A W-shaped structure welding process control method for a lightweight aviation radiator

Abstract

The invention discloses a welding process control method for the "W" - shaped structure of a lightweight aviation radiator, which includes the following steps: positioning and welding the air - collecting hood with the interface nozzle, corrugated plate, and cylinder body; sealing the inner cavity of the corrugated plate and the inner cavity of the air - collecting hood; introducing high - purity argon from the position of the interface nozzle, and connecting an argon gas detector at the distal end of the corrugated plate to detect the argon gas purity in the inner cavity of the corrugated plate. After the purity meets the standard, place a welding gun drag shield at the weld, then install a transparent ceramic nozzle on one end face of the welding gun drag shield, and install a gas - blocking and heat - absorbing tooling on the corrugated plate; additionally introduce argon to protect the weld area on the back of the cylinder body; adjust the welding parameters to implement the welding of the "W" - shaped structure weld, and wait for more than 15 seconds after welding is completed before disassembling various protection toolings. Through this control method, the embrittlement problem of materials during the welding process is solved, and the stability of the product is improved.

Description

Technical Field

[0001] The present invention belongs to the technical field of titanium alloy thin plates, and particularly relates to a welding process control method for the "W" - shaped structure of a lightweight aviation radiator. Background Art

[0002] The advantages of titanium and titanium alloys are high specific strength, good plasticity and toughness, and good heat resistance and corrosion resistance. They are first applied to new aircraft and aero - engines. With the rapid development of the aerospace industry, they have also been more and more widely used in the aerospace field. Titanium alloy materials are relatively active in the hot state, so their TIG welding process is special. During TIG welding, after absorbing harmful elements, the welded joints have a certain impact on the strength of the product. The TIG welding process of titanium alloys is somewhat different from the TIG welding processes of other aluminum - made and stainless - steel - made materials.

[0003] The welded joint area of titanium and titanium alloys is easily contaminated by gases and other impurities, resulting in embrittlement. The main elements causing embrittlement are O, N, H, C, etc. Titanium and titanium alloys start to absorb H at 250°C and absorb H rapidly above 300°C; start to absorb O at 400°C and absorb O rapidly above 600°C; start to absorb N at 600°C and absorb N rapidly at 700°C. As the temperature rises, the ability of titanium and titanium alloys to absorb N, H, and O increases significantly. O and N form interstitial solid solutions in Ti, playing a solid - solution strengthening role, causing lattice distortion of titanium, increasing strength and hardness, but significantly decreasing plasticity and toughness. Titanium has a high melting point, large heat capacity, and poor thermal conductivity. During welding, it is easy to form a large molten pool. The high temperature of the molten pool makes the metal in the weld and the heat - affected zone stay at a high temperature for a relatively long time, obvious grain growth, reducing the plasticity and toughness of the joint and making it easy to generate cracks. Titanium absorbs a large amount of H above 300°C. After cooling below 300°C, the solubility of H drops sharply. After eutectoid transformation, fine - flaky or needle - shaped γ - phase (titanium hydride TiH2) is precipitated. TiH2 has very low strength. The needle - shaped or flaky TiH2 is similar to a notch, thus significantly reducing the impact toughness of the weld. When the O and N contents in the weld are relatively high, the performance becomes brittle. Under the action of large welding stress, cold cracks and delayed cracks will appear. Delayed cracks sometimes also appear in the heat - affected zone. This kind of crack can occur several hours, days, or even months later. This phenomenon of delayed cracks is mainly caused by the H element. When the quality of the base metal and the welding wire is poor, especially when the welding wire has defects such as cracks and interlayers, harmful impurities will accumulate at the interlayers and cracks, causing hot cracks in the weld.

