CN114540746B - Special vacuum rotary nitriding furnace for rare earth nitride - Google Patents

Special vacuum rotary nitriding furnace for rare earth nitride Download PDF

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CN114540746B
CN114540746B CN202111305043.7A CN202111305043A CN114540746B CN 114540746 B CN114540746 B CN 114540746B CN 202111305043 A CN202111305043 A CN 202111305043A CN 114540746 B CN114540746 B CN 114540746B
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furnace
furnace body
nitriding
rare earth
earth nitride
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CN114540746A (en
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赵宇
沈定君
涂元浩
何馨怡
于京京
王栋
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Hangzhou Permanent Magnet Group Co ltd
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Hangzhou Permanent Magnet Group Co ltd
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    • C—CHEMISTRY; METALLURGY
    • C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
    • C23C—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL
    • C23C8/00—Solid state diffusion of only non-metal elements into metallic material surfaces; Chemical surface treatment of metallic material by reaction of the surface with a reactive gas, leaving reaction products of surface material in the coating, e.g. conversion coatings, passivation of metals
    • C23C8/06—Solid state diffusion of only non-metal elements into metallic material surfaces; Chemical surface treatment of metallic material by reaction of the surface with a reactive gas, leaving reaction products of surface material in the coating, e.g. conversion coatings, passivation of metals using gases
    • C23C8/08—Solid state diffusion of only non-metal elements into metallic material surfaces; Chemical surface treatment of metallic material by reaction of the surface with a reactive gas, leaving reaction products of surface material in the coating, e.g. conversion coatings, passivation of metals using gases only one element being applied
    • C23C8/24—Nitriding
    • C23C8/26—Nitriding of ferrous surfaces
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01F—MAGNETS; INDUCTANCES; TRANSFORMERS; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES
    • H01F41/00—Apparatus or processes specially adapted for manufacturing or assembling magnets, inductances or transformers; Apparatus or processes specially adapted for manufacturing materials characterised by their magnetic properties
    • H01F41/02—Apparatus or processes specially adapted for manufacturing or assembling magnets, inductances or transformers; Apparatus or processes specially adapted for manufacturing materials characterised by their magnetic properties for manufacturing cores, coils, or magnets
    • H01F41/0253—Apparatus or processes specially adapted for manufacturing or assembling magnets, inductances or transformers; Apparatus or processes specially adapted for manufacturing materials characterised by their magnetic properties for manufacturing cores, coils, or magnets for manufacturing permanent magnets
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
    • Y02P20/00—Technologies relating to chemical industry
    • Y02P20/10—Process efficiency

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Abstract

The invention relates to the technical field of powder processing, and discloses a special vacuum rotary nitriding furnace for rare earth nitride, which comprises a furnace body, a control unit, a nitrogen supply device, a vacuumizing device and a heating device, wherein the nitrogen supply device, the vacuumizing device and the heating device are connected with the furnace body; a rotary powder cylinder is arranged in the furnace body; the furnace body sequentially comprises a metal shell layer, a cooling circulating water layer and a composite material inner layer from outside to inside; the inner layer of the composite material sequentially comprises a graphene coating, a resin glass fiber layer and a fluorine adhesive layer from inside to outside. The inner wall of the nitriding furnace has certain toughness, can bear enough gas pressure, ensures nitriding diffusion rate and improves nitriding pressure; graphene isotropy can reduce nitriding temperature differences. In addition, in the vacuum pumping and exhausting state, the inner wall is concave lens-shaped under the double negative pressure effect, so that the exhausting efficiency and quality can be improved. In the state of heating and gas-filling nitriding, the concave lens shape plays a Pascal principle, and the angle of the product in all directions is nitrided at the same temperature. In addition, the structure can also effectively save the nitrogen consumption.

Description

Special vacuum rotary nitriding furnace for rare earth nitride
Technical Field
The invention relates to the technical field of powder processing, in particular to a special vacuum rotary nitriding furnace for rare earth nitrides.
