Method for improving corrosion resistance of welding seam of titanium alloy laser welding part through pulse electromagnetic field

Abstract

The invention discloses a method for improving corrosion resistance of a welding seam of a titanium alloy laser welding part through a pulse electromagnetic field. The method comprises the steps that a TC4 titanium alloy welding part to be treated is clamped through an electromagnetic treatment clamp; fixing the electromagnetic treatment clamp for clamping the TC4 titanium alloy welding part in an electromagnetic treatment device; setting a pulse electric field parameter and an electromagnetic coupling parameter of the electromagnetic processing device; based on the set pulse electric field parameters, a pulse electric field with the waveform being a square wave is independently applied to the TC4 titanium alloy welding part; and S4, based on the set electromagnetic coupling parameters, a pulsed electric field and a pulsed magnetic field with the waveform being triangular waves are applied to the TC4 titanium alloy welding part subjected to pulsed electric field treatment in the step S4 at the same time. The method directly treats the weld joint area, has the characteristics of high efficiency, energy conservation and environmental protection, and obviously improves the corrosion resistance of the weld joint, prolongs the service life of a welded part and keeps the simplicity and economy of the treatment process by optimizing the microstructure and component distribution of the weld joint.

Description

Technical Field

[0001] The invention belongs to the technical field of improving the performance of titanium alloys, and specifically relates to a method for improving the corrosion resistance of a weld of a titanium alloy laser welded part using a pulsed electromagnetic field. Background Art

[0002] TC4 titanium alloy is widely used in the manufacture of key components in the fields of aviation, aerospace, and medical due to its excellent strength, low density, and excellent corrosion resistance. Although TC4 titanium alloy has these excellent properties, the weld area often becomes a potential corrosion hotspot during laser welding, which seriously limits the overall performance and service life of the welded components.

[0003] At present, in order to improve the corrosion resistance of TC4 titanium alloy welded parts, common methods include solution treatment, heat treatment and other traditional treatment technologies. Although these methods can improve the performance of the weld area to a certain extent, they are usually cumbersome and inefficient. The application of these technologies may also be accompanied by disadvantages such as high energy consumption and long processing time, which affects production efficiency and may cause instability of workpiece size and increase production costs. Summary of the invention

[0004] The purpose of the present invention is to address the above-mentioned deficiencies in the prior art and to provide a method for improving the corrosion resistance of titanium alloy laser welded parts by using a pulsed electromagnetic field, so as to solve the corrosion problem of the welding joints of existing TC4 titanium alloy laser welded parts.

[0005] In order to achieve the above object, the technical solution adopted by the present invention is:

[0006] A method for improving the corrosion resistance of a titanium alloy laser welded part weld by using a pulsed electromagnetic field, comprising the following steps:

[0007] S1. Use electromagnetic treatment fixture to clamp the TC4 titanium alloy welded parts to be processed;

[0008] S2, fixing the electromagnetic treatment fixture holding the TC4 titanium alloy weldment in the electromagnetic treatment device;

[0009] S3, setting pulse electric field parameters and electromagnetic coupling parameters of the electromagnetic processing device;

[0010] S4, based on the set pulse electric field parameters, applying a pulse electric field with a square wave waveform to the TC4 titanium alloy weldment alone;

[0011] S5. Based on the set electromagnetic coupling parameters, a pulse electric field and a pulse magnetic field with a triangular waveform are simultaneously applied to the TC4 titanium alloy weldment after the pulse electric field treatment in S4.

[0012] Furthermore, the electromagnetic processing fixture in S1 includes two identical and oppositely arranged L-shaped copper plates, and interlayers are opened on the edge ends of the two L-shaped copper plates; the two ends of the TC4 titanium alloy weldment are respectively embedded in the interlayers in the two L-shaped copper plates; the interlayer is provided with positioning holes, and the TC4 titanium alloy weldment is fixed between the two L-shaped copper plates by the cooperation of positioning bolts and the positioning holes, and the weld part of the TC4 titanium alloy weldment is exposed to the air.