[0004] The Chinese invention patent with the publication number CN102554415A discloses a protection device for the argon arc welding seam of a titanium alloy part and its welding method. The bottom surface of the hollow rectangular drag cover composed of metal plates is open and obliquely installed with a copper mesh, and the other five surfaces are closed. One end of the drag cover is fixedly installed with a chuck for the welding torch and a protective cover for the welding torch head with a glass observation window below the chuck. The lower end of the argon gas delivery pipe installed on the top surface of the drag cover is inserted into the drag cover. The lower end of the argon gas delivery pipe is closed, and evenly distributed ventilation holes are drilled on the cylindrical surface. The welding method is as follows: cover the bottom surface of the drag cover with the copper mesh on the welding seam area of the welded part. Install the welding torch of the AC / DC argon arc welding machine in the welding torch chuck. Input argon gas with a purity of 99.99% from the argon gas delivery pipe. While manually or automatically moving the welding torch for welding at the welding speed specified by the process specifications, synchronously drag the drag cover along the high-temperature welding seam, so that the high-temperature area of the welding seam is protected by argon gas in the drag cover, ensuring the welding quality. This solution uses argon gas protection to prevent the titanium alloy from absorbing oxygen, nitrogen, and hydrogen in the air, which would cause the welding seam to become brittle and the plasticity to decrease. However, the welding seam of this solution is in a W shape, and conventional argon gas cannot uniformly protect the welding seam. Summary of the Invention

[0005] In order to solve the above problems, the present invention aims to provide a welding process control method for the "W" - shaped structure of a lightweight aviation radiator.

[0006] In order to achieve the above object, the present invention adopts the following technical solutions. A welding process control method for the "W" - shaped structure of a lightweight aviation radiator includes the following steps:

[0007] Step 1: Perform tack welding on the gas - collecting hood, interface nozzle, corrugated plate, and cylinder body.

[0008] Step 2: Seal the inner cavity of the corrugated plate and the inner cavity of the gas - collecting hood.

[0009] Step 3: Introduce high - purity argon gas from the position of the interface nozzle, and connect an argon gas detector at the distal end of the corrugated plate to detect the argon gas purity in the inner cavity of the corrugated plate. After the purity meets the standard, place a welding torch drag cover at the welding seam, then install a transparent ceramic nozzle on one end face of the welding torch drag cover, and install a gas - blocking and heat - absorbing tooling on the corrugated plate.

[0010] Step 4: Protect the back - side welding seam area of the cylinder body by introducing argon gas.

[0011] Step 5: Adjust the welding parameters to perform welding on the "W" - shaped structure welding seam.

[0012] Furthermore, the tack welding of the interface nozzle, corrugated plate, and gas - collecting hood uses argon arc welding, the tack welding of the gas - collecting hood and the cylinder body uses resistance welding, and the welding wire material is TA15 titanium alloy material.

[0013] Further, the flow rate of argon introduced in step 3 is 50 - 80 L / min, and the distal end of the corrugated plate refers to the outlet of the corrugated plate channel farthest from the interface nozzle.

[0014] Further, the welding coverage of the transparent ceramic nozzle in step 3 is greater than one pitch of the corrugated plate, and the material is high-temperature resistant quartz material.

[0015] Further, the air suction and heat shielding tooling in step 3 is made of aluminum alloy material, and the placement position is 15 - 20 mm away from the weld.

[0016] Further, the welding torch shroud is provided with heat-insulating cotton made of aluminum silicate around its perimeter.

[0017] Further, the welding parameters in step 5 are welding current 15 - 18 A, argon flow rate 35 - 40 L / min, and the length of the tungsten electrode extending out is 1.5 times the height of the corrugated plate.

[0018] Further, the welding process is as follows: starting welding from the peak position, stopping for 10 - 20 seconds when welding to the adjacent peak and then proceeding with welding.

[0019] Further, the weld is a "W"-shaped weld formed by the splicing of the corrugated plate and the gas collector hood.

[0020] Compared with the prior art, the present invention has the following advantages:

[0021] 1. In the present invention, argon is introduced into the inner cavity through the interface nozzle, and additional argon is connected to protect the back weld area of the cylinder body. With multi-faceted protection, it effectively isolates the welding area from external air contact, prevents the occurrence of oxidation reactions, keeps the weld area pure, ensures welding quality, and prevents embrittlement.

