Welding process control method for W-shaped structure of light aviation radiator

Abstract

The invention discloses a welding process control method for a W-shaped structure of a light aviation radiator. The welding process control method comprises the following steps that a gas collecting hood, a connector pipe nozzle, a corrugated plate and a barrel are subjected to positioned welding; the inner cavity of the corrugated plate and the inner cavity of the gas collecting hood are sealed; high-purity argon is introduced from the position of a connector pipe nozzle, an argon detector is connected to the far end of the corrugated plate to detect the purity of argon in an inner cavity of the corrugated plate, a welding gun dragging cover is placed at a weld joint after the purity reaches the standard, then a transparent ceramic nozzle is installed on one end face of the welding gun dragging cover, and a gas blocking and heat absorbing tool is installed on the corrugated plate; in addition, argon is introduced to protect the welding seam area on the back face of the barrel; welding parameters are adjusted, welding of the welding seam of the W-shaped structure is carried out, and after welding is finished, welding is stopped for 15 seconds or above, and various protection tools can be disassembled. Through the control method, the material embrittlement problem in the welding process is solved, and the product stability is improved.

Description

Technical Field

[0001] The invention belongs to the technical field of titanium alloy thin plates, and in particular relates to a welding process control method for a "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 were first used in new aircraft and aero engines. With the rapid development of the aerospace industry, they have been more and more widely used in the aerospace field. Titanium alloy materials are more active in the hot state, so their argon arc welding process is special. During argon arc welding, the welded joints absorb harmful elements and have a certain impact on the strength of the product. The argon arc welding process of titanium alloys is different from that of other aluminum and stainless steel materials.

[0003] The welding joint area of ​​titanium and titanium alloys is easily contaminated by impurities such as gases and becomes embrittled. The main elements that cause embrittlement are O, N, H, C, etc. Titanium and titanium alloys begin to absorb H at 250℃, and quickly absorb H above 300℃; they begin to absorb O at 400℃, and quickly absorb O above 600℃; they begin to absorb N at 600℃, and quickly absorb N at 700℃. With the increase of temperature, the ability of titanium and titanium alloys to absorb N, H, and O increases significantly. O and N form interstitial solid solutions in Ti, which play a role in solid solution strengthening, causing lattice distortion of titanium, increasing strength and hardness, but significantly reducing plasticity and toughness. Titanium has a high melting point, large heat capacity, and poor thermal conductivity. It is easy to form a large molten pool during welding. The high temperature of the molten pool makes the metal of the weld and heat-affected zone stay at high temperature for a long time, and the grains grow significantly, which reduces the plasticity and toughness of the joint and is prone to cracks. Titanium absorbs a large amount of H above 300℃. After cooling to below 300℃, the solubility of H drops sharply. After the eutectoid transformation, the γ phase (titanium H compound TiH2) in the form of thin flakes or needles is absorbed. The strength of TiH2 is very low, and the needle-shaped or flake-shaped TiH2 is similar to a notch, which significantly reduces the impact toughness of the weld. When the weld contains a high amount of O and N, the performance becomes brittle. Under the action of large welding stress, cold cracks and delayed cracks will appear. Delayed cracks sometimes occur in the heat-affected zone. This crack can be delayed to several hours, days, or even months later. This delayed crack phenomenon is mainly caused by the H element. When the quality of the base material and the welding wire is poor, especially when the welding wire has defects such as cracks and interlayers, harmful impurities will accumulate in the interlayers and cracks, causing hot cracks in the weld.

[0004] The Chinese invention patent with the publication number CN102554415A discloses a protective device for the argon arc welding weld of titanium alloy parts and a welding method thereof. The bottom surface of the hollow rectangular drag cover composed of metal plates is open and a copper mesh is installed obliquely, and the other five sides are closed; one end of the drag cover is fastened with a clamping ring of a welding gun and a welding gun head protective cover with a glass observation window located below the clamping ring; the lower end of the argon gas delivery pipe installed on the top surface of the drag cover is inserted into the drag cover, and the lower end of the argon gas delivery pipe is closed and the cylindrical surface is drilled with evenly distributed vents. The welding method is: the bottom surface of the drag cover equipped with a copper mesh is covered on the weld area of ​​the welded part, the welding gun of the AC / DC argon arc welding machine is installed in the welding gun clamping ring, argon gas with a purity of 99.99% is input from the argon gas delivery pipe, and the welding gun is manually or automatically moved at the welding speed of the process specification, and the drag cover is dragged along the high-temperature weld at the same time, so that the high-temperature area of ​​the weld is protected by argon gas in the drag cover to ensure the welding quality. This solution uses argon protection to prevent the titanium alloy from absorbing oxygen, nitrogen and hydrogen in the air, which may cause the weld to become brittle and plasticity to decrease. However, the weld of this solution is W-shaped, and conventional argon cannot evenly protect the weld. Summary of the invention