[0013] Furthermore, in S2, two L-shaped copper plates are respectively connected between two electrodes in the electromagnetic processing device, that is, both ends of the TC4 titanium alloy weldment are respectively connected to the pulse electric field circuit, and then the TC4 titanium alloy weldment is placed in the working chamber of the multi-turn excitation coil in the electromagnetic processing device.

[0014] Furthermore, the pulse electric field parameters in S3 include:

[0015] The pulse electric field voltage is 2.5V-3.5V, the pulse waveform is a square wave, and the action time is 300s;

[0016] Electromagnetic coupling parameters include:

[0017] The pulse magnetic field intensity is 0.5T-2T; the pulse electric field voltage is 0.5V-2V, the waveform is a triangle wave, and the electromagnetic coupling time is 5-7 minutes.

[0018] Furthermore, the pulse electric field parameters of the TC4 titanium alloy weldment with the process parameters of post-weld heat treatment at 510°C / 2h include:

[0019] The frequency of the pulse power AC power supply in the pulse electric field circuit charging the capacitor is 50Hz;

[0020] The pulse electric field voltage is 3V, the pulse waveform is square wave, and the current density is 58A / mm 2 The frequency of a single electric pulse is 10 Hz, the number of pulses in a single group is 1, and there is a gap of 500 ms after each pulse group is applied, for a total of 500 pulse groups.

[0021] Furthermore, the electromagnetic coupling parameters of the TC4 titanium alloy weldment with a post-weld heat treatment process parameter of 510°C / 2h include:

[0022] The frequency of the pulse power AC power supply in the pulse electric field circuit charging the capacitor is 50Hz;

[0023] The pulse electric field voltage is 0.8V, the pulse waveform is a triangle wave, and the current density is 15.01A / mm 2 The frequency of a single electric pulse is 100 Hz, the number of pulses in a single group is 15, and there is a 0.1s interval after each pulse group is applied, for a total of 25 pulse groups;

[0024] The pulse magnetic field intensity is 1T, the action time of a single magnetic pulse is 10s, there is a 1s interval after each magnetic pulse, and the total number of magnetic pulses is 30 times.

[0025] Furthermore, the pulse electric field parameters of the TC4 titanium alloy weldment with the process parameters of post-weld heat treatment at 700°C / 1.5h include:

[0026] The frequency of the pulse power AC power supply in the pulse electric field circuit charging the capacitor is 50Hz;

[0027] The pulse electric field voltage is 3.2V, the pulse waveform is square wave, and the current density is 64A / mm 2 The frequency of a single electric pulse is 10 Hz, the number of pulses in a single group is 1, and there is a gap of 500 ms after each pulse group is applied, for a total of 500 pulse groups.

[0028] Furthermore, the electromagnetic coupling parameters of the TC4 titanium alloy weldment with the process parameters of post-weld heat treatment of 700°C / 1.5h include:

[0029] The frequency of the pulse power AC power supply in the pulse electric field circuit charging the capacitor is 50Hz;

[0030] The pulse electric field voltage is 0.7V, the pulse waveform is a triangle wave, and the current density is 14.05A / mm 2 The frequency of a single electric pulse is 100 Hz, the number of pulses in a single group is 15, and there is a 0.1s interval after each pulse group is applied, for a total of 25 pulse groups;

[0031] The pulse magnetic field intensity is 1T, the action time of a single magnetic pulse is 10s, there is a 1s interval after each magnetic pulse, and the total number of magnetic pulses is 30 times.

[0032] Furthermore, in S4, based on the set pulse electric field parameters, the pulse power AC power supply in the pulse electric field circuit is turned on to apply a pulse electric field to the TC4 titanium alloy weldment. The total action time is 300 s. After the pulse electric field is applied, the power is turned off and the TC4 titanium alloy weldment is cooled to room temperature.

[0033] Furthermore, in S5, based on the set electromagnetic coupling parameters, the pulse electric field circuit and the pulse magnetic field circuit are turned on, and the pulse magnetic field and the pulse electric field are applied to the TC4 titanium alloy weldment that has been treated with the pulse electric field. The total action time is 420 seconds. After the treatment is completed, the power is turned off and the electromagnetic treatment fixture is taken out to remove the TC4 titanium alloy weldment.

