High-zinc aluminum alloy welding wire and method of making same and method of welding high-strength aluminum alloy sheet

Abstract

The application discloses a high-zinc aluminum alloy welding wire and a preparation method thereof and a welding method of a high-strength aluminum alloy plate, and the preparation method comprises the following steps: 1) Al is heated to 770-780 DEG C by using a smelting furnace, the temperature is reduced to 710-720 DEG C after the Al is sufficiently melted, then Al-Si alloy, Al-Cu alloy, Al-Fe alloy, Al-Mn alloy and Al-Ti-B alloy are sequentially added, and Zn and Mg are sequentially added after the Al-Ti-B alloy is completely melted; 2) after all the raw materials are sufficiently melted, refining and deslagging are carried out, and the melt is poured into a water-cooled copper mold to solidify after the melt temperature is stably kept at 690-720 DEG C; 3) the zinc aluminum alloy prepared in the step 2) is heated to 500-540 DEG C, and then the zinc aluminum alloy is subjected to softening annealing at 400-440 DEG C, and the high-zinc aluminum alloy welding wire is prepared by hot extrusion. The welding method of the high-strength aluminum alloy plate improves the solid solution content of the zinc element in the alpha-Al at room temperature, and effectively solves the problem of weld softening through solid solution strengthening.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of welding, in particular to a high-zinc aluminum alloy welding wire, a preparation method thereof and a welding method of high-strength aluminum alloy plate. BACKGROUND

[0002] In the field of automobiles, in order to pursue the light weight of automobiles, improve the safety of automobiles, and achieve the purpose of energy saving and emission reduction, high-strength aluminum alloy materials have been widely used to replace traditional steel materials to prepare high-aluminum vehicle bodies in order to reduce the self weight of the vehicle body. The vehicle body generally selects high-strength aluminum alloy profiles after heat treatment, but due to the process characteristics of local heating of welding, the original nanoscale strengthening phase in the base material in the weld zone of the high-strength aluminum alloy profile is remelted and loses the precipitation strengthening effect, resulting in obvious softening of the weld. The existing low heat input or weld alloying method can effectively solve the problem of weld softening, so that the laser welding and laser-arc composite welding process can not only meet the low heat input, but also meet the weld alloying through wire feeding. However, only through limited process wire feeding, the low alloying degree of the weld cannot be effectively solved, and the weld is still the weak position of the welded joint, which seriously deteriorates the mechanical properties of the welded joint. Patent CN104785950A and CN111334693A respectively disclose a preparation method of Al-Mg-Sc welding wire and Al-Mg-Zr welding wire, which are both through the method of adding rare earth elements Zr or Sc elements to refine the grains in the weld, so as to achieve the effect of fine-grain strengthening of the grains in the weld, although the mechanical properties of the weld are improved. However, fine-grain strengthening cannot effectively solve the problem of weld softening of high-performance heat-treatable alloys.

[0003] The information disclosed in this section of the background art is only intended to increase the understanding of the general background of the application, and should not be considered as acknowledging or implying in any form that the information constitutes prior art known to those skilled in the art. SUMMARY

[0004] The purpose of the present application is to provide a high-zinc aluminum alloy welding wire, a preparation method thereof and a welding method of high-strength aluminum alloy plate, which can enhance the strength of the high-strength aluminum alloy weld.

[0005] To achieve the above-mentioned purpose, the embodiment of the present application provides a preparation method of a high-zinc aluminum alloy welding wire, which comprises:

[0006] 1) heating Al to 770-780 DEG C using a smelting furnace, cooling to 710-720 DEG C after fully melting, then sequentially adding Al-Si alloy, Al-Cu alloy, Al-Fe alloy, Al-Mn alloy and Al-Ti-B alloy, and then sequentially adding Zn and Mg after fully melting;

[0007] 2) After all the raw materials are fully melted, refining, deslagging, and standing are performed, and the melt is poured into a water-cooled copper mold to solidify after the melt temperature is stabilized to 690-720 DEG C;

[0008] 3) The high-zinc aluminum alloy prepared in step 2) is heated to 500-540 DEG C, and then the high-zinc aluminum alloy is annealed at 400-440 DEG C, and then the high-zinc aluminum alloy wire is prepared by hot extrusion.

