CN101176955A - Welding wire for high-strength aluminum-copper alloys - Google Patents

Abstract

The invention belongs to the field of material science and engineering, and its chemical composition is as follows: (wt%): Cu 5.8～6.8, Mn 0.2～0.4, Ti 0.05～0.2, Zr 0.05～0.25, V 0.01～0.20, Cr 0.01～0.25, Fe 0.15, Si 0.08, Zn 0.05, Mg 0.02, and the balance is Al; the welding wire is refined by traditional melting and casting process according to the formula. The invention satisfies the manufacturing problem of high-strength aluminum-copper alloy matched welding wire by controlling the components. The welding wire of the invention has low sensitivity to welding cracks, small weld seam porosity sensitivity, and excellent joint mechanical properties.

Description

Welding wire for high-strength aluminum-copper alloys

technical field

The invention relates to a new welding material, which belongs to the field of material science and engineering.

Background technique

High-strength aluminum-copper alloys are widely used in the aerospace industry. They are the preferred materials for aircraft fuel tanks and rocket storage tanks. Similar materials abroad have been widely used in the manufacture of aircraft fuel tanks and rocket storage tanks. The application of domestic high-strength aluminum-copper alloys is relatively lagging behind. In recent years, with the development of the aerospace industry, the application of high-strength aluminum-copper alloys has been put on the agenda. However, the application of high-strength aluminum-copper alloys is inseparable from welding technology. With the development of welding wire. The same kind of high-strength aluminum-copper alloys in foreign countries have matured matching welding wires-aluminum-copper series welding wires, which have been used in foreign aerospace industries for many years. American aluminum-copper series welding wires are used for welding. The mechanical properties of the welded joints meet the design requirements. The existing problems are Weld seam porosity is more sensitive. There are aluminum-copper welding wires suitable for use at room temperature in China, but their low-temperature performance is poor.

Contents of the invention

The object of the present invention is to provide a welding wire suitable for high-strength aluminum-copper alloys. This welding wire can be used in conjunction with high-strength aluminum-copper alloys to meet the needs of aircraft fuel tanks and rocket storage tanks. The weld seam can obtain high normal Low temperature mechanical properties.

The welding wire suitable for high-strength aluminum-copper alloy of the present invention has a chemical composition (wt%): Cu 5.8-6.8, Mn 0.2-0.4, Ti 0.05-0.2, Zr 0.05-0.25, V0.01-0.20, Cr 0.01- 0.25, Fe 0.15, Si 0.08, Zn 0.05, Mg 0.02, and the balance is Al. Welding wire is refined by traditional melting and casting process according to the recipe.

The design principle of the chemical composition of the welding wire of the present invention is to adopt the method of multi-component composite alloying, so as to achieve the best matching between the welding wire and the base metal, that is, the chemical composition and physical and chemical properties are equivalent, so that the weld seam can obtain high strength and toughness. The present invention adopts the traditional melting and casting process to refine the welding wire. Because the high-strength aluminum-copper alloy metal is Al-Cu-Mn alloy, the main component of the welding wire is determined to use the system. In addition to Ti, Zr and V, the microalloy components are respectively added with Y, Ce, Sc, Cr, B, by adjusting the content of each alloy in the refining process, using different combinations: Ti-B, Ti-B-Y, Ti-Zr-Sc, Ti-Zr-V-Ce, Ti-Zr- V, Ti-Zr-B, Ti-Zr-V-Y, Ti-Zr-V-Sc, Ti-Zr-V-Cr, Ti-Zr-V-B, the welding wire is refined, and then the crack sensitivity evaluation and porosity sensitivity Performance evaluation, mechanical performance evaluation of joints at different temperatures (normal temperature, -196°C, -253°C), adaptability evaluation of different plate thicknesses, metallographic structure evaluation, fracture morphology evaluation, after several rounds of tests, finally screened out The welding wire that meets the requirements, the formula of the welding wire is the formula of the final welding wire.

Owing to adopt above-mentioned formula to manufacture welding wire of the present invention, so the present invention has following advantage and effect:

1. Since the present invention adopts Al-Cu-Mn as the main alloy system, Ti-Zr-V-Cr as the microalloy composition, and impurity elements such as Fe, Si, Zn, Mg are strictly controlled, so the welding crack sensitivity is low.

