CN114481008A - Auxiliary equipment, treatment system and method for ionic nitrogen carbon and sulfur multicomponent co-permeation - Google Patents

Abstract

The present disclosure provides auxiliary equipment, processing system and method for ionic nitrogen-carbon-sulfur multicomponent interpenetration. The auxiliary equipment includes: a hollow cathode ion source placed on the top of the furnace body of an ion diffusion infiltration furnace, and an insulating shell placed on the side wall of the furnace body. , and a plurality of electromagnets that are coaxial and are arranged in an insulating shell from the inside to the outside at intervals, the winding methods of two adjacent electromagnets are opposite, and the multiple electromagnets are used to form a controllable formation in the ion diffusion furnace. The magnetic field can change the trajectory of electrons on the surface of the metal workpiece and the magnetic domain of the metal workpiece. The treatment system includes: ion diffusion furnace, auxiliary equipment for ion nitrogen carbon sulfur multi-infiltration, transformer, vacuum pump, gas supply cylinder and electrical control cabinet. The treatment method includes feeding gas containing nitrogen element, carbon element, hydrogen element and sulfur element into the furnace body, and providing a controllable magnetic field to the metal workpiece. The present disclosure can reduce the gap of the sulfide on the surface of the workpiece, so that the hardness shows a trend of slow decline, and the surface hardness and service life of the workpiece are improved.

Description

Auxiliary equipment, treatment system and method for ion nitrogen carbon sulfur multi-component co-permeation

technical field

The present disclosure relates to the technical field of ion nitriding treatment on the surface of metal materials, in particular to auxiliary equipment, treatment systems and methods for ion nitrogen carbon-sulfur multicomponent co-nitridation.

Background technique

Infiltration is one of the common methods of metal surface modification. It is widely used in industrial production because it can greatly improve the hardness, wear resistance and corrosion resistance of metal surface. Diffusion is a heat treatment method that infiltrates atoms into the surface of the workpiece and changes the chemical composition and structure of the surface of the workpiece. Usually there are nitriding, carburizing, nitrocarburizing and multi-co-permeating and so on. There are two commonly used diffusion methods: gas diffusion and ion diffusion. Ion diffusion and infiltration is to ionize the gas by applying a voltage between the positive and negative electrodes in the furnace to transform the gas into a plasma state; under the action of the electric field, the free gas ions in the furnace bombard the surface of the workpiece at the cathode potential at high speed, making The surface of the workpiece adsorbs gas atoms and diffuses into the material to form a diffusion layer; at the same time, the sputtered metal atoms and free gas particles combine to form compounds and deposit on the surface of the workpiece.

With the development of modern industrial technology, workpieces need to meet various complex working conditions. Among them, the problem of how to improve the wear resistance and life of the workpiece under heavy load conditions can be solved by the multi-component co-permeation of nitrogen, carbon and sulfur. However, after adding sulfur in nitrocarburizing, there is a large gap between the sulfides on the surface of the workpiece, and the hardness decreases, which greatly reduces the service life of the workpiece in the heavy-duty friction pair.

SUMMARY OF THE INVENTION

The present disclosure aims to solve one of the above problems.

Therefore, the embodiments of the present disclosure can reduce the sulfide lattice gap on the surface of the workpiece, effectively increase the hardness of the sulfide layer in the diffusion layer, increase the thickness of the diffusion layer, improve the diffusion efficiency and the quality of the diffusion layer. The ionic nitrogen-carbon-sulfur multi-infiltration auxiliary equipment is suitable for being placed on the furnace body of the ion diffusion infiltration furnace, and the ion diffusion infiltration furnace has workpieces for placing metal workpieces. The ion nitriding auxiliary equipment includes:

a hollow cathode ion source adapted to be placed on top of the furnace body for emitting a plasma electron beam near the metal workpiece; and

A magnetic field auxiliary unit, the magnetic field auxiliary unit includes an insulating casing and a plurality of electromagnets; the insulating casing is suitable for being placed on the side wall of the furnace body; a plurality of the electromagnets are coaxial and from the inside to the outside Arranged in the insulating shell in sequence, two adjacent electromagnets are wound in opposite ways, and a plurality of the electromagnets are used to form a controllable magnetic field in the ion diffusion furnace to change all the electromagnets. The motion trajectory of electrons on the surface of the metal workpiece and the magnetic domain of the metal workpiece.

The ionic nitrogen-carbon-sulfur multi-component interpenetration auxiliary equipment provided by the embodiment of the first aspect of the present disclosure has the following characteristics and beneficial effects:

After the ion nitriding furnace is evacuated, the gas containing nitrogen elements and the gas containing hydrogen elements are ionized by the hollow cathode ion source, and plasmas such as nitrogen ions, hydrogen ions, sulfur ions and neutral nitrogen atoms are ionized, and a large amount of plasma is directly irradiated. At the same time, under the combined action of electric field and magnetic field, the plasma gathers on the surface of the metal workpiece. Under the action of the electric field, the plasma concentration of nitrogen ions, hydrogen ions and neutral nitrogen atoms on the surface of the metal workpiece increases; diffusion With the enhancement of deposition, the thickness of the diffusion layer is finally increased, and the diffusion efficiency is improved. In addition, the positive ions and electrons are subjected to the combined action of the Lorentz force of the magnetic field and the Coulomb force of the electric field in the coupled field. The electric field and the magnetic field are perpendicular to each other and act together on the electrons, making them perform cycloid motion near the metal workpiece; In conventional ion diffusion, the diffusion temperature is increased under the same conditions, and the diffusion of active nitrogen, carbon and sulfur atoms to the interior is deepened, the quality of the co-infiltration layer is improved, and the brittleness is reduced, which strengthens the diffusion effect. At the same time, the proportion of solid solution of sulfide in the diffusion layer increases, and the gap between sulfide lattices decreases. On the premise of not affecting the friction coefficient and improving the wear resistance of vulcanization, the surface hardness of the metal workpiece is improved, and the use requirements of heavy-duty friction pairs are met.

