Protective atmosphere heat treatment equipment and control method

Abstract

The invention relates to protective atmosphere heat treatment equipment and a control method, and aims to provide equipment capable of carrying out component heat treatment in an almost oxygen-free and water-vapor-free environment. The equipment comprises a pre-vacuumizing system, a three-dimensional inflation system, an exhaust system, an atmosphere uniform stirring system and a three-dimensional heating system. The control method comprises the steps of starting air exhaust, starting air exhaust, starting air inflation, starting heating, starting stirring and the like. The oxygen content in the heat treatment equipment can be lower than 30 ppm, and the water vapor content can be lower than 30 ppm; the atmosphere temperature in the furnace is uniform, and the temperature difference of different positions is lower than + / -5 DEG C; when the technology is adopted to heat the heated component, the advantages of high efficiency and environment friendliness are achieved.

Description

Technical Field

[0001] The present invention relates to the technical field of protective atmosphere heat treatment equipment, and particularly relates to a high-cleanliness, high-uniform-temperature, and high-efficiency protective atmosphere preparation equipment and control method. Background Art

[0002] Heat treatment equipment is a carrier for implementing heat treatment processes of materials, products, and components. By means of heat treatment equipment, materials, products, and components are heated, held, cooled, etc., to change the structure and stress state of the materials, products, and components, and obtain materials, products, and components that meet performance and shape accuracy requirements. In order to obtain certain special properties, materials, products, and components need to be heated and held in an environment that is nearly oxygen-free and water-vapor-free.

[0003] As medium and large superconducting magnets, which are core components of magnetic confinement fusion reactors, need to be heated and held for a long time in an environment that is nearly oxygen-free and nearly water-vapor-free during heat treatment, and heat treatment is often carried out in protective atmosphere heat treatment equipment or vacuum heat treatment equipment. At the same time, due to the use of a sheathed cable conductor structure in medium and large superconducting magnets, a certain amount of oxygen and water vapor will be released during the initial heating and holding stages, and the oxygen and water vapor in the heat treatment equipment need to be removed in a timely and rapid manner. Vacuum heat treatment equipment is difficult to quickly evacuate the oxygen and water vapor in the equipment. Therefore, medium and large superconducting magnets often use protective atmosphere heat treatment equipment for heat treatment, especially use argon protective atmosphere heat treatment equipment for heat treatment of medium and large superconducting magnets.

[0004] Existing protective atmosphere heat treatment equipment has problems such as long gas filling time and difficulty in achieving a truly "low-oxygen, low-water-vapor" protective atmosphere environment. For example, the Chinese invention patent application (application number 201910248386.0) discloses a multi-stage temperature equalization system for heat treatment of large Nb 3 Sn coils and its temperature control method. By setting structures such as a primary temperature equalization tank, a secondary temperature equalization cylinder, a tertiary temperature equalization cover, and a PLC control cabinet, a heat treatment equipment with high temperature uniformity is obtained. By injecting and exhausting protective gas into the tertiary temperature equalization cover, a "protective atmosphere" environment is obtained for the heat treatment equipment. The protective atmosphere obtained by the method of "injecting protective gas" to drive out the initial gas in the heat treatment equipment is complex, and the gas filling time is long, and it is difficult to obtain a truly "low-oxygen, low-water-vapor" protective atmosphere environment. Summary of the Invention

[0005] In view of this, the main purpose of the present invention is to provide a high-cleanliness, high-uniform-temperature, and high-efficiency protective atmosphere heat treatment equipment and control method for heat treatment of components that require a truly "low-oxygen, low-water-vapor" protective atmosphere environment, high temperature uniformity, and high-efficiency heating.

[0006] To achieve the above objectives, on the one hand, the present invention provides a protective atmosphere heat treatment device, comprising:

[0007] A pre-evacuation system is arranged at the four sides of the bottom of the heat treatment device. It converges towards one end through four branch pipelines, and is successively connected and merged into a manifold pipe, and then connected to a vacuum pump. Automatic stop valves 1-2 and check valves 1-3 are respectively arranged on the four branch pipelines.

