Titanium alloy welding multifunctional gas protection and cooling device and welding method

Abstract

The application provides a titanium alloy welding multifunctional gas protection and cooling control device and a welding method. A gas protection channel is formed by a plate, a bottom heat dissipation plate and a plug, so that the effectiveness of gas protection under various welding methods is fully ensured, and the surface quality of a weld can reach a bright silver color. A water cooling heat dissipation channel is arranged on the bottom plate and the bottom heat dissipation plate, so that heat can be quickly taken away, the risk of rapid temperature rise of a high-energy beam welding tool and a weld is reduced, the temperature of the weld area is controlled below 200 DEG C in real time, and the tool temperature is below 50 DEG C. Through the combination of different side plates and bottom heat dissipation plates, the diagonal joint weld can be assisted by gas protection and rapid heat dissipation and cooling. The application has the advantages of strong modularity, easy combination, consideration of gas protection and heat dissipation and cooling, can realize heat dissipation and gas protection of the diagonal joint weld and the butt joint weld, and is suitable for multi-position and various welding methods on large workpieces of domestic special vehicles.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of heat dissipation and gas protection in vehicle body welding process, and particularly relates to a multifunctional gas protection and cooling device for titanium alloy welding and a welding method. BACKGROUND

[0002] Titanium alloy has excellent bullet resistance and corrosion resistance, and also has good hot working and cold working performance. In recent years, it has become the main research direction of new special vehicle protection materials in China and is the preferred base material for future special vehicles. The welding seams of special vehicle bodies are mostly butt joints and corner joints, the welding seam form is long, the length is mostly 3-5m, and the welding methods are arc welding and high-energy beam welding and other welding methods. Titanium alloy has strong chemical activity when welding, and above 300℃, it will chemically react with nitrogen, oxygen, hydrogen and other gases, causing the plasticity and toughness of the joint to drop sharply. At the same time, titanium alloy has poor heat conduction performance, and when long straight welds and multi-layer multi-pass welding are performed, the weld area will accumulate a lot of heat, causing uncontrollable stress and deformation, which brings hidden dangers to the welding quality, often leading to overall vehicle body out-of-tolerance and not meeting the equipment delivery requirements.

[0003] Titanium alloy long-term heat accumulation leads to an increase in the temperature of the weld heat-affected zone, causing grain coarsening, a longer residence time in the high-temperature zone of the weld, a greater tendency for the grain of the molten pool metal to grow, and a decrease in the comprehensive mechanical properties of the joint, which adversely affects the quality of the welded joint.

[0004] The poor heat dissipation capacity of titanium alloy and the high gas protection requirements limit the application of these welding structures and processes in the manufacture of large vehicle body workpieces to some extent. The traditional gas protection device uses a groove composed of heat dissipation copper plates for gas protection, which has poor sealing performance, is easy to mix in impurity gases, and cannot be flexibly combined, which cannot meet the gas protection needs of various joints, especially for corner joint applications. At present, the gas protection and heat dissipation devices are basically for butt joints, and there is a blank in the heat dissipation and front auxiliary gas protection of corner joints. SUMMARY

[0005] (I) Technical problems to be solved

[0006] The present application proposes a multifunctional gas protection and cooling device for titanium alloy welding and a welding method, which realizes gas protection and rapid heat dissipation and cooling of the back of the titanium alloy workpiece butt joint and the front of the corner joint, to solve the technical problem of how to realize high-quality and stable welding of titanium alloy workpieces, prevent the welding seam and the surrounding area from being oxidized, and rapidly cool the welding seam to significantly reduce stress and deformation.