Background
With the rapid development of science and technology, particularly in the fields of automobiles, aerospace and the like, various materials have stricter requirements under various extreme environmental conditions. Permanent magnets are increasingly used as the most important functional materials in the national economy and science and technology fields. In 1990, coey et al prepared intermetallic compound R by gas-solid phase reaction 2 Fe 17 N x Wherein Sm is 2 Fe 17 N x Is attracting a great deal of attention. Sm on magnetic property 2 Fe 17 N x The saturation magnetization of (2) can reach 1.54T; sm (Sm) 2 Fe 17 N x Is 470 ℃; sm (Sm) 2 Fe 17 N x The anisotropy field of (2) reaches 14T; in the physical chemistryIn terms of properties, sm 2 Fe 17 N x The key performances of corrosion resistance, oxidation resistance, high temperature resistance and the like are excellent; in addition, in terms of price, samarium and iron raw materials are more in resources and low in price, wherein samarium raw materials are more surplus in productivity in China, and the raw material cost is low. To sum up, develop Sm 2 Fe 17 N x The magnet has wide market prospect and higher market value.
At present, the samarium iron nitrogen magnetic material has higher requirements on atmosphere in the preparation process, and nitriding pressure, temperature, oxygen content in nitriding environment and the like can directly influence the performance of the finally obtained product. The conventional nitriding furnace generally adopts the traditional heat-insulating material. For example, chinese patent application number CN201711046274.4 discloses a nitriding furnace, which comprises a furnace body, wherein a base is arranged in the furnace body, a workpiece cathode is arranged on the base, a power supply is connected with a transformer, the transformer is connected with a positive ion generating device arranged in the furnace body, a vacuum pump is further arranged for vacuumizing the furnace body, a gas supply device for supplying nitrogen to the furnace body is further arranged, and a gas circulating device is further arranged in the furnace body. The device is also provided with a control device, the control device is connected with a power supply, a vacuum pump and a gas supply, the control device is also connected with a memory, and the memory is connected with a display. The outer layer of the furnace body is provided with a heat preservation layer. The existing nitriding furnaces, including the above patents, have the disadvantages: conventional thermal insulation materials are commonly used, and the temperature range may be greatly different. In addition, the furnace body of the existing nitriding furnace is not specially designed generally, cannot bear higher pressure, raw material contact nitrogen area is small in nitriding process, nitriding time is long, nitriding efficiency is poor, and cost is increased and resources are wasted.
Disclosure of Invention
In order to solve the technical problems, the invention provides the special vacuum rotary nitriding furnace for the rare earth nitride, and the nitriding furnace has the advantages that nitriding temperature difference of each part in a furnace body is small when the nitriding furnace works, the exhaust efficiency/quality is high, the high pressure can be born, the nitriding efficiency is higher, and the nitrogen consumption can be saved.
The specific technical scheme of the invention is as follows: a vacuum rotary nitriding furnace special for rare earth nitride comprises a furnace body, a control unit, a nitrogen supply device, a vacuumizing device and a heating device, wherein the nitrogen supply device, the vacuumizing device and the heating device are connected with the furnace body. Wherein the control unit is used for controlling the operation of the nitriding furnace; a rotary powder cylinder is arranged in the furnace body. The furnace body sequentially comprises a metal shell layer, a cooling circulating water layer and a composite material inner layer from outside to inside; the inner layer of the composite material sequentially comprises a graphene coating, a resin glass fiber layer and a fluorine gel layer from inside to outside.
The nitriding furnace comprises the following specific operation processes: step one: the furnace body is opened, the rotating function of the rotating powder cylinder is started, the steering and rotating speed are set, the magnetic powder is thrown into the rotating powder cylinder, the furnace body is closed, and a program is started through the control unit. Step two: and starting the vacuumizing device to vacuumize the inside of the furnace body. Step three: and closing the vacuumizing device, starting the nitrogen supply device, and automatically executing a timing inflation and deflation process according to the set inflation (nitrogen) flow and time when the air pressure reaches the preset air pressure. Step four: after reaching the preset air pressure, starting a heating device, setting heating temperature and heating time, running a heating program, and carrying out nitriding treatment. Step five: and (5) discharging after nitriding is completed and cooled, opening the furnace body, controlling the rotary powder cylinder to rotate reversely, and discharging.
