Coaxial low pressure pulsed magnetic field welding apparatus and method

Abstract

The present application belongs to the technical field of metal material welding equipment, and discloses a coaxial low-pressure pulse magnetic field welding device and method. The device comprises a pulse magnetic field power supply, an excitation coil, a coil support, a welding power supply and a welding torch. The excitation coil is arranged at one end of the welding torch close to the molten pool, so as to ensure that the central magnetic line of the pulse magnetic field is coaxial and parallel to the central line of the electric arc during welding. The coil support is used for fixing the excitation coil. The excitation coil is connected with the pulse magnetic field power supply through a wire. The welding torch is connected with the welding power supply through a wire. By adjusting the parameters of the pulse magnetic field power supply and matching the welding parameters, the present application can effectively control the welding process, and obtain a high-quality welded joint with reduced macroscopic defects and refined microstructure.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of metal material welding equipment and technology, and more particularly to a coaxial low-voltage pulsed magnetic field welding device and method. BACKGROUND

[0002] In the process of arc welding of metal materials, the direct stirring effect of pulsed magnetic field on the welding pool can be used to change the solidification structure of the welded joint, and it is possible to change the shape of the arc by the action of the magnetic field to affect the welding process, thereby ultimately achieving effective control of the weld performance.

[0003] In previous related research, various pulsed magnetic field welding devices and related methods have been developed. The relative position of the excitation coil to the welding arc and the molten pool is different in different technical solutions, including setting the magnetic field on both sides of the molten pool, setting the magnetic field below the molten pool, and using the interaction of pulsed current and permanent magnet to generate pulsed magnetic field (it is necessary to use a wire to connect the welding electrode and the welding base material, and to form a loop through the arc), thereby achieving magnetic field control of the welding process.

[0004] However, actual welding is usually accompanied by frequent arc starting, arc moving, arc collecting, etc. The distance between the welding tungsten electrode and the molten pool changes at any time, and the existing pulsed magnetic field welding technology cannot solve the problem of accurate matching of the pulsed magnetic field and the welding point position, the shape of the arc under the action of the pulsed magnetic field changes at any time, causing the action area to be unstable, which easily causes unstable quality control of the welded joint. In addition, in some technologies, the excitation coil of the pulsed magnetic field needs to be additionally equipped with a power device to move the coil with the welding pool at any time, which has problems such as equipment cost and control accuracy. SUMMARY

[0005] The purpose of the present application is to solve the problems of existing pulsed magnetic field welding technology, such as the difficulty in accurately matching the magnetic field and the position of the molten pool, and the instability of the shape of the arc and the action area in the pulsed magnetic field, and to provide a coaxial low-voltage pulsed magnetic field welding device and method. By adjusting the parameters of the pulsed magnetic field power supply and matching the welding parameters, the present application can effectively control the welding process, and obtain a high-quality welded joint with reduced macroscopic defects and refined microstructure.

[0006] In order to achieve the above-mentioned purpose, the present application provides a coaxial low-voltage pulsed magnetic field welding device, which comprises a pulsed magnetic field power supply, an excitation coil, a coil support, a welding power supply and a welding torch.

[0007] The excitation coil is arranged at one end of the welding torch close to the molten pool, so as to ensure that the central magnetic line of the pulsed magnetic field is coaxial and parallel to the central line of the arc during welding.

[0008] The coil support is used to fix the excitation coil.

[0009] The excitation coil is connected with the pulse magnetic field power source through a wire; and the welding gun is connected with the welding power source through a wire.

[0010] According to the application, preferably, the coil support is an austenitic non-magnetic stainless steel coil support.

[0011] In the application, the excitation coil is manufactured according to different welding gun specifications, and the welding power source and the welding gun are selected according to different welding occasions. According to the application, preferably, the welding gun is a TIG welding gun; and the welding power source is Panasonic YC-400TX4 and / or Panasonic YC-500WX4.

[0012] According to the application, preferably, the device further comprises an argon cylinder and a cooling water tank.

[0013] Another aspect of the application provides a coaxial low-voltage pulse magnetic field welding method, which adopts the device and comprises the following steps:

[0014] During welding, the pulse magnetic field power source is turned on, the pulse magnetic field power source parameters are adjusted to obtain a pulse magnetic field; the welding power source is turned on, the welding parameters are matched with the corresponding pulse magnetic field, and the welding process is performed to obtain a welded joint.

[0015] According to the application, preferably, the pulse magnetic field power source is controlled by a PLC circuit.

[0016] According to the application, preferably, the pulse magnetic field power source parameters include excitation voltage, excitation current and excitation frequency.

[0017] According to the application, preferably, the excitation voltage is 0-300V, the excitation current is 0-100A, and the excitation frequency is 0-25Hz.

[0018] According to the application, preferably, the welding parameters include welding current, welding voltage and welding speed.

[0019] According to the application, preferably, the welding current is 60-120A, the welding voltage is 4-10V, and the welding speed is 2-6mm / min.