[0008] A three-dimensional inflating system is arranged on the inner linings of the four sides inside the heat treatment device. Atmosphere heating pipelines inside the device are arranged horizontally and in parallel and are evenly provided with air holes. Outside the heat treatment device, device outer gas transmission pipelines and an argon gas source are arranged. The atmosphere heating pipelines inside the device and the device outer gas transmission pipelines are connected to the argon gas source through multi-stage intersections. The diameters of the multi-stage pipelines gradually increase to quickly and evenly distribute argon gas in the furnace.

[0009] An exhaust system is arranged on one side above the furnace body of the heat treatment device. A cooler 3-2, a second detection air outlet 3-7, an intelligent pressure gauge 3-3, a check valve 3-4, a glass rotor flowmeter 3-5, and an automatic stop valve 3-6 are successively arranged through an exhaust pipeline from the end of the heat treatment device. And the check valve 3-4 controls that the gas can only flow from the heat treatment device to the automatic stop valve 3-6.

[0010] An atmosphere uniform stirring system is arranged inside the furnace body of the heat treatment device. It is composed of the lower end of a high-temperature and high-speed stirring fan located at the furnace top being docked with the upper end of an atmosphere equalizing air guiding device. The high-temperature and high-speed stirring fan circulates argon gas up and down and makes the heated argon gas directly act on the component evenly through the atmosphere equalizing air guiding device.

[0011] A three-dimensional heating system is composed of multiple groups of heating elements evenly arranged on the inner walls around the furnace body of the heat treatment device. The heating elements are arranged in a strip shape, horizontally, in parallel, and evenly up and down.

[0012] The beneficial effects of the above technical solutions are as follows. The pre-evacuation system is set to discharge as much as possible the initial gas inside the heat treatment device. Since the density of the filled argon gas is greater than the density of air (including the air after pre-evacuation), the exhaust system is arranged above the furnace body of the heat treatment device so that a small amount of miscellaneous gas after the heat treatment device is pre-evacuated and filled with argon gas can also be discharged. The three-dimensional inflating system is arranged around the inside of the heat treatment furnace. Through the evenly arranged air inlet devices, the uniformity of the filled atmosphere can be improved and the inflating efficiency can also be improved. The atmosphere uniform stirring system further evenly distributes the heated protective atmosphere inside the furnace body of the heat treatment device through the air equalizing device and the circulating fan and directly acts on the heated component through the air equalizing device, improving the heat treatment efficiency of the component.

[0013] The three-dimensional heating system is evenly arranged inside the equipment furnace, improving the heating efficiency of the protective atmosphere and the temperature uniformity inside the equipment furnace.

[0014] In one of the above technical solutions, the external gas pipeline of the equipment is composed of a main gas supply pipeline, several branch gas supply pipelines, and several main and branch gas supply pipelines. The main gas supply pipeline connects the argon gas source and the several branch gas supply pipelines; the branch gas supply pipelines are further connected to the several main and branch gas supply pipelines; the several main and branch pipelines are sequentially connected to the atmosphere heating pipelines inside the equipment with equal diameter and quantity from the middle of the four sides outside the heat treatment equipment.

[0015] It has the following advantages. With a multi-stage pipeline design, the main gas supply pipeline, branch pipelines, and main and branch pipelines gradually thicken, improving the transportation efficiency of argon gas from the gas source to the heat treatment equipment, ensuring that argon gas can be quickly and evenly distributed throughout the furnace body, shortening the inflation time, and improving the heat treatment efficiency.

[0016] In one of the above technical solutions, an automatic cut-off valve 2-10 and a filter 2-11 are provided on the main gas supply pipeline, and an automatic cut-off valve 2-3, an intelligent pressure gauge 2-4, a check valve 2-5, an intelligent mass flowmeter 2-6, and a pressure reducing and stabilizing valve 2-7 are respectively provided on the several main and branch pipelines from the furnace body end.

[0017] It has the following advantages. By controlling the valves and detection equipment, the equipment can be automatically controlled to enter the inflation state from the vacuum state, and the intake air volume can be adjusted according to the detection data, realizing precise control of the inflation process, ensuring that the filled argon gas meets the requirements of the heat treatment process, and improving the stability and controllability of the heat treatment process.