Further, the magnetic field will magnetize the metal workpiece placed in it. Under the action of the magnetic field, the magnetic domain rotation and magnetic wall displacement are generated on the surface of the metal workpiece, which increases the exchange energy and anisotropy energy. Strain increases the strain energy, accelerates the diffusion of infiltrating substances, and greatly increases the magnetization. In some embodiments, the current passed to the electromagnet satisfies: the metal workpiece is completely encompassed by the magnetic field generated by the electromagnet, and the magnetic field strength near the metal workpiece reaches 450 Gs˜550 Gs.

In some embodiments, each of the electromagnets is a ring electromagnet, respectively.

In some embodiments, the axial direction of each of the electromagnets is parallel to the upper plane of the workpiece table.

In some embodiments, the magnetic field assisting unit further includes a metal disk located in the furnace body and disposed as close as possible to the insulating shell, the metal disk is wrapped by the magnetic field lines generated by the electromagnet, the The material of the metal disk is the same as that of the metal workpiece, and the metal disk and the workpiece table share a power source.

The ionic nitrogen-carbon-sulfur multi-permeation treatment system provided by the embodiment of the second aspect of the present disclosure includes:

an ion diffusion and infiltration furnace, the ion nitriding furnace includes a furnace body and a workpiece table arranged in the furnace body for placing metal workpieces;

Auxiliary equipment for ionic nitrogen-carbon-sulfur multi-infiltration, the auxiliary equipment for ion-nitrogen-carbon-sulfur multi-infiltration is the auxiliary equipment for ionic nitrogen-carbon-sulfur multi-infiltration provided according to an embodiment of the first aspect of the present disclosure;

a transformer, which is connected with the coil, the workpiece table and the hollow cathode ion source, and is used for making the electromagnet generate a magnetic field and supplying an ionization voltage to the furnace body;

a vacuum pump, which is communicated with the furnace body and is used to make the furnace body in a vacuum state;

a gas supply cylinder, communicated with the furnace body, for supplying inert gas, nitrogen-containing gas, hydrogen-containing gas, carbon-containing gas and sulfur-containing gas into the furnace body; and

An electrical control cabinet is used to control the auxiliary equipment for ionic nitrogen, carbon and sulfur multi-component interpenetration, the ion diffusion furnace, the transformer, the vacuum pump and the gas supply cylinder.

The ionic nitrogen-carbon-sulfur multi-infiltration treatment method provided by the embodiment of the third aspect of the present disclosure is characterized in that, comprising:

The metal workpiece is placed in the furnace body of the ion diffusion furnace, the furnace body is evacuated, and an inert gas is introduced into the furnace body;

Passing a voltage into the furnace body and raising the temperature to ensure stable glow discharge in the furnace body, and turning on the hollow cathode ion source;

When the temperature in the furnace body reaches the first temperature, the gas containing nitrogen element and the gas containing hydrogen element are introduced into the furnace body, and the temperature in the furnace body is continued to rise;

When the temperature in the furnace body reaches the second temperature, the inert gas is stopped, and the gas containing carbon element is passed into the furnace body, using the ionic nitrogen carbon sulfur multicomponent copolymer provided according to the embodiment of the first aspect of the present disclosure. The infiltration auxiliary device provides a magnetic field of a first magnetic field strength to the metal workpiece;

After the temperature in the furnace body reaches the co-infiltration temperature, use the ionic nitrogen-carbon-sulfur multi-co-infiltration auxiliary equipment to provide the metal workpiece with a magnetic field of the second magnetic field strength;

In the heat preservation and pressure keeping stage, gradually reduce the intensity of the magnetic field provided by the ionic nitrogen carbon sulfur multi-component co-penetration auxiliary equipment to the metal workpiece;

Passing gas containing elemental sulfur into the furnace body, and reducing the temperature in the furnace body;

When the temperature in the furnace body is lowered to a third temperature, the metal workpiece is provided with a magnetic field of a third magnetic field strength by using the auxiliary equipment for ion nitrogen carbon sulfur multi-component co-penetration;

When the temperature in the furnace body is lowered to the fourth temperature, the auxiliary equipment for ionic nitrogen, carbon and sulfur multi-component interpenetration is turned off, and the gas containing hydrogen, nitrogen and carbon elements are stopped to pass into the furnace body. The gas and the gas containing sulfur element are introduced into the furnace body to clean the surface of the metal workpiece;

When the temperature in the furnace body is lowered to the fifth temperature, the inert gas is stopped flowing into the furnace body, and the metal workpiece is taken out.

In some embodiments, the fourth magnetic field strength is greater than the second magnetic field strength.

Description of drawings

FIG. 1 is a schematic structural diagram of an ion source nitrogen-carbon-sulfur multi-component interpenetration auxiliary device according to an embodiment of the first aspect of the present disclosure.

FIG. 2 is a schematic diagram of the distribution of the magnetic field generated by the auxiliary device shown in FIG. 1 .

FIG. 3 is a schematic structural diagram of an ion-source nitrogen-carbon-sulfur multi-permeation treatment system provided by an embodiment of the second aspect of the present disclosure.

FIG. 4 and FIG. 5 are respectively the cross-sectional metallographic diagrams of the ionic nitrogen-carbon-sulfur co-infiltration treatment method provided by the embodiment of the present disclosure and the cross-sectional metallographic diagram of the conventional co-infiltration treatment.

FIG. 6 is a graph showing the hardness gradient of the metal workpiece after using the ion nitrocarburizing treatment method provided by the embodiment of the present disclosure and after using the conventional co-infiltration treatment.

FIG. 7 is a UMT analysis diagram of a metal workpiece after using the ion nitrocarburizing treatment method provided by the embodiment of the present disclosure and after using the conventional co-infiltration treatment.

