WO2023116071A1 - Efficient welding method applicable to ultra-narrow gap welding of thick-walled titanium alloy member - Google Patents

Abstract

An efficient welding method applicable to ultra-narrow gap welding of a thick-walled titanium alloy member. The method comprises: step 1, machining a groove, performing pretreatment, and performing positioning and clamping; step 2, under the protection of an inert gas, performing laser welding with a hot filler wire, wherein a welding wire is a multi-stranded twisted welding wire (2), and is heated by a wire heating device (4), a first included angle is formed between a laser beam (1) and the normal of a board, a second included angle is formed between the welding wire and the board, and a point of incidence of the laser beam and an end of the welding wire are arranged without spacing therebetween; and step 3, after a welding bead is cleaned, repeating single-layer and single-bead welding until a welding seam is filled, so that welding is completed. Compared with a welding method using a hot solid welding wire, the welding method of the present invention can achieve a resistance heat improvement of 4.52 to 11.12 times, a wire feeding speed increase of about 2 to 3 times, a deposition efficiency improvement of about 2 to 3 times, and a reduction of 1 to 2 times in the number of filling beads, thus greatly improving the welding efficiency.

Description

A high-efficiency welding method suitable for ultra-narrow gap welding of thick-walled titanium alloy components

This application claims the priority of the Chinese patent application with the application number 202111603510.4 and the title of the invention "A high-efficiency welding method suitable for ultra-narrow gap welding of thick-walled titanium alloy components" submitted to the China Patent Office on December 24, 2021. The entire contents of which are incorporated by reference in this application.

technical field

The invention relates to the field of welding technology, in particular to a high-efficiency welding method suitable for ultra-narrow gap welding of thick-walled titanium alloy components.

Background technique

Titanium alloy has the advantages of low density, high specific strength, high specific stiffness, good mechanical properties, good heat resistance and corrosion resistance, and good machinability. It is a good structural material and is used in aerospace, vehicle engineering, mechanical engineering, etc. The field has very broad application prospects, so it has received extensive attention. The welding of titanium alloy plays a decisive role in the development of my country's aerospace technology, and even the improvement of my country's entire science and technology, industrial development and military strength. The development and utilization of advanced materials is a prerequisite for improving industrial technology, and manufacturing technology is a prerequisite for the application of advanced materials. Welding is an indispensable technology for material processing, and the development of advanced welding technology is of great significance to the utilization of advanced materials.

Titanium alloy has a great affinity for oxygen, and it is easy to form TiO ₂ oxide with oxygen. The weldability is poor, and it is difficult to obtain satisfactory results with general welding techniques. At present, thick-walled titanium alloys are often welded by non-melting gas shielded welding (TIG), electron beam welding (EBW) and other welding methods. The groove processing angle of thick-wall non-melting electrode gas shielded welding (TIG) generally needs to be greater than 30°, the welding efficiency is low, the welding deformation and residual stress are large, and defects are prone to exist in the weld; the energy density of electron beam welding (EBW) is high, The large depth-to-width ratio of the weld is suitable for welding thick-walled materials, but this method needs to be carried out under vacuum conditions, and the size of the workpiece to be welded is limited by the vacuum chamber, making it difficult to weld large-sized thick-walled components.

Laser wire-filled welding takes into account the advantages of small welding heat input, precise energy control, and weld structure control. Therefore, laser-filled wire welding technology will become a trend to achieve efficient connection of titanium alloys with thick walls and ultra-narrow gaps. However, at present, relevant researchers have proposed many solutions to the defects of laser wire-filling welding of thick-walled titanium alloys, but none of the existing solutions can solve the problem of low efficiency in laser wire-filling welding of thick-walled titanium alloys.

Since the ultra-narrow-gap laser wire-filled welding process of thick titanium alloy plates is the accumulation of single-pass multi-layer filler metals, the quality of each weld in the welding process directly poses a threat to the service safety of the welded components. The more welding passes, The higher the scrap rate, it is difficult to realize large-scale promotion in industry. Therefore, it is extremely important to develop a new type of high-efficiency laser wire-filling welding method for thick-walled titanium alloys suitable for industrial applications. It is extremely important to reduce welding costs and increase yields for large-scale applications of thick-walled titanium alloys.

Contents of the invention

The purpose of the present invention is to provide a high-efficiency welding method suitable for ultra-narrow gap welding of thick-walled titanium alloy components, and solve the technical problem of low efficiency existing in ultra-narrow gap laser wire-filled welding of thick-walled titanium alloy components.