[0022] 2. During the welding process of the present invention, the air shielding and heat absorption tooling is placed 15 - 20 mm away from the weld to block the erosion of air on the weld and absorb part of the heat of the welded joint. At the same time, the welding torch shroud is provided with heat-insulating cotton made of aluminum silicate around its perimeter, ensuring that air does not invade even when the welding torch is running during the welding process. Multiple devices and multiple processes prevent air from eroding the weld.

[0023] 3. In the present invention, arc welding starts from the peak position, stops for 10 - 20 seconds when welding to the adjacent peak and then proceeds with welding. At the same time, it cooperates with the air shielding and heat absorption tooling to absorb part of the heat of the welded joint, preventing the area with too high joint temperature caused by continuous welding from absorbing harmful N, O, and H elements. Description of the Drawings

[0024] To more clearly illustrate the technical solutions in the specific embodiments of the present invention, the following will briefly introduce the drawings required for the description of the embodiments. Obviously, the following-described drawings are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0025] Figure 1 Schematic diagram of the structure assembly of the lightweight aviation radiator in the present invention;

[0026] Figure 2 Schematic diagram of the positions for filling argon gas in the inner cavity and the back of the cylinder of the lightweight aviation radiator in the present invention;

[0027] Figure 3 Welding schematic diagram of the lightweight aviation radiator in the present invention;

[0028] In the figure, 1 - interface nozzle; 2 - corrugated plate; 3 - gas collection hood; 4 - cylinder; 5 - weld joint; 6 - inner cavity of the gas collection hood; 7 - inner cavity of the corrugated plate; 8 - back weld area of the cylinder; 9 - transparent ceramic nozzle; 10 - welding torch drag shield; 11 - gas-blocking and heat-absorbing tooling; 12 - tungsten electrode. Specific embodiments

[0029] The following further illustrates the present invention in conjunction with the drawings and specific embodiments. However, it should not be understood that the scope of the subject matter of the present invention is limited to the following embodiments. Without departing from the above technical idea of the present invention, all modifications, substitutions, and changes made according to the common general knowledge and customary means in the art are included in the scope of the present invention.

[0030] A welding process control method for the "W" - shaped structure of a lightweight aviation radiator includes the following steps:

[0031] Step 1: Position - weld the gas collection hood 3 with the interface nozzle 1 and the corrugated plate 2 by argon arc welding, and position - weld the gas collection hood 3 with the cylinder 4 by resistance welding. The gas collection hood 3, interface nozzle 1, corrugated plate 2, cylinder 4, and the welding wire are all made of TA15 titanium alloy material;

[0032] Step 2: Seal the inner cavity 7 of the corrugated plate and the inner cavity 6 of the gas collection hood with tooling. Each position for blocking the corrugated plate channels on the tooling is provided with through - holes to facilitate the discharge of the air in the inner cavity. The diameter of the through - holes is 1 mm;

[0033] Step 3: Introduce high - purity argon gas at a flow rate of 60 L / min from the position of the interface nozzle 1, and connect an argon gas detector at the outlet of the corrugated plate 2 channel that is farthest from the interface nozzle 1 on the corrugated plate 2 to detect the argon gas purity in the inner cavity;

[0034] Step 4: After the argon purity in the inner cavity reaches 99.99%, place the welding torch drag shield 10 at the "W"-shaped weld formed by the splicing of the corrugated plate 2 and the gas collecting hood 3, and install a transparent ceramic nozzle 9 with a diameter of Φ32 at one end of the welding torch drag shield 10. The protection range of the transparent ceramic nozzle 9 is greater than one pitch of the corrugated plate 2, and the material is high-temperature resistant quartz material. Place the aluminum alloy air-blocking and heat-absorbing tooling 11 at a position 15 mm away from the weld. The air-blocking and heat-absorbing tooling 11 is made of aluminum alloy material to block the erosion of air on the weld and absorb part of the heat of the welded joint;

