High-strength anti-cracking high-magnesium aluminum alloy welding wire

Abstract

The invention provides a high-strength anti-cracking high-magnesium aluminum alloy welding wire. The welding wire comprises the following components in percentage by weight: 0.5-0.8% of Mn, 5.8-6.8% of Mg, 0.02-0.10% of Ti, 0.08-0.15% of Zr, 0.16-0.30% of La, impurity elements including less than or equal to 0.40% of Si, less than or equal to 0.40% of Fe, less than or equal to 0.10% of Cu, less than or equal to 0.20% of Zn, less than or equal to 0.0003% of Be and the balance of Al. According to the welding wire, trace Zr and La elements are added, and the adding proportion of Zr, La and Ti is controlled, so that when the welding wire is used for welding a high-strength aluminum alloy plate, the mechanical property of a welding seam is remarkably improved. When the welding wire is used for welding a high-strength aluminum alloy plate, the heat affected zone range of a welding seam is effectively reduced, and the thermal cracking phenomenon of the welding seam disappears.

Description

Technical Field

[0001] The invention belongs to the field of welding wire production, and in particular relates to a high-strength and crack-resistant high-magnesium aluminum alloy welding wire. Background Art

[0002] In recent years, aluminum alloys have been increasingly used in the field of shipbuilding due to their light weight, high strength, good corrosion resistance and welding performance. A large number of high-strength aluminum alloy structural materials are widely used in shipbuilding. Due to the demand for lightweight, the connection between aluminum alloy plates cannot be mechanically connected, and only welding technology can be used. In order to ensure the high-quality development of the shipbuilding industry, solve the problems of poor weld performance and easy cracking of high-strength aluminum alloy plates, and improve the stability and strength of the weld, it is urgent to develop a high-strength and crack-resistant high-magnesium aluminum alloy welding wire. Summary of the invention

[0003] In view of this, the present invention aims to provide a high-strength and crack-resistant high-magnesium aluminum alloy welding wire to solve the above-mentioned problems.

[0004] To achieve the above object, the technical solution of the present invention is achieved as follows: A high-strength and crack-resistant high-magnesium aluminum alloy welding wire comprises the following components by weight percentage: Mn: 0.5-0.8%, Mg: 5.8-6.8%, Ti: 0.02-0.10%, Zr: 0.08-0.15%, La: 0.16-0.30%, impurity element content Si≤0.40%, Fe≤0.40%, Cu≤0.10%, Zn≤0.20%, Be≤0.0003%, and the balance is Al.

[0005] Furthermore, the mass ratio of La to Zr is 1.9 to 2.1:1.

[0006] Furthermore, the mass ratio of Ti to Zr is 0.6 to 0.7:1.

[0007] Furthermore, the raw materials of the welding wire include pure aluminum ingots, high-purity magnesium ingots, Al-10%Mn master alloys, Al-10%Zr master alloys, Al-10%La master alloys and Al-5Ti-B wires.

[0008] Furthermore, the Mg content in the high-purity magnesium ingot is >99.96%.

[0009] The present invention also provides a method for preparing the high-strength and crack-resistant high-magnesium aluminum alloy welding wire as described above, the method comprising the following steps: smelting a pure aluminum ingot, and after the aluminum ingot is completely melted, sequentially adding Al-10%Mn master alloy, Al-10%Zr master alloy, Al-10%La master alloy, high-purity magnesium ingot and Al-5Ti-B wire; after being fully stirred, sampling is performed for component detection, and after the components are qualified, refining and slag removal are performed, and after standing for 20 minutes, a round ingot is cast, and then the aluminum alloy welding wire of the required specifications is made through extrusion, annealing, drawing, reducing the diameter, and polishing.

[0010] Furthermore, the melting temperature of the pure aluminum ingot is 750-760°C.

[0011] The present invention also provides an application of the high-strength and crack-resistant high-magnesium aluminum alloy welding wire as described above in the welding of high-strength aluminum alloys mainly in the shipbuilding field, wherein the tensile strength of the weld deposited metal is above 330 MPa, the elongation after fracture is above 23%, and the impact absorption energy is above 25 J.