In order to achieve the above-mentioned purpose of the invention, the present invention provides the following technical solutions:

A high-efficiency welding method suitable for ultra-narrow gap welding of thick-walled titanium alloy components provided by the present invention is carried out according to the following steps:

Step 1: Groove processing of thick-walled titanium alloy plates to be welded, pretreatment after processing, and then clamping;

Step 2: Under the protection of an inert protective gas, laser hot wire welding is performed. The parameters of the laser hot wire welding are set as follows: the welding wire is a multi-strand stranded titanium alloy welding wire, and the welding wire is heated by a hot wire device, and the laser beam It forms the first angle with the normal line of the plate, the welding wire and the plate form the second angle, and the incident point of the laser beam is set with no distance from the end of the welding wire;

Step 3: After the single-layer welding, clean the weld bead, and then repeat the single-layer single-pass welding until the weld seam is filled and the welding is completed.

It is further defined that the thick-walled titanium alloy plate to be welded in step 1 has a thickness of 10 mm to 200 mm.

Further defined, the specific parameters of the groove processing in step 1 are: the groove is Y-shaped or X-shaped, the blunt side of the groove is 2mm-8mm, and the angle of the single groove is 1-3°.

It is further defined that the pretreatment in step 1 includes grinding and pickling, and the specific process of the pickling is: soaking in the mixed solution of HF and _HNO for 15min to 20min, then rinsing and drying with water, the HF and HNO The volume fraction of HF in the mixed solution of ₃ is 2%-4%, and the volume fraction of HNO ₃ is 30%-40%.

It is further defined that the inert shielding gas described in step 2 passes through the shielding gas hood and then sends gas for protection, the gas is fed in advance before welding, and the gas is delayed and stopped after welding.

It is further defined that the inert protective gas in step 2 is 99.999% high-purity argon, and the flow rate of the protective gas is 15L/min-30L/min.

It is further defined that the diameter of the multi-strand titanium alloy welding wire in step 2 is 1.2 mm to 3.6 mm, the multi-strand titanium alloy welding wire is twisted from 3 to 7 strands of titanium alloy welding wire, and the twist angle is 8 to 3.6 mm. 16°, the twist distance is 6mm~20mm.

Further defined, in step 2, the first included angle is 10-15°, and the second included angle is 30-60°.

It is further defined that the specific parameters for heating the welding wire by the heating wire device in step 2 are 50-200A.

It is further defined that in step 2, the laser beam swings in a circular swing, with a swing frequency of 50 Hz-200 Hz and a swing amplitude of 0.5 mm-4 mm.

It is further defined that in step 2, the laser power is 2000W-6000W, the defocus is -20mm-+20mm, and the welding speed is 0.3m/min-2m/min.

Advantages of the present invention compared to prior art:

The invention proposes a high-efficiency welding method suitable for ultra-narrow gap welding of thick-walled titanium alloy components, combining titanium alloy multi-strand welding wire with a hot wire device, and fully utilizing the characteristics of high deposition efficiency of titanium alloy multi-strand welding wire , and applied to thick-walled titanium alloy laser filler wire welding. Reduce the number of filling passes for narrow gap welding of thick-walled titanium alloy components, improve welding efficiency and reduce scrap rate, and provide a new method for high-efficiency and high-quality connection of thick-walled titanium alloys. The specific advantages are as follows:

1) During laser hot wire welding, the heat of melting welding wire mainly comes from resistance heat and laser energy. Resistance heat can reduce the dependence of welding wire melting on laser energy. Therefore, under the same welding parameters, increasing resistance heat can significantly improve wire feeding. speed. Under the same heating wire current conditions, compared with hot single-strand solid welding wire, the resistance heat of hot multi-strand stranded welding wire can be increased by 4.52 to 11.12 times, the wire feeding speed can be increased by about 2 to 3 times, and the deposition efficiency can be increased by about 2 to 3 times. 3 times, the number of filling channels is reduced by 1 to 2 times, the welding efficiency is greatly improved, the scrap rate is reduced, and it can be widely applied in the industry.

2) By adjusting the angle between the laser beam and the end of the welding wire, as well as the distance between the laser beam and the end of the welding wire, the welding wire can be melted smoothly, transitioning to the molten pool smoothly, reducing welding spatter, and improving the quality of welding joints.

3) By setting the laser welding swing mode and parameters, the welding quality is guaranteed and welding defects are reduced.