In the picture:

100- Ionic nitrogen-carbon-sulfur multi-component co-permeation auxiliary equipment, 110-insulating shell, 120-electromagnet, 122-coil, 130-metal disc, 140-hollow cathode ion source;

200-ion diffusion furnace, 210-furnace body, 220-workpiece table, 230-metal workpiece;

300-transformer;

400-vacuum pump;

500 - gas supply cylinder;

600 - Electrical control cabinet.

Detailed ways

In order to make the objectives, technical solutions and advantages of the present application clearer, the present application will be described in further detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application, but not to limit the present application.

On the contrary, this application covers any alternatives, modifications, equivalents and arrangements within the spirit and scope of this application as defined by the claims. Further, in order to give the public a better understanding of the present application, some specific details are described in detail in the following detailed description of the present invention. Those skilled in the art can fully understand the present application without the description of these detailed parts.

Referring to FIG. 1 , the ionic nitrogen-carbon-sulfur multi-component interpenetration auxiliary equipment 100 provided by the embodiment of the first aspect of the present disclosure is suitable for being placed in the furnace body of an ion diffusion infiltration furnace (the ion diffusion infiltration furnace is not shown in FIG. 1 ) 200 Above, the ion diffusion furnace 200 has a workpiece table 220 for placing the metal workpiece 230 . The ionic nitrogen-carbon-sulfur multicomponent co-permeating auxiliary equipment 100 of the present disclosure includes:

a hollow cathode ion source 140 adapted to be placed on top of the furnace body of the ion diffusion furnace 200 for emitting a plasma electron beam near the metal workpiece 230; and

A magnetic field auxiliary unit, the magnetic field auxiliary unit includes an insulating casing 110 and a plurality of electromagnets 120; the insulating casing 110 is suitable for being placed on the side wall of the furnace body of the ion diffusion furnace 200; the plurality of electromagnets 120 are coaxial and The electromagnets 120 are arranged at intervals in the insulating housing 110 from the outside in sequence, and the two adjacent electromagnets 120 are wound in opposite ways. The multiple electromagnets 120 are used to form a controllable magnetic field in the ion diffusion furnace 200 to change the metal workpiece. The trajectory of electrons on the surface of 230 and the magnetic domain of the metal workpiece 230 .

In some embodiments, the hollow cathode ion source 140 adopts a hollow cathode gun, which can generate a hollow cathode effect inside the hollow cathode ion source 140 to directly shoot a high-density plasma electron beam near the metal workpiece 230 in the furnace body to increase the ionization of the gas in the furnace. Rate.

In some embodiments, the distance between the bottom of the insulating shell 110 in the magnetic field assisting unit and the bottom of the furnace body of the ion diffusion furnace 200 is between 100 mm and 200 mm, and a part of the insulating shell 110 is located in the side wall of the furnace body, Another part of the insulating shell 110 is located outside the side wall of the furnace body, and the distance from the inner side of the insulating shell 110 to the side wall of the furnace body is 300 mm. Since the magnetic field assisting unit is located on the side wall of the furnace body of the ion infiltration furnace, the entire workpiece table 220 can be subjected to the action of the magnetic field, and will not hinder the infiltration infiltration. The metal workpiece 230 is placed on the workpiece table 220 so that the direction of the magnetic field is perpendicular to the direction of the electromagnetic field, and the ions move cycloidly near the surface of the metal workpiece to increase the ion concentration on the surface of the metal workpiece, thereby improving the diffusion efficiency.

Further, referring to FIG. 2 , the magnetic field assisting unit further includes a metal disk 130 located in the furnace body of the ion diffusion furnace 200 and as close as possible to the insulating shell 110 (the metal disk can be fixedly connected with the insulating shell, that is, in FIG. 2 . The method shown in the figure, or fixedly connected to the furnace body), is wrapped by the magnetic field lines generated by the electromagnet 120. The material of the metal disk 130 is the same as that of the metal workpiece 230, and its function is similar to that of the hollow cathode ion source 140. The metal disk 130 is directly bombarded to sputter a large amount of metal ions, which combine with the gas ions in the furnace to form metal compounds, thereby increasing the plasma concentration. Compared with the direct sputtering of the metal workpiece, this method reduces the degree of sputtering on the surface of the metal workpiece, which can greatly improve the surface quality of the metal workpiece 230 and avoid the phenomenon of increased surface roughness of the metal workpiece caused by direct bombardment of ions. On the other hand, the installation of the metal disk 130 can confine the plasma electron beam emitted by the hollow cathode ion source 140 to the metal workpiece 230 and the metal disk 130 , thereby greatly increasing the plasma concentration near the metal workpiece 230 .

In one embodiment, each electromagnet adopts an N-S-N pole arrangement from the inside to the outside. This arrangement can not only make the magnetic field intensity on the surface of the workpiece table higher, but also have a greater confinement effect on ions, and can reduce the magnetic field. Auxiliary unit takes up space and maximizes cost savings.

In some embodiments, in order to determine the magnitude of the DC current flowing into the coils 122 of each electromagnet 120, before the diffusion infiltration begins, the ion nitriding auxiliary device 100, the workpiece table 220 and the metal workpiece 230 to be treated by the present disclosure are Numerical simulation is performed on the components formed, and the input current of the coil 122 in the simulated electromagnet 120 is gradually increased, so that the metal workpiece 230 is completely covered by the magnetic field and the magnetic field strength near the metal workpiece 230 reaches about 450Gs-550Gs (preferably 500Gs), and record this. When inputting the current value of the coil 122 of the electromagnet 120 , it is used as the magnitude of the direct current finally passed into the coil 122 of the electromagnet 120 . When the magnetic field strength near the metal workpiece 230 is between 450Gs and 550Gs, a better magnetron effect can be provided, and the field strength will not be too large to avoid increasing the energy consumption of the auxiliary equipment.

In some embodiments, each electromagnet 120 is a ring electromagnet, which can ensure the uniformity of the magnetic field and is easy to process. See FIG. 2 for the distribution of the magnetic field generated by each electromagnet 120 .