[0007] (II) Technical solutions

[0008] In order to solve the above technical problems, the present application provides a titanium alloy welding multifunctional gas protection and cooling device, characterized in that the gas protection and cooling device comprises a bottom plate, a bottom heat dissipation plate, a plug block, a joint, a sealing screw and a side plate; different forms of combination are carried out according to the gas protection needs of butt weld and fillet weld, so as to realize the back protection of butt weld and the front auxiliary protection of fillet weld; wherein,

[0009] The bottom plate, the bottom heat dissipation plate, the plug block and the joint constitute a gas protection channel and a water cooling device for butt weld; wherein two bottom heat dissipation plates are respectively installed on the top of the bottom plate and left and right sides, and a gap corresponding to the position of the long straight weld of butt is formed in the middle; the surface of the bottom heat dissipation plate is stably attached to the stable attachment area of the long straight weld; two plug blocks are installed through the gap between the two bottom heat dissipation plates at the top of the bottom plate and the front and rear ends; two plug blocks are respectively provided with gas protection joints as gas inlet and outlet joints, and a stable gas protection channel is formed in the gap between the two bottom heat dissipation plates; a plurality of vertical and horizontal direction intersecting water cooling heat dissipation channels are processed in the inside of the bottom plate and the bottom heat dissipation plate, and a plurality of water cooling heat dissipation channel holes are provided on each side of the bottom plate and the bottom heat dissipation plate; water cooling joints as water inlet and return joints are respectively installed on the set water cooling heat dissipation channel holes, and other water cooling heat dissipation channel holes not in use are plugged;

[0010] The bottom heat dissipation plate, the side plate and the joint constitute a front auxiliary gas protection and water cooling device for fillet weld; wherein the side plate is installed on the top side of the bottom heat dissipation plate to form an L-shaped structure, and the bottom heat dissipation plate is attached to the fillet weld of the workpiece.

[0011] Further, the bottom plate, the bottom heat dissipation plate and the side plate are all long straight plates.

[0012] Further, the upper surface of the plug block is flush with the upper surface of the bottom heat dissipation plate.

[0013] Further, the interface between the plug block and the bottom heat dissipation plate is sealed with high-temperature resistant adhesive tape.

[0014] Further, the water cooling joint adopts the same joint as the gas protection joint.

[0015] Further, the diameter of the water cooling heat dissipation channel hole is ≥6mm.

[0016] Further, the bottom plate and the bottom heat dissipation plate are both made of copper plate.

[0017] Further, the copper plate is a red copper plate, and the thickness of the bottom plate and the bottom heat dissipation plate is ≥25mm.

[0018] Further, a plurality of gas protection and cooling devices are combined, and a connecting device is used to connect adjacent devices.

[0019] Further, the application proposes a welding method using the above titanium alloy welding multifunctional gas protection and cooling device, which comprises the following steps:

[0020] For butt welds:

[0021] S1. The multifunctional gas protection and cooling control device composed of the bottom plate and the bottom heat sink is clamped on the workpiece weld with the weld as the center, and fixed and sealed by using high-temperature resistant adhesive tape;

[0022] S2. Connect the gas protection connector and the water cooling connector, ventilate the gas protection channel, and circulate water in the water cooling and heat dissipation channel in the bottom heat sink and the bottom plate;

[0023] S3. The workpiece is automatically welded or manually welded;

[0024] For corner welds:

[0025] S1. The multifunctional gas protection and cooling control device composed of the side plate and the bottom heat sink is attached to the workpiece corner weld and kept flush on the upper surface, and the weld and the device edge are fixed and sealed by using high-temperature resistant adhesive tape;

[0026] S2. Connect the water cooling connector, and circulate water in the water cooling and heat dissipation channel in the bottom heat sink;

[0027] S3. The workpiece is automatically welded or manually welded.

[0028] (Three) beneficial effects

[0029] The application proposes a titanium alloy welding multifunctional gas protection and cooling control device and a welding method. The gas protection channel composed of the plate, the bottom heat sink and the plug fully guarantees the effectiveness of the gas protection under various welding methods, and the weld surface quality can reach a bright silver color. The water cooling and heat dissipation channel is provided on the bottom plate and the bottom heat sink, which can quickly take away heat and reduce the risk of rapid temperature rise of high-energy beam welding tooling and welds, and the weld area temperature is controlled below 200 DEG C and the tooling temperature is below 50 DEG C. The combination of different side plates and bottom heat sinks can realize auxiliary gas protection and rapid heat dissipation and cooling for corner welds. The application has the advantages of strong modularity, easy combination, and consideration of gas protection and heat dissipation and cooling, and can realize heat dissipation and gas protection for corner welds and butt welds, and is suitable for multi-position and various welding methods on large workpieces of domestic special vehicles. BRIEF DESCRIPTION OF DRAWINGS

