CN118002980A - Aluminum alloy welding wire for melting welding of 6XXX series aluminum alloy extruded profile, preparation method and application thereof - Google Patents

Abstract

The invention provides an aluminum alloy welding wire for melting and welding 6XXX series aluminum alloy extrusion profiles, which comprises the following components in percentage by mass: 0 to 0.2% of Si, 0 to 0.2% of Fe, 0 to 0.05% of Cu, 0.2 to 0.3% of Mn, 5.8 to 6.8% of Mg,0 to 0.04% of Ti, 0.1 to 0.12% of Zr, 0.25 to 0.35% of Sc, the balance of Al and unavoidable impurities, each unavoidable impurity being < 0.05%, and the total impurities being < 0.15%. The aluminum alloy welding wire has a specific aluminum alloy component ratio, contains Sc and Zr, can effectively refine a weld joint structure, can effectively reduce the liquidation crack tendency of a weld joint and improve the weld joint strength when being applied to the fusion welding of 6XXX series aluminum alloy extruded profiles.

Description

Aluminum alloy welding wire for melting welding of 6XXX series aluminum alloy extruded profile, preparation method and application thereof

Technical Field

The invention relates to the technical field of high-strength aluminum alloy welding wire manufacture, in particular to an aluminum alloy welding wire for melting welding of 6XXX series aluminum alloy extruded profiles, a preparation method and application thereof.

Background

The 6XXX aluminum alloy is an Al-Mg-Si aluminum alloy which can be strengthened by heat treatment, has good ductility, is a preferable material for manufacturing large-scale extrusion profiles, and is often applied to the fields of ships, rail transit and the like.

In the prior art, a melting welding mode is often adopted, and a 6XXX series aluminum alloy is used as a load bearing structure for assembly. However, the surface of the 6XXX series aluminum alloy material is affected by the extrusion process of the aluminum profile, the problem of coarse grains exists on the surface of the 6XXX series aluminum alloy material, a large amount of second phases exist in the grain boundary and the grain, after the aluminum alloy is applied to fusion welding, the obtained joint is easy to generate liquefaction cracks in a part of a fusion area, and the mechanical property of the joint is poor.

Disclosure of Invention

The invention mainly aims to provide an aluminum alloy welding wire for fusion welding of a 6XXX series aluminum alloy extrusion profile, a preparation method and application thereof, and aims to solve the problem that in the prior art, a joint part fusion area is easy to generate liquefaction cracks when a 6XXX series aluminum alloy material is fusion welded, so that the mechanical property of the joint is poor.

In order to achieve the above object, according to one aspect of the present invention, there is provided an aluminum alloy welding wire for use in fusion welding of a 6XXX series aluminum alloy extruded profile. The aluminum alloy welding wire comprises the following components in percentage by mass: 0 to 0.2% of Si, 0 to 0.2% of Fe, 0 to 0.05% of Cu, 0.2 to 0.3% of Mn, 5.8 to 6.8% of Mg,0 to 0.04% of Ti, 0.1 to 0.12% of Zr, 0.25 to 0.35% of Sc, the balance of Al and unavoidable impurities, each unavoidable impurity being < 0.05%, and the total impurities being < 0.15%.

Further, the aluminum alloy welding wire comprises the following components in percentage by mass: 0 to 0.06% of Si, 0 to 0.12% of Fe, 0 to 0.05% of Cu, 0.2 to 0.3% of Mn, 6 to 6.6% of Mg, 0 to 0.04% of Ti, 0.1 to 0.12% of Zr, 0.3 to 0.35% of Sc, the balance being Al and unavoidable impurities, each unavoidable impurity being < 0.05%, and the total impurities being < 0.15%.

Further, in the components of the aluminum alloy welding wire, the mass ratio of Zr to Sc is 1 (2-3).

According to another aspect of the present invention, a method of preparing an aluminum alloy welding wire for fusion welding of 6XXX series aluminum alloy extrusion is provided. The method comprises the following steps: step S1, mixing raw materials according to the composition of an aluminum alloy welding wire, and then performing casting to obtain an aluminum alloy cast rod; step S2, carrying out homogenizing annealing on the aluminum alloy casting rod, and then extruding to obtain a first wire rod; step S3, alternately drawing and intermediate annealing the first wire rod to obtain a second wire rod; step S4, sequentially carrying out rough scraping, wire drawing and fine scraping on the second wire rod to obtain a third wire rod; and S5, cleaning the third wire to obtain the aluminum alloy welding wire.

