CN115213536A - External magnetic field auxiliary resistance spot welding connection method - Google Patents
External magnetic field auxiliary resistance spot welding connection method Download PDFInfo
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- CN115213536A CN115213536A CN202110423837.7A CN202110423837A CN115213536A CN 115213536 A CN115213536 A CN 115213536A CN 202110423837 A CN202110423837 A CN 202110423837A CN 115213536 A CN115213536 A CN 115213536A
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- magnetic field
- external magnetic
- nugget
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
- B23K—SOLDERING OR UNSOLDERING; WELDING; CLADDING OR PLATING BY SOLDERING OR WELDING; CUTTING BY APPLYING HEAT LOCALLY, e.g. FLAME CUTTING; WORKING BY LASER BEAM
- B23K11/00—Resistance welding; Severing by resistance heating
- B23K11/10—Spot welding; Stitch welding
- B23K11/11—Spot welding
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
- B23K—SOLDERING OR UNSOLDERING; WELDING; CLADDING OR PLATING BY SOLDERING OR WELDING; CUTTING BY APPLYING HEAT LOCALLY, e.g. FLAME CUTTING; WORKING BY LASER BEAM
- B23K2103/00—Materials to be soldered, welded or cut
- B23K2103/18—Dissimilar materials
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Abstract
An external magnetic field auxiliary resistance spot welding connection method is characterized in that a pair of electrode rods with opposite polarities are respectively contacted with two metal workpieces to be connected with different melting points from the upper side and the lower side of the electrode rods, pressure is applied in opposite directions, the metal workpieces to be connected with lower melting points are melted along a workpiece contact interface under the action of continuous joule heat after current is applied to the electrode rods, a nugget grows into the metal workpieces to form a nugget, molten metal in the nugget flows at a high speed under the action of magnetic field force provided by an external magnetic field, a stirring effect is generated on defects near the workpiece contact interface, and dissimilar material connection is realized after the nugget is cooled and solidified; according to the invention, the defects of the oxide film are prevented from being gathered on the interface of the plate through electromagnetic stirring, meanwhile, the diffusion of the unmelted side elements to the nuggets is promoted, the hardness and the strength of the nuggets are increased, and the mechanical property of the joint is improved.
Description
Technical Field
The invention relates to the technology in the field of welding, in particular to an external magnetic field auxiliary resistance spot welding connection method.
Background
Resistance Spot Welding (RSW) is a major method of connecting metal points in the automobile industry. With the continuous improvement of the light weight requirement of the automobile body, the mixed use of high-strength steel, aluminum alloy, magnesium alloy and the like gradually becomes an important trend of the development of the automobile body material. However, the conventional RSW process is challenging due to the problems of large difference in physical properties of dissimilar materials, difficult metallurgical compatibility, and the like. In addition, the multi-layer hydrous oxide film existing on the surface of aluminum alloy, magnesium alloy and the like can cause the generation of nugget pore defects; the oxide film has high melting point and high resistivity, and inclusion defects are easily formed on the joint surface of heterogeneous materials in the welding process, so that the mechanical property of the joint is seriously influenced.
Disclosure of Invention
The invention provides an external magnetic field auxiliary resistance spot welding connecting method aiming at the defects in the prior art, which is based on resistance spot welding and adds an external magnetic field on an electrode cap to generate a radial magnetic field in a direction parallel to the surface of a plate to be welded. The magnetic field interacts with the welding current to produce an electromagnetic force. In the welding process, the defects of the oxide film can be driven to move under the action of electromagnetic force stirring, the defects of the oxide film are prevented from being gathered on the interface of the plate, meanwhile, the diffusion of unmelted side elements to a nugget is promoted, and the hardness and the strength of the nugget are improved.
The invention is realized by the following technical scheme:
the invention relates to an external magnetic field auxiliary resistance spot welding connection method, which is characterized in that a pair of electrode rods with opposite polarities are respectively contacted with two metal workpieces to be connected with different melting points from the upper side and the lower side and oppositely apply pressure, after current is applied to the electrode rods, the metal workpieces to be connected with lower melting points are melted along a contact interface of the workpieces under the action of continuous joule heat, a nugget grows into the nugget, molten metal in the nugget flows at high speed under the action of magnetic field force provided by an external magnetic field and generates stirring action on defects near the contact interface of the workpieces, and after the nugget is cooled and solidified, dissimilar materials are connected.
The free ends of the electrode rods are respectively provided with an electrode cap; an insulating sleeve is arranged outside the electrode rod.