[0012] The Zr element added in the present invention can form Al 3 Zr phase, these phases can serve as heterogeneous nucleation cores to promote microstructure refinement. When appropriate amounts of Ti and Zr elements are added to aluminum alloys at the same time, their microstructure refinement effect is better than adding Ti or Zr elements alone. With the increase of Ti and Zr content, the weld microstructure gradually refines. When the content of Ti and Zr reaches a ratio of 0.6 to 0.7:1, the weld microstructure is the finest, the weld refinement effect is the best, and the mechanical properties are also optimal. The slow diffusion of Zr in the α-Al matrix helps to improve the thermal stability of the alloy and reduce the tendency of hot cracking in the weld. In addition, the Zr element can also increase the recrystallization temperature of the aluminum alloy, thereby enhancing the toughness and stress corrosion resistance of the aluminum alloy.

[0013] The atomic radius of La is quite different from the size of the matrix Al, and the solid solubility of La in aluminum alloy is very small. Entering the lattice will cause a large lattice distortion, which will increase the potential energy and free energy. In order to reduce the free energy, compounds containing La will gather on the grain boundaries and distribute along the dendrites. When a small amount of La is distributed on the grain boundaries, it will reduce the growth rate of the grains and form tiny compounds in the crystals, which will become the core of heterogeneous nucleation, thereby increasing the nucleation rate and promoting the refinement of α-Al. The mixing enthalpy between La and Mg is lower than that between Al and Mg. The addition of La can promote the precipitation of solute Al and Mg from the matrix to form a dispersed phase, thereby improving the mechanical properties of the alloy. And within the required content range, when the addition ratio of La to Zr is close to 1.9~2.1:1, its effect on improving the mechanical properties of the weld is the best.

[0014] Compared with the prior art, the high-strength and crack-resistant high-magnesium aluminum alloy welding wire of the present invention has the following advantages: The high-strength and crack-resistant high-magnesium aluminum alloy welding wire of the present invention can achieve a tensile strength of more than 330 MPa, an elongation after fracture of more than 23%, and an impact absorption energy of more than 25 J after welding. At the same time, the welding wire can effectively solve the problems of weld cracking and internal cracks when welding high-strength aluminum alloy plates. DETAILED DESCRIPTION

[0015] It should be noted that, in the absence of conflict, the embodiments of the present invention and the features in the embodiments may be combined with each other.

[0016] The following will be combined with the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0017] Example 1

[0018] A high-strength, crack-resistant high-magnesium aluminum alloy welding wire, the welding wire comprises the following components by weight percentage: Mn content: 0.68%, Mg content: 5.83%, Ti content: 0.080%, Zr content: 0.12%, La content: 0.24%, Si content: 0.013%, Fe content: 0.062%, Cu content: 0.009%, Zn content: 0.031%, Be content 0.0002%, The balance is Al.

[0019] The high-strength and crack-resistant high-magnesium aluminum alloy welding wire is prepared by the following method: Take raw materials of pure aluminum ingot, high-purity magnesium ingot (>99.96%), Al-10%Mn master alloy, Al-10%Zr master alloy, Al-10%La master alloy and Al-5Ti-B wire; melt the pure aluminum ingot at a melting temperature of 750-760°C, and add Al-10%Mn master alloy, Al-10%Zr master alloy, Al-10%La master alloy, high-purity magnesium ingot and Al-5Ti-B wire in sequence after the aluminum ingot is completely melted; take samples for component detection after sufficient stirring, and refine and remove slag after the components are qualified, and cast into round ingots after standing for 20 minutes, and then make aluminum alloy welding wire of required specifications through extrusion, annealing, drawing and reducing, and polishing.

[0020] The diameter of the welding wire is 1.2 mm.

[0021] Example 2

[0022] A high-strength, crack-resistant high-magnesium aluminum alloy welding wire, the welding wire comprises the following components by weight percentage: Mn content: 0.67%, Mg content: 5.82%, Ti content: 0.088%, Zr content: 0.14%, La content: 0.27%, Si content: 0.019%, Fe content: 0.053%, Cu content: 0.008%, Zn content: 0.029%, Be content 0.0002%, The balance is Al.