[0020] The technical scheme of the application has the following beneficial effects:

[0021] 1) The core part of the device of the application is that an excitation coil is added to the welding gun, so that the central magnetic force line of the pulse magnetic field is coaxial and parallel with the central line of the electric arc during welding, i.e., the magnetic force line direction is parallel with the current direction, so that the electric arc is hardly affected by the magnetic field force, which can ensure that the pulse magnetic field does not affect the transition state of the welding arc, thereby ensuring the stability of the welding process and being conducive to the actual operation of the welder.

[0022] 2) In the process of using the device of the present application, there is no need to detect the position of the welding molten pool at any time, and there is no need for additional power devices to control the movement of the excitation coil.

[0023] 3) The device of the present application can maximize the use of magnetic field energy acting on the molten pool by controlling the close contact of the coil with the molten pool, and the magnetic field effect is obvious, thereby realizing effective control of the welding process.

[0024] 4) The excitation coil of the present application is small in size and light in weight, and can be easily and flexibly operated by hand, and can be used without special training or long practice, which is convenient for welders to operate.

[0025] 5) Because the excitation voltage is low, it is safe to use and will not pose an electric shock danger to the welder.

[0026] 6) The present application can realize effective control of the welding process by adjusting the pulse magnetic field power parameters and matching with the welding parameters, and obtain high-quality welded joints with reduced macroscopic defects and refined microstructure.

[0027] 7) The device of the present application has simple structure, low modification cost, flexible method and remarkable effect, and can be popularized to be used with various arc welding equipment, and is suitable for popularization and use in the fields of arc welding, surfacing, or arc additive manufacturing.

[0028] Other features and advantages of the present application will be described in detail in the following specific embodiments. BRIEF DESCRIPTION OF DRAWINGS

[0029] The above and other objects, features and advantages of the present application will become more apparent from the following detailed description when taken in conjunction with the accompanying drawings, in which like reference characters refer to like parts throughout the several views, and in which:

[0030] Figure 1 A schematic diagram of a coaxial low-voltage pulse magnetic field welding device provided by the present application is shown.

[0031] Figure 2 A nickel-based alloy surfacing layer cross-sectional macrostructure prepared by a coaxial low-voltage pulse magnetic field welding method provided by Example 1 of the present application is shown.

[0032] Figure 3 A nickel-based alloy weld microstructure prepared by a coaxial low-voltage pulse magnetic field welding method provided by Example 2 of the present application is shown.

[0033] Figure 4 A nickel-based alloy surfacing layer cross-sectional macrostructure prepared by a welding method without applying a pulse magnetic field provided by Comparative Example 1 of the present application is shown.

[0034] Figure 5 A nickel-based alloy weld microstructure prepared by a non-pulsed welding method provided by Comparative Example 2 of the present application is shown.

[0035] The reference signs are explained as follows:

[0036] 1 is a pulsed magnetic field power supply, 2 is an excitation coil, 3 is a coil support, 4 is a welding torch, 5 is a welding power supply, 6 is a welding workpiece, and 7 is a molten pool. DETAILED DESCRIPTION

[0037] The preferred embodiments of the present application will be described in more detail below. Although the preferred embodiments of the present application are described below, it should be understood that the present application can be implemented in various forms and should not be limited by the embodiments set forth herein. Rather, these embodiments are provided so that the present application will be thorough and complete, and will fully convey the scope of the present application to those skilled in the art.

[0038] Example 1

[0039] This embodiment provides a coaxial low-voltage pulsed magnetic field welding device, as shown in the figure, which includes a pulsed magnetic field power supply 1, an excitation coil 2, a coil support 3, a welding power supply 5, a welding torch 4, an argon cylinder (not shown), and a cooling water tank (not shown). Figure 1 The excitation coil 2 is arranged at one end of the welding torch 4 close to the molten pool 7, ensuring that the central magnetic line of the pulsed magnetic field is coaxial and parallel to the central line of the arc during welding.

[0040] The coil support 3 is used to fix the excitation coil 2.

[0041] The excitation coil 2 is connected to the pulsed magnetic field power supply 1 through a wire; the welding torch 4 is connected to the welding power supply 5 through a wire.

[0042] The welding torch 4 is also connected to the argon cylinder and the cooling water tank.

[0043] The coil support 3 is an austenitic non-magnetic stainless steel coil support.

[0044] The welding torch 4 used in this embodiment is a TIG welding torch; the welding power supply 5 is a Panasonic YC-400TX4.

[0045] The coaxial low-voltage pulsed magnetic field welding method using the device described in this embodiment includes the following steps, in which the welding workpiece 6 is a nickel-based alloy K4169 with a thickness of 10 mm, and a diameter of 1.6 mm ERNiFeCr-2 welding wire is used. The specific steps are as follows:

[0046]

[0047] ​S1: Place the welding workpiece on the welding experiment platform, connect the TIG welding torch with the excitation coil 2 with the welding power supply 5, argon cylinder and cooling water tank; connect the excitation coil 2 with the pulsed magnetic field power supply 1.