[0034] The method for improving the corrosion resistance of the weld of titanium alloy laser welded parts by using a pulse electromagnetic field provided by the present invention has the following beneficial effects:

[0035] 1. The present invention sets the intensity, voltage, waveform, current density and processing time of the pulse electric field and pulse magnetic field to ensure uniform processing and optimization effect of the weld of the welded parts. The treated weld of the TC4 titanium alloy welded parts shows significant improvement in corrosion resistance after heat treatment, effectively extending the service life of the material.

[0036] 2. The present invention directly processes the weld area and has the characteristics of high efficiency, energy saving and environmental protection. By optimizing the weld microstructure and component distribution, etc., the corrosion resistance of the weld is significantly improved, the service life of the weld is extended, and the simplicity and economy of the treatment process are maintained.

[0037] 3. The present invention adopts the multi-physical field coupling technology of pulsed electric field and pulsed magnetic field to directly apply an electromagnetic field to the weld of the welded part, thereby effectively improving the internal defects in the weld area without changing the dimensional accuracy of the welded part; on the other hand, through the extremely short electric field action time and the mixed pulse mode of different waveforms, it not only effectively avoids the phase change behavior caused by the thermal effect of Joule heat brought by the current, reduces the impact on the welded part, but also eliminates the defects and microcracks inside the welded part, improves its overall strength, and makes the stress distribution inside the welded part more uniform, reduces stress concentration, and thus improves the corrosion resistance of the welded part.

[0038] 4. Reduce residual stress. The present invention reduces or redistributes residual stress in the material to reduce the tendency of corrosion cracking. In particular, in stress corrosion cracking (SCC) sensitive materials, residual compressive stress can slow down the initiation and propagation of cracks, thereby improving the crack resistance of the material in a corrosive environment.

[0039] 5. Promote vacancy and atomic diffusion. Improving vacancy defects and atomic diffusion inside the material can promote the formation of a more uniform and dense crystal structure and reduce potential sources of corrosion starting points (defects and inclusions).

[0040] 6. Peak stress relaxation. The relaxation of peak stress can reduce the energy state of local areas of the material, reduce the possibility of corrosive media gathering in these high-energy areas, and slow down the formation of local corrosion.

[0041] 7. Regulation of dislocation and plastic deformation: Influencing the dislocation dynamics and plastic deformation behavior of materials through electromagnetically induced vibrations, leading to the redistribution of dislocation density in the crystal structure, as well as the improvement of grain boundaries and phase boundaries, helps to improve the corrosion resistance of materials.

[0042] 8. Microstructure optimization: Electromagnetic treatment will promote the optimization of the material's microstructure, including grain refinement and uniform distribution of the second phase. These structural optimizations help improve the stability of the material in corrosive media. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] Figure 1The present invention is a flow chart of the method for improving the corrosion resistance of the weld of titanium alloy laser welded parts by using a pulsed electromagnetic field.

[0044] Figure 2 It is a schematic diagram of the structure of the electromagnetic processing fixture of the present invention.

[0045] Figure 3 Schematic diagram of the circuit of the electromagnetic processing device of the present invention. DETAILED DESCRIPTION

[0046] The specific implementation modes of the present invention are described below so that those skilled in the art can understand the present invention. However, it should be clear that the present invention is not limited to the scope of the specific implementation modes. For those of ordinary skill in the art, as long as various changes are within the spirit and scope of the present invention as defined and determined by the attached claims, these changes are obvious, and all inventions and creations utilizing the concept of the present invention are protected.