[0009] In one or more embodiments of the present application, the burn loss rate of Al is between 1-3%; and / or, the burn loss rate of Zn is between 1-2%; and / or, the burn loss rate of Mg is between 10-12%.

[0010] Another embodiment of the present application provides a high-zinc aluminum alloy wire prepared by the above method.

[0011] In one or more embodiments of the present application, the zinc aluminum alloy is selected from one or more of Al-Si5-ZnX, Al-Si12-ZnX, Al-Mg5-ZnX, and Al-Cu5-ZnX.

[0012] In one or more embodiments of the present application, the mass percentage of X is between 15-35%.

[0013] Another embodiment of the present application provides a welding method of a high-strength aluminum alloy plate, which uses a high-zinc aluminum alloy wire for welding, and the method comprises:

[0014] 1) The high-strength aluminum alloy plate is removed from the surface scale, and the surface oil stain is removed with acetone or alcohol and dried for use;

[0015] 2) The high-strength aluminum alloy plate in step 1) is spliced and placed on a workbench and fixed, and the high-zinc aluminum alloy wire is used as a filler material, and a welding heat source is used for welding, and inert gas is introduced for protection during the welding process.

[0016] In one or more embodiments of the present application, the welding heat source is selected from one or more of a laser heat source, a laser wire filling heat source, a laser-MIG composite heat source, a laser-TIG composite heat source, and a laser-CMT composite heat source.

[0017] In one or more embodiments of the present application, the power of the welding heat source is 1.0-3.0 kW, the welding speed is 1.0-3.0 m / min, the wire feeding speed is 1.0-3.5 m / min, and the inert gas flow is 10-20 L / min.

[0018] In one or more embodiments of the present application, the high-strength aluminum alloy is selected from one or more of 6xxx and 2xxx high-strength aluminum alloys.

[0019] In one or more embodiments of the present application, the high-strength aluminum alloy has a thickness of between 1.0-3.0 mm.

[0020] Compared with the prior art, the preparation method of the high-zinc aluminum alloy welding wire according to the embodiments of the present application provides a high-zinc aluminum alloy welding wire. The high-zinc aluminum alloy welding wire can improve the mechanical properties of the weld and avoid the problem of weld softening. Moreover, the welding method of the high-strength aluminum alloy plate according to the embodiments of the present application takes advantage of the high cooling speed in the laser / laser-arc composite welding process and uses the high-zinc aluminum alloy welding wire as the filler material, thereby increasing the solid solution content of the zinc element in the α-Al under room temperature conditions and effectively solving the problem of weld softening through solid solution strengthening, so as to effectively improve the mechanical properties of the weld. DETAILED DESCRIPTION

[0021] The specific embodiments of the present application are described in detail below, but it should be understood that the scope of protection of the present application is not limited by the specific embodiments.

[0022] Unless otherwise explicitly indicated, throughout the specification and claims, the term "comprise" or its variants such as "comprises" or "comprising" will be understood to encompass the stated elements or components, without excluding the presence of other elements or components.

[0023] The preparation method of the high-zinc aluminum alloy welding wire according to the preferred embodiments of the present application includes the following steps:

[0024] 1) Heat Al to 770-780℃ using a smelting furnace, and after it is fully melted, cool it to 710-720℃, then sequentially add Al-Si alloy, Al-Cu alloy, Al-Fe alloy, Al-Mn alloy and Al-Ti-B alloy, and after they are fully melted, sequentially add Zn and Mg.

