Vacuum electron beam welding method for solid solution strengthening type nickel-based superalloy GH3536 strip

Abstract

The invention belongs to the technical field of high-temperature alloy strip preparation, and particularly relates to a vacuum electron beam welding method for a solid solution strengthening type nickel-based high-temperature alloy GH3536 strip. In order to prevent vaporization burn-through and incomplete penetration of the strip and fully guarantee the performance of the strip, the vacuum electron beam welding method comprises the steps of strip edge treatment, strip pre-welding cleaning, butt weld assembly, positioned welding, formal welding and post-welding heat treatment. By controlling welding process parameters, welding seams are small in width, flat and continuous, arc suppression is full, welding joints are free of defects such as holes, collapse and splashing, the strength of the welding joints reaches 93% or above of the strength of base metal, and the plasticity and tensile strength of the welding joints are equivalent to those of the base metal; and it is guaranteed that a welding joint has the mechanical property equivalent to that of base metal, and a strip part manufactured after welding has the advantages of being light in structure, high in safety and the like.

Description

Technical Field

[0001] The invention belongs to the technical field of high-temperature alloy strip preparation, and in particular relates to a vacuum electron beam welding method for a solid solution strengthened nickel-based high-temperature alloy GH3536 strip. Background Art

[0002] Thin-walled sheet metal parts made of high-temperature alloy strips account for a considerable proportion in aerospace engines, gas turbines, missiles and other equipment, and play a decisive role in reducing the structure, improving and enhancing engine performance. In advanced aero engines, high-temperature alloy thin-walled parts account for more than 28%. The honeycomb sealing device of high thrust-to-weight ratio aero engines mainly uses GH3536 strips (thickness of 0.1-0.3mm). GH3536 is a solid solution-strengthened nickel-based high-temperature alloy with excellent thermal corrosion resistance, oxidation resistance, high temperature stability and organizational stability. It can be used for a long time below 900℃, and the short-term working temperature can reach 1080℃. Welding is an important means of connecting these parts. At the same time, good welding of strips also makes it possible for the mass production of foils with a single roll weight exceeding 500kg. Due to the thin thickness of the material, the difficulty of welding increases significantly. Ordinary welding methods (such as TIG, MIG, etc.) have large heat input and serious welding deformation, which are not suitable for welding thin materials. The resistance welding method commonly used at present is prone to welding deformation due to the large heat input, which in many cases affects the use and appearance of the device; tungsten inert gas welding is suitable for thin plate welding, but it is difficult to achieve reliable welding of strips with a thickness of ≤0.3mm. Electron beam welding is a high energy density welding method. It has developed rapidly and is widely used in various modern industrial fields because electron beam welding has a series of advantages.

[0003] Compared with other types of fusion welding, electron beam welding has the following advantages: (1) High power density. The electron beam focus point diameter is about 0.1 to 1 mm, and the electron beam power density can reach 10 6 W / cm 2The above are high-energy beams. High-energy electron beams have a small beam diameter and can form a deep and narrow penetration weld with a weld depth ratio of up to 20:1. (2) Accurate and fast controllability. The electron beam can be quickly and accurately controlled through electric and magnetic fields. (3) Fast welding speed, small heat-affected zone, and small welding deformation. The electron beam welding speed is generally above 10000 Å. The heat-affected zone of the electron beam weld is very small, and sometimes almost non-existent. The small welding heat input makes the deformation of electron beam welding small. (4) The electron beam is easy to control. The electron beam welding parameters can be accurately controlled, and the repeatability and stability of the parameters during welding are good. Therefore, the penetration depth, size and characteristics of the weld can be strictly controlled, which improves the welding quality and stability of the product. (5) The vacuum environment is conducive to improving the quality of the weld. Vacuum electron beam welding is carried out in a vacuum chamber, eliminating the influence of harmful gases hydrogen and oxygen in the atmosphere on the molten metal. The chemical composition of the molten metal is pure, which improves the quality of the weld. Therefore, these characteristics make vacuum electron beam seam welding more suitable for welding thin materials than other welding methods. Summary of the invention

[0004] In order to prevent the vaporization and burning through of the strip and the lack of penetration, and to fully ensure the performance of the strip, the purpose of the present invention is to provide a vacuum electron beam welding method for a solid solution strengthened nickel-based high-temperature alloy GH3536 strip. By controlling the welding process parameters, the method can obtain a small-width, flat, continuous weld, and the weld joint has no defects such as holes, collapse, and spatter, and the tensile strength of the weld joint reaches more than 93% of the strength of the parent material.