Further, in the step S1, the liquid online hydrogen content is controlled to be less than or equal to 0.12 ml/100g when the casting is performed.

Further, in the step S2, the temperature of the homogenizing annealing is 440-470 ℃ and the time is 8-24 hours; and/or the diameter of the first wire rod is 10-11 mm.

Further, in the step S2, the temperature of the homogenizing annealing is 450-470 ℃ and the time is 8-12 hours.

In step S3, the reduction of each pass of drawing is 0.72-0.8 mm.

Further, in the step S3, the temperature of the intermediate annealing is 350-400 ℃ and the time is 2-3 hours; the diameter of the second wire rod is 2.05-2.25 mm.

Further, in the step S4, the wire scraping speed of rough scraping is 3.5-4.5 m/S; the diameter reduction of rough scraping is 0.1-0.2 mm; and/or the diameter reduction of the wire drawing is 0.45-0.8 mm; and/or the diameter reduction of the fine scraping is 0.1-0.12 mm.

Further, in step S5, the cleaning temperature is 50-60 ℃.

Further, in the step S5, the diameter of the aluminum alloy welding wire is 1.18-1.6 mm.

According to another aspect of the present invention, there is provided a method for welding an aluminum alloy, wherein an aluminum alloy extrusion of 6XXX series with coarse surface crystals is used as a base material and fusion-welded with the aluminum alloy welding wire.

Further, the atmosphere for fusion welding was 99.99% argon gas.

According to another aspect of the present invention, there is provided a welded joint, obtained using the above welding method, the welded joint being free of liquefied cracks.

The aluminum alloy welding wire has a specific aluminum alloy component ratio, and simultaneously contains Sc and Zr, in the solidification process of a molten pool of fusion welding, zr, sc and Al cooperate with each other, and formed Al ₃(Sc_xZr_1-x) particles can be used as heterogeneous nuclear particles, so that a weld joint structure is effectively thinned, the coarse columnar crystal orientation equiaxed crystal of a weld joint fusion zone is transformed, the permeation of Mg and Si elements along the crystal is reduced, the precipitation of MgSi (MgSiCu) eutectic with low melting point and the like among crystal boundaries is effectively reduced, the tendency of liquefying cracks generated in the fusion zone of a part of a fusion welding joint under the input of welding heat can be reduced, and the mechanical strength of the joint is further facilitated to be improved.

The aluminum alloy welding wire has good weldability, can effectively reduce the liquidation crack tendency of a welding line when being applied to the fusion welding of the 6XXX series aluminum alloy extruded section, improves the welding line strength, and lays a foundation for the popularization and application of the 6XXX series extruded section in the engineering field.

Drawings

The accompanying drawings, which are included to provide a further understanding of the application and are incorporated in and constitute a part of this specification, illustrate embodiments of the application and together with the description serve to explain the application. In the drawings:

FIG. 1 shows a surface topography of a 6XXX series extruded profile according to an embodiment of the present invention;

FIG. 2 shows a microstructure view of an aluminum alloy welding wire of example 1 of the present invention applied to a 6XXX series extruded profile weld;

FIG. 3 shows a microstructure view of an aluminum alloy welding wire of example 2 of the present invention applied to a 6XXX series extruded profile weld;

FIG. 4 shows a microstructure view of an aluminum alloy welding wire of comparative example 1 of the present invention applied to a 6XXX series extruded profile weld;

FIG. 5 shows a microstructure view of an aluminum alloy welding wire of comparative example 2 of the present invention applied to a 6XXX series extruded profile weld;

FIG. 6 shows a microstructure view of an aluminum alloy welding wire of comparative example 3 of the present invention applied to a 6XXX series extruded profile weld; and

FIG. 7 is a microstructure view of the weld portion molten zone of the welding wire of comparative example 1 of the present invention;

wherein the above figures include the following reference numerals:

1. A melting zone part 1; 2. a melting zone part 2.

Detailed Description

It should be noted that, without conflict, the embodiments of the present application and features of the embodiments may be combined with each other. The application will be described in detail below with reference to the drawings in connection with embodiments.