[0030] Figure 1 It is a structural diagram of the gas protection and cooling device of the application (butt weld);

[0031] Figure 2Structure diagram of the gas protection and cooling device of the present application (butt joint);

[0032] Figure 3 Top view of the internal structure of the base plate and the bottom heat sink plate of the present application;

[0033] Figure 4 Structure diagram of the internal structure of the base plate of the present application;

[0034] Figure 5 Structure diagram of the device combination of the present application (butt joint);

[0035] Figure 6 Structure diagram of the device combination of the present application (butt joint). DETAILED DESCRIPTION

[0036] In order to make the purpose, content and advantages of the present application more clear, the specific embodiments of the present application are described in further detail below in combination with the drawings and examples.

[0037] The present embodiment proposes a multifunctional gas protection and cooling device for titanium alloy welding, the structure of which is shown in Figure 1 and 2 , mainly comprising a base plate 1, a bottom heat sink plate 2, a plug 3, a joint 4, a sealing screw 5 and a side plate 7. The base plate 1, the bottom heat sink plate 2 and the side plate 7 are all long straight plates, which can be combined in different forms according to the gas protection needs of the butt joint and the corner joint, so as to realize the back protection of the butt joint and the front auxiliary protection of the corner joint. Among them, the base plate 1, the bottom heat sink plate 2, the plug 3 and the joint 4 can form a gas protection channel and a water cooling device for the butt joint; the bottom heat sink plate 2, the side plate 7 and the joint 4 can form a front auxiliary gas protection and water cooling device for the corner joint.

[0038] As shown in Figure 1 , according to the gas protection and cooling needs of the butt joint, two bottom heat sink plates 2 are respectively installed on the top of the base plate 1 at the left and right sides by screws, and a gap corresponding to the position of the long straight butt joint is formed in the middle. The surface of the bottom heat sink plate 2 is machined and leveled, so as to realize stable fitting with the heat affected zone of the long straight joint.

[0039] Two plugs 3 are installed at the front and rear ends of the top of the base plate 1 and located in the gap between the two bottom heat sink plates 2 by countersunk screws. The upper surface of the plug 3 is flush with the upper surface of the bottom heat sink plate 2, and the interface is sealed with high-temperature resistant adhesive tape.

[0040] Two plugs 3 are respectively installed with gas protection joints 4 as gas inlet and outlet joints, forming a stable gas protection channel in the gap between the two bottom heat sink plates 2, and the gas protection flow during welding is ≥25L / min.

[0041] The internal structures of the bottom plate 1 and the bottom heat dissipation plate 2 are shown in Figure 3 and 4 respectively. Both the bottom plate 1 and the bottom heat dissipation plate 2 are processed with a plurality of water-cooling heat dissipation channels arranged in vertical and horizontal directions, and a plurality of water-cooling heat dissipation channel holes are arranged on each side of the bottom plate 1 and the bottom heat dissipation plate 2. According to the welding cooling needs, water-cooling joints 4 as water inlet joints and water return joints are respectively arranged on the set water-cooling heat dissipation channel holes, and other water-cooling heat dissipation channel holes not needed are blocked to meet the heat dissipation and cooling needs of the welding seams. In the embodiment, the water-cooling joints 4 are the same as the gas protection joints 4. The diameter of the water-cooling heat dissipation channel holes is ≥6 mm, and the water flow is ≥30 L / min.

[0042] Both the bottom plate 1 and the bottom heat dissipation plate 2 are made of copper plates, and the heat accumulated in the titanium alloy welding seams can be quickly taken away by the good heat conductivity of the copper plates and the high specific heat capacity of water.

[0043] In the embodiment, the length of a single gas protection and cooling device is 500 mm, and the width is 200 mm. In order to meet the needs of welding seams of different lengths, a plurality of devices can be combined, and only the installation positions of the gas protection joints 4 and the water-cooling joints 4 need to be adjusted appropriately, and reliable connection between the joints can be achieved by using a hose and other connecting devices. As shown in Figure 5 , the length of the welding seam on the workpiece is more than 3 m, and the gas protection and cooling can be realized at one time. The combination of a plurality of devices or the sealing of the device and the edge of the workpiece by using high-temperature-resistant adhesive tape can ensure the air tightness and the adhesion between the device and the workpiece.