[0018] In one of the above technical solutions, a first detection air outlet 2-12 is provided on the main gas supply pipeline. The first detection air outlet 2-12 and the second detection air outlet 3-7 are connected through a transition pipeline to form a gas collection port. An automatic cut-off valve 7-3 and a check valve 7-4 are sequentially provided on the transition pipeline from the detection air outlet 2-12 to the gas collection port; a hydrocarbon analyzer 7-6, a dew point meter 7-7, a trace oxygen analyzer 7-8, and an automatic cut-off valve 7-9 are sequentially provided after the gas collection port.

[0019] It has the following advantages. By providing a detection air outlet on the main gas supply pipeline and connecting it with the detection air outlet on the exhaust pipeline to form a gas collection port, and cooperating with a hydrocarbon analyzer, a dew point meter, and a trace oxygen analyzer, the atmosphere components of the argon gas source and the atmosphere components filled into the furnace body of the heat treatment equipment can be monitored in real time, ensuring the high cleanliness of the inflation atmosphere, promptly discovering and handling gas impurities, and guaranteeing the heat treatment quality.

[0020] In one of the above technical solutions, a multi-component flow sheet is provided at the upper part of the atmosphere equalizing and gas guiding device, and atmosphere guiding channels are evenly distributed on the side surface. The high-speed stirring fan pumps the protective atmosphere inside the atmosphere equalizing and gas guiding device to the upper part, and evenly guides it through the multi-component flow sheet to the space formed between the side surface of the atmosphere equalizing and gas guiding device and the inner wall of the heat treatment equipment furnace. Subsequently, it enters the atmosphere equalizing and gas guiding device through the bottom arc of the atmosphere equalizing and gas guiding device and the atmosphere guiding channels, and circulates and impacts the heated component located inside the atmosphere equalizing and gas guiding device.

[0021] It has the following advantages: under the action of its guiding vane and gas guiding channel, the heated argon gas can act on the heated component evenly, improving the heat exchange efficiency, ensuring that the heated component can reach the preset temperature quickly and evenly, and improving the heat treatment efficiency.

[0022] In one of the above technical solutions, the number of the multi-group heating elements is equal to the number of the atmosphere heating pipelines inside the equipment. The multi-group heating elements are above the atmosphere heating pipelines inside the equipment, with a distance greater than 300 mm, a distance greater than 200 mm from the side surface of the atmosphere equalizing and gas guiding device, and a distance greater than 50 mm from the furnace lining of the heat treatment equipment.

[0023] It has the following advantages: the reasonable distance design between the heating elements and the atmosphere heating pipelines inside the equipment, the side surface of the atmosphere equalizing and gas guiding device, and the furnace lining of the heat treatment equipment ensures that the heating elements can efficiently heat the protective atmosphere, while avoiding heat loss and equipment damage, and improving the stability and service life of the heat treatment equipment.

[0024] To achieve the above object, on the other hand, the present invention also provides a control method for a protective atmosphere heat treatment equipment, including the following steps:

[0025] Start the pre-vacuum pumping system to pump out the gas in the furnace body of the heat treatment equipment until it reaches a vacuum degree below 10 -2 Torr;

[0026] After the equipment reaches the preset vacuum degree, close the pre-vacuum pumping system, and then open the exhaust system;

[0027] After the exhaust system is opened, start the three-dimensional inflation system to fill argon into the heat treatment equipment sequentially from the lower part to the upper part of the furnace body of the heat treatment equipment;

[0028] When the oxygen content and water vapor content in the discharged gas detected by the exhaust system reach the preset values, start the three-dimensional heating system, and at the same time throttle down the three-dimensional inflation system and the exhaust system to keep the pressure in the furnace at a state of 4000 - 6000 Pa;

[0029] When the heat treatment equipment reaches the preset temperature, start the atmosphere uniform stirring system, and contact the heated protective atmosphere with the preheated component, so as to heat the component to be heated.

[0030] One of the above technical solutions realizes the efficient and stable operation of the heat treatment process by starting the automatic control of steps such as air extraction, exhaust, inflation, heating, and stirring, reduces the error of manual operation, and improves the heat treatment efficiency and quality of the component.