As in the background art of the invention, the problem of poor mechanical properties of the joint caused by liquefaction cracks generated in the part of the melting zone of the joint of the 6XXX series aluminum alloy material exists in the prior art. In order to solve the above problems, in an exemplary embodiment of the present invention, there is provided an aluminum alloy welding wire comprising, in mass percent: 0 to 0.2% of Si, 0 to 0.2% of Fe, 0 to 0.05% of Cu, 0.2 to 0.3% of Mn, 5.8 to 6.8% of Mg, 0 to 0.04% of Ti, 0.1 to 0.12% of Zr, 0.25 to 0.35% of Sc, the balance of Al and unavoidable impurities, each unavoidable impurity being < 0.05%, and the total impurities being < 0.15%.

Mg can enhance the mechanical strength of the welded joint by solid solution strengthening. If the mass percentage of Mg in the components of the welding wire is lower than 5.8%, when the welding wire is used for fusion welding of 6XXX series aluminum alloy materials, less Mg element is dissolved in an alpha-Al matrix in the obtained joint, and the joint strength is weakened; if the mass percent of Mg is higher than 6.8%, the addition of Mg element is excessive, the cost of the welding wire is high, and meanwhile, excessive Mg is easy to absorb hydrogen in the casting process, so that the liquid online hydrogen content is too high, even higher than 0.12ml/100g.

The aluminum alloy welding wire has a specific aluminum alloy component ratio, and simultaneously contains Sc and Zr, in the molten pool solidification process of fusion welding, zr, sc and Al are mutually cooperated to form Al ₃(Sc_xZr_1-x (such as Al ₃(Sc_0.5Zr_0.5)) particles which can be used as heterogeneous nuclear particles, so that a weld joint structure is effectively thinned, a coarse columnar crystal of a weld joint fusion area is transformed into equiaxed crystals, the permeation of Mg and Si elements along crystals is reduced, the precipitation of MgSi (MgSiCu) eutectic with low melting point and the like among crystal boundaries is effectively reduced, the tendency of liquefying cracks generated in the fusion area of a fusion welding head part under welding heat input can be reduced, and the mechanical strength of the joint is further improved.

In a preferred embodiment, the aluminum alloy welding wire comprises the following components in percentage by mass: 0 to 0.06% of Si, 0 to 0.12% of Fe, 0 to 0.05% of Cu, 0.2 to 0.3% of Mn, 6 to 6.6% of Mg, 0 to 0.04% of Ti, 0.1 to 0.12% of Zr, 0.3 to 0.35% of Sc, the balance being Al and unavoidable impurities, each unavoidable impurity being < 0.05%, and the total impurities being < 0.15%. Under the above conditions, precipitation of MgSi (MgSiCu) eutectic phase between grain boundaries can be further reduced, and it is more advantageous to reduce liquefaction cracks generated by the welding heat input in the part of the molten weld head.

Regarding the mass ratio of Zr and Sc in the aluminum alloy wire component, in order to reduce the production cost, sc and Zr may be added in the wire component in the prior art at a mass ratio of 1:1. During the course of the experiment, the inventors have unexpectedly found that approximately 50% of the Sc atoms in the Al ₃(Sc_xZr_1-x) phase are replaced by Zr atoms. In order to further facilitate the formation of Al ₃(Sc_xZr_1-x particles as heterogeneous core particles and further facilitate the refinement of the weld structure, in a preferred embodiment, the mass ratio of Zr to Sc in the composition of the aluminum alloy wire is 1 (2-3). Under the above conditions, al ₃(Sc_xZr_1-x is more favorable to be obtained), and the phenomenon of MgSi (MgSiCu) eutectic phase precipitation caused by permeation of Mg and Si elements along the crystal is more effectively reduced.