In some embodiments, the axial direction of each electromagnet 120 is parallel to the upper plane of the workpiece table 220 , so that the magnetic field generated by each electromagnet 120 can contain the metal workpiece 230 .

In some embodiments, in order to make the structure of the device more compact, the insulating casing 110 is a cylinder matching the outer circumference formed by the second end of the outermost electromagnet group 120 , and the magnetic field can be protected by the insulating casing 110 The internal structure of the auxiliary unit allows the magnetic field auxiliary unit to cool down together with the furnace body of the ion diffusion furnace 200. On the other hand, the insulating shell 100 is insulated from the furnace body of the ion diffusion furnace 200 to ensure that the electrodes in the furnace body do not affect the magnetic field auxiliary. Electromagnet inside the unit.

The working process and principle of the auxiliary equipment for ionic nitrogen-carbon-sulfur multi-component interpenetration provided by the embodiment of the first aspect of the present disclosure are as follows:

Before infiltration, use simulation software to model the metal workpiece to be processed, and gradually increase the input current of the simulated electromagnet, so that the metal workpiece is completely covered by the magnetic field and the field strength near the metal workpiece reaches about 500Gs, and the input of the electromagnet at this time is recorded. current value.

After the ion nitriding furnace is evacuated, the medium gas containing nitrogen, hydrogen, carbon and sulfur elements is introduced into the furnace through the hollow cathode ion source, and the voltage required for ionization is connected, and the input to the coil of the electromagnet is at the same time. According to the current value determined by numerical simulation, the medium gas is ionized in the hollow cathode ion source and the furnace body, ionizing nitrogen ions, hydrogen ions, carbon ions, sulfur ions and neutral sulfur atoms, carbon atoms, nitrogen atoms and other plasmas, Through the hollow cathode ion source, a large number of plasma ions are directly directed to the metal workpiece. At the same time, the plasma is subjected to the combined action of the electric field and the magnetic field, and a large amount of plasma accumulates on the surface of the metal workpiece and the metal disk. Under the action of the electric field, the surface of the metal disk gathers. The plasma will move to the surface of the metal workpiece to increase the plasma concentration of nitrogen ions, hydrogen ions, carbon ions, sulfur ions and neutral sulfur atoms, carbon atoms, nitrogen atoms on the surface of the metal workpiece; at the same time, the plasma bombards the metal workpiece and metal disk. The surface causes some metal atoms to sputter out, escape more metal atoms, combine with nitrogen to form metal nitrides, combine with carbon to form metal carbides, and combine with sulfur to form metal sulfides, thereby increasing the binding probability of metal compounds, The concentration of the metal compound increases; it re-deposits on the surface of the metal workpiece due to condensation, and the metal compound is unstable at this time, and some nitrogen atoms, sulfur atoms, and carbon atoms diffuse into the surface of the metal workpiece to form a co-infiltration layer, which finally makes the co-infiltration layer. As the thickness of the layer increases, the diffusion efficiency increases. In addition, the positive ions and electrons are subjected to the combined action of the Lorentz force of the magnetic field and the Coulomb force of the electric field in the coupled field. The electric field and the magnetic field are perpendicular to each other and act together on the electrons, making them perform cycloid motion near the metal workpiece; In conventional ionic nitrogen-carbon-sulfur co-penetration, the auxiliary equipment provided by the embodiment of the present disclosure increases the co-infiltration temperature under the same conditions, the diffusion of active nitrogen, carbon and sulfur atoms into the metal workpiece deepens, the quality of the co-infiltration layer is improved, the brittleness is reduced, and the brittleness is reduced. Diffusion effect. The deposition of sulfide under the action of the magnetic field is strengthened, the lattice gap is reduced, and the surface hardness is increased without affecting the wear reduction. For heavy-load friction pairs, the nitrogen-carbon-sulfur ternary infiltration workpiece processed by the auxiliary equipment provided in the embodiments of the present disclosure has advantages. In addition, the auxiliary equipment provided by the embodiments of the present disclosure adopts the method of magnetron sputtering to confine the plasma with a magnetic field, and uses an electromagnet that is more convenient to control, thereby increasing the controllability of the co-infiltration process.

Further, the magnetic field will magnetize the metal workpiece placed in it. The main influence is: when an external magnetic field is provided for the metal workpiece, the internal materials of different metal workpieces are different, and the results are different when affected by the external magnetic field. The material is low-alloy structural steel, which is a ferromagnetic material. When an external magnetic field is applied, the magnetic domain is easily magnetized and moves toward the direction of the magnetic field strength. This change accelerates the diffusion of nitrogen, carbon, and sulfur atoms. On a plane perpendicular to the magnetic field direction, charged The particles move in a circular motion. It has been proved by experiments that when the magnetic field strength is above 270Gs, the nitrogen, carbon and sulfur atoms generated by ionization are most likely to move towards the metal surface in a directional motion to achieve the purpose of strengthening co-infiltration; under the action of the magnetic field, the surface of the metal workpiece produces The rotation of the magnetic domain and the displacement of the magnetic wall increase the exchange energy and anisotropy energy. At the same time, the magnetization near the surface of the material leads to magnetostriction, which increases the strain energy, accelerates the diffusion of infiltrating substances, and greatly improves the magnetization.

The ionic nitrogen-carbon-sulfur multi-permeation treatment system provided by the embodiment of the second aspect of the present disclosure, referring to FIG. 3 , includes:

The ion nitriding furnace 200 includes a furnace body 210 and a workpiece table 220 disposed in the furnace body 210 for placing the metal workpiece 230;

Auxiliary equipment 100 for ionic nitrogen, carbon and sulfur multicomponent co-infiltration is placed on the furnace body 210;

The transformer 300 is connected with the coil 122 of the electromagnet 120 in the auxiliary equipment 100 of ion nitrogen carbon sulfur multi-infiltration to generate a magnetic field, and supply the required 900V voltage for ionization into the furnace body 210 through the workpiece table, and the metal disk 140 is connected to the workpiece table. Common power supply, the transformer 300 is also used to provide the 800V voltage for the hollow cathode ion source;

The vacuum pump 400 is communicated with the furnace body 210 of the ion diffusion furnace 200, and is used to make the furnace body 210 in a vacuum state;

The gas supply cylinder 500 is communicated with the furnace body 210 of the ion diffusion furnace 200, and is used for supplying the inert gas and the gas containing nitrogen element, hydrogen element, carbon element and sulfur element into the furnace body 210;

The electrical control cabinet 600 is used to control the auxiliary equipment 100 of ion nitrogen carbon sulfur multi-component co-penetration, the ion nitriding furnace 200, the transformer 300, the vacuum pump 400 and the gas supply cylinder 500.