[0047] Example 1

[0048] This embodiment provides a method for improving the corrosion resistance of titanium alloy laser welded parts by pulse electromagnetic field. Figure 1 , which specifically includes the following steps:

[0049] Step S1, using an electromagnetic processing fixture to clamp the TC4 titanium alloy welded part to be processed;

[0050] Specifically, refer to Figure 2 The electromagnetic processing fixture of this embodiment includes two identical and oppositely arranged L-shaped copper plates, and interlayers are opened on the edge ends of the two L-shaped copper plates. The two ends of the TC4 titanium alloy weldment are respectively embedded in the interlayers of the two L-shaped copper plates. Positioning holes are provided on the interlayer, and the positioning holes run through the entire copper plate. When fixing the TC4 titanium alloy weldment, the TC4 titanium alloy weldment is fixed between the two L-shaped copper plates by the cooperation of the positioning bolts and the positioning holes, and the weld part of the TC4 titanium alloy weldment is exposed to the air.

[0051] Step S2, fixing the electromagnetic treatment fixture holding the TC4 titanium alloy weldment in an electromagnetic treatment device;

[0052] Specifically, two L-shaped copper plates are connected between two electrodes in the electromagnetic processing device, that is, both ends of the TC4 titanium alloy weldment are connected to the pulse electric field circuit respectively, and then the TC4 titanium alloy weldment is placed in the working chamber of the multi-turn excitation coil in the electromagnetic processing device.

[0053] Step S3, setting pulse electric field parameters and electromagnetic coupling parameters of the electromagnetic processing device;

[0054] Among them, the pulse electric field parameters include:

[0055] The pulse electric field voltage is 2.5V-3.5V, the pulse waveform is a square wave, and the action time is 300s;

[0056] Electromagnetic coupling parameters include:

[0057] The pulse magnetic field intensity is 0.5T-2T; the pulse electric field voltage is 0.5V-2V, the waveform is a triangle wave, and the electromagnetic coupling time is 5-7 minutes.

[0058] In this embodiment, an electromagnetic treatment device is used to first apply a pulse electric field with a square wave waveform to the weldment, and then a pulse electric field and a pulse magnetic field with a triangular wave waveform are applied simultaneously. With this design, on the one hand, a strong electric shock is generated by using the pulse electric field with a square wave waveform. In the first step, a large Joule heat is generated by means of the "tip effect" when the pulse current flows through the defect to effectively eliminate the defects and microcracks inside the TC4 titanium alloy weldment material. However, under the large electric shock, stress concentration will occur in the material; on the other hand, in the second step of electromagnetic coupling, since the voltage of the triangular wave pulse electric field rises and falls linearly and the change is relatively gentle, the electroplasticity caused by it will promote the vacancy defects and atomic diffusion behavior in the material, relax the peak stress, and thus make the stress distribution inside the TC4 titanium alloy weldment material more uniform and reduce stress concentration; its coupling with the pulse magnetic field can use the magnetoplasticity of the pulse magnetic field to further eliminate the internal structural defects of the weld of the weldment, make the stress distribution more uniform, and optimize the microstructure.

[0059] Step S4, based on the set pulse electric field parameters, applying a pulse electric field with a square wave waveform to the TC4 titanium alloy weldment alone;

[0060] Specifically, refer to Figure 3 , turn on the pulse power AC power supply in the pulse electric field circuit, apply the pulse electric field to the TC4 titanium alloy weldment, the total action time is 300s, after the pulse electric field is applied, turn off the power and wait for the TC4 titanium alloy weldment to cool to room temperature.

[0061] Step S5: Based on the set electromagnetic coupling parameters, a pulse electric field and a pulse magnetic field having a triangular waveform are simultaneously applied to the TC4 titanium alloy weldment after the pulse electric field treatment in S4.

[0062] Specifically, refer to Figure 3 , turn on the pulse electric field circuit and the pulse magnetic field circuit, and simultaneously apply the pulse magnetic field and the pulse electric field to the TC4 titanium alloy weldment treated by the pulse electric field. The total action time is 420s. After the treatment is completed, turn off the power and take out the electromagnetic treatment fixture to remove the TC4 titanium alloy weldment.