In yet another exemplary embodiment of the present invention, there is also provided a method for preparing an aluminum alloy welding wire for fusion welding of a 6XXX series aluminum alloy extrusion, comprising the steps of: step S1, mixing raw materials according to the composition of an aluminum alloy welding wire, and then performing casting to obtain an aluminum alloy cast rod; step S2, carrying out homogenizing annealing on the aluminum alloy casting rod, and then extruding to obtain a first wire rod; step S3, alternately drawing and intermediate annealing the first wire rod to obtain a second wire rod; step S4, sequentially carrying out rough scraping, wire drawing and fine scraping on the second wire rod to obtain a third wire rod; and S5, cleaning the third wire to obtain the aluminum alloy welding wire.

The invention firstly mixes and founds the raw materials of the aluminum alloy welding wire to obtain the casting rod. And then, carrying out homogenizing annealing on the casting rod to eliminate dendrite segregation in the casting rod and homogenize the structure of each element. And extruding the annealed cast rod, alternately drawing and intermediate annealing to obtain a second wire rod. Extrusion and drawing are mutually cooperated, which is beneficial to eliminating segregation of casting rod and reducing shrinkage porosity of tissue. The drawing and the intermediate annealing are alternately performed, so that the drawn casting rod can be softened, and the drawing operation of the casting rod can be conveniently and alternately performed.

And then, sequentially carrying out rough scraping, wire drawing and fine scraping on the second wire rod to obtain a third wire rod. The process of adding wire drawing in the middle of two wire scraping processes can effectively improve the surface quality of wires and ensure continuous and stable wire feeding of welding wires. Finally, the third wire is cleaned, so that the surface quality of the aluminum alloy welding wire can be further improved, and the diameter of the wire is not reduced. In the present invention, the drawing and the intermediate annealing are alternately performed, and the "single drawing-single intermediate annealing-single drawing-single intermediate annealing" cycle is defined.

The preparation method provided by the invention does not need to modify a production line, can realize processing production on a conventional production line, is controllable in cost, and the prepared aluminum alloy welding wire crystal grains have good weldability. When the welding wire is applied to the fusion welding of the 6XXX series extrusion profile, the tendency of liquefying and cracking of the welding seam can be effectively reduced, the strength of the welding seam can be improved, and a foundation is laid for the popularization and application of the subsequent 6XXX series extrusion profile.

In order to further reduce the defects of air holes, micro-porosity and the like of the aluminum alloy casting rod, thereby further improving the quality of the welding wire, in a preferred embodiment, in the step S1, the liquid online hydrogen content is controlled to be less than or equal to 0.12 ml/100g when the casting is performed.

In the prior art, the homogenizing annealing system is divided into short-time annealing and long-time annealing, so as to effectively reduce energy consumption and welding wire cost, the homogenizing annealing system with shorter time consumption is particularly selected, and in a preferred embodiment, the homogenizing annealing temperature is 440-470 ℃ and the homogenizing annealing time is 8-24 h in step S2. Under the above conditions, the process is shorter in time consumption, less in energy consumption and better in uniform organization effect, and the mechanical properties of the joint obtained during welding are further increased. If the temperature of the homogenizing annealing is too high or the time is too long, the energy consumption is large, the cost is high, and if the temperature of the homogenizing annealing is too low or the time is too short, the segregation of the casting rod cannot be effectively eliminated, and the uniform structure is not facilitated. In order to further shorten the process time and reduce the energy consumption, in a preferred embodiment, in the step S2, the temperature of the homogenizing annealing is 450-470 ℃ and the time is 8-12 hours. Under the above conditions, the prepared welding wire structure is still uniform. Preferably, the diameter of the first wire rod is 10-11 mm.

In a preferred embodiment, in step S3, the reduction of each pass of drawing is 0.72-0.8 mm. The number of drawing passes can be set based on the reduction of each pass, as will be understood by those skilled in the art, and will not be described in detail herein. If the reduction of drawing in each pass is too small, the number of drawing passes is too large, the processing flow is large, the steps are complex, the time is long, and the cost is high. If the reduction amount of each pass of drawing is too large on the premise of the same total reduction amount, the wire is easy to break in the drawing process, the wire surface quality is poor, pits and cracks are large, and the wire is easy to jump arc when being applied to the fusion welding of the 6XXX series extruded profile. In a preferred embodiment, the diameter of the second wire is 2.05-2.25 mm.