In some embodiments, the electrical control cabinet 600 is used as the control port of the entire ion nitrogen carbon sulfur multi-permeation treatment system, integrating the ion diffusion furnace power supply, electromagnet power supply, gas flow meter, cooling water flow meter, ammeter and cooling water control Valve and other switches in one. The furnace body 210 of the ion diffusion furnace 200 is a cavity for infiltrating the metal workpiece 230, and has good sealing performance. A magnetic field auxiliary unit is placed on the outer wall of the furnace body 210, and a hollow cathode ion source 140 is placed on the top of the furnace body 210. The electromagnet is used to generate a magnetic field around the metal workpiece, and the cooling components of the ion diffusion furnace 200 are the furnace body 210 , the hollow cathode ion source 140 , and the electromagnet 120 and the hollow cathode ion of the auxiliary equipment 100 The source 140 cools down. The transformer 200 is used to convert 380V industrial power into practical experimental power (including 220V for the coil of the electromagnet, 800V for the hollow cathode ion source, and 900V for the cathode and anode in the furnace. ). The vacuum pump 400 is used to provide a power source for vacuuming the furnace 210 .

The working process of the ionic nitrogen-carbon-sulfur multi-infiltration treatment system provided by the embodiment of the second aspect of the present disclosure is as follows:

Before the infiltration, the metal workpiece to be processed is placed in the ion infiltration infiltration with auxiliary equipment of ionic nitrogen, carbon and sulfur, and placed on the workpiece table. The negative pole of the power supply of the infiltration furnace is connected. Then close the furnace cover and the air release valve, open the vacuum pump to evacuate, open the electrical control cabinet, and adjust the current to maintain the magnetic field strength around 500Gs. Adjust the duty cycle and output voltage of the transformer, open the intake valve to introduce the required gas into the furnace, and heat up in this state, and open the hollow cathode ion source at the same time. After the temperature in the furnace reaches the set temperature, keep it warm for the required time. After reaching the diffusion time, turn off the power of the ion diffusion furnace, the electromagnet and the hollow cathode ion source, and continue to inject inert gas to cool the metal workpiece with the ion diffusion furnace.

The working principle of the ionic nitrogen-carbon-sulfur multi-permeation treatment system provided by the embodiment of the second aspect of the present disclosure is as follows:

Using the glow discharge effect between the hollow cathode ion source and the furnace body, the incoming gas is ionized into an ion state, and the workpiece table, metal disk and metal workpiece are bombarded and sputtered, and the magnetic field of the electromagnet is used to accelerate the bombardment of the ions, and at the same time Change the magnetic domain of the metal workpiece, improve the various properties of the workpiece surface, accelerate the diffusion of nitrogen atoms to the workpiece, and increase the thickness of the diffusion layer.

The ionic nitrogen-carbon-sulfur multi-permeation treatment method proposed by the embodiment of the third aspect of the present disclosure is completed by using the ionic nitrogen-carbon-sulfur multi-permeation treatment system proposed in the present disclosure. The processing method of the present disclosure includes the following steps:

1) Place the metal workpiece on the workpiece table of the ion diffusion furnace equipped with the auxiliary equipment of ion nitrogen carbon sulfur multi-infiltration, close the furnace cover and the air release valve, and open the vacuum pump to remove the air in the furnace until the vacuum degree is 10~ 30Pa for 10-20min;

2) Maintain the vacuum degree in the furnace, pass inert gas (such as argon, helium and/or neon, etc.) into the furnace, and the electrical control cabinet controls the air pressure in the furnace to maintain 30-50Pa through the flow meter;

3) Adjust the voltage (800V-900V) and duty ratio (70%-80%) of the transformer through the electrical control cabinet, so that the furnace is heated up in an inert gas atmosphere, so as to ensure stable glow discharge in the furnace and open the hollow core at the same time. Cathode ion source; keep the gas pressure in the furnace stable at 30-50Pa, and clean the workpiece surface by ionizing inert gas;

4) When the temperature in the furnace reaches 300°C to 350°C, open the inlet valve of the furnace body and pass in a gas containing nitrogen (such as nitrogen N ₂ ) and a gas containing hydrogen (such as hydrogen H ₂ ), which contains nitrogen The volume flow ratio of element gas to hydrogen-containing gas is 1:4 to 1:5, adjust the flow meter to intake air, keep the air pressure in the furnace at 200Pa-500Pa, and continue to heat up the furnace through the electrical control cabinet;

5) When the temperature in the furnace body reaches 400℃～450℃, stop feeding the inert gas, and feed the gas containing carbon element (such as acetylene C ₂ H ₂ ) into the furnace, because the carbon element will not penetrate into the metal workpiece at low temperature, Therefore, after the temperature is raised, acetylene is introduced to prevent gas waste), and the volume flow ratio of hydrogen-containing gas, nitrogen-containing gas and carbon-containing gas is kept at 75-83: 20-15: 5- 2. Keep the total intake air pressure unchanged at 300Pa~350Pa, reduce the voltage to 600~700V, and when the temperature in the furnace reaches 400~450℃, apply a voltage to the coil of the electromagnet, so that the magnetic field strength at the metal workpiece is maintained at 50Gs～80Gs;