[0063] Example 2

[0064] This embodiment uses a TC4 titanium alloy welded part with a post-weld heat treatment process parameter of 510°C / 2h as a sample object, and provides a method for improving the corrosion resistance of a titanium alloy laser welded part weld by using a pulsed electromagnetic field, which specifically includes the following steps:

[0065] Step A1, using an electromagnetic processing fixture to clamp the TC4 titanium alloy welded part to be processed;

[0066] Specifically, refer to Figure 2 The electromagnetic processing fixture of this embodiment includes two identical and oppositely arranged L-shaped copper plates, and interlayers are opened on the edge ends of the two L-shaped copper plates. The two ends of the TC4 titanium alloy weldment are respectively embedded in the interlayers of the two L-shaped copper plates. Positioning holes are provided on the interlayer, and the positioning holes run through the entire copper plate. When fixing the TC4 titanium alloy weldment, the TC4 titanium alloy weldment is fixed between the two L-shaped copper plates by the cooperation of the positioning bolts and the positioning holes, and the weld part of the TC4 titanium alloy weldment is exposed to the air.

[0067] Step A2, fixing the electromagnetic treatment fixture holding the TC4 titanium alloy weldment in the electromagnetic treatment device;

[0068] Specifically, two L-shaped copper plates are connected between two electrodes in the electromagnetic processing device, that is, both ends of the TC4 titanium alloy weldment are connected to the pulse electric field circuit respectively, and then the TC4 titanium alloy weldment is placed in the working chamber of the multi-turn excitation coil in the electromagnetic processing device.

[0069] Step A3, setting pulse electric field parameters and electromagnetic coupling parameters of the electromagnetic processing device;

[0070] Among them, the pulse electric field parameters include:

[0071] The frequency of the pulse power AC power supply in the pulse electric field circuit charging the capacitor is 50Hz;

[0072] The pulse electric field voltage is 3V, the pulse waveform is square wave, and the current density is 58A / mm 2 The frequency of a single electric pulse is 10 Hz, the number of pulses in a single group is 1, and there is a gap of 500 ms after each pulse group is applied, for a total of 500 pulse groups.

[0073] Electromagnetic coupling parameters include:

[0074] The frequency of the pulse power AC power supply in the pulse electric field circuit charging the capacitor is 50Hz;

[0075] The pulse electric field voltage is 0.8V, the pulse waveform is a triangle wave, and the current density is 15.01A / mm 2The frequency of a single electric pulse is 100 Hz, the number of pulses in a single group is 15, and there is a 0.1s interval after each pulse group is applied, for a total of 25 pulse groups;

[0076] The pulse magnetic field intensity is 1T, the action time of a single magnetic pulse is 10s, there is a 1s interval after each magnetic pulse, and the total number of magnetic pulses is 30 times.

[0077] Step A4, based on the set pulse electric field parameters, applying a pulse electric field with a square wave waveform to the TC4 titanium alloy weldment alone;

[0078] Specifically, refer to Figure 3 , turn on the pulse power AC power supply in the pulse electric field circuit, apply the pulse electric field to the TC4 titanium alloy weldment, the total action time is 300s, after the pulse electric field is applied, turn off the power and wait for the TC4 titanium alloy weldment to cool to room temperature.

[0079] Step A5: Based on the set electromagnetic coupling parameters, a pulse electric field and a pulse magnetic field having a triangular waveform are simultaneously applied to the TC4 titanium alloy weldment after the pulse electric field treatment in S4.

[0080] Specifically, refer to Figure 3 , turn on the pulse electric field circuit and the pulse magnetic field circuit, and apply the pulse magnetic field and the pulse electric field to the TC4 titanium alloy weldment treated with the pulse electric field at the same time. The total action time is 420s. After the treatment is completed, turn off the power and take out the electromagnetic treatment fixture, remove the TC4 titanium alloy weldment, and perform electromagnetic coupling strengthening treatment on the welds of paired weldments.

