A welding method and a welding protection device for a ball flat titanium butt joint

Abstract

The application relates to a welding method of a ball flat titanium butt joint, which comprises the following steps: selecting two ball flat titanium test pieces meeting the requirements, setting corresponding welding grooves on the test pieces; performing surface cleaning on the ball flat titanium test pieces, then fixing the ball flat titanium test pieces needing to be welded by using a tool clamp; installing a welding back gas protection device, pre-charging the gas protection device with inert gas; respectively installing an arc striking plate and an arc extinguishing plate at the web root and the ball head end of the ball flat titanium test piece; completing web backing, filling and surface welding; polishing the weld joint at the connection between the ball head and the web of the ball flat titanium test piece; starting welding from the connection between the ball head and the web to the ball head end, and completing the backing welding of the ball head part of the ball flat titanium in the form of arc breaking welding; and completing the filling and surface welding of the ball head part of the ball flat titanium. The welding sequence of the welding method of the ball flat titanium butt joint is reasonable and close to production, different angle grooves are set at the ball head and the web, the weld joint can be completely penetrated, and the joint strength can be ensured; through the front and back gas protection measures, the weld joint is prevented from being oxidized during the welding and cooling processes, the joint strength is greatly reduced, and the welding quality is improved.

Description

Technical Field

[0001] This invention relates to the technical field of profile welding, specifically a welding method and welding protection device for a spherical flat titanium butt joint. Background Technology

[0002] Titanium spherical flattened profiles are asymmetrical profiles made of titanium alloy, consisting of a flat web and spherical face plates. Spherical flattened profiles are commonly used in shipbuilding, typically made of steel; however, as shipbuilding demands higher structural strength and lighter weights, the use of titanium alloys to replace carbon steel in the manufacture of spherical flattened profiles has emerged.

[0003] Because welding titanium alloys differs significantly from welding carbon steel, they exhibit characteristics such as poor molten pool fluidity, shallow penetration, and susceptibility to spatter during welding. Inert gas protection is required during both welding and cooling processes to prevent oxidation of the titanium alloy at high temperatures, which would affect joint performance.

[0004] Existing welding processes are prone to poor weld formation, with issues such as incomplete welding, weld overheating, and severe oxidation occurring at the ball joint. Furthermore, interference between the welding torch and protective device can lead to welding interruptions or instability.

[0005] Therefore, there is an urgent need in the market for a welding method for spherical flat titanium butt joints, as well as an auxiliary device that can provide effective protection for this welding method. Summary of the Invention

[0006] The purpose of this invention is to provide an improved welding method and welding protection device for spherical flat titanium butt joints. Through process improvement and the setting of protection device, the weld can be fully penetrated and the joint strength can be guaranteed, while avoiding oxidation of the weld during welding and cooling, thereby improving the welding quality.

[0007] To achieve the above objectives, the technical solution of the present invention is: a welding method for a spherical flat titanium butt joint, characterized in that the welding method includes the following steps: a) selecting two spherical flat titanium specimens that meet the requirements, and opening corresponding welding bevels on the specimens; b) cleaning the surface of the spherical flat titanium specimens, and then using tooling fixtures to fix the spherical flat titanium specimens to be welded; c) installing a gas protection device on the back of the weld, and pre-filling the gas protection device with inert gas; d) installing arc-starting and arc-extinguishing plates at the root of the web and the end of the ball of the spherical flat titanium specimen, respectively; e) completing the root pass, fill pass, and cover pass welding of the web; f) grinding the weld at the connection between the ball and the web of the spherical flat titanium specimen; g) starting from the connection between the ball and the web and welding towards the end of the ball, completing the root pass welding of the ball head of the spherical flat titanium using intermittent arc welding; h) completing the fill pass and cover pass welding of the ball head of the spherical flat titanium.

[0008] Preferably, in step a, the spherical flat titanium specimen includes a ball head and a web, with a 25°±5° welding bevel on the end face of the ball head and a 30°±5° welding bevel on the side of the web.

[0009] Furthermore, in step b, a stainless steel wire brush is used to clean impurities from the surface of the weldment, and ethanol or acetone is used to clean oil stains inside the weld and within a 30mm radius around the weld cut.

[0010] Furthermore, in step c, the length of the gas shielded device on the back of the weld is more than 20 mm longer than the weld length, and the width of the gas shielded device on the back of the weld is more than 60 mm wider than the width of the bevel on the back of the weld.