6) After reaching the required co-infiltration temperature (500-550 °C), keep the current in the coil of the ionic nitrogen-carbon-sulfur multi-co-infiltration auxiliary device stable between 5-15A, and increase the magnetic field strength to 100-120Gs;

7) The pressure is maintained at 250-300Pa, and the temperature is maintained for 3h-7h, and the magnetic field strength of the electromagnetic field is reduced by 10Gs by reducing the current passing through the electromagnet every 1h;

8) After the heat preservation and pressure keeping, the gas containing sulfur element (such as hydrogen sulfide H ₂ S) is introduced into the furnace, and the gas containing hydrogen element, the gas containing nitrogen element, the gas containing carbon element and the gas containing sulfur element are adjusted again. The flow volume ratio of the gas is 60~65:15~2:5~10:10~15, and the total pressure in the furnace is increased to 350Pa~400Pa;

9) After reducing the temperature in the furnace to 450-500℃, keep the temperature for 0.5h-1h, and keep the magnetic field strength of the metal workpiece accessories in the furnace to about 100Gs-150Gs.

10) After reaching the holding time, slowly reduce the voltage, and at the same time slowly reduce the flow rate of hydrogen-containing gas, nitrogen-containing gas, carbon-containing gas and sulfur-containing gas, reduce the pressure in the furnace, and finally maintain the pressure in the furnace At about 50Pa, the magnetic field strength of the electromagnetic field remains unchanged;

11) After the temperature drops below 400°C, turn off the electromagnetic field, stop feeding hydrogen-containing gas, nitrogen-containing gas, carbon-containing gas and sulfur-containing gas, and then pass in a small amount of inert gas to keep the air pressure at 30Pa-50Pa, clean the surface of the metal workpiece after infiltration for 20min;

12) After cleaning, slowly lower and turn off the power of the ion diffusion furnace and the hollow cathode ion source.

13) After the furnace is cooled to below 150°C, turn off the inert gas and take out the metal workpiece.

In general, in order to prevent a large number of ion motion collisions in the magnetic field from hindering the deposition of nitrogen-carbon-sulfur compounds, and the magnetic field will limit the sulfur ions and reduce the lattice gap of the sulfide on the surface of the workpiece, so the magnetic field during carbonitriding is required. Appropriately decreased with time, and the magnetic field should be appropriately increased during ternary co-osmosis.

In some embodiments, the direct current flowing into the coil is to build a 1:1 simulation model for the ion diffusion furnace, the auxiliary equipment for ion nitrogen-carbon-sulfur multi-infiltration, the metal workpiece and the workpiece table, and the simulated electromagnet is gradually increased. The input current value of the electromagnet corresponds to when the metal workpiece is completely encompassed by the magnetic field and the field strength near the metal workpiece reaches about 500Gs.

In some embodiments, before the metal workpieces are put into the furnace, the workpieces to be processed are sequentially polished with sandpapers labeled 240#, 400#, 800#, 1000#, 1500#, and 2000#, and polished on a polishing machine to Scratch-free, then ultrasonically cleaned with acetone and alcohol and blow-dried to keep metal workpiece surfaces clean.

In actual use, the ionic nitrogen-carbon-sulfur multi-permeation treatment system provided by the embodiment of the present disclosure can change the magnetic field intensity by adjusting the current of the coil in the ion-nitrogen carbon-sulfur multi-permeation auxiliary equipment, thereby changing the thickness of the diffusion layer. At the same time, the diffusion layer increases, and the sulfide has a higher proportion in the diffusion layer. The deposition of sulfide under the action of the magnetic field is strengthened, the lattice gap is reduced, and the surface hardness is increased without affecting the wear reduction. For heavy-load friction pairs, the nitrogen-carbon-sulfur ternary co-infiltration workpiece treated by the treatment method provided by the embodiment of the present disclosure has advantages. The method of magnetron sputtering is used to limit the magnetic field of the plasma, use electromagnets that are more convenient to control, increase the controllability of the diffusion process, improve the co-infiltration efficiency, and increase the thickness of the diffusion layer. energy.

The specific example 1 of the ionic nitrogen-carbon-sulfur multi-component co-permeation treatment method provided by the present disclosure is described below, which specifically includes the following steps:

Before infiltration, first use the simulation software to establish a 1:1 model of the ion infiltration furnace and electromagnetic field, and establish a cylindrical metal workpiece model with a diameter of 25mm and a thickness of 8mm. The model material is selected as a ferromagnetic material, and the input of the simulated electromagnet is gradually increased. current, so that the workpiece is completely surrounded by the magnetic field and the field strength near the workpiece reaches 500Gs, and the input current value of the electromagnet at this time is recorded; then the cylindrical 38CrMoAl sample block with diameter 25mm and thickness 8mm is used as a metal workpiece. 400#, 800#, 1000#, 1500#, 2000# sandpaper is smooth, polished on a polishing machine to no scratches, ultrasonically cleaned with acetone and alcohol and dried.

1) Place the metal workpiece sample on the workpiece table of the ion diffusion furnace equipped with the auxiliary equipment of ion nitrogen carbon sulfur multi-infiltration, connect it with the cathode of the power supply, close the furnace cover and the air release valve, and turn on the vacuum pump to remove the furnace. Air, to a vacuum of 30Pa, maintained for 10min;

2) Maintain the vacuum degree in the furnace, pass argon gas into the furnace, and the electrical control cabinet controls the air pressure in the furnace to maintain 50Pa through the flow meter; then lower the furnace shell and close the air release valve, and open the vacuum pump to remove the air in the furnace to 50Pa. When the pressure in the furnace is lower than 50Pa, turn on the power supply system of the infiltration furnace to adjust the voltage (800V) and slowly increase the duty ratio to 70%.

3) Adjust the voltage (800V) and duty ratio (70%) of the transformer through the electrical control cabinet, so that the furnace is heated up in an argon gas atmosphere to ensure stable glow discharge in the furnace; open the air inlet valve and let in argon Keep the air pressure in the furnace stable at 50Pa to clean the surface of the workpiece.

