CN115555689A - Electric arc surface cladding method under vacuum condition - Google Patents

Electric arc surface cladding method under vacuum condition Download PDF

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Publication number
CN115555689A
CN115555689A CN202211308275.2A CN202211308275A CN115555689A CN 115555689 A CN115555689 A CN 115555689A CN 202211308275 A CN202211308275 A CN 202211308275A CN 115555689 A CN115555689 A CN 115555689A
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China
Prior art keywords
welding gun
welding
vacuum
arc
gas
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CN202211308275.2A
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Chinese (zh)
Inventor
张凌峰
王飞
刘红兵
王基尧
赵克勇
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Huazhi Welding Technology Suzhou Co ltd
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Huazhi Welding Technology Suzhou Co ltd
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Priority to CN202211308275.2A priority Critical patent/CN115555689A/en
Publication of CN115555689A publication Critical patent/CN115555689A/en
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    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
    • B23K—SOLDERING OR UNSOLDERING; WELDING; CLADDING OR PLATING BY SOLDERING OR WELDING; CUTTING BY APPLYING HEAT LOCALLY, e.g. FLAME CUTTING; WORKING BY LASER BEAM
    • B23K9/00—Arc welding or cutting
    • B23K9/16—Arc welding or cutting making use of shielding gas
    • B23K9/173—Arc welding or cutting making use of shielding gas and of a consumable electrode
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
    • B23K—SOLDERING OR UNSOLDERING; WELDING; CLADDING OR PLATING BY SOLDERING OR WELDING; CUTTING BY APPLYING HEAT LOCALLY, e.g. FLAME CUTTING; WORKING BY LASER BEAM
    • B23K9/00—Arc welding or cutting
    • B23K9/12—Automatic feeding or moving of electrodes or work for spot or seam welding or cutting
    • B23K9/133—Means for feeding electrodes, e.g. drums, rolls, motors
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
    • B23K—SOLDERING OR UNSOLDERING; WELDING; CLADDING OR PLATING BY SOLDERING OR WELDING; CUTTING BY APPLYING HEAT LOCALLY, e.g. FLAME CUTTING; WORKING BY LASER BEAM
    • B23K9/00—Arc welding or cutting
    • B23K9/24—Features related to electrodes
    • B23K9/28—Supporting devices for electrodes
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
    • B23K—SOLDERING OR UNSOLDERING; WELDING; CLADDING OR PLATING BY SOLDERING OR WELDING; CUTTING BY APPLYING HEAT LOCALLY, e.g. FLAME CUTTING; WORKING BY LASER BEAM
    • B23K9/00—Arc welding or cutting
    • B23K9/32—Accessories

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  • Engineering & Computer Science (AREA)
  • Physics & Mathematics (AREA)
  • Plasma & Fusion (AREA)
  • Mechanical Engineering (AREA)
  • Arc Welding In General (AREA)

Abstract

The invention discloses an arc surface deposition method under vacuum conditions, which comprises the following steps that 1) a vacuum cabin body for realizing arc deposition by using an air suction pump is adopted, so that the influence of air on the deposition process is avoided; 2) The MIG welding gun and the TIG welding gun are combined together and connected through a welding power supply, so that the stability of a deposition process is ensured and the high efficiency is realized; 3) The TIG welding gun adopts a hollow tungsten electrode, gas flows downwards from the center of the electrode, and stable electric arc can be kept under a vacuum condition; 4) The welding current of the intermediate frequency direct current pulse is adopted, which is beneficial to electric arc contraction and molten drop transition. The invention can reduce the reaction of air and molten metal to the maximum extent, simultaneously, the electric arc generated by the combined welding gun directly heats the deposited wire, the melting efficiency is high, the dilution rate of the base metal is low, the preparation of the high-efficiency and high-quality electric arc surface deposited layer is realized, the problem of poor deposited effect caused by insufficient protection in the existing electric arc depositing process is solved, the range of the fusible metal material is widened, and the invention has practical application value.