Instructions attached

Figure 1 is a schematic diagram of welding assembly; 1-laser beam, 2-multi-stranded welding wire, 3-wire feeding device, 4-hot wire device, → represents the welding direction, ← represents the current direction;

Fig. 2 is embodiment 1 groove schematic diagram;

Figure 3 is a schematic cross-sectional view of the welding wire, a-multi-strand, b-single-strand solid;

Fig. 4 is the schematic diagram of split wire twisting system;

Figure 5 is a comparison diagram of the microscopic morphology of the typical weld section of Example 1 and Comparative Example 1; a-multi-strand, b-single-strand solid;

Fig. 6 is the comparative figure of molten metal amount under different hot wire currents of embodiment 1 and comparative example 1;

Fig. 7 is embodiment 2 groove schematic diagrams;

Fig. 8 is a microscopic view of the cross-section of the weld after welding in Example 2.

Detailed ways

A high-efficiency welding method suitable for ultra-narrow gap welding of thick-walled titanium alloy components provided by the present invention will be described in detail below in conjunction with examples, but they should not be understood as limiting the protection scope of the present invention.

Embodiment 1 (see Fig. 1): a kind of high-efficiency welding method applicable to ultra-narrow gap welding of thick-walled titanium alloy components of the present embodiment is carried out according to the following steps:

Step 1: Groove processing of the thick-walled titanium alloy plate to be welded (thickness 10mm, TC4 titanium alloy plate) (see Figure 2 for the specific form and size), and pretreatment after the processing is completed, the pretreatment includes grinding and pickling, The specific process of pickling is: immerse in the mixed solution of HF and _HNO3 for 20min, then rinse and dry with water, the volume fraction of HF in the mixed solution of HF and _HNO3 is 3%, and the volume fraction of _HNO3 35%, and then clamping;

Step 2: Under the protection of an inert protective gas, laser hot wire welding is performed. The parameters of the laser hot wire welding are set as follows: the welding wire is a multi-strand stranded titanium alloy welding wire, and the welding wire is heated by a hot wire device, and the laser beam It forms the first angle with the normal line of the plate, the welding wire and the plate form the second angle, and the incident point of the laser beam is set with no distance from the end of the welding wire; the inert shielding gas is protected by post-supply gas supply through the shielding gas cover, and the gas is supplied in advance before welding. The gas is delayed after welding, the inert protective gas is 99.999% high-purity argon, the protective gas flow rate is 20L/min, the diameter of the multi-strand titanium alloy welding wire is 1.6mm, and the multi-strand titanium alloy welding wire is composed of 3 It is made of twisted titanium alloy welding wire with a twist angle of 12.88° and a lay distance of 11.8mm (see Figure 3-4), the first included angle is 10°, and the second included angle is 40°. The specific parameters for the wire device to heat the welding wire are 60A~100A, the laser beam swings in a circular swing, the swing frequency is 200Hz, the swing amplitude is 2mm, the laser power is 3500W, the defocus is +15mm, and the welding speed is 0.6m /min, wire feeding speed 7m/min.

Step 3: After the single-layer welding, clean the weld bead, and then repeat the single-layer single-pass welding until the weld seam is filled and the welding is completed.

Embodiment 2: The difference between this embodiment and Embodiment 1 is that the thick-walled titanium alloy plate to be welded is a TC4 titanium alloy plate with a thickness of 80mm, and the groove schematic diagram is shown in Figure 7, and the specific parameters for heating the welding wire by the hot wire device 120A. Other steps and parameters are the same as in Example 1.

Comparative example 1: the difference between this embodiment and embodiment 1 is that the welding wire used is a single-strand solid welding wire, the diameter of the welding wire is 1.6 mm, and the wire feeding speed is 3.5 m/min. Other steps and parameters are the same as in Example 1.

The comparison of the cross-sectional morphology of the typical weld seam after welding in Example 1 and Comparative Example 1 is shown in Figure 5, and the deposition efficiency of the multi-strand welding wire is significantly higher than that of the solid welding wire.

The comparison of the amount of molten metal in Example 1 and Comparative Example 1 under different heating wire currents is shown in Figure 6, and the deposition efficiency of the multi-strand welding wire is significantly improved.

The cross-sectional microscopic morphology comparison of typical welded joints after welding in Example 2 is shown in Figure 8. There is no obvious defect in the cross-section, and the side walls are well fused.

The above is only a preferred embodiment of the present invention, it should be pointed out that for those skilled in the art, without departing from the principle of the present invention, some improvements and modifications can also be made, and these improvements and modifications are also It should be regarded as the protection scope of the present invention.