[0035] Step 5: Install the back protection tooling on the back weld area 8 of the cylinder body, and introduce argon at a flow rate of 40 L / min for protection inside the back protection tooling;

[0036] Step 6: Move the welding torch drag shield 10, adjust the welding current to 15 - 18 A, the argon flow rate to 35 - 40 L / min, and the protruding length of the tungsten electrode 12 to 1.5 times the height of the corrugated plate 2. Perform the welding of the "W"-shaped structure weld. Start welding from the peak position, stop for 10 - 20 seconds when welding to the adjacent peak, and then continue welding. The welding torch drag shield 10 is provided with heat-insulating cotton made of aluminum silicate around it to ensure that air does not invade during the operation of the welding torch during the welding process;

[0037] Step 7: Stop for 30 seconds after welding and then disassemble various protection toolings.

[0038] This method solves the problem of embrittlement of materials during the welding process and improves the stability of the product.

[0039] The above has introduced in detail a "W"-shaped structure welding process control method for a lightweight aviation radiator provided by the present invention. Specific examples are used in this article to elaborate on the structure and working principle of the present invention. The description of the above embodiments is only used to help understand the method and core idea of the present invention. It should be noted that for those of ordinary skill in the art of this technology, without departing from the principle of the present invention, several improvements and modifications can be made to the present invention, and these improvements and modifications also fall within the scope of protection of the claims of the present invention.

Claims

1. A welding process control method for the "W"-type structure of a lightweight aviation radiator, characterized in that, It includes the following steps: Step 1: Carry out tack welding on the gas collecting hood (3), interface nozzle (1), corrugated plate (2), and cylinder body (4). Step 2: Seal the inner cavity (7) of the corrugated plate and the inner cavity (6) of the gas collecting hood. Step 3: Introduce high-purity argon from the position of the interface nozzle (1), and connect an argon detector at the distal end of the corrugated plate (2) to detect the argon purity in the inner cavity of the corrugated plate (2). After the purity meets the standard, place a welding torch drag shield (10) at the weld. Subsequently, install a transparent ceramic nozzle (9) on one end face of the welding torch drag shield (10), and install a gas blocking and heat absorbing tooling (11) on the corrugated plate (2). Step 4: Protect the back weld area (8) of the cylinder body by introducing argon. Step 5: Adjust the welding parameters to implement the welding of the "W"-shaped structure weld. The weld is the "W"-shaped weld formed by the splicing of the corrugated plate (2) and the gas collecting hood (3). The welding process starts from the peak position and stops for 10 - 20 seconds when welding to the adjacent peak and then continues welding. The argon flow rate introduced in Step 3 is 50 - 80 L / min. The distal end of the corrugated plate (2) refers to the channel outlet of the corrugated plate (2) farthest from the interface nozzle (1). The transparent ceramic nozzle (9) is made of high-temperature resistant quartz material, and a tungsten electrode (12) is connected to it. The welding coverage of the transparent ceramic nozzle (9) is greater than one pitch of the corrugated plate (2). The gas blocking and heat absorbing tooling (11) is made of aluminum alloy material and is placed 15 - 20 mm away from the weld.

2. The welding process control method for the "W"-type structure of the lightweight aviation radiator according to claim 1, characterized in that: The tack welding of the interface nozzle (1), corrugated plate (2), and gas collecting hood (3) uses argon arc welding, and the tack welding of the gas collecting hood (3) and the cylinder body (4) uses resistance welding. The welding wire material is TA15 titanium alloy material.

3. The welding process control method for the "W" type structure of the lightweight aviation radiator according to claim 1, characterized in that: The welding torch drag shield (10) is provided with heat-insulating cotton made of aluminum silicate around it.

4. The welding process control method for the "W"-type structure of the lightweight aviation radiator according to claim 1, characterized in that: The welding parameters in Step 5 are welding current 15 - 18 A, argon flow rate 35 - 40 L / min, and the protruding length of the tungsten electrode (12) is 1.5 times the height of the corrugated plate (2).

Images