The external magnetic field is distributed on one side or two sides of the metal workpiece to be connected, and when the external magnetic field is arranged on one side, the external magnetic field is preferentially arranged on the outer side of the electrode rod close to the metal workpiece to be connected with a lower melting point; when the external magnetic field is arranged on both sides, the shape, the material, the size, the strength and the working distance of the upper magnetic field source and the lower magnetic field source can be asymmetrically distributed.
The external magnetic field intensity is constant or periodically applied along with the change of welding current; the distance between the end face of the external magnetic field and the workpiece to be connected is 1-10 mm.
The external magnetic field is a tubular body, including a cylindrical tube, a square tube, a triangular tube or other tubular bodies with more complex shapes, or a plurality of small-radian tubular bodies arranged on the linear driving device.
The current is applied to the electrode rod, and is specifically constant current, square wave current, pulse current, ramp current or combination thereof.
The diameter of the nugget is
Wherein: t is the thickness of the metal pieces to be joined having the lower melting point.
The included angle between the nugget and the interface of the metal workpiece to be connected is 10-45 degrees.
One of the two metal workpieces to be connected with different melting points is made of pure aluminum, aluminum alloy, pure copper, copper alloy, pure magnesium or magnesium alloy; the other piece is steel, pure titanium or titanium alloy.
Technical effects
The invention integrally solves the problems of welding spot mechanical property reduction, welding spot brittle fracture and the like caused by a plurality of interface defects of dissimilar material resistance spot welding joints and large nugget tissues. Compared with the prior art, the movable external magnetic field is arranged to be suitable for different welding working conditions and material combinations, the interface oxide film in the nugget is broken and moves under the action of electromagnetic stirring, and the distribution of the interface oxide film is reduced; under the action of electromagnetic force, the unmelted metal workpiece elements to be connected with higher melting point accelerate to diffuse to the nugget in the connecting metal workpiece with lower melting point, so as to strengthen the nugget; the introduction of electromagnetic force hinders the growth of columnar crystals in the solidification process of the nugget in the first connecting metal workpiece, and a multi-layer fine columnar crystal structure is formed at the edge of the nugget.
Drawings
FIG. 1 is a schematic diagram of the structure of the present invention;
in the figure: a is a front view; b is a top view;
FIG. 2 is a schematic diagram of an application of the present invention;
FIG. 3 is a schematic illustration of the weld specification and nugget growth variation of example 1;
FIG. 4 is a schematic illustration of the weld specification and nugget growth variations of example 2;
FIG. 5 is a schematic illustration of the weld specification and nugget growth variations of example 3;
FIG. 6 is a schematic illustration of the weld specification and nugget growth variations of example 4;
in the figure: the device comprises an upper electrode rod 1, an insulating sleeve 2, an upper electrode cap 3, a movable clamp 4, an external magnetic field 5, a lower electrode cap 6, a lower electrode rod 7, a first metal workpiece to be connected 8, a second metal workpiece to be connected 9, a nugget 10 and an intermediate reaction compound 11.
Detailed Description
Example 1
As shown in fig. 1 and 2, the present embodiment relates to an external magnetic field-assisted resistance spot welding connection device including: go up electrode rod 1, insulating sleeve 2, go up electrode cap 3, removal anchor clamps 4, external magnetic field 5, electrode cap 6 and electrode rod 7 down, wherein: the movable external magnetic field 5 is movably arranged on the insulating sleeve 2 through the movable clamp 4, the insulating sleeve 2 is sleeved on the upper electrode rod 1 and the lower electrode rod 7, the upper electrode cap 3 and the lower electrode cap 6 are correspondingly arranged on the free ends of the upper electrode rod 1 and the lower electrode rod 7 respectively, the upper electrode cap 3 is in contact with a first metal workpiece 8 to be connected, and the lower electrode cap 6 is in contact with a second metal workpiece 9 to be connected.
The insulating sleeve 2 is in interference connection with the electrode rod.
The movable arrangement means that the external magnetic field 5 can move along the length direction of the electrode rod or rotate along the circumferential direction of the electrode rod.
The radial magnetic field generated by the external magnetic field 5 between the interfaces of the metal workpieces to be connected can be periodically applied or removed along with the change of welding current.
The external magnetic field 5 is a neodymium magnet and is in the shape of a tubular body.
The tubular body is a cylindrical pipe, a square pipe, a triangular pipe or a plurality of tubular bodies which can be fixedly arranged on the linear driving device.