[0011] Further, in step e, the back gas shielding device of the weld is pre-vented with inert gas for 10 seconds, the root pass of the web plate at a bevel of 30°±5° is first performed, then the web plate at a bevel of 30°±5° is filled and capped, and then the back gas shielding device of the weld is removed.

[0012] Furthermore, a gas protection device is installed on the welding torch to perform the root pass welding on the 25°±5° bevel of the ball head, followed by the filling and cover pass welding on the 25°±5° bevel of the ball head.

[0013] A protective device for a welding method of a flat titanium ball joint is characterized in that the protective device includes a gas protection device for the back of the weld and a gas protection device for the welding torch.

[0014] Furthermore, the gas protection device on the back of the weld includes a square cover with a handle at one end and a mesh cover at the top.

[0015] Furthermore, the welding torch gas protection device includes a cylindrical cover, a handle on one side of the cylindrical cover, and a vent pipe connected to the outer wall of the cylindrical cover.

[0016] Compared with the prior art, the technical solution of the present invention not only improves the overall technical solution, but also includes many improvements in details. Specifically, it has the following beneficial effects: 1. The improved solution of the present invention selects two spherical flat titanium specimens that meet the requirements, and opens corresponding welding bevels on the specimens. The end face of the ball is provided with a 25°±5° welding bevel, and the side of the web is provided with a 30°±5° welding bevel. The two different welding bevels can ensure that the weld is fully penetrated and guarantee the joint strength, effectively improving the welding quality.

[0017] 2. In the technical solution of the present invention, the protective device includes a gas protection device for the back of the weld and a gas protection device for the welding torch. During welding, the protective cover is used to provide inert gas protection for the weld in the high-temperature zone to prevent oxidation of the titanium alloy, thereby improving the performance of the welded joint and the welding quality. 3. The welding method described in this invention involves a simple and clear welding sequence and a reasonable welding bevel design, which is beneficial for component welding; 4. The process steps of this invention are reasonably set, which improves welding efficiency, saves labor, reduces production costs, and is easy to promote and utilize. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the structure of the weld bevel end face of the spherical flat titanium of the present invention.

[0019] Figure 2 This is a schematic diagram of the welding structure of the spherical flat titanium butt joint of the present invention.

[0020] Figure 3 This is a schematic diagram of the structure of the ball head welding bevel and the web welding bevel of the spherical flat titanium specimen of the present invention.

[0021] Figure 4 This is a schematic diagram of the gas protection device for the back side of the weld of the present invention.

[0022] Figure 5 This is a schematic diagram of the structure of the welding torch gas protection device of the present invention.

[0023] Figure label: 1. Flat titanium specimen, 2. Ball head welding bevel, 3. Web plate welding bevel, 4. Gas shielding device for back side of weld, 5. Gas shielding device for welding torch; 41. Square cover; 42. Handle; 43. Mesh cover; 51 Cylindrical cover, 52 Handle, 53 Vent tube. Detailed Implementation

[0024] The technical solution of the present invention will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0025] This invention provides a welding method for a spherical flat titanium butt joint, see details below. Figure 1The difference between this method and existing technologies lies in the following steps: a) Select two spherical flat titanium specimens 1 that meet the requirements, and open corresponding welding bevels on the specimens; b) Clean the surface of the spherical flat titanium specimens, and then use tooling fixtures to fix the spherical flat titanium specimens to be welded; c) Install the gas protection device on the back of the weld and pre-fill the gas protection device with inert gas; d) Install the arc initiation and extinguishing plates at the root of the web and the end of the ball of the spherical flat titanium specimen, respectively; e) Complete the root pass, fill pass, and cover pass welding of the web; f) Grind the weld at the connection between the ball and the web of the spherical flat titanium specimen; g) Start welding from the connection between the ball and the web and proceed to the end of the ball, and complete the root pass welding of the ball head of the spherical flat titanium specimen using intermittent arc welding; h) Complete the fill pass and cover pass welding of the ball head of the spherical flat titanium specimen.

[0026] In practice, the welding method of the ball-flat titanium butt joint of the present invention has a reasonable welding sequence that is close to production. The ball head and web are beveled at different angles to ensure complete weld penetration and joint strength. Through positive and negative gas protection measures, oxidation of the weld during welding and cooling is avoided, which would lead to a significant decrease in joint strength, thereby improving welding quality.