The nitriding furnace has the advantages that: the inner and outer walls of the conventional common nitriding furnace are made of steel, and the middle of the conventional common nitriding furnace is a water-passing layer. The inner wall (i.e. the inner layer) of the nitriding furnace adopts a composite material, and the inner side from the outer side is respectively: fluorine gum, resin glass fiber and graphene coating. Wherein: the fluorine rubber is used for sealing the water jacket and insulating resin glass fiber, and particularly can resist deformation and provide certain toughness, and the cavity can bear enough gas pressure, so that nitriding diffusion rate is ensured and nitriding pressure is improved; the isotropy of the graphene can realize better uniform heat transfer, and for the traditional vacuum nitriding equipment, the lower the temperature is, the worse the temperature uniformity is, the traditional equipment uniformity of the nitriding furnace with the highest temperature of 600 ℃ is +/-10 ℃, and the temperature uniformity of the nitriding furnace with the highest temperature can reach +/-2 ℃ by adopting the graphene. The most critical is that the inner wall of the nitriding furnace has toughness, so that the inner wall can be in a concave lens shape under the double negative pressure action of a vacuum pump and a water jacket water pump in a vacuumizing and exhausting state, and the exhausting efficiency and quality can be improved. In the state of heating and gas-filling nitriding, the concave lens shape of the inner wall plays a pascal principle, and the angle of each direction of the product is nitrided at the same temperature, which is incomparable with the traditional nitriding furnace. In addition, from the energy saving aspect, the nitriding pressure of an inflation valve of a common nitriding furnace is 0.2MPa, the water jacket pressure of a water pump is 0.3MPa, and the actual internal pressure of equipment is 0.2MPa. On the premise of the same basic size of the furnace body, the water pump, the vacuum pump and the air charge, the actual internal pressure of the equipment is 0.3MPa, so that nitrogen can be greatly saved, and the air consumption is 2/3 of that of common equipment.
Preferably, the minimum bearing pressure of the composite material inner layer is not less than 0.4MPa.
Preferably, the furnace body comprises a furnace cylinder, a front furnace door and a rear furnace door which are positioned at two ends of the furnace cylinder; and a plurality of water inlets and water return ports are distributed on each part of the furnace body. And an observation window is arranged on the front furnace door.
Preferably, the rotary powder cylinder comprises a spiral material cylinder, a rotary driving mechanism and a plurality of rolling bearings; the spiral charging barrel is fixedly connected with the rotary driving mechanism fixed on the furnace body and driven by the rotary driving mechanism; the rolling bearing is fixed in the furnace body and positioned below the spiral charging barrel and used for supporting the spiral charging barrel.
Preferably, the rotary driving mechanism comprises a servo motor fixed on the rear furnace door, wherein the rated power of the servo motor is 1.2KW, the rated torque is 6N.M, the rated rotating speed is 2000r/min, and the servo motor is provided with a speed reducer of 1:100, so that the rotating speed of the powder tank reaches 2-4r/min.
Preferably, the spiral charging barrel comprises a barrel body and spiral blades axially arranged in the barrel body; one end of the cylinder body is provided with a powder inlet and a powder outlet. The screw blade is designed to enable feeding and discharging at different directions.
The spiral charging barrel is specially designed, and spiral blades are arranged in the spiral charging barrel. Feeding is carried out during forward rotation, and discharging is carried out during reverse rotation. The spiral structure can disturb the nitrogen flow, so that the gas is more uniform, and the nitriding efficiency is improved.
Preferably, the heating device comprises a plurality of heating rods which are fixed in the furnace body and uniformly surround the outer side of the spiral charging barrel.
Preferably, the heating rod is a U-shaped aluminum oxide chromium heating rod, the highest temperature is 650 ℃, and the maximum heating power is 75KVA.
Preferably, the nitrogen supply device comprises a main air pipe and a plurality of branch air pipes communicated with the furnace body; the bronchus is connected with one end of the main air pipe in a parallel mode; the air inlet valve, the flowmeter, the safety valve, the exhaust valve, the angle control valve, the ionization gauge and the resistance gauge are connected to the main air pipe, and the other end of the main air pipe is connected with the butterfly valve.
Preferably, the bronchus comprises a plurality of primary bronchi which are connected in parallel and communicated with the main bronchus, and a plurality of secondary bronchi which are connected in parallel and communicated with the primary bronchi and the furnace body; the secondary bronchus is U-shaped. And a plurality of secondary bronchi are uniformly connected at different parts at the bottom of the furnace body.