[0044] As shown in Figure 2 , according to the needs of gas protection and cooling of the fillet weld, the side plate 7 is installed on the top side of the bottom heat dissipation plate 2 by using a screw 6 to form an L-shaped structure, so that the bottom heat dissipation plate 2 can be attached to the fillet weld of the workpiece to realize auxiliary gas protection of the front of the welding seam. Most of the heat in the fillet weld is absorbed by the bottom heat dissipation plate 2 parallel to the welding gun, which can quickly reduce the temperature of the workpiece and prevent oxidation and deformation caused by high temperature.

[0045] In the embodiment, both the bottom heat dissipation plate 2 and the side plate 7 are made of red copper plates, the thickness of the bottom heat dissipation plate 2 is ≥25 mm, and the thickness of the side plate 7 is ≥10 mm. In order to meet the needs of fillet welds of different lengths, a plurality of devices can be combined, as shown in Figure 6 .

[0046] The welding method using the above-mentioned multifunctional gas protection and cooling device for titanium alloy welding includes the following steps:

[0047] For butt welds:

[0048] S1. The multifunctional gas protection and cooling control device composed of the bottom plate and the bottom heat sink is clamped on the weld of the workpiece with the weld as the center, a plurality of devices are connected for long straight welds, and high-temperature-resistant adhesive tape is used for fixation and sealing;

[0049] S2. The gas protection connector and the water cooling connector are connected, the gas protection channel is ventilated, and the water cooling and heat dissipation channel in the bottom heat sink and the bottom plate is circulated;

[0050] S3. The workpiece is automatically welded or manually welded.

[0051] For fillet welds:

[0052] S1. The multifunctional gas protection and cooling control device composed of the side plate and the bottom heat sink is closely attached to the fillet weld of the workpiece and the upper surfaces are flush, the weld and the edge of the device are fixed and sealed with high-temperature-resistant adhesive tape;

[0053] S2. The water cooling connector is connected, and the water cooling and heat dissipation channel in the bottom heat sink is circulated;

[0054] S3. The workpiece is automatically welded or manually welded.

[0055] In the above scheme, the welding method can use high-energy beam welding, such as plasma welding, or arc welding, such as automatic argon arc welding and automatic gas shielded welding; the protective gas of the welding gun is high-purity argon; the back protective gas is high-purity argon; the cooling circulating water is pure water. In order to further improve the welding quality, the welding current during welding is 200-320 A, the back protective gas flow is 25-35 L / min, the welding gun protective gas flow is 20-30 L / min, and the welding speed is 100-200 mm / min.

[0056] Example 1

[0057] The multifunctional gas protection and cooling control is used to weld a certain type of titanium alloy plate workpiece with a plate thickness of 12 mm+12 mm and a structure size of 4200 mm×3200 mm×12 mm. The welding process uses plasma welding, the welding joint form is butt welding, the multifunctional gas protection and cooling control device is placed on the back of the weld, and multiple blocks are connected. The protective gas is high-purity argon with a flow rate of 25 L / min, the cooling water circulation speed is 35 L / min, the welding current is 295 A, the welding gun protective gas flow is 20 L / min, and the welding speed is 120 mm / min.

[0058] Compared with the conventional welding gas protection and temperature control method, the temperature of the area near the weld seam is kept below 100 DEG C during the welding process, the post-weld deformation is significantly reduced, far less than the technical requirements of the drawing, the back weld seam quality is excellent, and the long straight weld seam can be formed by one-time welding protection.

[0059] Example 2

[0060] The multifunctional gas protection and cooling device is used to weld a titanium alloy car body corner joint workpiece with a plate thickness of 6 mm+12 mm and a structure size of 5000 mm*800 mm*1200 mm. Laser-arc hybrid welding is used in the welding process, the multifunctional gas protection and cooling control device is placed on the side of the corner joint weld seam, and multiple pieces are connected. The cooling water circulation speed is 30 L / min, the welding current is 180 A, the flow rate of the welding gun protection gas is 25 L / min, and the welding speed is 500 mm / min.