[0025] 2) After all the raw materials are fully melted, perform refining and slag removal, and stand for 30 minutes, and wait for the melt temperature to stabilize to 690-720℃, and then pour the melt into a water-cooled copper mold to solidify.

[0026] 3) Heat the zinc aluminum alloy prepared in step 2) to 500-540℃, and then perform softening annealing of the zinc aluminum alloy at 400-440℃, and then prepare a high-zinc aluminum alloy welding wire through hot extrusion. In this step, the burn loss rate of Al is between 1-3%; the burn loss rate of Zn is between 1-2%; and the burn loss rate of Mg is between 10-12%.

[0027] A high-zinc aluminum alloy welding wire is prepared by the above method, wherein the zinc aluminum alloy is selected from one or more of Al-Si5-ZnX, Al-Si12-ZnX, Al-Mg5-ZnX and Al-Cu5-ZnX, and X is the mass percentage of Zn, between 15-35%.

[0028] A welding method of a high-strength aluminum alloy plate according to a preferred embodiment of the present application, the method comprising:

[0029] 1) Remove the surface oxide scale of the high-strength aluminum alloy plate, and remove the surface oil with acetone or alcohol and dry for use.

[0030] 2) Place the high-strength aluminum alloy plate in step 1) in a splicing manner on a workbench and fix it, use a high-zinc aluminum alloy welding wire as a filler material, and use a welding heat source to weld.

[0031] Wherein, the welding heat source is selected from one or more of a laser heat source, a laser wire filling heat source, a laser-MIG composite heat source, a laser-TIG composite heat source and a laser-CMT composite heat source. And the power of the welding heat source is 1.0-3.0kW, the welding speed is 1.0-3.0m / min, and the wire feeding speed is 1.0-3.5m / min. In the welding process, inert gas is introduced for protection, and the inert gas flow is 10-20L / min.

[0032] The application is suitable for 6xxx and 2xxx high-strength aluminum alloys, and the thickness of the high-strength aluminum alloy is between 1.0-3.0mm.

[0033] Example 1:

[0034] 1) A high-zinc aluminum alloy welding wire is prepared nominally with alloy Al-Cu5-Zn15.

[0035] 2) Two pieces of 2.0mm thick 2xxx high-strength aluminum alloy plates are selected, with a tensile strength of about 365MPa, the surface oxide scale is removed by mechanical method, and the surface oil is removed with acetone and dried for use.

[0036] 3) The high-strength aluminum alloy plates prepared in step 2) are placed in a splicing manner on a workbench and fixed with a welding fixture.

[0037] 4) The Al-Cu5-Zn15 high-zinc aluminum alloy welding wire prepared in step 1) is used as a filler wire, and a CWX-3000 fiber laser and a CMT500i are used to form a composite welding system to perform laser-CMT composite welding on the high-strength aluminum alloy plate, using a laser guide method, the welding power is 2300W, the welding speed is 2.5m / min, the wire feeding speed is 2.5m / min, and inert gas is introduced for protection during the welding process, and the inert gas flow is 12L / min.

[0038] 5) After welding, the macroscopic morphology of the weld was observed to be good without obvious spatter. The content of zinc element in the weld was measured by direct-reading spectrometer to be 5.5%, and the EPMA detection result showed that the content of zinc element in the α-Al matrix was 5.2%.

[0039] 6) The hardness and tensile strength of the weld were tested according to the national standard, and the test results were as follows: the average hardness of the weld was 84HV, and the tensile strength was 276MPa.

[0040] Comparative Example 1

[0041] 1) Commercial Al-Cu5 welding wire (ER2319 welding wire produced by Lincoln welding material in the United States) was used as the filler welding wire, and the same parameters and methods as in Example 1 were used to weld the high-strength aluminum alloy plate.

[0042] 2) The performance of the weld was detected according to the method of Example 1, and the detection results were as follows: the average hardness of the weld was 60HV, and the tensile strength was 235MPa.