[0081] Example 3

[0082] This embodiment uses a TC4 titanium alloy welded part with a post-weld heat treatment process parameter of 700°C / 1.5h as a sample object, and provides a method for improving the corrosion resistance of a titanium alloy laser welded part weld using a pulsed electromagnetic field, which specifically includes the following steps:

[0083] Step B1, using an electromagnetic processing fixture to clamp the TC4 titanium alloy welded part to be processed;

[0084] Specifically, refer to Figure 2 The electromagnetic processing fixture of this embodiment includes two identical and oppositely arranged L-shaped copper plates, and interlayers are opened on the edge ends of the two L-shaped copper plates. The two ends of the TC4 titanium alloy weldment are respectively embedded in the interlayers of the two L-shaped copper plates. Positioning holes are provided on the interlayer, and the positioning holes run through the entire copper plate. When fixing the TC4 titanium alloy weldment, the TC4 titanium alloy weldment is fixed between the two L-shaped copper plates by the cooperation of the positioning bolts and the positioning holes, and the weld part of the TC4 titanium alloy weldment is exposed to the air.

[0085] Step B2, fixing the electromagnetic treatment fixture holding the TC4 titanium alloy weldment in the electromagnetic treatment device;

[0086] Specifically, two L-shaped copper plates are connected between two electrodes in the electromagnetic processing device, that is, both ends of the TC4 titanium alloy weldment are connected to the pulse electric field circuit respectively, and then the TC4 titanium alloy weldment is placed in the working chamber of the multi-turn excitation coil in the electromagnetic processing device.

[0087] Step B3, setting the pulse electric field parameters and electromagnetic coupling parameters of the electromagnetic processing device;

[0088] Among them, the pulse electric field parameters include:

[0089] The frequency of the pulse power AC power supply in the pulse electric field circuit charging the capacitor is 50Hz;

[0090] The pulse electric field voltage is 3.2V, the pulse waveform is square wave, and the current density is 64A / mm 2 The frequency of a single electric pulse is 10 Hz, the number of pulses in a single group is 1, and there is a gap of 500 ms after each pulse group is applied, for a total of 500 pulse groups.

[0091] Electromagnetic coupling parameters include:

[0092] The frequency of the pulse power AC power supply in the pulse electric field circuit charging the capacitor is 50Hz;

[0093] The pulse electric field voltage is 0.7V, the pulse waveform is a triangle wave, and the current density is 14.05A / mm 2 The frequency of a single electric pulse is 100 Hz, the number of pulses in a single group is 15, and there is a 0.1s interval after each pulse group is applied, for a total of 25 pulse groups;

[0094] The pulse magnetic field intensity is 1T, the action time of a single magnetic pulse is 10s, there is a 1s interval after each magnetic pulse, and the total number of magnetic pulses is 30 times.

[0095] Step B4, based on the set pulse electric field parameters, applying a pulse electric field with a square wave waveform to the TC4 titanium alloy weldment alone;

[0096] Specifically, refer to Figure 3 , turn on the pulse power AC power supply in the pulse electric field circuit, apply the pulse electric field to the TC4 titanium alloy weldment, the total action time is 300s, after the pulse electric field is applied, turn off the power and wait for the TC4 titanium alloy weldment to cool to room temperature.

[0097] Step B5: Based on the set electromagnetic coupling parameters, a pulse electric field and a pulse magnetic field with a triangular waveform are simultaneously applied to the TC4 titanium alloy weldment after the pulse electric field treatment in S4.

[0098] Specifically, refer to Figure 3 , turn on the pulse electric field circuit and the pulse magnetic field circuit, and apply the pulse magnetic field and the pulse electric field to the TC4 titanium alloy weldment treated with the pulse electric field at the same time. The total action time is 420s. After the treatment is completed, turn off the power and take out the electromagnetic treatment fixture, remove the TC4 titanium alloy weldment, and perform electromagnetic coupling strengthening treatment on the welds of paired weldments.

[0099] The present invention conducted electrochemical corrosion tests on the weld seams of TC4 titanium alloy welded parts that were treated with pulse electric field and electromagnetic coupling in sequence and the weld seams of untreated welded parts under the same test conditions. The results showed that the weld seams of the treated welded parts exhibited lower corrosion rate and higher polarization resistance. Specific data showed that the corrosion current density of the weld seams of the welded parts that were treated with pulse electric field and electromagnetic coupling in sequence was reduced to 0.6μA / cm 2 , while the weld of the untreated weld is 1.2μA / cm 2 This shows that the corrosion resistance of the weld of the welded parts treated with pulse electric field and electromagnetic coupling is improved by 50%, which significantly improves the corrosion resistance of the weld area, which helps to extend the service life of structural components in corrosive environments.