In order to facilitate processing of the wire rod, in a preferred embodiment, the intermediate annealing temperature is 350-400 ℃ and the time is 2-3 hours. If the annealing temperature is too low or the annealing time is too short, the annealing is not thorough, so that the wire rod is harder, and the subsequent drawing process is not facilitated. If the annealing temperature is too high or the annealing time is too long, the surface of the wire rod is obviously oxidized, the oxide skin of the wire rod is too thick, more impurities are caused during welding, the mechanical property is poor, and the wire rod is not suitable for being applied to fusion welding.

For the purpose of facilitating continuous and stable wire feeding of the welding wire, in a preferred embodiment, in the step S4, the wire scraping speed of rough scraping is 3.5-4.5 m/S. If the rough scraping speed is too high, the surface quality of the wire is poor, and if the rough scraping speed is too low, the production efficiency is too low. In a preferred embodiment, the diameter reduction of the rough scratch is 0.1-0.2 mm; and/or the diameter reduction of the wire drawing is 0.45-0.8 mm; and/or the diameter reduction of the fine scraping is 0.1-0.12 mm. In a preferred embodiment, in step S5, the diameter of the aluminum alloy welding wire is 1.18 to 1.6mm.

In a preferred embodiment, in step S5, the cleaning temperature is 50 to 60 ℃. If the cleaning temperature is too low, the greasy dirt on the surface of the welding wire is not easy to clean. In a preferred embodiment, step S5 further includes a step of drying and coiling the washed third wire once. Under the above conditions, the storage and transportation of the aluminum alloy welding wire are facilitated.

In still another exemplary embodiment of the present invention, there is also provided a method for welding an aluminum alloy, in which a 6 XXX-series aluminum alloy extrusion with coarse surface crystals is used as a base material, and fusion welding is performed with the aluminum alloy welding wire.

In a preferred embodiment, the atmosphere for fusion welding is 99.99% argon. Under the above conditions, the welding effect of fusion welding is better, and the joint quality is better.

In yet another exemplary embodiment of the present invention, there is also provided a welded joint, obtained using the aforementioned welding method, the welded joint being free of liquefied cracks. The welded joint has high strength and good quality.

The invention ensures that the aluminum alloy welding wire has better weldability from the angles of limiting the components of the aluminum alloy welding wire, limiting the preparation method of the welding wire and optimizing the welding process, and effectively reduces the generation of joint liquefying cracks when being applied to the fusion welding of the 6XXX series aluminum alloy extruded section, improves the welding seam strength, obviously improves the mechanical properties of the joint and lays a foundation for the popularization and application of the 6XXX series extruded section in the engineering field.

Typically, but not by way of limitation, an aluminum alloy welding wire for fusion welding of 6XXX series aluminum alloy extruded profiles is composed of the following components in mass percent: si 0, 0.01%, 0.02%, 0.04%, 0.06%, 0.08%, 0.1%, 0.12%, 0.14%, 0.15%, 0.16%, 0.18%, 0.2% or any two values thereof; fe 0, 0.01%, 0.02%, 0.04%, 0.06%, 0.08%, 0.1%, 0.12%, 0.14%, 0.15%, 0.16%, 0.18%, 0.2% or any two values thereof; cu 0, 0.01%, 0.02%, 0.03%, 0.04%, 0.05% or any two values thereof; mn 0.2%, 0.22%, 0.24%, 0.26%, 0.28%, 0.3% or any two values thereof; mg 5.8%, 6%, 6.2%, 6.4%, 6.6%, 6.8% or any two values thereof; ti 0%, 0.01%, 0.02%, 0.03%, 0.04% or any two values thereof; zr 0.1%, 0.11%, 0.12% or any two values thereof; sc 0.25%, 0.27%, 0.29%, 0.3%, 0.31%, 0.33%, 0.35% or any two values thereof; the balance of Al and unavoidable impurities, each unavoidable impurity is less than 0.05%, and the total impurity is less than 0.15%.

Typically, but not by way of limitation, the mass ratio of Zr to Sc in the composition of the aluminum alloy welding wire is 1:2, 1:2.2, 1:2.4, 1:2.6, 1:2.8, 1:3, or any two values thereof.