[0031] One of the above technical solutions, the control of extracting the gas in the furnace body of the heat treatment equipment is carried out through the following formula:

[0032]

[0033] In the formula, P 极限 is the ultimate vacuum degree of the vacuum pump in the pre-vacuum system; P is the required vacuum degree in the heat treatment equipment below 10 -2 Torr; Q 0 is the total gas release amount of the heat treatment equipment, with the unit of Pa*L / s; Q t is the total air leakage amount of the heat treatment equipment, with the unit of Pa*L / s; S y is the effective air extraction rate of the heat treatment equipment, with the unit of L / s; V is the volume of the heat treatment equipment, with the unit of m 3 ; t is the required air extraction time, with the unit of h; K is the vacuum coefficient, generally 1.1 - 1.25.

[0034] It has the following advantages: it can accurately control the vacuum degree of the pre-vacuum system according to the specific parameters and requirements of the heat treatment equipment, ensure that almost all the initial gas in the equipment is discharged, and provide a more reliable basis for realizing a high-purity protective atmosphere environment.

[0035] One of the above technical solutions, the amount of argon gas filled into the heat treatment equipment is calculated through the following formula:

[0036] V 充标 =(1.5 - 3)V

[0037] The V 充标 is the amount of argon gas filled into the heat treatment equipment before heating.

[0038] It has the following advantages: it can accurately control the gas amount according to the specific parameters and requirements of the heat treatment equipment, ensure that the protective atmosphere in the equipment meets the heat treatment requirements, and guarantee the heat treatment quality.

[0039] One of the above technical solutions, the temperature difference of the atmosphere in the atmosphere uniform stirring system is obtained through the following formula:

[0040]

[0041] Q = vA 炉

[0042]

[0043] Where α C is the surface heat transfer coefficient of the heated component during heating in the protective atmosphere heat treatment furnace, with the unit of W / m 2 *℃; M is the weight of the heated component, with the unit of kg; c is the specific heat capacity of the heated component, with the unit of J / kg*℃; A is the surface area of the heated component, with the unit of m 2 ; tg is the set temperature of the heat treatment equipment, with the unit of ℃; ts is the initial temperature of the heated component, with the unit of ℃; t is the final heating temperature of the heated component, with the unit of ℃; v is the flow rate of the atmosphere in the heat treatment equipment, with the unit of m / s; Q is the flow rate of the protective atmosphere in the heat treatment equipment, with the unit of m 3 / s; A 炉 is the effective cross-sectional area of the heat treatment equipment, with the unit of m 2 ; is the heat loss at the top of the heat treatment equipment, with the unit of W / m 2 ; S is the heat dissipation area at the top of the heat treatment equipment, with the unit of m 2 ; C g is the specific heat of the atmosphere inside the heat treatment equipment, with the unit of J / kg*℃; ρ is the density of the atmosphere in the heat treatment equipment, with the unit of kg / m 3 ; Δt is the temperature difference between the first and the last contact of the protective atmosphere with the surface of the heated component during the circulation process, with the unit of ℃.

[0044] It has the following advantages. By calculating the atmosphere flow rate of the high-temperature resistant stirring fan through the formula, the flow rate of the stirring fan can be accurately controlled according to the specific parameters of the heated component and the heat treatment requirements, ensuring that the protective atmosphere can act on the heated component efficiently and uniformly, improving the heat treatment efficiency and quality, and reducing energy waste.

[0045] In summary, the protective atmosphere obtained by the present invention has the characteristic of high cleanliness, with the oxygen content in the heat treatment equipment being lower than 30 ppm and the water vapor content being lower than 30 ppm; the furnace atmosphere temperature obtained by the present invention has the characteristic of high uniformity, with the temperature difference at different positions being lower than ±5℃; when heating the heated component using the technology of the present invention, it has the advantages of high efficiency and greenness, and the heating time can be shortened by 30%. Brief Description of the Drawings

[0046] Figure 1 is a schematic structural diagram of the present invention, Figure 1-1 being the front view, Figure 1-2 and being the top view.

[0047] Figure 2 This is the control flow chart of the present invention. Specific Embodiments

[0048] The following will clearly and completely describe the technical solutions in the embodiments of the present invention with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0049] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the technical field to which the present invention belongs. The terms used herein are only for the purpose of describing the embodiments of the present invention and are not intended to limit the present invention.