[0043] Example 2

[0044] 1) High-zinc aluminum alloy wire was nominally prepared with alloy Al-Si5-Zn20.

[0045] 2) Two pieces of 2.0mm thick 6xxx high-strength aluminum alloy with a tensile strength of about 400MPa were selected, the surface oxide was removed by mechanical method, and the surface oil stain was removed with acetone and dried for use.

[0046] 3) The high-strength aluminum alloy plates prepared in step 2) were placed on the workbench in a splicing manner and fixed with a welding fixture.

[0047] 4) The Al-Si5-Zn20 high-zinc aluminum alloy wire prepared in step 1) was used as the filler welding wire, and a laser-CMT composite welding system was used to perform laser-CMT composite welding on the high-strength aluminum alloy plate, using laser guiding mode, welding power was 2800W, welding speed was 3m / min, wire feeding speed was 3.5m / min, inert gas was introduced for protection during welding, and the flow rate of inert gas was 15L / min.

[0048] 5) After welding, the macroscopic morphology of the weld was observed to be good without obvious spatter. The content of zinc element in the weld was measured by direct-reading spectrometer to be 10.2%, and the EPMA detection result showed that the content of zinc element in the α-Al matrix was 9.8%.

[0049] 6) The hardness and tensile strength of the weld were tested according to the national standard, and the test results were as follows: the average hardness of the weld was 101HV, and the tensile strength was 315MPa.

[0050] Comparative Example 2:

[0051] 1) : Commercial Al-Si5 welding wire (ER4043 welding wire produced by Lincoln welding material in the United States) was used as filler welding wire, and the same parameters and methods as in Example 2 were used to weld high-strength aluminum alloy plates.

[0052] 2) : The weld performance was detected according to the method of Example 2, and the detection results were that the average hardness of the weld was 75 HV, and the tensile strength was 250 MPa.

[0053] Example 3:

[0054] 1) : High-zinc aluminum alloy welding wire was nominally prepared with alloy Al-Si5-Zn30.

[0055] 2) : Two pieces of 2.0 mm thick 6xxx high-strength aluminum alloy with a tensile strength of about 400 MPa were selected, the surface oxide was removed by mechanical method, and the surface oil was removed with acetone and dried for use.

[0056] 3) : The high-strength aluminum alloy plates prepared in step 2) were placed on the workbench in a splicing manner and fixed with a welding fixture.

[0057] 4) : The Al-Si5-Zn30 high-zinc aluminum alloy welding wire prepared in step 1) was used as filler welding wire, and a laser-CMT composite welding system was used to perform laser-CMT composite welding on the high-strength aluminum alloy plates, using laser guiding mode, welding power was 2800 W, welding speed was 3 m / min, wire feeding speed was 3.6 m / min, inert gas was introduced for protection during welding, and the flow rate of inert gas was 15 L / min.

[0058] 5) : After welding, the weld macroscopic morphology was good, and there was no obvious spatter. The zinc content in the weld was measured by direct-reading spectrometer to be 18.5%, and the EPMA detection results showed that the zinc content in the α-Al matrix was 15.1%.

[0059] 6) : The hardness and tensile strength of the weld were tested according to the national standard, and the test results were: the average hardness of the weld was 112 HV, and the tensile strength was 340 MPa.

[0060] Comparative Example 3:

[0061] 1) : Commercial Al-Si5 welding wire (ER4043 welding wire produced by Lincoln welding material in the United States) was used as filler welding wire, and the same parameters and methods as in Example 3 were used to weld high-strength aluminum alloy plates.

[0062] 2): The weld performance was detected according to the method of Example 3, and the detection result was that the average hardness of the weld was 75 HV, and the tensile strength was 250 Mpa.