[0023] The preparation method of the welding wire is the same as that of Example 1.

[0024] The diameter of the welding wire is 1.2 mm.

[0025] Example 3

[0026] A high-strength, crack-resistant high-magnesium aluminum alloy welding wire, the welding wire comprises the following components by weight percentage: Mn content: 0.69%, Mg content: 5.83%, Ti content: 0.063%, Zr content: 0.09%, La content: 0.185%, Si content: 0.011%, Fe content: 0.067%, Cu content: 0.006%, Zn content: 0.033%, Be content 0.0002%, The balance is Al.

[0027] The preparation method of the welding wire is the same as that of Example 1.

[0028] The diameter of the welding wire is 1.2 mm.

[0029] Comparative Example 1: No La added The welding wire includes the following components by weight percentage: Mn content: 0.56%, Mg content: 5.81%, Ti content: 0.087%, Zr content: 0.13%, Si content: 0.021%, Fe content: 0.081%, Cu content: 0.007%, Zn content: 0.022%, Be content 0.0002%, The balance is Al.

[0030] The diameter of the welding wire is 1.2 mm.

[0031] Comparative Example 2 Low Zr content The welding wire includes the following components by weight percentage: Mn content: 0.061%, Mg content: 5.96%, Ti content: 0.046%, Zr content: 0.035%, La content: 0.16%, Si content: 0.011%, Fe content: 0.062%, Cu content: 0.008%, Zn content: 0.029%, Be content: 0.0003% The diameter of the welding wire is 1.2 mm.

[0032] Comparative Example 3 Zr content is high The welding wire includes the following components by weight percentage: Mn content: 0.59%, Mg content: 5.91%, Ti content: 0.042%, Zr content 0.20%, La content: 0.18%, Si content: 0.033%, Fe content: 0.079%, Cu content: 0.003%, Zn content: 0.041%, Be content: 0.0002% The diameter of the welding wire is 1.2 mm.

[0033] Comparative Example 4: Low La content The welding wire includes the following components by weight percentage: Mn content: 0.59%, Mg content: 5.81%, Ti content: 0.093%, Zr content: 0.14%, La content: 0.13%, Si content: 0.033%, Fe content: 0.079%, Cu content: 0.003%, Zn content: 0.041%, Be content: 0.0002% The diameter of the welding wire is 1.2 mm.

[0034] Comparative Example 5: High La content Mn content: 0.60%, Mg content: 5.83%, Ti content: 0.073%, Zr content: 0.11%, La content: 0.35%, Si content: 0.030%, Fe content: 0.069%, Cu content: 0.003%, Zn content: 0.036%, Be content 0.0002%, The diameter of the welding wire is 1.2 mm.

[0035] Comparative Example 6 The mass ratio of La to Zr is not 1.9-2.1:1 A high-strength, crack-resistant high-magnesium aluminum alloy welding wire, the welding wire comprises the following components by weight percentage: Mn content: 0.73%, Mg content: 5.90%, Ti content: 0.080%, Zr content: 0.12%, La content: 0.20%, Si content: 0.015%, Fe content: 0.060%, Cu content: 0.009%, Zn content: 0.035%, Be content 0.0002%, The balance is Al.

[0036] The diameter of the welding wire is 1.2 mm.

[0037] Comparative Example 7 The ratio of Ti to Zr is not 0.6~0.7:1 A high-strength, crack-resistant high-magnesium aluminum alloy welding wire, the welding wire comprises the following components by weight percentage: Mn content: 0.68%, Mg content: 5.93%, Ti content: 0.084%, Zr content: 0.09%, La content: 0.18%, Si content: 0.013%, Fe content: 0.063%, Cu content: 0.008%, Zn content: 0.032%, Be content 0.0002%, The balance is Al.

[0038] The diameter of the welding wire is 1.2 mm.

[0039] test The welding wires prepared in the examples and comparative examples were used to weld the deposited metal using 5059 aluminum alloy as the welding base material by MIG welding. The welding specifications are shown in Table 1.

