Pure aluminum single-sided welding double-sided forming welding process

Abstract

This invention provides a single-sided welding process for double-sided forming of pure aluminum, comprising the following steps: Step 1: Trimming the double-beveled edges of the base material and then cleaning it; Step 2: Assembling and fixing the base material on a rotating fixture; Step 3: Pointing the welding wire, with the welding point positioned to the upper right of the base material rotating clockwise, at an elevation angle (α) of 30–45° from the center of the base material and an angle (β) of 70–80° between the welding wire and the horizontal plane; Step 4: During welding, the rotating fixture drives the base material to rotate, while the welding wire moves uniformly from point A on one side of the base material along an arc trajectory to the other side, then folds back horizontally to point B between the two base materials for a temporary stop, and finally moves diagonally. This process is repeated to complete the welding. This invention achieves the advantage of single-sided welding with double-sided forming.

Description

Technical Field

[0001] This invention relates to the field of welding technology, and in particular to a welding process for single-sided welding and double-sided forming of pure aluminum. Background Technology

[0002] For two aluminum jacketed coil units in a certain project, 100% RT inspection is required for Class A and B welds with DN≥250mm, and 100% MT inspection is required for Class A and B welds with DN<250mm. The equipment contains a large number of elbows and bends that cannot be welded using double-sided synchronous TIG welding, making it impossible to control the internal welding quality.

[0003] Because 1050A aluminum plates have good thermal conductivity, the welding wire melts the blunt edge of the plate during weld seam welding. After the plate melts, the molten pool flows inward, resulting in sags that lead to poor appearance and low flaw detection pass rate. Summary of the Invention

[0004] To address the above problems, this invention discloses a single-sided welding process for double-sided forming of pure aluminum, comprising the following steps:

[0005] Step 1: Trim the double beveled edges of the base material, then clean it;

[0006] Step 2: Assemble and fix the base material onto the rotary fixture, which can be pushed manually or driven by a motor;

[0007] Step 3: Point welding with welding wire. The welding point is set on the upper right side of the base material in a clockwise rotation, with an elevation angle (α) of 30-45° from the center of the base material and an angle (β) of 70-80° between the welding wire and the horizontal plane. During the welding process, the welding wire melts. The position of the welding point at this time causes the molten welding wire to flow to both sides, thereby filling the bevel gap between the two base materials and completing the welding.

[0008] Step 4: During welding, the rotary fixture rotates the base material, while the welding wire moves at a constant speed along an arc from point A on one side of the base material to the other side. It then folds back horizontally to point B between the two base materials, pauses briefly, and finally moves diagonally. This process is repeated to complete the welding. The purpose of pausing at point B is to allow more of the welding wire to melt and fill the bevel.

[0009] Preferably, the welding process also includes welding machine modification: replacing the original rubber hose with a PTFE hose. After prolonged use, rubber hoses produce rubber powder, which forms pores at the welding point and affects the quality of the weld.

[0010] Preferably, in step one: the double bevel is divided into an outer bevel and an inner bevel, as well as an inner blunt edge. The included angle of the outer bevel is 50-60°, the included angle of the inner bevel is 20-30°, the depth (X) of the blunt edge is 1mm, and the depth ratio of the inner bevel to the outer bevel is Y:Z = 1:1-5. The double bevel not only increases the welding surface area but also helps control the overflow of molten welding wire towards the blunt edge.

[0011] Preferably, in step one: the repaired base material is soaked in an aluminum cleaning agent for at least half an hour, then rinsed with deionized water and dried. This ensures the surface quality of the weld joint, thereby improving the welding quality.

[0012] Preferably, in step two, the gap (L) between the two base materials is 1-2 mm. This avoids incomplete fusion due to a small gap and sagging problems due to a large gap.

[0013] Preferably, in step three: the base material is preheated to 120-150°C. Since aluminum has good thermal conductivity, it is preheated to a higher temperature.

[0014] Preferably, in step four: during welding, the welding machine current is controlled at 240-260A, and 99.99% pure argon gas is used for protection. This ensures stable melting of the welding wire and prevents oxidation.

[0015] Preferably, in step four, the welding wire used is ER1100. This welding wire is a commonly used solder for welding aluminum parts.

[0016] The beneficial effects of the present invention are as follows: By setting a double bevel and simultaneously setting the welding posture and position, the present invention greatly avoids the welding wire melting and flowing inside the base material, thereby improving the internal welding quality. Therefore, the present invention has the advantage of single-sided welding and double-sided forming. Attached Figure Description

[0017] Figure 1 This is a side view of the present invention;

[0018] Figure 2 This is a schematic diagram of the bevel structure of the present invention;

[0019] Figure 3 This is a schematic diagram of the welding wire path of the present invention. Detailed Implementation

[0020] The present invention will be further illustrated below with reference to the accompanying drawings and specific embodiments. It should be understood that the following specific embodiments are for illustrative purposes only and are not intended to limit the scope of the invention. It should be noted that the terms "front," "rear," "left," "right," "up," and "down" used in the following description refer to directions in the accompanying drawings, and the terms "inner" and "outer" refer to directions toward or away from the geometric center of a specific component, respectively.