[0005] The technical solution of the present invention is:

[0006] A vacuum electron beam welding method for a solid solution strengthened nickel-based high temperature alloy GH3536 strip comprises the following steps:

[0007] (1) The edge of the strip to be welded is machined to ensure the smoothness and straightness of the edge, and the surface roughness of the edge is less than 0.5μm;

[0008] (2) Chemical cleaning of the base material before welding. The specific process is: degreasing → water washing → alkali washing → water washing → acid washing → water washing, and drying after cleaning;

[0009] (3) Assemble the strips. To ensure the welding quality, the gap at the weld after assembly should be ≤0.05mm;

[0010] (4) Place the butted GH3536 strip into the vacuum chamber of the welding machine, and then evacuate the vacuum chamber until the pressure in the vacuum chamber is lower than 1×10 -4 mbar;

[0011] (5) Electron beam welding is used to perform symmetrical positioning welding on the weld to control the deformation of the component during the formal welding process. The process parameters of symmetrical positioning welding are as follows: voltage 30 kV, welding speed 2200 ± 10 mm / min, beam current 0.5-3 mA, welding heat input 0.4 J / mm-2.5 J / mm, focusing current 1605 mA, X-direction swing amplitude 0.5 mm, Y-direction swing amplitude 0.5 mm;

[0012] (6) The weld of the GH3536 strip after positioning welding was formally welded. The process parameters of formal welding were as follows: voltage 30 kV, welding speed 2200 ± 10 mm / min, focusing current 1605 mA, beam current 1.5-9 mA, welding heat input 1.2 J / mm-7.4 J / mm, swing amplitude in the X direction 0.5 mm, and swing amplitude in the Y direction 0.5 mm;

[0013] (7) After formal welding, cool in the vacuum chamber of the welding machine for 10 minutes and then take out the sample.

[0014] In the vacuum electron beam welding method for solid solution strengthened nickel-based high temperature alloy GH3536 strip, in step (1), the thickness of the solid solution strengthened nickel-based high temperature alloy GH3536 strip to be welded is 0.1 to 0.3 mm.

[0015] In the vacuum electron beam welding method for the solid solution strengthened nickel-based high-temperature alloy GH3536 strip, in step (5), when performing symmetrical positioning welding, for a strip with a thickness of 0.3 mm: the electron beam current is 2 to 2.3 mA, the welding speed is 36.7 mm / s, and the welding heat input is 1.6 to 2.5 J / mm; for a strip with a thickness of 0.2 mm: the electron beam current is 1 to 1.7 mA, the welding speed is 36.7 mm / s, and the welding heat input is 0.8 to 1.3 J / mm; for a strip with a thickness of 0.1 mm: the electron beam current is 0.5 to 0.6 mA, the welding speed is 36.7 mm / s, and the welding heat input is 0.4 to 0.5 J / mm.

[0016] The vacuum electron beam welding method for the solid solution strengthened nickel-based high-temperature alloy GH3536 strip, in step (6), when performing formal welding, for a strip with a thickness of 0.3 mm: the electron beam current is 6 to 7 mA, the welding speed is 36.7 mm / s, and the welding heat input is 4.9 to 7.4 J / mm; for a strip with a thickness of 0.2 mm: the electron beam current is 3 to 5 mA, the welding speed is 36.7 mm / s, and the welding heat input is 2.5 to 4.1 J / mm; for a strip with a thickness of 0.1 mm: the electron beam current is 1.5 to 1.75 mA, the welding speed is 36.7 mm / s, and the welding heat input is 1.2 to 1.4 J / mm.

[0017] The vacuum electron beam welding method for the solid solution strengthened nickel-based high temperature alloy GH3536 strip has a weld width of 0.7 to 1.2 mm for a GH3536 strip with a thickness of 0.3 mm; a weld width of 0.5 to 1 mm for a GH3536 strip with a thickness of 0.2 mm; and a weld width of 0.5 to 0.8 mm for a GH3536 strip with a thickness of 0.1 mm.

[0018] The vacuum electron beam welding method for the solid solution strengthened nickel-based high temperature alloy GH3536 strip is characterized in that conventional stress relief heat treatment is performed after welding, the heat treatment temperature is 150±10° C., and the holding time is 20 to 30 minutes.

