole twisted wire arc magnetic spin control welding method.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of the quality control of the flux-cored wire arc welding, in particular to a flux-cored wire arc magnetic spin control welding method. BACKGROUND

[0002] Multi-stranded twisted welding wire is a new type of flux-cored welding material, and its concept was first proposed by Professor Gao Ding of China University of Mining and Technology in 2009. The multi-stranded twisted welding wire is made by twisting single wires into a spiral shape. Compared with ordinary welding wires, the multi-stranded twisted welding wire can be combined by single wires with different diameters or numbers, and the composition can be precisely controlled by single wires with different compositions and numbers. In particular, in terms of welding physical properties, the multi-stranded twisted welding wire forms a multi-spot current conduction during welding, which is more conducive to improving the distribution of arc energy and the uniform transition of droplets. Therefore, the welding process can be better stabilized at a larger current, thereby having higher deposition rate, easy realization of shape and property control, and other technical advantages. However, in the prior art, a large number of pores are easily generated in the welding seam during high-current welding of the twisted wire, and the high heat input also causes changes in the structure and performance of the joint area, such as the growth of the grain size in the welding seam, the decrease of the plasticity and toughness of the joint, and other mechanical properties. SUMMARY

[0003] The purpose of the present application is to provide a flux-cored wire arc magnetic spin control welding method, which is centered on the flux-cored wire arc welding point of the twisted wire, and a coaxial coil is added around it to effectively improve the technical deficiencies of pores in the twisted wire welding and joint performance, and to further control the structure and performance of the welding seam.

[0004] The above-mentioned purpose is achieved by the following technical solutions:

[0005] A flux-cored wire arc magnetic spin control welding method, which comprises a flux-cored wire arc welding point of the twisted wire, characterized in that a coaxial coil is added around the flux-cored wire arc welding point of the twisted wire, a direct current is passed through the coaxial coil to form a longitudinal magnetic field, the force direction of the longitudinal magnetic field on the twisted wire welding arc is consistent with the self-rotation direction of the twisted wire welding arc and opposite to the twisting direction of the twisted wire, and the direction of the longitudinal magnetic field is controlled by the direction of the direct current.

[0006] The twisted wire welding arc is released in the longitudinal magnetic field while being affected by the Lorentz force to rapidly increase the rotation angle speed of the twisted wire welding arc, thereby realizing high-speed directional rotation of the twisted wire welding arc.

[0007] The twist wire welding arc is in high-speed directional rotation, the welding current is 100-260 A, the welding voltage is 15-30 V, the frequency is 0-200 Hz, the proportion is 20%-100%, and the process parameter control increases the stirring intensity of the molten pool, so that the molten pool generates directional rotating flow, and the dendritic crystal is stirred into equiaxed crystal in the solidification process.

[0008] The process parameters of the melting electrode twist wire arc magnetic rotation control welding method are as follows: the welding object is 5A06 aluminum alloy, the welding speed is 0.6 m / min, the welding voltage is 26 V, and the wire feeding speed is 11 m / min.

[0009] The melting electrode twist wire arc magnetic rotation control welding method, the coaxial coil has a magnetic core, the overall size is 40mm-150mm in outer diameter, 30mm-140mm in inner diameter, and 4mm-50mm in width, the coil has 50-2000 turns, and the direct current is 0-10A.

[0010] Beneficial effects:

[0011] 1. The melting electrode twist wire arc magnetic rotation control welding method is characterized in that a longitudinal magnetic field is arranged around the twist wire welding melting electrode arc, the Lorentz force is used to quickly increase the self-rotation angular velocity of the twist wire welding arc, the high-speed directional rotation of the twist wire welding arc can greatly increase the stirring intensity of the molten pool, the molten pool generates directional rotating flow, thereby, the grain refinement effect can be realized, the dendritic crystal can be stirred into equiaxed crystal in the solidification process, the grain homogenization, the isotropy of the grain, and the reduction of segregation are achieved, and the mechanical properties such as plasticity and toughness of the welded joint are enhanced.