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

[0006] In order to achieve the above object, the present invention adopts the following technical scheme, a method for controlling the welding process of a "W"-shaped structure of a lightweight aviation radiator, comprising the following steps: Step 1: Position weld the gas collecting hood, the interface nozzle, the corrugated plate and the cylinder; Step 2: Seal the inner cavity of the corrugated plate and the inner cavity of the gas collecting hood; Step 3: Introduce high-purity argon gas from the interface nozzle position, and connect an argon gas detector at the far end of the corrugated plate to detect the purity of argon gas in the inner cavity of the corrugated plate. After the purity meets the standard, place a welding gun drag cover at the weld, then install a transparent porcelain nozzle on one end face of the welding gun drag cover, and install a gas blocking and heat absorbing tooling on the corrugated plate; Step 4: Pass argon gas to protect the weld area on the back of the cylinder; Step 5: Adjust welding parameters to implement "W" type structural weld welding.

[0007] Furthermore, argon arc welding is used for positioning welding of the interface nozzle, the corrugated plate and the gas collecting hood, and resistance welding is used for positioning welding of the gas collecting hood and the cylinder, and the welding wire material is TA15 titanium alloy material.

[0008] Furthermore, the flow rate of argon gas introduced in step 3 is 50-80 L / min, and the far end of the corrugated plate refers to the outlet of the corrugated plate channel farthest from the interface nozzle.

[0009] Furthermore, the transparent porcelain nozzle welding coverage of step 3 is larger than one wave pitch of the corrugated plate, and the material is high temperature resistant quartz material.

[0010] Furthermore, the air suction heat shielding tooling in step 3 is made of aluminum alloy material and is placed 15-20 mm away from the weld.

[0011] Furthermore, the welding gun hood is provided with aluminum silicate thermal insulation cotton around it.

[0012] Furthermore, the welding parameters in step 5 are welding current 15-18A, argon gas flow rate 35-40L / min, and tungsten electrode extension length 1.5 times the height of the corrugated plate.

[0013] Furthermore, the welding process is to start welding from the wave crest position, stop welding for 10-20 seconds when welding to the adjacent wave crest, and then continue welding.

[0014] Furthermore, the weld is a "W"-shaped weld formed by splicing the corrugated plate and the gas collecting hood.

[0015] Compared with the prior art, the present invention has the following advantages: 1. The present invention introduces argon into the inner cavity through the interface nozzle, and also connects argon to protect the weld area on the back of the cylinder. The multi-directional protection effectively isolates the welding area from the outside air, prevents the occurrence of oxidation reaction, keeps the weld area pure, ensures welding quality, and prevents embrittlement.

[0016] 2. During the welding process of the present invention, the air intake baffle is placed 15-20 mm away from the weld to block the erosion of the weld by air and absorb part of the heat of the welding joint. At the same time, aluminum silicate insulation cotton is arranged around the welding gun hood to ensure that air does not invade when the welding gun is running during the welding process. Multiple devices and multiple processes prevent the erosion of the weld by air.

[0017] 3. The present invention starts arc welding from the wave crest position, stops welding for 10-20 seconds when welding to the adjacent wave crest, and then continues welding. At the same time, it cooperates with air blocking and heat absorbing tooling to absorb part of the heat of the welding joint to prevent the area with excessively high temperature of the joint from absorbing harmful N, O, and H elements due to continuous welding. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In order to more clearly illustrate the technical solutions in the specific embodiments of the present invention, the drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0019] Figure 1 This is a schematic diagram of the assembly of the lightweight aviation radiator structure in the present invention; Figure 2 This is a schematic diagram of the argon filling position of the inner cavity and the back of the cylinder of the lightweight aviation radiator in the present invention; Figure 3 This is a schematic diagram of welding of a lightweight aviation radiator in the present invention; In the figure, 1-interface nozzle; 2-corrugated plate; 3-gas collecting hood; 4-cylinder; 5-weld joint; 6-inner cavity of gas collecting hood; 7-inner cavity of corrugated plate; 8-weld area on the back of cylinder; 9-transparent porcelain nozzle; 10-welding gun drag cover; 11-gas shielding and heat absorbing tooling; 12-tungsten electrode. DETAILED DESCRIPTION

[0020] The present invention is further described below in conjunction with the accompanying drawings and specific embodiments, but it should not be understood that the scope of the subject matter described in the present invention is limited to the following embodiments. Without departing from the above-mentioned technical ideas of the present invention, various modifications, substitutions and changes made according to the common technical knowledge and customary means in the field are included in the scope of the present invention.