[0027] Example 1 The welding method for a spherical flat titanium butt joint described in this embodiment includes the following steps: a) Select two spherical flat titanium specimens 1 that meet the requirements, and open corresponding welding bevels on the specimens; b) Clean the surface of the spherical flat titanium specimens, and then use tooling fixtures to fix the spherical flat titanium specimens to be welded; c) Install a gas protection device on the back of the weld and pre-fill the gas protection device with inert gas; d) Install arc-starting and arc-extinguishing plates at the root of the web and the end of the ball of the spherical flat titanium specimen, respectively; e) Complete the root pass, fill pass, and cover pass welding of the web; f) Grind the weld at the connection between the ball and the web of the spherical flat titanium specimen; g) Start welding from the connection between the ball and the web towards the end of the ball, and complete the root pass welding of the ball of the spherical flat titanium using intermittent arc welding; h) Complete the fill pass and cover pass welding of the ball of the spherical flat titanium.

[0028] Specifically, in step a, the spherical flat titanium specimen includes a ball head and a web. A 20° ball head welding bevel 2 is made on the end face of the ball head, and a 25° web welding bevel 3 is made on the side of the web. In step b, a stainless steel wire brush is used to clean impurities from the weldment surface, and ethanol or acetone is used to clean oil stains inside the weld and within a 30mm radius around the weld bevel. In step c, the length of the gas shielded device on the back of the weld is at least 20mm longer than the weld length, and the width of the gas shielded device on the back of the weld is at least 60mm wider than the width of the bevel on the back of the weld.

[0029] Further, in step e, the back gas shielding device of the weld is pre-ventilated with inert gas for 10 seconds. First, a root pass weld is performed on the 25° bevel of the web, followed by filling and capping welds on the 25° bevel of the web. Then, the back gas shielding device is removed. The welding torch gas shielding device is then installed, and a root pass weld is performed on the 20° bevel of the ball head, followed by filling and capping welds on the 20° bevel of the ball head. The gap between the webs of the two spherical flat titanium specimens is 2-4 mm, preferably 2.8 mm.

[0030] A protective device for welding a flat titanium butt joint includes a back-side gas shielding device and a welding torch gas shielding device. The back-side gas shielding device 4 includes a square cover 41 with a handle 42 at one end and a mesh cover 43 at the top. The welding torch gas shielding device 5 includes a cylindrical cover 51 with a handle 52 on one side and a vent pipe 53 connected to the outer wall of the cylindrical cover.

[0031] Example 2 This invention provides a spherical flat titanium butt assembly, comprising two spherical flat titanium pieces connected by welding. The spherical flat titanium pieces include a ball head and a web. The end face of the ball head is provided with a 25°±5° welding bevel, and the side of the web is provided with a 30°±5° welding bevel. The two 25°±5° bevels are butted together, and the two 30°±5° bevels are butted together.

[0032] A further optimization of this invention is that the welding bevels for both the ball head and the web are located on the outer side of the part, facilitating on-site welding. When welding flat titanium spheres, a protective shield must be used to provide inert gas protection to the high-temperature weld seam to prevent oxidation of the titanium alloy and thus maintain the weld joint performance.

[0033] The welding method for spherical flat titanium components includes the following steps: Pre-welding preparation: Select two flat titanium specimens with the required straightness and shape. Use a stainless steel wire brush to clean the impurities on the surface of the specimens. Use ethanol or acetone to clean the inside of the weld and the oil stains within 30mm around the weld. Assembly: Fix the weldment with tooling fixtures according to the required welding gap, and assemble the arc extinguishing plate of the same material as the base material at the root of the web and the end of the ball head and fix it by spot welding; Root pass welding: Pre-ventilate the protective cover for 10 seconds, then perform root pass welding on the 30°±5° bevel of the web plate. Afterward, remove the rear protective cover and perform root pass welding on the 25°±5° bevel of the ball head using the welding torch protective cover; the rear protective cover is as follows... Figure 4 The image shows a strip shape, while the welding torch protective cover is round. Filling and covering: Under the gas protection of the gun cover and the drag cover, the 30°±5° bevel of the web plate and the 25°±5° bevel of the ball head are filled and covered to complete the welding; To improve the quality of the welded joint, the gap between the webs of the two flat titanium spheres is 2-4 mm.