[0012] 2. The arc stirring is also used, the heat and mass transfer speed in the molten pool can be improved, the solidification speed of the bottom of the molten pool is delayed in terms of the crystallization temperature and nucleation conditions, the convection and stirring effect of the molten pool can effectively precipitate the gas in the molten pool, and the generation tendency of the process type porosity is reduced.

[0013] 3. The directional rotation speed of the twist wire welding arc can be adjusted through the magnetic field strength control, the stability of the twist wire welding arc can be effectively improved after the high-speed directional rotation of the twist wire welding arc, the arc length can be obviously shortened, the electric field strength of the arc is increased, the droplet transfer frequency is increased, the impact effect of a single droplet on the molten pool is smaller, therefore, the welding spatter can be effectively reduced when the welding current is large, the welding process is more stable, and the deposition rate is effectively improved.

[0014] 4. The present invention can effectively adjust the heat field distribution within the twisted wire welding arc heat source, making the heat flux distribution within the arc heat source more uniform, thereby making the molten pool surface heated more evenly, and the molten pool heat field heat distribution gradient smaller, which has a more obvious effect on the weld morphology after crystallization and also has a certain improvement effect on the performance of the joint after welding.

[0015] 5. The present invention can effectively solve the problems of porosity defects, coarse grains, and decreased joint performance during twisted wire welding at high current, thereby further enhancing the potential technical advantages of the twisted wire welding method. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Attachment Figure 1 It is a structural schematic diagram of the present invention.

[0017] Attachment Figure 2 It is a cross-sectional view of the weld of the twisted wire welding of the present invention.

[0018] Attachment Figure 3 This is a cross-sectional view of the weld of conventional twisted wire welding.

[0019] Attachment Figure 4 It is an X-ray image of the weld of the twisted wire welding of the present invention.

[0020] Attachment Figure 5 This is an X-ray image of the weld of conventional twisted wire welding.

[0021] Attachment Figure 6 It is a metallographic group diagram of the weld area of ​​twisted wire welding of the present invention.

[0022] Attachment Figure 7 This is a metallographic group diagram of the weld area of ​​conventional twisted wire welding. DETAILED DESCRIPTION

[0023] Example 1:

[0024] A method for magnetic rotation control welding of twisted wire arc with a consumable electrode, comprising: a twisted wire welding consumable electrode arc welding point; and characterized in that: a coaxial coil is arranged around the twisted wire welding consumable electrode arc welding point as the center, a direct current is passed through the coaxial coil to form a longitudinal magnetic field, the direction of the longitudinal magnetic field exerting force on the twisted wire welding arc being consistent with the direction of the twisted wire welding arc's self-rotation and opposite to the twisting direction of the twisted wire, and the direction of the longitudinal magnetic field is controlled by the direction of the direct current;

[0025] The twisted wire welding arc is in a longitudinal magnetic field. When the twisted wire melts and forms its own twist angle, it is affected by the Lorentz force, causing the twisted wire welding arc's rotational angular velocity to increase rapidly, thereby achieving high-speed directional rotation of the twisted wire welding arc.

[0026] The twisting wire welding arc is in high-speed directional rotation, combined with welding current of 100-260 A, welding voltage of 15-30 V, frequency of 0-200 Hz, duty ratio of 20%-100% and process parameter control, the stirring intensity on the molten pool is increased, so that the molten pool generates directional rotating flow, and the dendritic crystal is stirred into equiaxed crystal in the solidification process, and the grain is refined.

[0027] Embodiment 2

[0028] According to the method for the magnetic rotation control of the GTAW arc in the embodiment 1, the process parameters are as follows: the welding object is 5A06 aluminum alloy, the welding speed is 0.6 m / min, the welding voltage is 26 V, and the wire feeding speed is 11 m / min.

[0029] Embodiment 3

[0030] According to the method for the magnetic rotation control of the GTAW arc in the embodiment 2, the coaxial coil has a magnetic core, the overall size is as follows: the outer diameter is 40 mm-150 mm, the inner diameter is 30 mm-140 mm, the width is 4 mm-50 mm, the number of turns is 50-2000 turns, and the direct current is 0-10 A, and the coaxial coil can be replaced by a permanent magnet.