Typically, but not limited to, in step S2, the homogenization treatment is carried out at a temperature of 440 ℃, 445 ℃, 450 ℃, 455 ℃, 460 ℃, 465 ℃, 470 or any two values thereof; the time is 8h, 10h, 12 h, 14 h, 16 h, 18 h, 20 h, 22 h, 24 h or any two values thereof.

Typically, but not limited to, in step S3, the reduction of each pass is 0.72mm, 0.74 mm, 0.76 mm, 0.78 mm, 0.8 mm or any two values thereof.

Typically, but not limited to, in step S3, the temperature of the intermediate anneal is 350 ℃, 360 ℃, 370 ℃, 380 ℃, 390 ℃, 400 ℃, for a period of time of 2h, 2.2 h, 2.4 h, 2.6 h, 2.8 h, 3h, or any two values thereof.

Typically, but not limited to, in step S5, the temperature of the washing is 50 ℃, 52 ℃, 54 ℃, 56 ℃, 58 ℃, 60 ℃ or a range of values consisting of any two of these values.

The application is described in further detail below in connection with specific examples which are not to be construed as limiting the scope of the application as claimed.

Example 1

S1, referring to the composition of an aluminum alloy welding wire, mixing raw materials, then performing casting, and controlling the liquid online hydrogen content to be 0.11ml/100g to obtain an aluminum alloy cast rod with the phi of 140 mm;

step S2, homogenizing annealing the aluminum alloy casting rod at 455 ℃ for 10 hours; then extruding the casting rod into a first wire rod with the diameter of 10.18 mm;

step S3, alternately carrying out 11-pass drawing and 11-pass intermediate annealing on the first wire rod to obtain a second wire rod with the diameter of 2.15 mm; the reduction of each pass of drawing is 0.73mm, the intermediate annealing system is 375 ℃, and the heat preservation time is 2.5 hours;

S4, adopting a flat die to roughly scrape the second wire rod, wherein the scraping speed is 4m/S, and scraping the phi 2.15mm aluminum alloy wire rod to phi 2mm; then, carrying out water tank wire drawing on the phi 2mm wire by adopting small processing amount until the phi 1.3mm wire is drawn; precisely scraping the wire with the diameter of phi 1.3mm by adopting a flat die, wherein the diameter reduction of the precisely scraping is 0.11mm, and obtaining a third wire with the diameter of phi 1.19 mm;

And S5, carrying out ultrasonic cleaning on the third wire rod with the diameter of 1.19mm, and controlling the water temperature at 55 ℃. And then, drying the third wire, and finally coiling to obtain the aluminum alloy welding wire.

And S6, under the protection of 99.99% of argon, adopting the 6XXX extruded profile with the coarse surface crystals as a base material, and carrying out fusion welding with an aluminum alloy welding wire, wherein no liquefied crack is generated in a welding joint.

Examples 2 to 8

The only difference from example 1 is that:

The compositions of the aluminum alloy welding wires are different, and are shown in Table 1 in detail.

Example 9

Step S1, referring to the composition of the aluminum alloy welding wire in the embodiment 1, mixing raw materials, and then performing casting, wherein the liquid online hydrogen content is controlled to be 0.10 ml/100g, so as to obtain an aluminum alloy casting rod with the phi of 140 mm;

Step S2, carrying out homogenizing annealing on the aluminum alloy casting rod at 440 ℃ for 9 hours; then extruding the casting rod into a first wire rod with the diameter of 10.15 mm;

step S3, alternately carrying out 10-pass drawing and 10-pass intermediate annealing on the first wire rod to obtain a second wire rod with the diameter of 2.15 mm; the reduction of each pass of drawing is 0.8mm, the intermediate annealing system is 350 ℃, and the heat preservation time is 3 hours;

S4, adopting a flat die to roughly scrape the second wire rod, wherein the scraping speed is 4m/S, the diameter reduction of the roughly scraped wire rod is 0.1mm, and the phi 2.15mm aluminum alloy wire rod is scraped to phi 2.05mm; then, carrying out water tank wire drawing on the wire with the diameter of phi 2.05mm by adopting small processing amount, wherein the diameter reduction amount of the wire drawing is 0.45mm; drawing to phi 1.6mm; precisely scraping the silk material with the diameter of phi 1.6mm by adopting a flat die, wherein the diameter reduction of the precisely scraping is 0.1mm, and obtaining a third silk material with the diameter of phi 1.5 mm;