[0040] Table 1 Welding specifications

[0041] After welding, the deposited metal was tested for performance and the results are shown in the following table.

[0042] Table 2 Comparison of welding performance between examples and comparative examples

[0043] By comparing the above embodiments and comparative examples, it can be seen that the welding wire prepared according to the scheme of the present invention has better performance. Among them, the embodiment with a mass ratio of La to Zr of 1.9-2.1:1 and a mass ratio of Ti to Zr of 0.6-0.7:1 has the best performance.

[0044] Comparative Examples 1 and 4 show that when La is not added or the content is low, the mechanical properties of the weld are significantly reduced compared to Example 1; and Comparative Example 5 shows that when the La content is too high, the mechanical properties of the weld will also be reduced.

[0045] From Comparative Example 2, it can be found that when the Zr element content is too little, thermal cracks occur in the weld during welding, resulting in a sharp drop in the mechanical properties of the weld; from Comparative Example 3, it can be found that when the Zr element content is too high, the impact absorption energy of the weld is significantly reduced.

[0046] Through comparative example 6, it can be found that when the mass ratio of La to Zr is not 1.9~2.1:1, the mechanical properties of the weld are reduced compared with the embodiment; through comparative example 7, it can be found that when the ratio of Ti to Zr is not 0.6~0.7:1, the mechanical properties of the weld are reduced compared with the embodiment; only when the mass ratio of La to Zr and the mass ratio of Ti to Zr satisfy the proportional relationship at the same time, the effect will be better.

[0047] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A high-strength, crack-resistant high-magnesium aluminum alloy welding wire, characterized in that: The welding wire comprises the following components by weight percentage: Mn: 0.5-0.8%, Mg: 5.8-6.8%, Ti: 0.02-0.10%, Zr: 0.08-0.15%, La: 0.16-0.30%, the impurity element content Si≤0.40%, Fe≤0.40%, Cu≤0.10%, Zn≤0.20%, Be≤0.0003%, and the balance is Al.

2. The high-strength, crack-resistant high-magnesium aluminum alloy welding wire according to claim 1, characterized in that: The mass ratio of La to Zr is 1.9 to 2.1:

1.

3. The high-strength, crack-resistant high-magnesium aluminum alloy welding wire according to claim 1, characterized in that: The mass ratio of Ti to Zr is 0.6-0.7:

1.

4. The high-strength, crack-resistant high-magnesium aluminum alloy welding wire according to claim 1, characterized in that: The raw materials of the welding wire include pure aluminum ingot, high-purity magnesium ingot, Al-10%Mn master alloy, Al-10%Zr master alloy, Al-10%La master alloy and Al-5Ti-B wire.

5. The high-strength, crack-resistant high-magnesium aluminum alloy welding wire according to claim 4, characterized in that: The Mg content in high-purity magnesium ingots is >99.96%.

6. A method for preparing a high-strength, crack-resistant high-magnesium aluminum alloy welding wire according to any one of claims 1 to 5, characterized in that: The method comprises the following steps: melting a pure aluminum ingot, and after the aluminum ingot is completely melted, sequentially adding an Al-10%Mn master alloy, an Al-10%Zr master alloy, an Al-10%La master alloy, a high-purity magnesium ingot and an Al-5Ti-B wire; sampling after being fully stirred for component detection, refining and deslagging after the components are qualified, casting into a round ingot after being left still for 20 minutes, and then extruding, annealing, drawing, reducing the diameter, and polishing to make an aluminum alloy welding wire of required specifications.

7. The method for preparing the high-strength and crack-resistant high-magnesium aluminum alloy welding wire according to claim 6, characterized in that: The melting temperature of pure aluminum ingot is 750-760℃.

8. Application of the high-strength, crack-resistant high-magnesium aluminum alloy welding wire according to any one of claims 1 to 5 in high-strength aluminum alloy welding, mainly in the field of ships, characterized in that: The tensile strength of the weld deposited metal is over 330MPa, the elongation after fracture is over 23%, and the impact absorption energy is over 25J.

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