[0019] The vacuum electron beam welding method for the solid solution strengthened nickel-based high temperature alloy GH3536 strip has a welding joint tensile strength of more than 93% of the base material tensile strength.

[0020] The design idea of ​​the present invention is:

[0021] Thin-walled sheet metal parts made of GH3536 strips with a thickness of 0.1 to 0.3 mm account for a considerable proportion in the aerospace field, and need to be welded during use; at the same time, good welding of the strips also makes it possible to mass-produce a single roll of foil with a weight exceeding 500 kg. In order to prevent a series of defects such as oxidation, large deformation, and incomplete penetration and welding, the present invention uses vacuum electron beam welding to obtain a small-width, flat weld without welding defects and achieve a strong match between the weld strength and the parent material strength, ensuring the safety and reliability of the structure and strip connection. First, in order to prevent welding deformation, symmetrical positioning welding is adopted; second, high-speed vacuum electron beam welding is carried out to improve welding efficiency while enabling the weld metal to have rapid cooling capabilities, improve the solidification state of the weld metal, and make the structure dense, uniform, and without segregation, thereby improving the strength of the weld joint; third, the welding heat input is controlled to obtain a small, flat, and continuous weld without the need for subsequent grinding processing, and to avoid the appearance of coarse grain areas and wide columnar crystals to prevent deterioration of material properties; fourth, low-temperature stress relief heat treatment is carried out to obtain good strength and plasticity.

[0022] The advantages and beneficial effects of the present invention are:

[0023] 1. The technical key of the present invention is to use low acceleration voltage and high-speed welding parameters to perform vacuum electron beam welding on a solid solution strengthened nickel-based high-temperature alloy GH3536 strip, effectively control the welding heat input, not only improve the welding efficiency, but also prevent burn-through, which is conducive to effective fusion of the weld root.

[0024] 2. The present invention reduces welding heat input and accurately controls vacuum electron beam welding parameters to obtain a small, flat, continuous weld. For GH3536 strips with a thickness of 0.1 to 0.3 mm, the weld width is 0.5 to 1.2 mm, the weld is well formed, the weld surface is bright, and the weld joint is free of defects such as holes, collapses, spatter, and cracks.

[0025] 3. The tensile strength of the welded joint of the present invention is more than 93% of the strength of the parent material. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 This is the tensile stress-strain curve of the 0.2 mm thick GH3536 alloy strip welded joint; in the figure, the abscissa Engineering strain is the engineering strain (%), and the ordinate Engineering stress is the engineering stress (MPa).

[0027] Figure 2 This is the tensile stress-strain curve of the 0.1 mm thick GH3536 alloy strip welded joint; in the figure, the abscissa Engineering strain is the engineering strain (%), and the ordinate Engineering stress is the engineering stress (MPa).

[0028] Figure 3 (a) Macroscopic morphology of the front side of the vacuum electron welding weld of 0.2 mm thick GH3536 alloy strip (beam current 3 mA, welding heat input 2.5 J / mm).

[0029] Figure 3 (b) The macroscopic morphology of the back side of the vacuum electron welding weld of 0.2 mm thick GH3536 alloy strip (beam current 3 mA, welding heat input 2.5 J / mm).

[0030] Figure 3 (c) is the macroscopic morphology of the front side of the vacuum electron welding weld of 0.2 mm thick GH3536 alloy strip (beam current 4 mA, welding heat input 3.3 J / mm).

[0031] Figure 3 (d) is the macroscopic morphology of the back side of the vacuum electron welding weld of 0.2 mm thick GH3536 alloy strip (beam current 4 mA, welding heat input 3.3 J / mm).

[0032] Figure 3 (e) is the macroscopic morphology of the front side of the vacuum electron welding weld of 0.2 mm thick GH3536 alloy strip (beam current 5 mA, welding heat input 4.1 J / mm).

[0033] Figure 3(f) shows the macroscopic morphology of the back side of the vacuum electron welding weld of a 0.2 mm thick GH3536 alloy strip (beam current 5 mA, welding heat input 4.1 J / mm). DETAILED DESCRIPTION

[0034] The present invention is further described below by way of examples, but the present invention is not limited to the scope of the examples. The experimental methods without specific conditions in the following examples are based on conventional methods and conditions.