Description

Electric arc surface cladding method under vacuum condition
Technical Field
The invention belongs to the field of metal surface processing, and particularly relates to an electric arc surface deposition method under a vacuum condition.
Background
More and more mechanical parts in modern industry need to work stably for a long time under severe environments such as corrosion, abrasion, high temperature, high pressure and the like, in particular to engineering equipment in the fields of ships, oceans, aerospace and the like. However, most parts only need to ensure the hardness, corrosion resistance and wear resistance of the surface of the part in practical application, and the service life of the parts can be directly influenced by the quality of the surface performance. Therefore, the surface welding technology for forming the thin layer with excellent performance on the surface of the substrate by a heating mode has good application value.
Currently, main methods of surface welding techniques include laser welding, arc welding, and plasma arc welding. The arc deposition has the advantages of high binding force, simple equipment, low cost and wide material adaptability, and is widely applied to actual industrial production. In order to realize a good cladding effect, three requirements of low dilution rate, high cladding rate and high cladding quality need to be met, the existing arc cladding process is difficult to meet simultaneously, for example, a large-current TIG arc is adopted to effectively improve cladding efficiency, but the dilution rate is increased due to larger heat input, and the quality of a cladding layer cannot be ensured due to excessive mixing of a matrix and a cladding material; the MIG/MAG electric arc can carry out high-efficiency and low-dilution-rate cladding, but the molten drop transition process is complex, the electric arc is not as stable as the TIG electric arc, and the quality of a cladding layer cannot be well controlled. Meanwhile, when the cladding layer is prepared, the metal after heating and melting needs to be isolated from air, so that the component in the air is prevented from reacting with the component in the air, when the requirement on the cladding performance is not high and the weldability of the material is better, the requirement can be met by adopting high-purity argon or helium for protection, but when the cladding material contains chemically active metal or refractory metal, the protection effect generated by introducing a large amount of compressed inert gas is difficult to achieve the ideal effect, the cost is high, and the method does not accord with the actual industrial production. It can be seen that the existing arc deposition process still has an imperfect means of protecting the molten metal, requiring further reinforcement.
Therefore, it is of practical and economic importance to develop an arc surface deposition method with a low dilution rate and complete protection measures.
Disclosure of Invention
The invention provides an arc surface deposition method under vacuum condition, aiming at solving the problems that the existing arc deposition layer preparation process is difficult to simultaneously meet low dilution rate, high deposition rate and high-quality deposition layer and the protection measure is incomplete.
In order to achieve the purpose, the invention provides the following technical scheme:
a method of arc surface deposition under vacuum conditions, comprising:
1) The vacuum cabin body is realized through the air pump, and the cladding is carried out in the cabin body, so that the influence of air on the cladding process is avoided;
2) The combined welding gun is formed by combining an MIG welding gun and a TIG welding gun in a vacuum chamber and is connected through a welding power supply, so that the stability of a deposition process is ensured and the high efficiency is realized;
3) A hollow tungsten electrode, in which gas flows downward from the center of the electrode, and a stable arc can be maintained under a vacuum condition;
4) The direct current pulse adopts intermediate frequency welding current, which is beneficial to electric arc contraction and molten drop transition.
Preferably, the equipment for the arc surface cladding method comprises a vacuum system and a welding system. Wherein, the vacuum system comprises a suction pump and a vacuum cabin body. One side of the vacuum chamber body is connected with an air pump, and the internal vacuum degree is kept stable through the air pump; the welding system comprises a welding power supply, an MIG welding gun, a TIG welding gun, a wire feeding mechanism and a gas cylinder.
Preferably, one side of the vacuum cabin body is provided with an observation window; a controllable three-axis moving mechanism is arranged in the vacuum cabin body and used for moving a workpiece to be deposited; an MIG welding gun and a TIG welding gun are fixed above the inner part of the vacuum cabin body.
Preferably, the MIG welding gun is connected with the positive electrode of a welding power supply and a wire feeding mechanism; and the TIG welding gun is connected with the negative electrode of the welding power supply and the gas cylinder.
Preferably, the included angle between the MIG welding gun and the TIG welding gun can be freely adjusted; the deposited welding material in the MIG welding gun and the tungsten electrode in the TIG welding gun are in the same plane; the two welding guns are kept stable in the arc deposition process.
Preferably, a needle valve, a rotor flow meter, a digital mass flow meter and an air inlet manifold are sequentially connected between the TIG welding gun and the air bottle, so that the gas flow meter is suitable for inputting single or mixed gas and can reduce the influence in the gas flow regulation process.
Preferably, the gas is a single gas, and the gas component is pure argon.