The embodiment relates to an external magnetic field auxiliary resistance spot welding connection method based on the device, which specifically comprises the following steps:
the method comprises the following steps: a pre-pressing stage: the upper electrode rod 1 and the lower electrode rod 7 with opposite polarities are respectively arranged on two sides of a corresponding first metal workpiece 8 to be connected and a corresponding second metal workpiece 9 to be connected, and welding pressure is provided in the welding process;
step two: a preheating stage: preheating current is applied, and the first metal workpiece to be connected 8 and the second metal workpiece to be connected 9 start to be heated through the current between the upper electrode cap 3 and the lower electrode cap 6;
step three: and (3) a growth stage: a nugget 10 of a first metal workpiece 8 to be connected grows along the interface of the plate under the action of continuous joule heat;
step four: and (3) stirring: the molten metal in the nugget 10 of the first metal workpiece 8 to be connected rotates at a high speed under the action of electromagnetic force, and the high-temperature metal fluid flows at a high speed;
step five: and (3) solidification stage: stopping applying the current, and solidifying the nugget 10 of the first metal workpiece 8 to be connected on the interface to form a multi-layer crystal structure nugget;
the multilayer crystal structure is a multilayer columnar crystal structure distributed at the edge of the nugget 10, and a single-layer fine columnar crystal structure is arranged at the central part of the nugget 10.
The first metal workpiece 8 to be connected is 1.2mm aluminum alloy 5754-O.
The second metal workpiece 9 to be connected is low-carbon steel with the thickness of 2.0 mm.
As shown in fig. 3, the welding pressure is 3.5kN, the pre-pressing time of the pre-pressing stage is 200ms, the preheating current of the preheating stage is 7kA, the preheating time is 40ms, the welding current of the growing stage and the stirring stage is 10kA, the welding time is 400ms, and the dwell time of the solidification stage is 250ms.
The strength of the external magnetic field 5 is 1.41T.
The working distance from the external magnetic field 5 to the end face of the electrode cap is 3mm.
The diameter d of the nugget 10 is 5.6mm; the included angle alpha between the edge of the nugget 10 and the interface of the metal workpieces to be connected is 18.
In the embodiment, the movable external magnetic field 5 assists in welding dissimilar materials, so that the defect distribution of an interface oxide film is effectively reduced, the mechanical property of a welding spot is obviously improved, and the fracture mode of the welding spot is changed.
The maximum thickness of the intermediate reaction compound 11 of the aluminum steel spot-welded joint obtained in the embodiment is 5 micrometers, the interface has no obvious oxide film inclusion defect, the stripping peak force is 268N, the stripping fracture energy absorption is 3.14J, compared with the traditional resistance spot-welded joint under the same welding specification, the stripping peak force is improved by 90.4%, the stripping fracture energy absorption is improved by 1327.2%, and the fracture mode is changed from interface brittle fracture into part of button fracture.
Example 2
Compared with embodiment 1, the first metal workpiece to be connected 8 of this embodiment is an aluminum plate 6022 of 3 mm; the second metal workpiece 9 to be joined is a 2.0mm steel plate DP980.
As shown in fig. 4, the welding pressure is 3kN, the pre-pressing time of the pre-pressing stage is 200ms, the preheating current of the preheating stage is 8kA, the preheating time is 40ms, the growing stage adopts five pulse currents with the heating time of 80ms and the cooling time of 10ms, the current is increased from 15kA to 18kA, the stirring stage adopts eight pulse currents with the welding time of 40ms and the cooling time of 10ms, the welding current is increased from 18kA to 20kA, and the dwell time of the solidification stage is 250ms.
The strength of the external magnetic field 5 is 2T.
The working distance from the external magnetic field 5 to the end face of the electrode cap is 1.5mm.
The diameter d of the nugget 10 is 8.6mm; the included angle alpha between the edge of the nugget 10 and the interface of the metal workpieces to be connected is 28.
The maximum thickness of the intermediate reactant 11 of the aluminum-steel spot-welded joint obtained in the embodiment is 6 μm, the interface has no obvious oxide film inclusion defect, and compared with the traditional resistance spot-welded joint, the stripping mechanical property is improved by 30-60%, and the energy absorption is improved by 80-100%.
Example 3
Compared with embodiment 1, the first metal workpiece 8 to be connected of the present embodiment is an aluminum plate 5754 of 0.8 mm; the second metal workpiece to be joined 9 is a 0.8mm steel plate DP980.
As shown in fig. 5, the welding pressure is 2kN, the pre-pressing time of the pre-pressing stage is 250ms, the preheating current of the preheating stage is 6kA, the preheating time is 20ms, the current of the growing stage is 8kA, the welding time is 50ms, the stirring stage adopts eight pulse currents with the welding time of 40ms and the cooling time of 5ms, the welding current is increased from 10kA to 11kA, and the dwell time of the solidification stage is 250ms.