[0034] The welding method for the above-mentioned spherical flat titanium components involves a simple and clear welding sequence and a reasonable welding groove design, which is beneficial to the welding of the components; the welding protection fixture can provide effective inert gas protection for the high-temperature area of ​​the weld, avoiding the oxidation of the weld from affecting the joint performance.

[0035] Example 3 A spherical flat titanium butt joint includes two welded spherical flat titanium profiles. Each spherical flat titanium profile includes a web and a ball head. The ball head end face has a 28° welding bevel, and the web side face has a 33° welding bevel. The two 28° bevels are butted together, and the two 33° bevels are butted together. The welding method for the spherical flat titanium butt joint includes the following steps: Two flat titanium profiles are joined together using their flat surfaces as the base. Install a gas shielding device on the back of the weld. The effective protection length of the device must be 20mm longer than the weld length, and the effective protection width must be 30mm longer than the left and right sides of the back bevel gap. The gas protection device is pre-charged with inert gas; Install arc-inducing and arc-extinguishing plates (not less than 50mm in length and made of the same material as the base material) at the root of the web and the end of the ball head, respectively; Complete the underlayment, filling, and cover welding of the web plate; Grind the weld at the connection between the ball head and the web; Welding begins from the connection between the ball head and the web and proceeds towards the end of the ball head, using intermittent arc welding to complete the root pass welding of the flat titanium ball head. Complete the filling and capping welding of the flat titanium ball head area; The web assembly clearance is 2~4mm; The weld back cover must effectively protect the entire height of the web plate; As can be seen from the above, the welding sequence of the welding method for the spherical flat titanium butt joint is reasonable and close to production. The bevels at different angles on the ball head and web plate can ensure complete weld penetration and guarantee joint strength. Through positive and negative gas protection measures, oxidation of the weld during welding and cooling is avoided, which would lead to a significant decrease in joint strength, thereby improving welding quality.

[0036] The above description, in conjunction with specific preferred embodiments, provides a further detailed explanation of the present invention. It should not be construed that the specific implementation of the present invention is limited to these descriptions. For those skilled in the art, various simple deductions or substitutions can be made without departing from the concept of the present invention, and all such modifications and substitutions should be considered within the scope of protection of the present invention.

Claims

1. A welding method for a spherical flat titanium butt joint, characterized in that: The welding method includes the following steps: a) Select two spherical flat titanium specimens that meet the requirements, and open corresponding welding bevels on the specimens; b) Clean the surface of the spherical flat titanium specimens, and then use tooling fixtures to fix the specimens to be welded; c) Install the back gas shielding device for the weld seam and pre-charge the device with inert gas; d) Install the arc-starting and arc-extinguishing plates at the root of the web and the end of the ball of the spherical flat titanium specimen, respectively; e) Pre-purge the back gas shielding device for the weld seam for 10 seconds. Inert gas is used to first perform root pass welding on the 30°±5° bevel of the web, then fill and cover the 30°±5° bevel of the web, and then remove the gas shielding device on the back of the weld; f, grind the weld at the connection between the ball head and the web of the spherical flat titanium specimen; g, install the gas shielding device of the welding gun, and start welding from the connection between the ball head and the web towards the end of the ball head, using intermittent arc welding to perform root pass welding on the 25°±5° bevel of the ball head; h, complete the fill and cover welding of the ball head of the spherical flat titanium specimen.

2. The welding method for a spherical flat titanium butt joint according to claim 1, characterized in that: In step b, use a stainless steel wire brush to clean impurities from the surface of the weldment, and use ethanol or acetone to clean oil stains inside the weld and within a 30mm radius around the weld bevel.

3. The welding method for a spherical flat titanium butt joint according to claim 1, characterized in that: In step c, the length of the gas shielded device on the back of the weld is more than 20mm longer than the weld length, and the width of the gas shielded device on the back of the weld is more than 60mm wider than the width of the bevel on the back of the weld.

4. The welding method for a spherical flat titanium butt joint according to claim 2, characterized in that: The gap between the webs of the two spherical flat titanium specimens is 2-4 mm.

5. The protective device for the welding method of a spherical flat titanium butt joint according to claim 1, characterized in that: The gas protection device on the back of the weld includes a square cover with a handle at one end and a mesh cover at the top.

6. The protective device for the welding method of a spherical flat titanium butt joint according to claim 1, characterized in that: The welding torch gas protection device includes a cylindrical cover with a handle on one side and a vent pipe connected to the outer wall of the cylindrical cover.

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