The invention is designed with a plurality of stages of gas pipelines, in particular to a two-stage bronchus which is uniformly distributed at the bottom of the furnace body, thereby realizing porous uniform air extraction, and the air extraction is faster and more uniform, and the efficiency of the dominant multi-air extraction time in viscous flow-molecular flow (transitional flow) and molecular flow is greatly improved. From atmospheric pressure to 5X 10 -2 Pa, the same pump set pumping time was reduced from 60 minutes to 30 minutes. The pipeline and the supporting piece are shared by the air suction, inflation, air exhaust and product support, so that the equipment cost can be reduced, and the production efficiency and quality of the product can be improved.
As a further preferable mode, the number of the primary bronchi is 2, the primary bronchi are connected in an I shape through connecting pipes, and the connecting pipes are communicated with a main bronchi; the number of the secondary bronchi is six, and every three secondary bronchi are communicated with one primary bronchi in a parallel and parallel mode.
Preferably, the vacuumizing device comprises a Roots pump and a mechanical pump which are connected in series, and the Roots pump is communicated with the main air pipe. Maximum vacuum degree of vacuum pumping device is 3.5×10 -2 Pa。
Preferably, a bracket is arranged in the furnace body, and the bracket is enclosed on the outer sides of the rotary powder cylinder and the heating device.
Compared with the prior art, the invention has the beneficial effects that:
(1) The inner wall of the nitriding furnace is made of composite materials, so that certain toughness can be provided, the chamber can bear enough gas pressure, the nitriding diffusion rate is ensured, and the nitriding pressure is improved; graphene isotropy can reduce nitriding temperature differences. The most critical is that in the vacuum-pumping and exhausting state, the inner wall can be in the shape of a concave lens under the double negative pressure effect, so that the exhausting efficiency and quality can be improved. In the state of heating and gas-filling nitriding, the concave lens shape of the inner wall plays a pascal principle, and the angle of the product in all directions is nitrided at the same temperature. In addition, the structure can effectively save the nitrogen consumption.
(2) The invention designs a unique spiral charging barrel, and the spiral blades are arranged in the spiral charging barrel, so that forward and reverse rotation charging and discharging can be realized; and the spiral structure can disturb the nitrogen flow, so that the gas is more uniform, and the nitriding efficiency is improved.
(3) The invention is designed with a plurality of stages of gas pipelines, in particular to a two-stage bronchus which is uniformly distributed at the bottom of the furnace body, thereby realizing porous uniform air extraction, and the air extraction is faster and more uniform, and the efficiency of the dominant multi-air extraction time in viscous flow-molecular flow (transitional flow) and molecular flow is greatly improved. From atmospheric pressure to 5X 10 -2 Pa, the same pump set pumping time was reduced from 60 minutes to 30 minutes. The pipeline and the supporting piece are shared by the air suction, inflation, air exhaust and product support, so that the equipment cost can be reduced, and the production efficiency and quality of the product can be improved.
Drawings
FIG. 1 is a schematic view showing the appearance of a nitriding furnace according to the present invention;
FIG. 2 is a schematic front view of a nitriding furnace according to the present invention;
FIG. 3 is a schematic side view of a nitriding furnace according to the present invention;
FIG. 4 is a schematic top view of the nitriding furnace of the present invention;
FIG. 5 is a schematic top view of the nitriding furnace body of the present invention;
FIG. 6 is a schematic view of a rotary powder cylinder, nitrogen supplying means and heating means in the nitriding furnace according to the present invention;
FIG. 7 is a schematic top view of a rotary powder cylinder, nitrogen supply means and heating means in a nitriding furnace according to the present invention;
FIG. 8 is a schematic side view of a rotary powder cylinder, nitrogen supply means and heating means in a nitriding furnace according to the present invention;
FIG. 9 is a schematic side view of a rotary powder cylinder, nitrogen supplying means and heating means in a nitriding furnace according to the present invention;
FIG. 10 is a schematic cross-sectional view of a rotary powder cylinder in a nitriding furnace according to the present invention;
FIG. 11 is a schematic view of a structure of a screw blade cylinder in a nitriding furnace according to the present invention;
FIG. 12 is a schematic side view of a rotating powder cylinder in a nitriding furnace according to the present invention;
the reference numerals are: furnace body 1, control unit 2, rotary powder cylinder 101, metal shell 102, cooling circulation water layer 103, composite material inner layer 104, furnace cylinder 105, front furnace door 106, rear furnace door 107, water inlet 108, water return port 109, observation window 110, support 111, heating rod 301, main gas pipe 401, primary gas pipe 402, secondary gas pipe 403, gas inlet valve 404, flow meter 405, safety valve 406, gas outlet valve 407, angle control valve 408, ionization gauge 409, butterfly valve 410, resistance gauge 411, roots pump 501, mechanical pump 502, cylinder 1011, rolling bearing 1012, servo motor 1013, and spiral vane 1014. Powder inlet and outlet 1015.