The strength of the external magnetic field 5 is 1T.
The working distance from the external magnetic field 5 to the end face of the electrode cap is 2mm.
The diameter d of the nugget 10 is 4.2mm; and the included angle alpha between the edge of the nugget 10 and the interface of the metal workpiece to be connected is 10.
The maximum thickness of the intermediate reaction compound 11 of the aluminum steel spot-welded joint obtained in the embodiment is 1.5 μm, the interface has no obvious oxide film inclusion defect, and compared with the traditional resistance spot-welded joint, the stripping mechanical property is improved by 40-70%, and the energy absorption is improved by 80-120%.
Example 4
Compared with embodiment 1, the first metal workpiece 8 to be connected of the present embodiment is an aluminum plate 5754 of 1.2 mm; the second metal workpiece to be joined 9 is a 2.5mm steel plate DP980.
As shown in fig. 6, the welding pressure is 3.0kN, the pre-pressing time of the pre-pressing stage is 200ms, the preheating current of the preheating stage is 6kA, the preheating time is 60ms, the welding current of the growing stage and the stirring stage is 12kA, the welding time is 400ms, and the pressure maintaining time of the solidification stage is 250ms.
The strength of the external magnetic field 5 is 1.3T.
The working distance from the external magnetic field 5 to the end face of the electrode cap is 3.5mm.
The diameter d of the nugget 10 is 5.9mm; and the included angle alpha between the edge of the nugget 10 and the interface of the metal workpiece to be connected is 19.
The maximum thickness of the intermediate reactant 11 of the aluminum steel spot-welded joint obtained by the embodiment is 5.5 mu m, the interface has no obvious oxide film inclusion defect, and compared with the traditional resistance spot-welded joint, the stripping mechanical property is improved by 40-60%, and the energy absorption is improved by 90-100%.
Through specific practical experiments, when 1.2mm5754 and 2.0mm low-carbon steel are connected, the method is operated at the preheating current of 7kA and 40ms, the welding current of 10kA and 400ms and the welding pressure of 3.5kN, the maximum thickness of a reaction compound in the middle of a welding spot is reduced from 10 mu m to 5 mu m, the inclusion defect of an interface oxide film is changed from existence to nonexistence, the nugget hardness is improved from 78Hv to 88Hv, the peak peeling force is 268N, and the welding spot is peeled, broken and absorbs energy by 3.14J. Compared with the traditional resistance spot welding joint under the same welding specification, the stripping peak force is improved by 90.4%, and the stripping fracture energy absorption is improved by 1327.2%. The fracture mode transitions from interfacial brittle fracture to partial button fracture.
Compared with the prior art, the movable external magnetic field can solve the problem of interference between a magnetic field source and a workpiece in production, the defect of oxide inclusion without melting of an interface can be effectively reduced by introducing a dissimilar material for connection through electromagnetic force, the thickness of a middle reaction compound is reduced, diffusion of unmelted plate elements to a nugget side is promoted, meanwhile, growth of thick columnar crystals in the nugget is hindered by electromagnetic force stirring, a multi-layer fine crystal grain structure is formed at the edge of the nugget, the mechanical property and fracture toughness of a welding spot are favorably improved, the peel strength of the spot welding joint is remarkably improved by 30% -90%, energy absorption is improved by 80% -1000%, and the welding spot is converted from brittle fracture into ductile fracture.
The foregoing embodiments may be modified in many different ways by those skilled in the art without departing from the spirit and scope of the invention, which is defined by the appended claims and all changes that come within the meaning and range of equivalency of the claims are therefore intended to be embraced therein.
Claims (8)
1. An external magnetic field auxiliary resistance spot welding connection method is characterized in that a pair of electrode rods with opposite polarities are respectively contacted with two metal workpieces to be connected with different melting points from the upper side and the lower side and oppositely apply pressure, after current is applied to the electrode rods, the metal workpieces to be connected with lower melting points are melted along a workpiece contact interface under the action of continuous joule heat, a nugget grows into the nugget, molten metal in the nugget flows at high speed under the action of magnetic field force provided by an external magnetic field and generates a stirring effect on defects near the workpiece contact interface, and after the nugget is cooled and solidified, dissimilar materials are connected;
the external magnetic field is distributed on one side or two sides of the metal workpieces to be connected.