2. Because the present invention contains Cr trace elements, it can inhibit the pores of aluminum alloy welds, and the hydrogen content of the welding wire is controlled below 0.2ml/100g metal, so the sensitivity of weld pores is small.

3. The present invention contains 0.01-0.25Cr, Fe, Si, Zn, Mg and other impurity elements are strictly controlled, Cr has obvious strengthening effect during welding, and the negative effect of impurities is controlled to the minimum, so the joint performance is excellent.

Detailed ways

Example 1

According to the formula, aluminum ingots are refined by traditional smelting technology, and then extruded and drawn into welding wire. The chemical composition of the welding wire is:

Al-6.2, Cu-0.32, Mn-0.1, Cr-0.12, Ti-0.15, Zr-0.1, V.

The welding wire made of the above chemical composition is used to weld the high-strength aluminum-copper alloy base metal, including welding crack sensitivity test, weld porosity sensitivity test, and joint mechanical performance test. Simultaneously compare American aluminum-copper welding wire, domestic aluminum-copper welding wire and welding wire of the present invention. The result is as follows:

(1) Welding crack sensitivity is better than that of domestic aluminum-copper welding wire and American aluminum-copper welding wire, see Table 1.

Table 1 Weld crack sensitivity

(2) The porosity sensitivity of the weld is equivalent to that of domestic aluminum-copper welding wire, and better than that of American-made aluminum-copper welding wire, see Table 2.

Table 2 Weld Porosity Sensitivity

Wire grade this invention Domestic aluminum copper welding wire American aluminum copper welding wire Pore sensitivity (welding 10 welds) 10 qualified and 0 unqualified 10 qualified and 0 unqualified 3 qualified and 7 failed

(3) Joint performance: the performance of the present invention is better than domestic aluminum-copper welding wire and American aluminum-copper welding wire on thin plates; it is better than domestic aluminum-copper welding wire on thick plates, and is equivalent to American aluminum-copper welding wire, see Table 3 .

Table 3 Mechanical properties of joints

Example 2

According to the formula, aluminum ingots are refined by traditional smelting technology, and then extruded and drawn into welding wire. The chemical composition of the welding wire is:

Al-6.7, Cu-0.38, Mn-0.1, Cr-0.12, Ti-0.1, Zr-0.08, V.

The welding wire made of the above chemical composition is used to weld the high-strength aluminum-copper alloy base metal, including welding crack sensitivity test, weld porosity sensitivity test, and joint mechanical performance test. Simultaneously compare the aluminum-copper welding wire produced in the United States, the domestic aluminum-copper welding wire and the welding wire of the present invention. The result is as follows:

(1) Welding crack sensitivity is better than that of domestic aluminum-copper welding wire and American aluminum-copper welding wire, see Table 4.

Table 4 Welding Crack Sensitivity

(2) The porosity sensitivity of the weld is equivalent to that of domestic aluminum-copper welding wire, and better than that of American-made aluminum-copper welding wire, see Table 5.

Table 5 Weld Porosity Sensitivity

Wire grade this invention Domestic aluminum copper welding wire American aluminum copper welding wire Pore sensitivity (welding 10 welds) 10 qualified and 0 unqualified 10 qualified and 0 unqualified 3 qualified and 7 failed

(3) Joint performance: on thin plates, the performance is better than that of domestic aluminum-copper welding wire and American aluminum-copper welding wire; on thick plates, the performance is better than that of domestic aluminum-copper welding wire, which is equivalent to that of American aluminum-copper welding wire, see Table 6.

Table 6 Mechanical properties of joints

The welding wire involved in the invention will definitely play a huge role in the localization of welding materials used in my country's aerospace industry and in reducing production costs.

Claims (1)

1. A welding wire suitable for high-strength aluminum-copper alloys, characterized in that: chemical composition (wt%): Cu 5.8-6.8, Mn 0.2-0.4, Ti 0.05-0.2, Zr 0.05-0.25, V 0.01-0.20, Cr 0.01～0.25, Fe 0.15, Si 0.08, Zn 0.05, Mg 0.02, the balance is Al.