Preferably, the gas is injected only from the center of the hollow tungsten electrode after entering a gas pressure stabilizing cavity in the TIG welding gun, and no gas exists outside the hollow tungsten electrode.
Preferably, the form of molten drop transition in the deposition process is stable jet flow transition, and the molten drop transition is realized by adjusting welding parameters.
Compared with the prior art, the invention has the beneficial effects that:
(1) The vacuum environment implemented by the invention is realized by the air pump, so that the reaction of air and molten metal can be avoided to the greatest extent, the quality of a cladding layer is ensured, and the weldability of the material is improved.
(2) The combined welding gun is adopted, the electric arc can directly heat deposited wires, the melting efficiency is high, the dilution rate of the base metal is low, and the range of depositing metal materials is expanded.
(3) The invention adopts intermediate frequency direct current pulse to ensure that the electric arc is always in an incomplete unfolding state, so that the energy is more concentrated, the fuse wire efficiency is favorably improved, and meanwhile, under the condition of the same average current, the invention has larger instantaneous current and is favorable for droplet transition.
(4) The arc surface deposition method under the vacuum condition can effectively solve the problems that the existing arc surface deposition layer preparation process is difficult to simultaneously meet the requirements of low dilution rate, high deposition rate, high-quality deposition layer and incomplete protection measures, and has practical popularization value.
Drawings
FIG. 1 is a schematic view of an apparatus for arc surface deposition under vacuum according to the present invention;
FIG. 2 is a schematic view of the structure of the welding gun and the workpiece inside the vacuum chamber;
FIG. 3 is a schematic illustration of a combined MIG and TIG welding gun cladding process;
FIG. 4 is a schematic structural diagram of a TIG welding gun using a hollow tungsten electrode;
FIG. 5 is a schematic diagram of a waveform of a medium frequency DC pulse welding current.
The reference numbers are as follows:
1-welding power supply, 2-wire feeder, 3-MIG welding gun, 4-TIG welding gun, 5-needle valve, 6-rotor flow meter, 7-digital mass flow meter, 8-air inlet manifold, 9-air bottle, 10-air pump, 11-vacuum cabin, 12-observation window, 13-bracket, 14-three-shaft moving mechanism, 15-clamp, 16-workpiece, 17-welding wire, 18-hollow tungsten electrode, 19-electric arc, 20-molten drop, 21-cladding layer, 22-pressure stabilizing cavity, 23-air inlet, 24-water inlet, 25-water outlet, 26-tungsten electrode clamp, X, Y and Z are directions of three shafts of moving mechanism respectively, I is I 0 Is a base current, I 1 Is the peak current, f is the pulse current frequency, and T is the pulse current period.
Detailed Description
The invention is further described with reference to the following figures and specific examples.
The arc surface deposition method under vacuum of the present invention uses a kit including a vacuum system and a welding system as shown in fig. 1. Wherein, the vacuum system comprises a suction pump 10 and a vacuum cabin 11; the welding system comprises a welding power supply 1, an MIG welding gun 3, a TIG welding gun 4, a wire feeding mechanism 2 and a gas cylinder 9.
The vacuum cabin body 11 is stabilized through a bracket 13, an observation window 12 is arranged on the vacuum cabin body 11, which is convenient for observing the molten drop transition form in the deposition process, and the right side of the vacuum cabin body is connected with an air pump 10 for keeping the internal vacuum degree stable; the MIG welding gun 3 is connected with the anode of the welding power supply 1 and the wire feeding mechanism 2; and the TIG welding gun 4 is connected with the cathode of the welding power supply 1 and the gas cylinder 9.
The control of the gas flow rate is important for the arc deposition process under vacuum conditions, and therefore, an intake manifold 8, a digital mass flow meter 7, a rotameter 6, and a needle valve 5 are connected in order to a connection path between the gas cylinder 9 and the TIG welding gun 4.
Arc welding under vacuum conditions may require the use of multiple gases (e.g., he, ar, H) 2 Etc.) to accommodate different applications for maintaining the arc, these single or mixed gas inputs may be provided through the intake manifold 8; after the gas flows in, the gas flow is measured and displayed by a digital mass flowmeter 7; the rotor flowmeter 6 allows the gas to be further regulated through the digital mass flowmeter 7, so that the influence on the gas in the instrument regulation process can be reduced; the needle valve 5 is the last component of the gas flow control instrument assembly. It is located above the hollow tungsten electrode port that delivers gas, and this valve with the ability to precisely regulate pressure and flow provides a fixed orifice that is not affected by vacuum pressure. The specific gas flow and pressure can be controlled by the above mentioned instruments to enter the vacuum chamber 11, and the influence of the gas flow adjusting process can be reduced.
As shown in fig. 2, the vacuum chamber 11 is provided with a controllable three-axis movement mechanism 14 inside to allow a wide range of movement of the workpiece 16 to be deposited within the vacuum chamber 11, which allows an operator to change the motion control program and adjust the movement path of the workpiece 16 without affecting the vacuum level.
In addition, the MIG welding gun 3 and the TIG welding gun 4 are fixed at the center above the inside of the vacuum cabin body 11 through a clamp 15, and the included angle between the MIG welding gun 3 and the TIG welding gun 4 can be freely adjusted by changing the rotation direction of the clamp 15; a deposited welding material 17 in the MIG welding gun 3 and a hollow tungsten electrode 18 in the TIG welding gun 4 are in one plane; and keeping the MIG welding gun 3 and the TIG welding gun 4 stable and motionless in the arc deposition process.