[0061] Compared with the conventional welding gas protection and temperature control method, the temperature of the area near the weld seam is kept below 50 DEG C during the welding process, there is almost no deformation after welding, and the long straight corner weld seam can be formed by one-time welding protection and cooling.

[0062] The above only describes the preferred embodiments of the present application, and it should be noted that for ordinary skilled persons in the art, several improvements and modifications can be made without departing from the technical principles of the present application, and these improvements and modifications should also be considered as the protection scope of the present application.

Claims

1. A multifunctional gas protection and cooling device for titanium alloy welding, characterized in that, The gas protection and cooling device includes a base plate, a bottom heat dissipation plate, a plug, a connector, sealing screws, and side plates; different combinations are used according to the gas protection requirements of butt welds and fillet welds to achieve back protection for butt welds and front auxiliary protection for fillet welds; wherein, The base plate, bottom heat sink, plugs, and connectors constitute a gas protection channel and water cooling device for butt welds. Two bottom heat sinks are installed on the top left and right sides of the base plate, forming a gap in the middle corresponding to the position of the long straight butt weld. The surface of the bottom heat sink is stably fitted to the heat-affected zone of the long straight weld. Two plugs are installed at the front and rear ends of the top of the base plate, located in the gap between the two bottom heat sinks. Gas protection connectors, serving as inlet and outlet connectors, are installed on the two plugs, forming a stable gas protection channel in the gap between the two bottom heat sinks. Multiple vertically and horizontally intersecting water cooling channels are machined inside the base plate and bottom heat sinks, and multiple water cooling channel holes are provided on each side of the base plate and bottom heat sinks. Water cooling connectors, serving as inlet and outlet connectors, are installed on the designated water cooling channel holes, and other unused water cooling channel holes are sealed. The bottom heat sink, side plate, and joint constitute a front auxiliary gas protection and water cooling device for fillet welds; wherein, the side plate is installed on the top side of the bottom heat sink to form an L-shaped structure, and the bottom heat sink is in contact with the fillet weld of the workpiece.

2. The gas protection and cooling device as described in claim 1, characterized in that, The base plate, bottom heat sink, and side plates are all long, straight flat plates.

3. The gas protection and cooling device as described in claim 1, characterized in that, The upper surface of the plug is flush with the upper surface of the bottom heat sink.

4. The gas protection and cooling device as described in claim 1, characterized in that, The interface between the plug and the bottom heat sink is sealed with high-temperature resistant tape.

5. The gas protection and cooling device as described in claim 1, characterized in that, The water-cooled connector uses the same connector as the gas-protected connector.

6. The gas protection and cooling device as described in claim 1, characterized in that, The diameter of the water-cooling heat dissipation channel holes is ≥6mm.

7. The gas protection and cooling device as described in claim 1, characterized in that, Both the base plate and the bottom heat sink are made of copper.

8. The gas protection and cooling device as described in claim 7, characterized in that, The copper plate is made of pure copper, and the thickness of both the base plate and the bottom heat sink plate is ≥25mm.

9. The gas protection and cooling device as described in claim 1, characterized in that, Multiple gas protection and cooling devices are combined, and a connecting device is used to connect the joints of adjacent devices.

10. A welding method employing the multifunctional gas protection and cooling device for titanium alloy welding as described in any one of the preceding claims, characterized in that, The method includes the following steps: For butt welds: S1. The multi-functional gas protection and cooling control device, consisting of the base plate and the bottom heat dissipation plate, is mounted on the weld seam of the workpiece with the weld seam as the center, and is fixed and sealed with high-temperature resistant tape. S2. Connect the gas protection connector and the water cooling connector to ventilate the gas protection channel and circulate water through the bottom heat sink and the water cooling channel inside the bottom plate. S3. The workpiece is subjected to automated welding or manual welding; For fillet welds: S1. The multi-functional gas protection and cooling control device, consisting of the side plate and the bottom heat dissipation plate, is attached to the corner weld of the workpiece and kept flush with the upper surface. The weld and the edge of the device are fixed and sealed with high-temperature resistant tape. S2. Connect the water cooling connector to circulate water through the water cooling channels inside the bottom heat sink. S3. The workpiece is welded automatically or manually.

Images