4) When the temperature in the furnace reaches 300°C, open the inlet valve of the furnace body and introduce nitrogen and hydrogen, wherein the volume flow ratio of nitrogen and hydrogen is 1:4. 200Pa, reduce the voltage of the transformer to 700V through the electrical control cabinet;

5) When the temperature in the furnace body reaches 400°C, feed acetylene, stop feeding argon, keep the volume flow ratio of the gas H ₂ : N ₂ : C ₂ H ₂ =75:20:5, and keep the total intake air pressure When the voltage remains unchanged at 300Pa, the voltage is reduced to 600V again. At this time, the electromagnet controller of the ionic nitrogen-carbon-sulfur multi-infiltration auxiliary device is turned on to keep the magnetic field strength at the metal workpiece at 50Gs;

6) After reaching the required co-infiltration temperature (500°C), if the current is too large, reduce the voltage again, keep the current in the coil of the ionic nitrogen-carbon-sulfur multi-co-infiltration auxiliary device stable at 10A, and increase the magnetic field strength to 120Gs;

7) Hold for a period of time, the holding time is 7h, and the magnetic field strength of the electromagnetic field is reduced by 10Gs every 1h;

8) After the end time of the heat preservation, pass H ₂ S into the furnace, adjust the gas volume flow ratio H ₂ : N ₂ : C ₂ H ₂ : H ₂ S = 65:20: 5:10 again, and increase the furnace Total air pressure to 400Pa;

9) After reducing the temperature in the furnace to 450 °C, continue to keep the temperature for 1 hour, keep the metal workpiece accessories in the furnace and increase the magnetic field strength of the electromagnet to about 150Gs;

10) After reaching the holding time, slowly reduce the voltage, and at the same time slowly reduce the flow of H ₂ , N ₂ , C ₂ H ₂ , H ₂ S, reduce the air pressure in the furnace, and finally keep the air pressure in the furnace at about 50Pa, and the magnetic field strength of the electromagnetic field remains unchanged ;

11) After the temperature drops below 400°C, turn off the electromagnetic field, stop feeding H ₂ , N ₂ , C ₂ H ₂ , and H ₂ S, and then feed a small amount of inert gas argon to keep the air pressure at about 50Pa, to prevent the diffusion and permeation. The surface of the metal workpiece after nitrogen is cleaned for 20min;

12) Slowly lower and turn off the power of the ion diffusion furnace after cleaning.

13) After the furnace is cooled to below 150°C, turn off the argon gas and take out the metal workpiece sample block.

The treated metal workpiece was cut, the cut surface was polished and etched with 4% nitric acid to observe the morphology of the diffusion layer. The results are shown in Figure 5. Comparing the cross-sectional view of the sample without the use of the ionic nitrogen-carbon-sulfur multi-infiltration auxiliary device (as shown in Figure 4), it can be seen that the use of the ionic nitrogen-carbon-sulfur multi-infiltration auxiliary device increases the thickness of the infiltration layer. Figure 4 and Figure 5 show the cross-sectional metallographic diagram of the infiltration treatment and the use of the ionic nitrogen-carbon-sulfur co-infiltration treatment system and method provided by the embodiment of the present disclosure, the hardness gradient diagram is shown in Figure 6, and the UMT analysis diagram is shown in Figure 5. shown in Figure 7. The results show that after the treatment of Case 1, the thickness of the co-infiltration layer reaches 483 μm. Compared with 173 μm in the conventional co-infiltration treatment, the co-infiltration depth is increased by nearly 2 times using the device and method of the present disclosure. Figure 6 shows that the surface hardness of the metal workpiece is increased from 450HV _0.05 treated by conventional co-infiltration to 600HV _0.05 . Coefficient of Friction (COF) Compared with the conventional co-infiltration treatment, the coefficient of friction of the present disclosure is significantly lower. In this case, the thickness of the nitrogen-carbon-sulfur co-infiltration layer is significantly improved, and the surface hardness is higher, which is suitable for low-frequency and heavy-load friction conditions.

To sum up, the ionic nitrogen-carbon-sulfur multi-component interpenetration treatment method provided by the embodiment of the present disclosure has the following advantages compared with the existing ion diffusion infiltration:

1. Compared with conventional ion diffusion infiltration, the temperature in the furnace is increased under the same conditions, the diffusion of activated nitrogen carbon and sulfur atoms to the interior is deepened, the quality of the compound layer is improved, the brittleness is reduced, and the diffusion infiltration effect is strengthened. At the same time, the proportion of solid solution of sulfide in the diffusion layer increases, and the gap between sulfide lattices decreases. The surface hardness is improved on the premise of not affecting the friction coefficient and improving the wear resistance of vulcanization. For heavy-duty friction pairs, the nitrogen-carbon-sulfur ternary co-infiltration workpiece treated by the treatment method of the present disclosure has advantages.

2. Different limited magnetic fields are required for different workpieces, and the magnetron sputtering method of permanent magnets cannot be applied to all workpieces. The electromagnetic field designed by the present disclosure has the advantage of strong controllability.

3. The adjustment of auxiliary equipment and the diffusion process are coordinated to maximize the benefits of the auxiliary equipment. Compared with the conventional ion-nitrogen-carbon-sulfur co-seepage, the depth of the compound layer and the infiltration-diffusion layer can be increased with the assistance of the auxiliary equipment. The peak hardness of the infiltrated layer increases, the wear resistance increases, the quality of nitriding is higher, the sulfide on the surface layer is denser, and the surface hardness is higher. And save energy.

In the description of this specification, reference to the terms "one embodiment," "some embodiments," "exemplary embodiment," "example," "specific example," or "some examples", etc., is meant to incorporate the embodiments A particular feature, structure, material, or characteristic described by an example or example is included in at least one embodiment or example of the present disclosure. In this specification, schematic representations of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the particular features, structures, materials or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

Although embodiments of the present disclosure have been shown and described, it will be understood by those of ordinary skill in the art that various changes, modifications, substitutions, and alterations can be made in these embodiments without departing from the principles and spirit of the present disclosure, The scope of the present disclosure is defined by the claims and their equivalents.