[0035] Example

[0036] In the embodiment, a solid solution strengthened nickel-based high-temperature alloy GH3536 strip with a thickness of 0.1 mm, 0.2 mm, and 0.3 mm is selected, and its specific composition and content, by weight percentage, are: Cr: 21.5, Fe: 18.5, Mo: 9.0, Co: 1.32, W: 0.37, C: 0.066, Si: 0.31, Mn: 0.82, S: 0.005, P: 0.005, and Ni balance.

[0037] The vacuum electron beam welding method includes strip edge processing, strip cleaning before welding, butt weld assembly, positioning welding, formal welding and post-weld heat treatment. The specific steps are as follows:

[0038] 1. The edge of the strip to be welded is machined to ensure the smoothness and straightness of the edge, and the surface roughness of the edge is 0.3μm;

[0039] 2. Before welding, the base material, liner, etc. shall be chemically cleaned, specifically: degreasing → water washing → alkali washing → water washing → acid washing → water washing, etc., and then dried after cleaning;

[0040] 3. Assemble the strips. To ensure the welding quality, the gap at the weld should be ≤0.05mm after assembly.

[0041] 4. Evacuate the vacuum chamber until the pressure is lower than 1×10 -4 mbar;

[0042] 5. Electron beam welding is used to perform positioning welding on the weld to control the deformation of the component during the formal welding process: the process parameters of the symmetrical positioning welding are as follows: the acceleration voltage is controlled to be 30 kV, the welding speed is 2200 mm / min, the focusing current is 1605 mA, the swing amplitude in the X direction is 0.5 mm, and the swing amplitude in the Y direction is 0.5 mm. The specific vacuum electron beam welding process is shown in Table 1.

[0043] 6. The weld of the high-temperature alloy GH3536 strip after positioning welding was formally welded. The process parameters of formal welding were as follows: acceleration voltage 30 kV, welding speed 2200 mm / min, focusing current 1605 mA, X-direction swing amplitude 0.5 mm, Y-direction swing amplitude 0.5 mm, and the specific vacuum electron beam welding process is shown in Table 1;

[0044] 7. After welding, cool in the vacuum chamber of the welding machine for 10 minutes and then take out the sample.

[0045] 8. After welding, conventional stress relief heat treatment is carried out at a temperature of (150±10)℃, with a holding time of 20 to 30 minutes, and the furnace is cooled to room temperature to eliminate welding stress.

[0046] Table 1

[0047]

[0048] The weld area was subjected to X-ray flaw detection, and no cracks, incomplete penetration, or incomplete fusion were found inside the weld. The tensile strength of the welded sample and the proportion of its strength to the strength of the parent material are shown in Table 2.

[0049] Table 2

[0050]

[0051] like Figure 1 As shown in the figure, the tensile stress-strain curve of the welded joint of 0.2mm thick GH3536 alloy strip is shown. It can be seen from the figure that when the electron beam current of the vacuum electron beam welding is controlled at 3-5mA and the welding heat input is 2.5-4.1J / mm, the strength of the welded joint does not change significantly, and can reach 93%-97% of the parent material strength.

[0052] like Figure 2 As shown in the figure, the tensile stress-strain curve of the welded joint of 0.1mm thick GH3536 alloy strip is shown. It can be seen from the figure that when the electron beam current of the vacuum electron beam welding is controlled at 1.5-1.75mA and the welding heat input is 1.2-1.4J / mm, the strength of the welded joint does not change significantly, and can reach 94%-97% of the strength of the parent material.

[0053] like Figure 3 (a)-(f) show the macroscopic morphology of the vacuum electron welding weld of 0.2 mm thick GH3536 alloy strip. It can be seen from the figure that when the electron beam current is 3-5 mA and the welding heat input is 2.5-4.1 J / mm, the front and back sides of the weld are small, flat, and continuous, and the arc is fully closed. In addition, the weld joint has no defects such as holes, collapse, and spatter, and no subsequent grinding processing is required.

[0054] The implementation results show that the welding method of the present invention not only has a small, flat, continuous weld width and a full arc termination, but also has no defects such as holes, collapse, spatter, etc. in the weld joint, and the tensile strength of the weld joint reaches more than 93% of the strength of the parent material, and the plasticity and tensile strength of the weld joint are equivalent to those of the parent material, ensuring that the weld joint has mechanical properties equivalent to those of the parent material, and the strip components produced after welding have the advantages of lightweight structure and high safety.