As shown in fig. 3, the welding process of the combined MIG welding gun and TIG welding gun is performed by introducing gas into the TIG welding gun 4, passing through a hollow tungsten electrode 18 inside the welding gun 4, and reaching the inside of the vacuum chamber 11, and continuously extracting the gas from the inside of the vacuum chamber 11 by an air pump 10 to maintain a constant degree of vacuum. In this dynamic vacuum environment, the arc 19 is stably burned between the end of the hollow tungsten electrode 18 of the TIG welding gun 4 and the deposited welding material 17 delivered by the MIG welding gun 3, and the droplet transition form is made to be stable jet flow transition by adjusting suitable welding parameters, so as to obtain a good-quality and beautiful cladding layer 21.
As shown in fig. 4, the internal structure of the TIG welding gun comprises a pressure stabilizing cavity 22, an air inlet 23, a water inlet 24, a water outlet 25, a tungsten electrode clamp 26 and a hollow tungsten electrode 18.
The pressure stabilizing cavity 22 is used for stabilizing the fluctuation of air pressure and mainly plays a role of buffering, and the material of the pressure stabilizing cavity is a material with good heat conduction and electric conduction performance, so that the functions of electric conduction and cooling can be realized at the same time, and better economic benefit is achieved; a cooling water channel is arranged outside the pressure stabilizing cavity 22, cooling water enters from a water inlet 24 on one side and flows out from a water outlet 25 on the other layer after circulating for a circle, and the function of quick cooling can be realized; the gas enters the pressure stabilizing cavity 22 from the gas inlet 23 and then is ejected through the bottom outlet of the hollow tungsten electrode 18 fixed by the tungsten electrode clamp 26.
As shown in FIG. 5, the intermediate frequency DC pulse welding current waveform adopted by arc deposition under vacuum condition is in the form of DC square wave pulse, and the main parameter to be adjusted is base value current I 0 Peak current I 1 Pulse period T, pulse frequency f and duty ratio q. When the current 19 is in the base value stage, the arc 19 is contractive, and expands outwards along with the gradual increase of the current, and after the current reaches the peak value for a period of time, the arc reaches a stable state, the heating area is increased, the heat in unit area is reduced, and the rapid fuse is not facilitated. By adjusting the above parameters, the arc 19 is always in an insufficiently spread state, so that the heating energy of the arc 19 to the deposited welding material 17 is concentrated, which is advantageous for improving the fuse efficiency. In addition, the pulse current has larger instantaneous current under the condition of the same average current, so that the electromagnetic force acting on the molten drop 20 is increased, and the molten drop transition is facilitated.
Example 1
The preparation of the cladding layer is carried out by the matched equipment of the method, and the materials and the parameters are as follows:
the deposited substrate is Inconel 718, the thickness of the deposited substrate is 8mm, the length of the deposited substrate is 1000mm, and the width of the deposited substrate is 500mm; the deposited welding material is made of Incoloy903 high-temperature alloy, and the diameter of the deposited welding material is 1.6mm; the hollow tungsten electrode is made of cerium tungsten, the outer diameter of the hollow tungsten electrode is 3.2mm, and the inner diameter of the hollow tungsten electrode is 0.5mm; a single gas was introduced with a composition of 99.999% high purity argon.
The vacuum degree of the vacuum cabin 11 is maintained at 2mTorr, the included angle between the MIG welding gun 3 and the horizontal direction is 30 degrees, the included angle between the TIG welding gun 4 and the horizontal direction is 75 degrees, the gas flow is 10ccm, the moving speed of the workpiece is 2.5mm/s, the wire feeding speed is 13mm/s, the deposition average current I is 75A, and the base value current I 0 30A, peak current I 1 120A, a pulse frequency f of 600Hz and a duty cycle q of 50%.
The specific deposition working process is as follows: the gas is introduced into the TIG welding gun, firstly reaches the pressure stabilizing cavity 22 inside the welding gun 4, then reaches the vacuum cabin body 11 through the hollow tungsten electrode 18, and simultaneously the gas in the vacuum cabin body 11 is continuously pumped out by the air pump 10 so as to maintain a certain vacuum degree. After arc ignition, the electric arc 19 is stably burnt between the end part of the hollow tungsten electrode 18 of the TIG welding gun 4 and the deposited welding material 17 sent out by the MIG welding gun 3, the molten drop transition form is jet flow transition, the transition process is stable, and a high-quality and attractive cladding layer is obtained. Compared with the conventional arc cladding process, the cross section of the cladding layer sample has no obvious microcrack, so that the arc cladding layer under the vacuum condition has better cladding effect.
The above is only a preferred embodiment of the present invention, and the protection scope of the present invention is not limited to the above-mentioned embodiments, and all technical solutions belonging to the idea of the present invention belong to the protection scope of the present invention. It should be noted that modifications to the described embodiments without departing from the principles of the invention should be considered within the scope of the invention by those skilled in the art.