[0031] Under the same welding process conditions, the GTAW arc magnetic rotation control welding and the conventional GTAW are compared, and the actual welding process parameters and the comparison test results are as follows:

[0032] The comparison test results are as follows:

[0033] (1) The comparison results of the weld cross sections of the application and the conventional twisting wire welding are shown in the attached Figure 2 and Figure 3 , and the observation shows that:

[0034] 1) The bottom of the weld obtained by using the welding method of the application is in a relatively smooth "arc" shape, while the bottom of the weld obtained by using the conventional twisting wire welding has a significant "protrusion", which shows that the heat source distribution formed by the welding method of the application is more uniform, and the thermal field distribution gradient in the center region of the molten pool is smaller;

[0035] 2) The weld aspect ratio obtained by using the welding method of the application is larger, which is increased by about 18.37% than that of the conventional twisting wire welding, and the weld width is smaller, which is reduced by about 26.23% than that of the conventional twisting wire welding, which shows that the heat source distribution formed by the welding method of the application is more concentrated, and the binding effect on the twisting wire arc is better;

[0036] 3) From the cross-sectional porosity, no porosity is observed in the weld cross section obtained by using the welding method of the application, while there is obvious process porosity in the weld cross section obtained by using the conventional twisting wire welding, which shows that the welding method of the application has a good inhibitory effect on the porosity defect.

[0037] (2) The comparison results of the porosity of the weld seam between this application and conventional twisted wire welding are shown in the attached Figure 4 , Attachment Figure 5 As shown, it can be observed that: no obvious process-related pores can be seen inside the weld obtained by the welding method of the present application, while more pores can be observed inside the weld obtained by conventional twisted wire welding, further indicating that the welding method of the present application has a good inhibitory effect on pore defects.

[0038] (3) The metallographic structure comparison results of the weld area of ​​this application and conventional twisted wire welding are shown in the attached Figure 6 , Attachment Figure 7 As shown, it can be observed that the weld joint obtained by the welding method of the present application has a significant refinement effect on the metallographic structure in the weld area compared to conventional twisted wire welding, and exhibits a certain homogenization effect.

Claims

1. A method for arc magnetic rotation welding of a consumable pole stranded wire, the method comprising: The twisted wire welding consumable electrode arc welding point is characterized in that: a coaxial coil is arranged around the twisted wire welding consumable electrode arc welding point as the center, a direct current is passed through the coaxial coil to form a longitudinal magnetic field, the direction of the longitudinal magnetic field exerting force on the twisted wire welding arc is consistent with the direction of rotation of the twisted wire welding arc and opposite to the twisting direction of the twisted wire, and the direction of the longitudinal magnetic field is controlled by the direction of the direct current; The twisted wire welding arc is in a longitudinal magnetic field. When the twisted wire melts and forms its own twist angle, it is affected by the Lorentz force, causing the twisted wire welding arc's rotational angular velocity to increase rapidly, thereby achieving high-speed directional rotation of the twisted wire welding arc. The molten pool is stirred by electric arc to produce directional rotating flow in the molten pool; The twisted wire welding arc rotates in a high-speed directional manner, combined with a welding current of 100-260A, a welding voltage of 15-30V, a frequency of 0-200Hz and process parameter control, to increase the stirring force of the molten pool, so that the molten pool produces a directional rotating flow, and during the solidification process, the dendrites are broken into equiaxed crystals, thereby refining the grains.

2. The consumable pole twisted wire arc magnetic rotation control welding method according to claim 1, characterized in that: The process parameters are: welding object 5A06 aluminum alloy, welding speed 0.6m / min, wire feeding speed 11m / min.

3. The consumable pole twisted wire arc magnetic rotation control welding method according to claim 2, characterized in that: The coaxial coil has a magnetic core, and its overall dimensions are 40mm-150mm in outer diameter, 30mm-140mm in inner diameter, 4mm-50mm in width, 50-2000 turns of coil, and 10A in DC current. The coaxial coil can be replaced by a permanent magnet.

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