Detailed Description
The invention is further described below with reference to examples.
General examples
As shown in figures 1-4, the special vacuum rotary nitriding furnace for rare earth nitride comprises a furnace body 1, a control unit 2, and a nitrogen supply device, a vacuumizing device and a heating device which are connected with the furnace body. Specifically:
the control unit is used for controlling the operation of the whole nitriding furnace, including rotation, heating, vacuumizing, pumping/charging nitrogen and the like, and can be a control unit commonly used in the prior art.
As shown in fig. 5, the furnace body comprises a furnace cylinder 105, a front furnace door 106 and a rear furnace door 107 positioned at two ends of the furnace cylinder; a plurality of water inlets 108 and water return inlets 109 for cooling are uniformly distributed on each part of the furnace body; the front door is also provided with an observation window 110. The furnace body sequentially comprises a metal shell layer 102, a cooling circulating water layer 103 and a composite material inner layer 104 from outside to inside; the composite material inner layer sequentially comprises a graphene coating, a resin glass fiber layer and a fluorine adhesive layer from inside to outside, and the minimum bearing pressure of the composite material inner layer is not less than 0.4MPa. As shown in fig. 6, a rotary powder cylinder 101 and a bracket 111 are arranged in the furnace body, and the bracket is arranged on the outer side of the rotary powder cylinder and the heating device in a surrounding manner. As shown in fig. 1 and 9, the rotary powder cartridge includes a screw cartridge, a rotary drive mechanism, and a plurality of rolling bearings 1012. As shown in fig. 10, the screw barrel further comprises a barrel 1011 and a screw blade 1014 axially disposed within the barrel; one end of the cylinder is provided with a powder inlet and outlet 1015. As shown in fig. 11, the screw blade is designed to achieve feeding and discharging at different directions. As shown in fig. 1, the spiral charging barrel is fixedly connected with and driven by a rotary driving mechanism fixed on the furnace body; as shown in fig. 9, a rolling bearing is fixed in the furnace body and positioned below the screw cylinder for supporting the screw cylinder. The rotary driving mechanism comprises a servo motor 1013 fixed on the rear furnace door, wherein the rated power of the servo motor is 1.2KW, the rated torque is 6N.M, the rated rotating speed is 2000r/min, and the servo motor is provided with a reducer of 1:100, so that the rotating speed of the powder tank reaches 2-4r/min.
As shown in fig. 7 to 8, the heating means includes a plurality of heating rods 301 fixed in the furnace body and uniformly surrounding the outside of the screw cylinder. The heating rod is preferably a U-shaped aluminum oxide chromium heating rod, the highest temperature is 650 ℃, and the maximum heating power is 75KVA.
As shown in fig. 6-9, the nitrogen supply device comprises a main air pipe 401 and a plurality of branch air pipes communicated with the furnace body; the bronchus is connected with one end of the main bronchus in a parallel mode; the main gas pipe is connected with a gas inlet valve 404, a flow meter 405, a safety valve 406, a gas outlet valve 407, an angle control valve 408, an ionization gauge 409 and a resistance gauge 411, and the other end of the main gas pipe is connected with a butterfly valve 410. Preferably, the bronchi comprise a plurality of primary bronchi 402 which are connected in parallel and are communicated with the main bronchi, and a plurality of secondary bronchi 403 which are connected in parallel and are communicated with the primary bronchi and the furnace body; the secondary bronchus is U-shaped. And each secondary bronchus is uniformly distributed at different parts of the bottom of the furnace body. Most preferably, the number of primary bronchi is 2, and the primary bronchi are connected in an I shape through connecting pipes, and the connecting pipes are communicated with the main bronchi; the number of the secondary bronchi is six, and every three secondary bronchi are communicated with one primary bronchi in a parallel and parallel mode.