[0100] In the pulsed electric field and electromagnetic coupling treatment external field provided by the electromagnetic treatment device, pulsed electric fields of different waveforms and pulsed magnetic fields act together on the TC4 titanium alloy weldment, resulting in microscopic changes in the metal structure of the weld zone. The mixed electric shock of different waveforms improves the defects inside the material and makes its stress distribution more uniform. The skin effect generated by the pulsed electric field heats the weld zone, and the non-uniform temperature distribution further triggers changes in the microstructure, such as grain refinement, which helps to improve the corrosion resistance of the material. In addition, the intervention of the magnetic field changes the energy state of the electrons, thereby reducing the resistance between atoms and enhancing the corrosion resistance of the metal. Through this composite electromagnetic effect, the chemical uniformity and density of the weld zone are significantly improved, reducing the corrosion rate and corrosion penetration ability of the material. Therefore, the welds of the welded parts that have been treated successively by pulsed electric fields and electromagnetic coupling show lower corrosion rates and stronger surface protection effects in corrosive media, significantly extending their service life in harsh environments.

[0101] Although the specific implementation of the invention is described in detail in conjunction with the drawings, it should not be understood as limiting the scope of protection of this patent. Within the scope described in the claims, various modifications and variations that can be made by those skilled in the art without creative work still fall within the scope of protection of this patent.

Claims

1. A method for improving the corrosion resistance of titanium alloy laser welded parts by using a pulsed electromagnetic field, characterized in that: The following steps are involved: S1. Use electromagnetic treatment fixture to clamp the TC4 titanium alloy welded parts to be processed; S2, fixing the electromagnetic treatment fixture holding the TC4 titanium alloy weldment in the electromagnetic treatment device; S3, setting pulse electric field parameters and electromagnetic coupling parameters of the electromagnetic processing device; S4, based on the set pulse electric field parameters, applying a pulse electric field with a square wave waveform to the TC4 titanium alloy weldment alone; S5. Based on the set electromagnetic coupling parameters, a pulse electric field and a pulse magnetic field with a triangular waveform are simultaneously applied to the TC4 titanium alloy weldment after the pulse electric field treatment in S4.

2. The method for improving the corrosion resistance of titanium alloy laser welded parts by using pulsed electromagnetic field according to claim 1 is characterized in that: The electromagnetic processing fixture in S1 includes two identical and oppositely arranged L-shaped copper plates, and interlayers are provided on the edge ends of the two L-shaped copper plates; the two ends of the TC4 titanium alloy weldment are respectively embedded in the interlayers of the two L-shaped copper plates; the interlayer is provided with positioning holes, and the TC4 titanium alloy weldment is fixed between the two L-shaped copper plates by the cooperation of positioning bolts and the positioning holes, and the weld part of the TC4 titanium alloy weldment is exposed to the air.

3. The method for improving the corrosion resistance of titanium alloy laser welded parts by using pulsed electromagnetic field according to claim 2 is characterized in that: In S2, two L-shaped copper plates are respectively connected between two electrodes in the electromagnetic processing device, that is, both ends of the TC4 titanium alloy weldment are respectively connected to the pulse electric field circuit, and then the TC4 titanium alloy weldment is placed in the working chamber of the multi-turn excitation coil in the electromagnetic processing device.

4. The method for improving the corrosion resistance of titanium alloy laser welded parts by using pulsed electromagnetic field according to claim 1 is characterized in that: The pulse electric field parameters in S3 include: The pulse electric field voltage is 2.5V-3.5V, the pulse waveform is a square wave, and the action time is 300s; Electromagnetic coupling parameters include: The pulse magnetic field intensity is 0.5T-2T; the pulse electric field voltage is 0.5V-2V, the waveform is a triangle wave, and the electromagnetic coupling time is 5-7 minutes.