[0021] A method for controlling the welding process of a "W"-shaped structure of a lightweight aviation radiator comprises the following steps: Step 1: The gas hood 3, the interface nozzle 1, and the corrugated plate 2 are tack welded by argon arc welding, and the gas hood 3 and the cylinder 4 are tack welded by resistance welding. The gas hood 3, the interface nozzle 1, the corrugated plate 2, the cylinder 4, and the welding wire are all made of TA15 titanium alloy; Step 2: Use a tool to seal the inner cavity 7 of the corrugated plate and the inner cavity 6 of the gas collecting hood. A through hole is arranged at the sealing position of each corrugated plate channel on the tool to facilitate the discharge of the inner cavity air. The diameter of the through hole is 1 mm; Step 3: Introduce 60L / min of high-purity argon gas from the interface nozzle 1, and connect an argon gas detector to the outlet of the corrugated plate 2 channel farthest from the interface nozzle 1 to detect the purity of the argon gas in the inner cavity; Step 4: After the purity of the argon gas in the inner cavity reaches 99.99%, a welding gun drag cover 10 is placed at the "W"-shaped weld formed by the splicing of the corrugated plate 2 and the gas collecting cover 3, and a transparent porcelain nozzle 9 with a diameter of Φ32 is installed at one end of the welding gun drag cover 10. The protection range of the transparent porcelain nozzle 9 is larger than one wave pitch of the corrugated plate 2, and the material is a high-temperature resistant quartz material. An aluminum alloy air-blocking heat-absorbing tooling 11 is placed at a distance of 15 mm from the weld. The air-blocking heat-absorbing tooling 11 is made of aluminum alloy material to block the erosion of the weld by air and absorb part of the heat of the weld joint; Step 5: Install a back protection tooling on the back weld area 8 of the cylinder, and introduce 40L / min argon gas into the back protection tooling for protection; Step 6: Move the welding gun hood 10, adjust the welding current to 15-18A, the argon gas flow rate to 35-40L / min, the tungsten electrode 12 extends to 1.5 times the height of the corrugated plate 2, and implement the "W" type structural weld. Start arc welding from the wave crest position, stop welding for 10-20 seconds when welding to the adjacent wave crest, and then continue welding. The welding gun hood 10 is surrounded by aluminum silicate insulation cotton to ensure that air does not invade when the welding gun is running during the welding process; Step 7: After welding, stop for 30 seconds to remove all kinds of protective tools.

[0022] This method solves the problem of material embrittlement during welding and improves the stability of the product.

[0023] The above is a detailed introduction to the welding process control method of the "W"-shaped structure of a lightweight aviation radiator provided by the present invention. This article uses specific examples to illustrate 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 pointed out that for ordinary technicians in this technical field, without departing from the principles of the present invention, the present invention can also be improved and modified in a number of ways, and these improvements and modifications also fall within the scope of protection of the claims of the present invention.

Claims

1. A method for controlling the welding process of a "W" type structure of a lightweight aviation radiator, characterized in that: The following steps are involved: Step 1: Position welding the gas collecting hood (3) with the interface nozzle (1), the corrugated plate (2) and the cylinder (4); Step 2: Sealing the inner cavity of the corrugated plate (7) and the inner cavity of the gas collecting hood (6); Step 3: high-purity argon gas is introduced from the interface nozzle (1), and an argon gas detector is connected to the far end of the corrugated plate (2) to detect the purity of the argon gas in the inner cavity of the corrugated plate (2). After the purity reaches the standard, a welding gun drag cover (10) is placed at the weld, and then a transparent porcelain nozzle (9) is installed on one end surface of the welding gun drag cover (10), and a gas blocking and heat absorbing tooling (11) is installed on the corrugated plate (2); Step 4: Pass argon gas to protect the weld area (8) on the back of the cylinder; Step 5: Adjust welding parameters to implement "W" type structural weld welding.

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

3. The method for controlling the welding process of the "W" type structure of a lightweight aviation radiator according to claim 1 is characterized in that: The flow rate of the argon gas introduced in step 3 is 50-80 L / min, and the far end of the corrugated plate (2) refers to the channel outlet of the corrugated plate (2) farthest from the interface nozzle (1).

4. The method for controlling the welding process of the "W" type structure of a lightweight aviation radiator according to claim 1 is characterized in that: The transparent porcelain nozzle (9) in step 3 is connected to a tungsten electrode (12), the welding coverage of the transparent porcelain nozzle (9) is larger than one wave pitch of the corrugated plate (2), and the material is a high temperature resistant quartz material.

5. The method for controlling the welding process of the "W" type structure of a lightweight aviation radiator according to claim 1 is characterized in that: The air blocking and heat absorbing tooling (11) in step 3 is made of aluminum alloy material and is placed 15-20 mm away from the weld.

6. The method for controlling the welding process of the "W" type structure of a lightweight aviation radiator according to claim 1 is characterized in that: The welding gun hood (10) is provided with aluminum silicate thermal insulation cotton around its periphery.

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

8. The method for controlling the welding process of the "W" type structure of a lightweight aviation radiator according to claim 1 is characterized in that: The welding process is to start welding from the wave crest position, stop welding for 10-20 seconds when welding to the adjacent wave crest, and then continue welding.

9. The method for controlling the welding process of the "W" type structure of a lightweight aviation radiator according to claim 1 or 5, characterized in that: The weld is a "W"-shaped weld formed by splicing the corrugated plate (2) and the gas collecting hood (3).

Images