As shown in fig. 1,2 and 4, the vacuum pumping device comprises a Roots pump 501 and a mechanical pump 502 which are connected in series, wherein the Roots pump is communicated with a main air pipe. Maximum vacuum degree of vacuum pumping device is 3.5×10 -2 Pa。
Example 1
As shown in figures 1-4, the special vacuum rotary nitriding furnace for rare earth nitride comprises a furnace body 1, a control unit 2, and a nitrogen supply device, a vacuumizing device and a heating device which are connected with the furnace body. Specifically:
the control unit is used for controlling the operation of the whole nitriding furnace, including rotation, heating, vacuumizing, pumping/charging nitrogen and the like, and can be a control unit commonly used in the prior art.
As shown in fig. 5, the furnace body comprises a furnace cylinder 105, a front furnace door 106 and a rear furnace door 107 positioned at two ends of the furnace cylinder; four water inlets 108 and water return openings 109 for cooling are uniformly distributed on two sides of the furnace body respectively; the front door is also provided with an observation window 110. The furnace body sequentially comprises a metal shell layer 102, a cooling circulating water layer 103 and a composite material inner layer 104 from outside to inside; the composite material inner layer sequentially comprises a graphene coating, a resin glass fiber layer and a fluorine adhesive layer from inside to outside, and the minimum bearing pressure of the composite material inner layer is not less than 0.4MPa. As shown in fig. 6, a rotary powder cylinder 101 and a bracket 111 are arranged in the furnace body, and the bracket is arranged on the outer side of the rotary powder cylinder and the heating device in a surrounding manner. As shown in fig. 1 and 9, the rotary powder cartridge includes a screw cartridge, a rotary drive mechanism, and two sets (two each) of rolling bearings 1012. As shown in fig. 10, the screw barrel further comprises a barrel 1011 and a screw blade 1014 axially disposed within the barrel; one end of the cylinder is provided with a powder inlet and outlet 1015. As shown in fig. 11, the screw blade is designed to achieve feeding and discharging at different directions. As shown in fig. 1, the spiral charging barrel is fixedly connected with and driven by a rotary driving mechanism fixed on the furnace body; as shown in fig. 9, two sets of rolling bearings are fixed in the furnace body and positioned below both ends of the spiral cylinder for supporting the spiral cylinder. The rotary driving mechanism comprises a servo motor 1013 fixed on the rear furnace door, wherein the rated power of the servo motor is 1.2KW, the rated torque is 6N.M, the rated rotating speed is 2000r/min, and the servo motor is provided with a reducer of 1:100, so that the rotating speed of the powder tank reaches 2-4r/min.
As shown in fig. 7 to 8, the heating apparatus comprises four heating rods 301 (U-shaped alumina chrome heating rod with a maximum temperature of 650 c and a maximum heating power of 75 KVA) fixed in the furnace body and uniformly surrounding the outside of the screw cylinder.
As shown in fig. 6-9, the nitrogen supply device comprises a main air pipe 401 and a branch air pipe communicated with the furnace body; the bronchus is connected with one end of the main bronchus in a parallel mode; the bronchi comprise two primary bronchi 402 (i-shaped connection through a connecting pipe) which are connected in parallel and communicated with the main bronchi, and six secondary bronchi 403 (U-shaped) which are connected in parallel and communicated with the primary bronchi and the furnace body, and each three secondary bronchi are communicated with one primary bronchi in a parallel and parallel mode. And each secondary bronchus is uniformly distributed at different parts of the bottom of the furnace body. The main gas pipe is connected with a gas inlet valve 404, a flow meter 405, a safety valve 406, a gas outlet valve 407, an angle control valve 408, an ionization gauge 409 and a resistance gauge 411, and the other end of the main gas pipe is connected with a butterfly valve 410.