And S5, carrying out ultrasonic cleaning on the third wire rod with the diameter of 1.5mm, and controlling the water temperature at 60 ℃. Then, drying the third wire, and finally coiling to obtain an aluminum alloy welding wire;

And S6, under the protection of 99.99% of argon, adopting the 6XXX extruded profile with the coarse surface crystals as a base material, and carrying out fusion welding with an aluminum alloy welding wire, wherein no liquefied crack is generated in a welding joint.

Example 10

The only difference from example 1 is that:

In the step S2, the homogenizing annealing temperature is 450 ℃ and the homogenizing annealing time is 12 hours.

Comparative example 1

The only difference from example 1 is that:

the aluminum alloy welding wire raw material does not contain Sc, and the mass percentage of Mg is 5%.

Comparative example 2

The only difference from example 1 is that:

The compositions of the aluminum alloy welding wires are different, and are shown in Table 1 in detail.

Comparative example 3

The only difference from example 1 is that:

The aluminum alloy welding wire raw material does not contain Sc, and the mass percentage of Mg is 6.3%.

Comparative example 4

The only difference from example 1 is that:

the aluminum alloy wire raw material does not contain Zr.

Comparative example 5

The only difference from example 1 is that:

The drawing passes were 7 times, and the reduction of drawing per pass was 1.0mm.

Comparative example 6

The only difference from example 1 is that:

the fine scraping process is not included.

Comparative example 7

The only difference from example 1 is that:

The cleaning temperature was 20 ℃.

The raw material compositions of the aluminum alloy welding wire of the above examples and comparative examples are shown in table 1; the mechanical properties of the welded joints formed on the 6XXX series extrusion profile by the aluminum alloy welding wires of the above examples and comparative examples are shown in Table 2.

The surface topography of the 6XXX series extruded profile is shown in FIG. 1; application of the aluminum alloy welding wire of example 1 to 6XXX series extrusion profile weld microstructure is shown in fig. 2; the microstructure of the weld joint of the aluminum alloy welding wire of the embodiment 2 applied to the 6XXX series extrusion profile is shown in FIG. 3; the microstructure diagram of the welding seam of the aluminum alloy welding wire of the comparative example 1 applied to the 6XXX series extrusion profile is shown in FIG. 4; the microstructure diagram of the welding seam of the extrusion profile of the 6XXX series, which is applied to the aluminum alloy welding wire of the comparative example 2, is shown in FIG. 5; the aluminum alloy welding wire of comparative example 3 was applied to a 6XXX series extrusion profile weld microstructure diagram, see fig. 6. The microstructure of the molten zone of the welding wire weld part of comparative example 1 is shown in fig. 7, the elemental content analysis was performed on the molten zone part 1 and the molten zone part 2, and the spectrogram label is shown in table 3.

The testing method comprises the following steps:

Element content testing: reference (J) Test.

Tensile test: reference is made to GB/T2651-2023 transverse tensile test for destructive test of metallic Material weldTest.

TABLE 1

TABLE 2

TABLE 3 Table 3

Compared with the comparative examples, the specific aluminum alloy component proportion is controlled, and Sc and Zr are contained simultaneously, so that Zr, sc and Al are mutually cooperated to form Al ₃(Sc_xZr_1-x) particles as heterogeneous core particles in the solidification process of a molten pool in fusion welding, the weld joint structure is effectively thinned, the coarse columnar crystals of the weld joint fusion zone are transformed into equiaxed crystals, the permeation of Mg and Si elements along the crystals is reduced, the precipitation of MgSi (MgSiCu) eutectic with low melting point and the like among crystal boundaries is effectively reduced, the tendency of liquefying cracks generated in the fusion zone of a fusion welding joint part under the input of welding heat is reduced, and the mechanical strength of the joint is further improved. The aluminum alloy welding wire has better weldability, and can effectively reduce the liquidation crack tendency of a welding line and improve the welding line strength when being applied to the fusion welding of 6XXX series aluminum alloy extruded profiles. In addition, it can be seen that the mechanical strength of the welding wire is higher when the process parameters are within the preferred ranges of the present invention.