Claims (20)

1. A high-efficiency welding method suitable for ultra-narrow gap welding of thick-walled titanium alloy components, characterized in that the method is carried out according to the following steps:

   Step 1: Groove processing of thick-walled titanium alloy plates to be welded, pretreatment after processing, and then clamping;

   Step 2: Under the protection of an inert protective gas, laser hot wire welding is performed. The parameters of the laser hot wire welding are set as follows: the welding wire is a multi-strand stranded titanium alloy welding wire, and the welding wire is heated by a hot wire device, and the laser beam It forms the first angle with the normal line of the plate, the welding wire and the plate form the second angle, and the incident point of the laser beam is set with no distance from the end of the welding wire;

   Step 3: After the single-layer welding, clean the weld bead, and then repeat the single-layer single-pass welding until the weld seam is filled and the welding is completed.
2. The high-efficiency welding method according to claim 1, characterized in that the thickness of the thick-walled titanium alloy plate to be welded in step 1 is 10mm-200mm.
3. The high-efficiency welding method according to claim 2, characterized in that the thickness of the thick-walled titanium alloy plate to be welded is 10 mm to 80 mm.
4. The high-efficiency welding method according to claim 1, 2 or 3, characterized in that, the thick-walled titanium alloy plate to be welded is a TC4 titanium alloy plate.
5. The high-efficiency welding method according to claim 1, wherein the specific parameters of the groove processing in step 1 are: the groove is Y-shaped or X-shaped, the blunt edge of the groove is 2 mm to 8 mm, and the single groove angle 1 to 3°.
6. The high-efficiency welding method according to claim 1, wherein the pretreatment in step 1 includes grinding and pickling, and the specific process of pickling is: soaking in a mixed solution of HF and _HNO for 15min to 20min , and then washed and dried with water, the volume fraction of HF in the mixed solution of HF and HNO ₃ is 2%-4%, and the volume fraction of HNO ₃ is 30%-40%.
7. The high-efficiency welding method according to claim 6, characterized in that, in the mixed solution of HF and HNO ₃ , the volume fraction of HF is 3%, and the volume fraction of HNO ₃ is 35%.
8. The high-efficiency welding method according to claim 1, characterized in that the inert shielding gas in step 2 passes through the shielding gas cover to provide gas protection, the gas is fed in advance before welding, and the gas is delayed after welding, and the inert protection in step 2 The gas is 99.999% high-purity argon, and the flow rate of the inert protective gas is 15L/min～30L/min.
9. The high-efficiency welding method according to claim 1, wherein the diameter of the multi-stranded titanium alloy welding wire in step 2 is 1.2 mm to 3.6 mm, and the multi-stranded titanium alloy welding wire consists of 3 to 7 strands Titanium alloy welding wire is twisted, the twist angle is 8-16°, and the twist distance is 6mm-20mm.
10. The high-efficiency welding method according to claim 9, characterized in that the diameter of the stranded titanium alloy welding wire in step 2 is 1.6mm-3.6mm.
11. The high-efficiency welding method according to claim 9, wherein the multi-strand stranded titanium alloy welding wire is twisted from 3 strands of titanium alloy welding wire, the twist angle is 8-12.88°, and the twist length is 6mm-11.8mm .
12. The high-efficiency welding method according to claim 1, characterized in that in step 2, the first included angle is 10-15°, and the second included angle is 30-60°.
13. The high-efficiency welding method according to claim 12, characterized in that, the second included angle is 40-60°.
14. The high-efficiency welding method according to claim 1, characterized in that in step 2, the specific parameters for heating the welding wire by the heating wire device are 50A-200A.
15. The high-efficiency welding method according to claim 14, characterized in that in step 2, the specific parameters for heating the welding wire by the heating wire device are 60A-120A.
16. The high-efficiency welding method according to claim 1, characterized in that in step 2, the laser beam swings in a circular swing with a swing frequency of 50Hz-200Hz and a swing amplitude of 0.5mm-4mm.
17. The high-efficiency welding method according to claim 16, characterized in that, in step 2, the laser beam swing range is 0.5mm-2mm.
18. The high-efficiency welding method according to claim 1, characterized in that in step 2, the laser power is 2000W-6000W, the defocus is -20mm-+20mm, and the welding speed is 0.3m/min-2m/min.
19. The high-efficiency welding method according to claim 1, characterized in that, in step 2, the wire feeding speed of laser-filled hot wire welding is 7m/min.
20. The high-efficiency welding method according to claim 18, characterized in that in step 2, the laser power is 3500W-6000W, the defocus is -20mm-+15mm, and the welding speed is 0.6m/min-2m/min.

Images