Claims (8)

1. An ionic nitrogen-carbon-sulfur multi-component co-infiltration auxiliary device, the ionic nitrogen-carbon-sulfur multi-component co-infiltration auxiliary device is suitable for being placed on the furnace body of an ion diffusion infiltration furnace, and the ion diffusion infiltration furnace has a structure for placing metal The workpiece table of the workpiece is characterized in that, the ion nitriding auxiliary equipment comprises: a hollow cathode ion source adapted to be placed on top of the furnace body for emitting a plasma electron beam near the metal workpiece; and A magnetic field auxiliary unit, the magnetic field auxiliary unit includes an insulating casing and a plurality of electromagnets; the insulating casing is suitable for being placed on the side wall of the furnace body; a plurality of the electromagnets are coaxial and from the inside to the outside Arranged in the insulating shell in sequence, two adjacent electromagnets are wound in opposite ways, and a plurality of the electromagnets are used to form a controllable magnetic field in the ion diffusion furnace to change all the electromagnets. The motion trajectory of electrons on the surface of the metal workpiece and the magnetic domain of the metal workpiece. 2. The ionic nitrogen-carbon-sulfur multi-component interpenetration auxiliary equipment according to claim 1, wherein the current passed to the electromagnet satisfies: the metal workpiece is completely encompassed by the magnetic field generated by the electromagnet and all The magnetic field strength near the metal workpiece reaches 450Gs～550Gs. 3 . The ionic nitrogen-carbon-sulfur multicomponent interpenetration auxiliary equipment according to claim 1 , wherein each of the electromagnets is a ring electromagnet, respectively. 4 . 4. The ionic nitrogen-carbon-sulfur multicomponent interpenetration auxiliary equipment according to claim 1, wherein the axial direction of each electromagnet is parallel to the upper plane of the workpiece table. 5. The ionic nitrogen-carbon-sulfur multi-component interpenetration auxiliary equipment according to claim 1, wherein the magnetic field auxiliary unit further comprises a metal plate located in the furnace body and arranged as close as possible to the insulating shell, so The metal disk is wrapped by the magnetic field lines generated by the electromagnet, the material of the metal disk is the same as the material of the metal workpiece, and the metal disk and the workpiece table share a power source. 6. an ionic nitrogen carbon sulfur multicomponent co-permeation treatment system, is characterized in that, comprises: an ion diffusion and infiltration furnace, the ion nitriding furnace includes a furnace body and a workpiece table arranged in the furnace body for placing metal workpieces; Auxiliary equipment for ionic nitrogen-carbon-sulfur multi-infiltration, wherein the magnetic auxiliary equipment for ionic nitrogen-carbon-sulfur multi-infiltration is the auxiliary equipment for ionic nitrogen-carbon-sulfur multi-infiltration according to any one of claims 1 to 5; a transformer, which is connected with the electromagnet, the workpiece table and the hollow cathode ion source, and is used for making the electromagnet generate a magnetic field and supplying an ionization voltage to the furnace body; a vacuum pump, which is communicated with the furnace body and is used to make the furnace body in a vacuum state; a gas supply cylinder, communicated with the furnace body, for supplying inert gas, nitrogen-containing gas, hydrogen-containing gas, carbon-containing gas and sulfur-containing gas into the furnace body; and An electrical control cabinet is used to control the auxiliary equipment for ionic nitrogen, carbon and sulfur multi-component interpenetration, the ion diffusion furnace, the transformer, the vacuum pump and the gas supply cylinder. 7. an ion nitrogen carbon sulfur multicomponent co-permeation treatment method, is characterized in that, comprises: The metal workpiece is placed in the furnace body of the ion diffusion furnace, the furnace body is evacuated, and an inert gas is introduced into the furnace body; Passing a voltage into the furnace body and raising the temperature to ensure stable glow discharge in the furnace body, and turning on the hollow cathode ion source; When the temperature in the furnace body reaches the first temperature, the gas containing nitrogen element and the gas containing hydrogen element are introduced into the furnace body, and the temperature in the furnace body is continued to rise; When the temperature in the furnace body reaches the second temperature, the feeding of the inert gas is stopped, and the gas containing carbon element is fed into the furnace body, and the ionized nitrogen carbon according to any one of claims 1 to 5 is used. The sulfur multicomponent interpenetration auxiliary equipment provides a magnetic field with a first magnetic field strength to the metal workpiece; After the temperature in the furnace body reaches the co-infiltration temperature, use the ionic nitrogen-carbon-sulfur multi-component co-infiltration auxiliary equipment to provide a magnetic field with a second magnetic field strength to the metal workpiece; In the heat preservation and pressure keeping stage, gradually reduce the intensity of the magnetic field provided by the ionic nitrogen-carbon-sulfur multi-infiltration auxiliary equipment to the metal workpiece to a third magnetic field intensity; Passing gas containing sulfur into the furnace body, and reducing the temperature in the furnace body; When the temperature in the furnace body is lowered to a third temperature, use the ion nitrogen carbon sulfur multi-component common field auxiliary equipment to provide a magnetic field with a fourth magnetic field strength to the metal workpiece; When the temperature in the furnace body is lowered to the fourth temperature, the auxiliary equipment for ion nitrogen carbon sulfur multi-component co-permeation is turned off, and the gas containing hydrogen, nitrogen and carbon elements are stopped to pass into the furnace body. The gas and the gas containing sulfur element are introduced into the furnace body to clean the surface of the metal workpiece; When the temperature in the furnace body is lowered to the fifth temperature, the inert gas is stopped flowing into the furnace body, and the metal workpiece is taken out. 8 . The ionic nitrogen-carbon-sulfur multi-infiltration treatment method according to claim 7 , wherein the fourth magnetic field strength is greater than the second magnetic field strength. 9 .

Images