[0063] The preparation method of the high-zinc aluminum alloy welding wire provides a high-zinc aluminum alloy welding wire. The high-zinc aluminum alloy welding wire can improve the mechanical properties of the weld and avoid the problem of weld softening. Moreover, the welding method of the high-strength aluminum alloy plate in the embodiment of the application uses the high cooling speed characteristics in the laser / laser-arc composite welding process and the high-zinc aluminum alloy welding wire as the filler material, improves the solid solution content of the zinc element in the alpha-Al under room temperature conditions, effectively solves the problem of weld softening through solid solution strengthening, and thus effectively improves the mechanical properties of the weld.

[0064] The foregoing description of specific exemplary embodiments of the application is intended to be illustrative only and is not intended to limit the application to the precise forms described. Many modifications and variations are possible in light of the above teachings without departing from the spirit or essential characteristics of the application. The exemplary embodiments were chosen and described in order to explain the principles of the application and its practical application and to allow others skilled in the art to understand the application for various exemplary embodiments with various modifications being applicable. The scope of the application is intended to be defined by the claims and their equivalents.

Claims

1. A method for preparing a high-zinc aluminum alloy welding wire, characterized in that, include: 1) Heat Al to 770℃~780℃ in a melting furnace. After it is fully melted, cool it down to 710~720℃. Then add Al-Si alloy, Al-Cu alloy, Al-Fe alloy, Al-Mn alloy and Al-Ti-B alloy in sequence. After they are completely melted, add Zn and Mg in sequence. 2) After all the raw materials have been fully melted, they are refined, slag is removed, and the mixture is allowed to stand until the temperature of the melt stabilizes at 690~720℃. The melt is then poured into a water-cooled copper mold to solidify. 3) Heat the zinc-aluminum alloy prepared in step 2) to 500-540℃ and hold it at that temperature. Then, soften and anneal the zinc-aluminum alloy at 400-440℃. Finally, prepare high-zinc-aluminum alloy welding wire by hot extrusion. The high-zinc-aluminum alloy is selected from one or more of Al-Si5-ZnX, Al-Si12-ZnX, Al-Mg5-ZnX and Al-Cu5-ZnX, where X is the mass percentage of Zn, which is between 15-35%.

2. The method for preparing the high-zinc aluminum alloy welding wire as described in claim 1, characterized in that, The burn-off rate of Al is between 1-3%; and / or, the burn-off rate of Zn is between 1-2%; and / or, the burn-off rate of Mg is between 10-12%.

3. A high-zinc aluminum alloy welding wire, characterized in that, The high-zinc aluminum alloy welding wire is a high-zinc aluminum alloy welding wire prepared by any one of the preparation methods of claims 1-2.

4. A welding method for high-strength aluminum alloy plates, characterized in that, Welding is performed using the high-zinc aluminum alloy welding wire as described in claim 3, and the welding method includes: 1) Remove the oxide scale from the surface of the high-strength aluminum alloy plate, and remove the surface oil stains with acetone or alcohol. Let it dry before use. 2) Place the high-strength aluminum alloy plates from step 1) on the workbench and fix them in place. Use the high-zinc aluminum alloy welding wire as the filler material and use a welding heat source to weld. Inert gas is introduced for protection during the welding process.

5. The welding method as described in claim 4, characterized in that, The welding heat source is selected from one or more of the following: laser heat source, laser filler wire heat source, laser-MIG composite heat source, laser-TIG composite heat source, and laser-CMT composite heat source.

6. The welding method as described in claim 4, characterized in that, The welding heat source has a power of 1.0-3.0kW, a welding speed of 1.0-3.0m / min, a wire feeding speed of 1.0-3.5m / min, and an inert gas flow rate of 10-20L / min.

7. The welding method as described in claim 4, characterized in that, The high-strength aluminum alloy is selected from one or more of 6xxx and 2xxx high-strength aluminum alloys.

8. The welding method as described in claim 4, characterized in that, The thickness of the high-strength aluminum alloy is between 1.0 and 3.0 mm.