Claims (7)

1. A method of arc surface deposition under vacuum conditions, comprising:
1) The vacuum cabin body is realized by a suction pump, and the cladding process is completely carried out in the cabin body;
2) The combined welding gun is characterized in that an MIG welding gun and a TIG welding gun in a vacuum chamber are combined together and connected through a welding power supply;
3) A hollow tungsten electrode, in which gas flows downward from the center of the electrode, and a stable arc can be maintained under vacuum conditions;
4) The direct current pulse adopts intermediate frequency welding current to make the electric arc in an incomplete extension state.
2. The method of claim 1 wherein the associated equipment includes a vacuum system and a welding system.
The vacuum system comprises a suction pump and a vacuum cabin body. One side of the vacuum chamber body is connected with a suction pump, and the internal vacuum degree is kept to be 2 mTorr-10 mTorr stably through the suction pump.
The welding system comprises a welding power supply, an MIG welding gun, a TIG welding gun, a wire feeding mechanism and a gas cylinder. The MIG welding gun is connected with the anode of a welding power supply and a wire feeding mechanism; and the TIG welding gun is connected with the negative electrode of the welding power supply and the gas cylinder.
3. The apparatus as claimed in claim 2, wherein the vacuum chamber has a controllable three-axis moving mechanism for moving the workpiece to be welded, and the MIG and TIG welding guns are fixed above the chamber.
4. The corollary equipment for an arc surface cladding method under vacuum condition according to claim 3, characterized in that an included angle between an MIG welding gun and a TIG welding gun can be freely adjusted; the deposited welding material in the MIG welding gun and the tungsten electrode in the TIG welding gun are in the same plane; the two welding guns are kept stable in the arc deposition process.
5. The corollary equipment of an arc surface deposition method under vacuum condition according to claim 2, characterized in that a needle valve, a rotor flow meter, a digital mass flow meter and an intake manifold are connected between the TIG welding gun and the gas cylinder in sequence to satisfy multiple input conditions of single or mixed gas.
6. The method of arc surface deposition under vacuum as claimed in claim 1, wherein gas is injected from the center of the hollow tungsten electrode after entering a gas pressure stabilizing chamber inside a TIG welding torch, and no gas is present outside the hollow tungsten electrode.
7. The method of claim 1 wherein the pulse frequency and welding parameters are adjusted to provide a droplet transfer in the form of a stable jet flow transfer.
CN202211308275.2A 2022-10-25 2022-10-25 Electric arc surface cladding method under vacuum condition Pending CN115555689A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CN202211308275.2A CN115555689A (en) 2022-10-25 2022-10-25 Electric arc surface cladding method under vacuum condition

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CN202211308275.2A CN115555689A (en) 2022-10-25 2022-10-25 Electric arc surface cladding method under vacuum condition

Publications (1)

Publication Number Publication Date
CN115555689A true CN115555689A (en) 2023-01-03

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ID=84746651

Family Applications (1)

Application Number Title Priority Date Filing Date
CN202211308275.2A Pending CN115555689A (en) 2022-10-25 2022-10-25 Electric arc surface cladding method under vacuum condition

Country Status (1)

Country Link
CN (1) CN115555689A (en)

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