Claims

1. A vacuum electron beam welding method for solid solution strengthened nickel-based high temperature alloy GH3536 strip, characterized in that: The steps include: (1) The edge of the strip to be welded is machined to ensure the smoothness and straightness of the edge, and the surface roughness of the edge is less than 0.5μm; (2) Chemical cleaning of the base material before welding. The specific process is: degreasing → water washing → alkali washing → water washing → acid washing → water washing, and drying after cleaning; (3) Assemble the strips. To ensure the welding quality, the gap at the weld after assembly should be ≤0.05mm; (4) Place the butted GH3536 strip into the vacuum chamber of the welding machine, and then evacuate the vacuum chamber until the pressure in the vacuum chamber is lower than 1×10 -4 mbar; (5) Electron beam welding is used to perform symmetrical positioning welding on the weld to control the deformation of the component during the formal welding process. The process parameters of symmetrical positioning welding are as follows: voltage 30 kV, welding speed 2200 ± 10 mm / min, beam current 0.5-3 mA, welding heat input 0.4 J / mm-2.5 J / mm, focusing current 1605 mA, X-direction swing amplitude 0.5 mm, Y-direction swing amplitude 0.5 mm; (6) The weld of the GH3536 strip after positioning welding was formally welded. The process parameters of formal welding were as follows: voltage 30 kV, welding speed 2200 ± 10 mm / min, focusing current 1605 mA, beam current 1.5-9 mA, welding heat input 1.2 J / mm-7.4 J / mm, swing amplitude in the X direction 0.5 mm, and swing amplitude in the Y direction 0.5 mm; (7) After formal welding, cool in the vacuum chamber of the welding machine for 10 minutes and then take out the sample.

2. The vacuum electron beam welding method for solid solution strengthened nickel-based high temperature alloy GH3536 strip according to claim 1, characterized in that: In step (1), the thickness of the solid solution strengthened nickel-based high temperature alloy GH3536 strip to be welded is 0.1 to 0.3 mm.

3. The vacuum electron beam welding method for solid solution strengthened nickel-based high temperature alloy GH3536 strip according to claim 2, characterized in that: In step (5), when performing symmetrical positioning welding, for the strip with a thickness of 0.3 mm: electron beam current 2 to 2.3 mA, welding speed 36.7 mm / s, welding heat input 1.6 to 2.5 J / mm; for the strip with a thickness of 0.2 mm: electron beam current 1 to 1.7 mA, welding speed 36.7 mm / s, welding heat input 0.8 to 1.3 J / mm; for the strip with a thickness of 0.1 mm: electron beam current 0.5 to 0.6 mA, welding speed 36.7 mm / s, welding heat input 0.4 to 0.5 J / mm.

4. The vacuum electron beam welding method for solid solution strengthened nickel-based high temperature alloy GH3536 strip according to claim 2, characterized in that: In step (6), when performing formal welding, for the strip with a thickness of 0.3 mm: the electron beam current is 6 to 7 mA, the welding speed is 36.7 mm / s, and the welding heat input is 4.9 to 7.4 J / mm; for the strip with a thickness of 0.2 mm: the electron beam current is 3 to 5 mA, the welding speed is 36.7 mm / s, and the welding heat input is 2.5 to 4.1 J / mm; for the strip with a thickness of 0.1 mm: the electron beam current is 1.5 to 1.75 mA, the welding speed is 36.7 mm / s, and the welding heat input is 1.2 to 1.4 J / mm.

5. The vacuum electron beam welding method for solid solution strengthened nickel-based high temperature alloy GH3536 strip according to claim 2, characterized in that: For GH3536 strip with a thickness of 0.3mm, the weld width is 0.7-1.2mm; for GH3536 strip with a thickness of 0.2mm, the weld width is 0.5-1mm; for GH3536 strip with a thickness of 0.1mm, the weld width is 0.5-0.8mm.

6. The vacuum electron beam welding method for solid solution strengthened nickel-based high temperature alloy GH3536 strip according to claim 1 or 2, characterized in that: After welding, conventional stress relief heat treatment is carried out at a temperature of 150±10℃ and a holding time of 20 to 30 minutes.

7. The vacuum electron beam welding method for solid solution strengthened nickel-based high temperature alloy GH3536 strip according to claim 1 or 2, characterized in that: The tensile strength of the welded joint is more than 93% of the tensile strength of the parent material.

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