[0048] S2: Turn on the pulsed magnetic field power supply 1, set the excitation voltage to 100V, the excitation current to 18A and the excitation frequency to 10Hz, and at the same time, turn on the welding power supply, set the welding current to 85A, the welding voltage to 5.6V and the welding speed to 2.5-3.0mm / min, and use the above welding wire to carry out surfacing in an argon protective atmosphere.

[0049] After the welding is completed, observe the appearance and cross-section macrostructure of the surfacing layer, as shown in Figure 2

[0050] The surfacing sample prepared by the coaxial low-voltage pulsed magnetic field welding device and method in the embodiment is subjected to appearance detection, and the welding sample prepared by applying the pulsed magnetic field has no macroscopic defects such as surface pits, cracks, undercut or welding tumor, and the grain structure is obviously refined after the pulsed magnetic field is applied.

[0051] Example 2

[0052] The embodiment provides a coaxial low-voltage pulsed magnetic field welding device, and the difference between the embodiment and example 1 is only that the welding power supply 5 is a Panasonic YC-500WX4.

[0053] The coaxial low-voltage pulsed magnetic field welding method using the device in the embodiment is different from that in example 1 only in that:

[0054] The welding workpiece 6 is a nickel-based alloy K4169 with a thickness of 15mm, and a diameter of 2.0mm ERNiFeCr-2 welding wire is used;

[0055] The excitation voltage is set to 150V, the excitation current is set to 27A, and the excitation frequency is set to 7.5Hz;

[0056] The welding current is set to 110A, the welding voltage is set to 6.8V, and the welding speed is set to 2.8-3.2mm / min.

[0057] After the welding is completed, first observe the appearance of the weld, then cut along the direction perpendicular to the weld to prepare a metallographic sample, and observe the microstructure of the weld, as shown in Figure 3

[0058] The welding sample prepared by the coaxial low-voltage pulsed magnetic field welding device and method in the embodiment is subjected to macroscopic and microscopic observation, and the welding sample prepared by applying the pulsed magnetic field has no macroscopic defects such as oxidation or undercut, welding tumor and the like; metallographic analysis shows that the grain structure is significantly refined after the pulsed magnetic field is applied, and the average columnar grain length in the weld zone is about 465μm or so. ​​

[0059] Comparative Example 1

[0060] This comparative example provides a welding method, which is different from Example 1 in that no pulsed magnetic field is applied, and the cross-section macrostructure of the surfacing layer is shown in Figure 4

[0061] Comparative Example 2

[0062] This comparative example provides a welding method, which is different from Example 2 in that no pulsed magnetic field is applied, and the microstructure of the weld is shown in Figure 5

[0063] The above has described various embodiments of the present application, and the above description is exemplary, not exhaustive, and is not limited to the disclosed embodiments. Many modifications and changes are obvious to those skilled in the art without departing from the scope and spirit of the described embodiments.​​

Claims

1. A coaxial low pressure pulsed magnetic field welding method, characterized by, The device used in the method comprises a pulsed magnetic field power supply, an excitation coil, a coil support, a welding power supply and a welding torch. The excitation coil is arranged at one end of the welding torch close to the molten pool, so as to ensure that the central magnetic line of the pulsed magnetic field is coaxial and parallel to the central line of the electric arc during welding. The coil support is used for fixing the excitation coil. The excitation coil is connected to the pulsed magnetic field power supply through a wire, and the welding torch is connected to the welding power supply through a wire. The method comprises the following steps: During welding, the pulsed magnetic field power supply is turned on, the pulsed magnetic field power supply parameters are adjusted, and a pulsed magnetic field is obtained. The welding power supply is turned on, the welding parameters are matched with the corresponding pulsed magnetic field, the welding process is carried out, and a welded joint is obtained. The pulsed magnetic field power supply parameters comprise excitation voltage, excitation current and excitation frequency; the excitation voltage is 0-300 V, the excitation current is 0-100 A, and the excitation frequency is 0-25 Hz. The welding parameters comprise welding current, welding voltage and welding speed; the welding current is 60-120 A, the welding voltage is 4-10 V, and the welding speed is 2-6 mm / min.

2. The coaxial low-pressure pulsed magnetic field welding method of claim 1, wherein, The coil support is an austenitic non-magnetic stainless steel coil support.

3. The coaxial low-pressure pulsed magnetic field welding method according to claim 1, wherein, The welding torch is a TIG welding torch. The welding power supply is Panasonic YC-400TX4 and / or Panasonic YC-500WX4.

4. The coaxial low-pressure pulsed magnetic field welding method of claim 1, wherein, The device further comprises an argon cylinder and a cooling water tank.

5. The coaxial low-pressure pulsed magnetic field welding method of claim 1, wherein, The pulsed magnetic field power supply is controlled by a PLC circuit.

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