The above description is only of the preferred embodiments of the present invention and is not intended to limit the present invention, but various modifications and variations can be made to the present invention by those skilled in the art. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims (15)

1. An aluminum alloy welding wire for fusion welding of 6XXX series aluminum alloy extruded profiles, characterized in that the aluminum alloy welding wire comprises the following components in percentage by mass:

0-0.2% of Si, 0-0.2% of Fe, 0-0.05% of Cu, 0.2-0.3% of Mn, 5.8-6.8% of Mg, 0-0.04% of Ti, 0.1-0.12% of Zr, 0.25-0.35% of Sc, the balance being Al and unavoidable impurities, each of which is less than 0.05%, and the total impurities is less than 0.15%.

2. The aluminum alloy welding wire as recited in claim 1, wherein the aluminum alloy welding wire comprises, in mass percent:

0-0.06% of Si, 0-0.12% of Fe, 0-0.05% of Cu, 0.2-0.3% of Mn, 6-6.6% of Mg, 0-0.04% of Ti, 0.1-0.12% of Zr, 0.3-0.35% of Sc, the balance Al and unavoidable impurities, wherein each unavoidable impurity is less than 0.05%, and the total impurity is less than 0.15%.

3. The aluminum alloy welding wire according to claim 1 or 2, wherein the mass ratio of Zr to Sc in the components of the aluminum alloy welding wire is 1 (2-3).

4. A method for producing an aluminum alloy welding wire for fusion welding of 6XXX series aluminum alloy extruded profiles as claimed in any one of claims 1 to 3, characterized by comprising the steps of:

step S1, mixing raw materials according to the composition of the aluminum alloy welding wire, and then performing casting to obtain an aluminum alloy cast rod;

step S2, carrying out homogenizing annealing on the aluminum alloy casting rod, and then extruding to obtain a first wire rod;

Step S3, alternately drawing and intermediate annealing the first wire rod to obtain a second wire rod;

step S4, sequentially carrying out rough scraping, wire drawing and fine scraping on the second wire rod to obtain a third wire rod;

and S5, cleaning the third wire to obtain the aluminum alloy welding wire.

5. The method according to claim 4, wherein in the step S1, the liquid on-line hydrogen content is controlled to be not more than 0.12 ml/100g when the casting is performed.

6. The method according to claim 4, wherein in the step S2,

The temperature of the homogenizing annealing is 440-470 ℃ and the time is 8-24 hours; and/or

The diameter of the first wire rod is 10-11 mm.

7. The method according to claim 4, wherein in the step S2,

The temperature of the homogenizing annealing is 450-470 ℃ and the time is 8-12 h.

8. The method according to claim 4, wherein in the step S3,

The diameter reduction of each pass of drawing is 0.72-0.8 mm.

9. The method according to claim 4, wherein in the step S3,

The temperature of the intermediate annealing is 350-400 ℃ and the time is 2-3 h;

The diameter of the second wire rod is 2.05-2.25 mm.

10. The method according to claim 4, wherein in the step S4,

The scraping speed of the rough scraping is 3.5-4.5 m/s;

the diameter reduction of the rough scraping is 0.1-0.2 mm; and/or

The diameter reduction of the wire drawing is 0.45-0.8 mm; and/or

The diameter reduction of the fine scraping is 0.1-0.12 mm.

11. The method according to claim 4, wherein in the step S5,

The cleaning temperature is 50-60 ℃.

12. The method according to claim 4, wherein in the step S5,

The diameter of the aluminum alloy welding wire is 1.18-1.6 mm.

13. A welding method of an aluminum alloy, characterized in that a 6XXX series aluminum alloy extrusion with surface coarse grains is used as a base material, and fusion welding is performed with the aluminum alloy welding wire according to any one of claims 1 to 3.

14. The welding method according to claim 13, wherein the atmosphere of the fusion welding is 99.99% argon gas.

15. A welded joint, characterized in that it is obtained using the welding method according to claim 13 or 14, said welded joint being free from liquefied cracks.