2. The external magnetic field-assisted resistance spot welding connection method according to claim 1, wherein when the external magnetic field is set one-sidedly, it is preferentially set to the outside of the electrode rod near the metal workpieces to be connected having a lower melting point; when the external magnetic field is arranged on both sides, the shape, the material, the size, the strength and the working distance of the upper magnetic field source and the lower magnetic field source can be asymmetrically distributed.
3. The external magnetic field-assisted resistance spot welding connection method according to claim 1 or 2, wherein the external magnetic field strength is constant or periodically applied as the welding current is varied.
4. The external magnetic field-assisted resistance spot welding connection method according to claim 1 or 2, wherein the external magnetic field is at least one tubular body provided on the linear driving device.
5. The external magnetic field-assisted resistance spot welding connection of claim 1, wherein said nugget has a diameter of
Wherein: t is the thickness of the metal workpieces to be joined having the lower melting point.
6. The external magnetic field assisted resistance spot welding connection method according to claim 1 or 5, wherein an angle between the nugget and an interface of the metal workpieces to be connected is 10 to 45 °.
7. The external magnetic field assisted resistance spot welding connection method according to claim 1, wherein one of the two metal workpieces to be connected with different melting points is made of pure aluminum, aluminum alloy, pure copper, copper alloy, pure magnesium or magnesium alloy; the other piece is steel, pure titanium or titanium alloy.
8. The external magnetic field-assisted resistance spot welding connection method according to claim 1, wherein a distance between an end surface of the external magnetic field and a workpiece to be connected is 1 to 10mm.
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Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN115770938A (en) * | 2022-11-01 | 2023-03-10 | 中国第一汽车股份有限公司 | Steel-aluminum dissimilar metal resistance spot welding electrode cap and spot welding method |
Citations (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101844260A (en) * | 2010-05-13 | 2010-09-29 | 重庆大学 | Method and device for performing electric magnetization resistance welding-braze welding compounding on dissimilar materials |
| CN105108272A (en) * | 2015-09-18 | 2015-12-02 | 邢台职业技术学院 | Method and device for welding dissimilar metal |
| CN108655552A (en) * | 2018-06-01 | 2018-10-16 | 上海交通大学 | Radial magnetizing unilateral side magnetic control resistance spot welding device |
| CN108788419A (en) * | 2017-04-27 | 2018-11-13 | 上海交通大学 | Split type magnetic control resistance spot welding device |
| CN109759686A (en) * | 2019-03-22 | 2019-05-17 | 哈尔滨工业大学（威海） | A kind of resistance spot welding method under controllable rotating magnetic fields |
| CN110125525A (en) * | 2018-02-09 | 2019-08-16 | 丰田自动车株式会社 | The joint method of dissimilar metal plate |
| CN111201105A (en) * | 2017-08-14 | 2020-05-26 | 诺维尔里斯公司 | Electromagnet enhanced resistance spot welding |
| CN112122758A (en) * | 2020-09-22 | 2020-12-25 | 哈尔滨工业大学（威海） | Ni element-regulated magnetic field-assisted resistance unit welding method for aluminum alloy and steel |
-
2021
- 2021-04-20 CN CN202110423837.7A patent/CN115213536A/en active Pending
Patent Citations (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101844260A (en) * | 2010-05-13 | 2010-09-29 | 重庆大学 | Method and device for performing electric magnetization resistance welding-braze welding compounding on dissimilar materials |
| CN105108272A (en) * | 2015-09-18 | 2015-12-02 | 邢台职业技术学院 | Method and device for welding dissimilar metal |
| CN108788419A (en) * | 2017-04-27 | 2018-11-13 | 上海交通大学 | Split type magnetic control resistance spot welding device |
| CN111201105A (en) * | 2017-08-14 | 2020-05-26 | 诺维尔里斯公司 | Electromagnet enhanced resistance spot welding |
| CN110125525A (en) * | 2018-02-09 | 2019-08-16 | 丰田自动车株式会社 | The joint method of dissimilar metal plate |
| CN108655552A (en) * | 2018-06-01 | 2018-10-16 | 上海交通大学 | Radial magnetizing unilateral side magnetic control resistance spot welding device |
| CN109759686A (en) * | 2019-03-22 | 2019-05-17 | 哈尔滨工业大学（威海） | A kind of resistance spot welding method under controllable rotating magnetic fields |
| CN112122758A (en) * | 2020-09-22 | 2020-12-25 | 哈尔滨工业大学（威海） | Ni element-regulated magnetic field-assisted resistance unit welding method for aluminum alloy and steel |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN115770938A (en) * | 2022-11-01 | 2023-03-10 | 中国第一汽车股份有限公司 | Steel-aluminum dissimilar metal resistance spot welding electrode cap and spot welding method |
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