5. The method for improving the corrosion resistance of titanium alloy laser welded parts by using pulse electromagnetic field according to claim 4 is characterized in that: The pulse electric field parameters of TC4 titanium alloy welded parts with post-weld heat treatment process parameters of 510℃ / 2h include: The frequency of the pulse power AC power supply in the pulse electric field circuit charging the capacitor is 50Hz; The pulse electric field voltage is 3V, the pulse waveform is square wave, and the current density is 58A / mm 2 The frequency of a single electric pulse is 10 Hz, the number of pulses in a single group is 1, and there is a gap of 500 ms after each pulse group is applied, for a total of 500 pulse groups.

6. The method for improving the corrosion resistance of titanium alloy laser welded parts by using pulse electromagnetic field according to claim 4 is characterized in that: The electromagnetic coupling parameters of TC4 titanium alloy welded parts with post-weld heat treatment process parameters of 510℃ / 2h include: The frequency of the pulse power AC power supply in the pulse electric field circuit charging the capacitor is 50Hz; The pulse electric field voltage is 0.8V, the pulse waveform is a triangle wave, and the current density is 15.01A / mm 2 The frequency of a single electric pulse is 100 Hz, the number of pulses in a single group is 15, and there is a 0.1s interval after each pulse group is applied, for a total of 25 pulse groups; The pulse magnetic field intensity is 1T, the action time of a single magnetic pulse is 10s, there is a 1s interval after each magnetic pulse, and the total number of magnetic pulses is 30 times.

7. The method for improving the corrosion resistance of titanium alloy laser welded parts by using pulsed electromagnetic field according to claim 4 is characterized in that: The pulse electric field parameters of TC4 titanium alloy welded parts with post-weld heat treatment process parameters of 700℃ / 1.5h include: The frequency of the pulse power AC power supply in the pulse electric field circuit charging the capacitor is 50Hz; The pulse electric field voltage is 3.2V, the pulse waveform is square wave, and the current density is 64A / mm 2 The frequency of a single electric pulse is 10 Hz, the number of pulses in a single group is 1, and there is a gap of 500 ms after each pulse group is applied, for a total of 500 pulse groups.

8. The method for improving the corrosion resistance of titanium alloy laser welded parts by using pulse electromagnetic field according to claim 4 is characterized in that: The electromagnetic coupling parameters of TC4 titanium alloy welded parts with post-weld heat treatment process parameters of 700℃ / 1.5h include: The frequency of the pulse power AC power supply in the pulse electric field circuit charging the capacitor is 50Hz; The pulse electric field voltage is 0.7V, the pulse waveform is a triangle wave, and the current density is 14.05A / mm 2 The frequency of a single electric pulse is 100 Hz, the number of pulses in a single group is 15, and there is a 0.1s interval after each pulse group is applied, for a total of 25 pulse groups; The pulse magnetic field intensity is 1T, the action time of a single magnetic pulse is 10s, there is a 1s interval after each magnetic pulse, and the total number of magnetic pulses is 30 times.

9. The method for improving the corrosion resistance of titanium alloy laser welded parts by using pulsed electromagnetic field according to claim 4 is characterized in that: In the S4, based on the set pulse electric field parameters, the pulse power AC power supply in the pulse electric field circuit is turned on to apply the pulse electric field to the TC4 titanium alloy weldment. The total action time is 300s. After the pulse electric field is applied, the power is turned off and the TC4 titanium alloy weldment is cooled to room temperature.

10. The method for improving the corrosion resistance of titanium alloy laser welded parts by using pulsed electromagnetic field according to claim 4, characterized in that: In S5, based on the set electromagnetic coupling parameters, the pulse electric field circuit and the pulse magnetic field circuit are turned on, and the pulse magnetic field and the pulse electric field are applied to the TC4 titanium alloy weldment treated by the pulse electric field at the same time. The total action time is 420s. After the treatment is completed, the power is turned off and the electromagnetic treatment fixture is taken out to remove the TC4 titanium alloy weldment.

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