As shown in fig. 1,2 and 4, the vacuum pumping device comprises a Roots pump 501 and a mechanical pump 502 which are connected in series, wherein the Roots pump is communicated with a main air pipe. Maximum vacuum degree of vacuum pumping device is 3.5×10 -2 Pa。
Application example 1
Nitriding operation was performed using the nitriding furnace of example 1.
(1) Opening a front furnace door of the vacuum rotary nitriding furnace, setting the steering direction of the rotary powder cylinder to be forward, and setting the rotating speed to be 1r/mn. Samarium iron nitrogen powder (Sm) 2 Fe 17 N 3 Average grain size 5 microns) is placed in a rotary powder cylinder, the mass of the powder cylinder is 50kg, then the front furnace door is closed, and the rotary powder cylinder is controlled to rotate positively and negatively alternately; the forward rotation time is 6min, the reverse rotation time is 5min, and the total rotation time is 11min; the rotation speed is 1r/min.
(2) Firstly locking a front furnace door of the furnace body, opening a mechanical pump and a Roots pump to carry out vacuumizing treatment until the vacuum degree reaches 5 multiplied by 10 -2 Pa。
(3) Closing the Roots pump and the mechanical pump, and starting the nitrogen supply device: opening an air inlet valve, observing a flowmeter, enabling the nitrogen filling flow to be 20L/min, closing the air inlet valve when the air pressure reaches 0.25MPa, setting an air filling and discharging program, and performing alternating nitrogen filling and discharging treatment: firstly, nitrogen filling and natural exhaust are carried out, wherein the air filling flow is 20L/min, and the exhaust flow is 10L/min; then, nitrogen filling and constant-pressure exhaust are carried out, wherein the filling flow = 20L/min of exhaust flow; the two are alternately carried out every 2 hours, and a heating device is started to heat and nitrid the furnace body; the heating temperature is 500 ℃ and the heating time is 12 hours.
(4) Cooling and deflating after nitriding is completed, opening a furnace door in front of the furnace body, and controlling the rotary powder cylinder to reversely rotate for discharging.
The properties of the above obtained product were as follows:
product(s) Remanence (kGs) Intrinsic coercivity (kOe) Maximum magnetic energy product (MGOe)
Sm 2 Fe 17 N 3 6.58 6.91 9.64
The raw materials and equipment used in the invention are common raw materials and equipment in the field unless specified otherwise; the methods used in the present invention are conventional in the art unless otherwise specified.
The foregoing description is only a preferred embodiment of the present invention, and is not intended to limit the present invention, and any simple modification, variation and equivalent transformation of the above embodiment according to the technical substance of the present invention still fall within the scope of the technical solution of the present invention.

Claims (10)

1. A special vacuum rotary nitriding furnace for rare earth nitride comprises a furnace body (1), a control unit (2), a nitrogen supply device, a vacuumizing device and a heating device, wherein the nitrogen supply device, the vacuumizing device and the heating device are connected with the furnace body; the control unit is used for controlling the operation of the nitriding furnace; a rotary powder cylinder (101) is arranged in the furnace body; the method is characterized in that: the furnace body sequentially comprises a metal shell layer (102), a cooling circulating water layer (103) and a composite material inner layer (104) from outside to inside; the inner layer of the composite material is sequentially provided with a graphene coating, a resin glass fiber layer and a fluorine glue layer from inside to outside.
2. The vacuum rotary nitriding furnace special for rare earth nitride according to claim 1, wherein: the minimum bearing pressure of the composite material inner layer is not less than 0.4MPa.
3. The vacuum rotary nitriding furnace special for rare earth nitride according to claim 1, wherein: the rotary powder barrel comprises a spiral material barrel, a rotary driving mechanism and a plurality of rolling bearings (1012); the spiral charging barrel is fixedly connected with the rotary driving mechanism fixed on the furnace body and driven by the rotary driving mechanism; the rolling bearing is fixed in the furnace body and positioned below the spiral charging barrel and used for supporting the spiral charging barrel.
4. A rare earth nitride dedicated vacuum rotary nitriding furnace according to claim 3, wherein: the spiral charging barrel comprises a barrel body (1011) and a spiral blade (1014) axially arranged in the barrel body; one end of the cylinder body is provided with a powder inlet and outlet (1015).