[0021] like Figures 1 to 3 As shown, the single-sided welding and double-sided forming welding process for pure aluminum includes the following steps:

[0022] Step 1: Double bevel trimming of the base material edge. The double bevel consists of an outer bevel and an inner bevel. The purpose of setting the outer and inner bevels is to increase the surface area of ​​the base material end face and the inner blunt edge. The included angle of the outer bevel is 50-60°, and the included angle of the inner bevel is 20-30°. The included angle of the inner bevel is smaller than that of the outer bevel to avoid excessive flow of molten welding wire, which would cause unevenness inside the aluminum part. The depth (X) of the blunt edge is 1mm. The depth ratio of the inner bevel to the outer bevel is Y:Z = 1:1-5. Then, clean the part by soaking it in aluminum cleaning agent for at least half an hour, then rinse it with deionized water and blow it dry. The soaking, rinsing and drying process results in a high surface cleanliness of the end, which helps to ensure the quality of the welding.

[0023] Step 2: Assemble and fix the base materials on the rotary fixture. The rotary fixture can be rotated manually or by a drive motor. The gap (L) between the two base materials should be 1-2mm to avoid incomplete fusion due to small gaps and sagging due to large gaps.

[0024] Step 3: Welding wire alignment. The welding point is set at the upper right of the base material as it rotates clockwise. During the welding process, the base material rotates with the rotating fixture. The angle of elevation (α) of the center of the base material is 30-45°, and the angle (β) between the welding wire and the horizontal plane is 70-80°. The welding angle and welding point position of the welding wire ensure that the molten welding wire can flow into the inside of the base material and avoid the problem of overflow and sagging.

[0025] Step 4: During welding, preheat the base material to 120-150℃. Since the base material being welded is aluminum, which has better thermal conductivity, it needs to be welded at a higher temperature. Control the welding machine current to 240-260A to ensure the welding wire melts fully and provides a certain degree of fluidity. At the same time, use 99.99% pure argon gas for protection to improve the welding quality. The welding wire type is ER1100, which is a common welding material for aluminum. The rotary fixture drives the base material to rotate, and at the same time, the welding wire moves from point A on one side of the base material to the other side of the base material at a uniform speed in an arc trajectory. During the arc movement, the end point of the welding wire will also sink radially, and then bend horizontally back to point B between the two base materials for temporary holding. The purpose of temporary holding is to melt more welding wire and fill the gap at the bevel. The holding time depends on whether the blunt edge is completely filled. Finally, move diagonally and repeat the above operation. If necessary, a re-welding can be performed.

[0026] The welding process also includes welding machine modification: replacing the original rubber air hose with PTFE tubing. Traditional rubber hoses produce rubber powder after long-term use, which falls on the welding area, causing porosity and affecting the welding quality. This problem can be solved after the modification.

[0027] The technical means disclosed in this invention are not limited to those disclosed in the above embodiments, but also include technical solutions composed of any combination of the above technical features.

Claims

1. A single-sided welding and double-sided forming welding process for pure aluminum, characterized in that, Includes the following steps: Step 1: Trim the double beveled edges of the base material and then clean it. The double bevel consists of an outer bevel and an inner bevel, as well as an inner blunt edge. The included angle of the outer bevel is 50-60°, the included angle of the inner bevel is 20-30°, the depth (X) of the blunt edge is 1mm, and the depth ratio of the inner bevel to the outer bevel is Y:Z = 1:1-5. Step 2: Assemble and fix the base materials on the rotary tooling. The gap (L) between the two base materials should be 1-2 mm. Step 3: Point welding with welding wire. The welding point is set on the upper right side of the base material in a clockwise rotation, with an elevation angle (α) of 30-45° from the center of the base material and an angle (β) of 70-80° between the welding wire and the horizontal plane. Step 4: During welding, the rotary fixture drives the base material to rotate, while the welding wire moves from point A on one side of the base material at a constant speed along an arc trajectory to the other side of the base material. Then it folds back horizontally to point B between the two base materials and pauses there. Finally, it moves diagonally and repeats the above operation to complete the welding. The welding wire used is ER1100.

2. The pure aluminum single-sided welding double-sided forming welding process according to claim 1, characterized in that: The welding process also includes welding machine modification: replacing the original rubber air hose with a PTFE hose.

3. The pure aluminum single-sided welding double-sided forming welding process according to claim 1, characterized in that: In step one: the repaired base material is soaked in aluminum cleaning agent for no less than half an hour, then rinsed with deionized water and dried.

4. The pure aluminum single-sided welding double-sided forming welding process according to claim 1, characterized in that: In step three: the base material is preheated to 120-150°C.

5. The pure aluminum single-sided welding double-sided forming welding process according to claim 1, characterized in that: In step four: during welding, the welding machine current is controlled at 240-260A, and 99.99% pure argon gas is used for protection.

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