5. A rare earth nitride dedicated vacuum rotary nitriding furnace according to claim 1, 3 or 4, wherein: the heating device comprises a plurality of heating rods (301) which are fixed in the furnace body and uniformly surround the outer side of the spiral charging barrel.
6. The vacuum rotary nitriding furnace special for rare earth nitride according to claim 1, wherein: the nitrogen supply device comprises a main air pipe (401) and a plurality of branch air pipes communicated with the furnace body; the bronchus is connected with one end of the main air pipe in a parallel mode; the gas pipe is connected with a gas inlet valve (404), a flow meter (405), a safety valve (406), a gas outlet valve (407), an angle control valve (408), an ionization gauge (409) and a resistance gauge (411), and the other end of the gas pipe is connected with a butterfly valve (410).
7. The vacuum rotary nitriding furnace special for rare earth nitride according to claim 6, wherein: the bronchus comprises a plurality of primary bronchi (402) which are connected in parallel and communicated with the main bronchus, and a plurality of secondary bronchi (403) which are connected in parallel and communicated with the primary bronchi and the furnace body; the secondary bronchus is U-shaped.
8. The vacuum rotary nitriding furnace special for rare earth nitride according to claim 7, wherein: the number of the primary bronchi is 2, the primary bronchi are connected in an I shape through connecting pipes, and the connecting pipes are communicated with the main bronchi; the number of the secondary bronchi is six, and every three secondary bronchi are communicated with one primary bronchi in a parallel and parallel mode.
9. A rare earth nitride dedicated vacuum rotary nitriding furnace according to claim 6 or 7 or 8, wherein: the vacuumizing device comprises a Roots pump (501) and a mechanical pump (502) which are connected in series, and the Roots pump is communicated with the main air pipe.
10. The vacuum rotary nitriding furnace special for rare earth nitride according to claim 1, wherein: a bracket (111) is arranged in the furnace body, and the bracket is enclosed on the outer sides of the rotary powder cylinder and the heating device.
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Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN103898437A (en) * 2014-03-19 2014-07-02 江苏益科热处理设备有限公司 High-temperature carburizing multi-purpose furnace by adopting composite furnace liner structure
CN214529213U (en) * 2021-03-04 2021-10-29 中原工学院 Horizontal high-pressure continuous vacuum nitriding furnace

Family Cites Families (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS58144468A (en) * 1982-02-19 1983-08-27 Toyota Motor Corp Gas replacement of heat treating furnace
CN2417181Y (en) * 2000-05-16 2001-01-31 上海嘉顿环保科技有限公司 Micro-pulsation plasma nitriding hot wall stove
JP5410652B2 (en) * 2007-02-26 2014-02-05 Ｄｏｗａサーモテック株式会社 Heat treatment furnace
JP5966225B2 (en) * 2012-03-28 2016-08-10 Ｄｏｗａサーモテック株式会社 Heat treatment furnace
CN104195503B (en) * 2014-05-25 2017-10-20 北京华翔电炉技术有限责任公司 Horizontal high-pressure air quenching backfire nitrogenizes multi-purpose vacuum stove
CN105274467A (en) * 2014-07-17 2016-01-27 哈尔滨宏万智科技开发有限公司 Furnace lining structure of well type gas carburizing furnace
CN105296913A (en) * 2014-07-18 2016-02-03 哈尔滨宏万智科技开发有限公司 Double-cavity carburizing pot
CN106011621B (en) * 2016-06-08 2017-09-26 东莞市本润机器人科技股份有限公司 A kind of preparation technology of harmonic reducer flexible wheel
CN107974671B (en) * 2017-11-18 2019-09-17 西北有色金属研究院 A kind of preparation method of photo catalytic reduction graphene oxide composite membrane
WO2020008977A1 (en) * 2018-07-06 2020-01-09 株式会社カネカ Pellicle complex and production method therefor

Patent Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN103898437A (en) * 2014-03-19 2014-07-02 江苏益科热处理设备有限公司 High-temperature carburizing multi-purpose furnace by adopting composite furnace liner structure
CN214529213U (en) * 2021-03-04 2021-10-29 中原工学院 Horizontal high-pressure continuous vacuum nitriding furnace

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