[0050] Before further elaborating on the specific embodiments of the present invention, the nouns and terms involved in the embodiments of the present invention, as well as their corresponding uses / functions / roles in the present invention, are described. The nouns and terms involved in the embodiments of the present invention are subject to the following explanations.

[0051] 1. Protective atmosphere heat treatment equipment: A device used for heat treating metal materials or products, mainly aiming to prevent oxidation, decarburization, or other harmful reactions during the heat treatment process. The protective atmosphere can be inert gases such as nitrogen, argon, helium, or a specific atmosphere mixture, which can isolate oxygen in the air to achieve the purpose of protecting the material.

[0052] 2. High cleanliness: In the present invention, high cleanliness means that during the heating and holding processes of materials, products, and components, the contents of oxygen and water vapor in the protective atmosphere heat treatment equipment are extremely low, with the oxygen content being lower than 30 ppm and the water vapor content being lower than 30 ppm.

[0053] 3. High uniformity temperature: In the present invention, high uniformity temperature means that the temperature deviation of the atmosphere in different regions of the protective atmosphere heat treatment equipment is very small, with the temperature deviation being lower than ±5°C.

[0054] 4. High efficiency: In the present invention, high efficiency means that when materials, products, and components are heated in the protective atmosphere heat treatment equipment, due to the impact of the protective atmosphere on the surfaces of the materials, products, and components, the heat exchange between the protective atmosphere and the materials, products, and components is improved, thereby enhancing the heating efficiency.

[0055] 5. Equivalent radius: Non-circular shapes such as rectangles, squares, and polygons are equivalent to circles. To obtain the equivalent radius, first calculate the area S of the non-circular shape, and then solve for R according to S = 4πR 2 to obtain R, and the obtained R is the equivalent radius.

[0056] The technical solutions in the present application will be described below in conjunction with the accompanying drawings.

[0057] As shown in Figure 1, a protective atmosphere heat treatment device includes a pre-evacuation system 1, a three-dimensional gas filling system 2, an exhaust system 3, an atmosphere uniform stirring system 4, a three-dimensional heating system 5, etc.

[0058] The pre-evacuation system 1 is below the furnace body 6 of the heat treatment device. Four air extraction ports 6-1 are evenly reserved below the furnace body of the heat treatment device. The pre-evacuation system 1 is connected to the above four reserved air extraction ports 6-1. The four reserved air extraction ports are connected to four groups of seamless air extraction branch pipes 1-1. Automatic stop valves 1-2 and check valves 1-3 are provided on each of the four groups of seamless air extraction branch pipes 1-1. The four groups of seamless air extraction branch pipes are connected to an air extraction main pipe 1-4. The other end of the air extraction main pipe is connected to a vacuum pump 1-5; and the check valve controls that the gas can only flow from the heat treatment device to the vacuum pump.

[0059] The three-dimensional gas filling system 2 is arranged around the furnace body 6 of the heat treatment device. Six (6 atmosphere filling ports are arranged in the furnace body height direction) * four (4 groups of atmosphere filling ports are arranged in the furnace body circumferential direction) groups of atmosphere filling ports 6-2 are reserved in the furnace body of the heat treatment device. One end of a number of atmosphere filling ports 6-2 is connected to a number of in-device atmosphere pipelines 2-1, and the other end of a number of atmosphere filling ports 6-2 is connected to a number of gas supply main and branch pipelines 2-2. Automatic stop valves 2-3, intelligent pressure gauges 2-4, check valves 2-5, intelligent mass flow meters 2-6 and pressure reducing valves 2-7 are arranged on each of the number of gas supply main and branch pipelines 2-2; Six gas supply main and branch pipelines on each side are connected in parallel to form a gas supply branch pipeline; The four groups of gas supply branch pipelines are connected in parallel and then connected to a gas supply main pipeline 2-8. The other end of the gas supply main pipeline 2-8 is connected to an argon gas source 2-9. A stop valve 2-10 and a filter 2-11 are provided on the gas supply main pipeline. The diameter of the gas supply main pipeline is 2-3 times the diameter of the gas supply branch pipeline, and the diameter of the gas supply branch pipeline is 2-3 times the diameter of the gas supply main and branch pipelines.

[0060] The exhaust system 3 is on one side above the furnace body 6 of the heat treatment device. One centralized exhaust port 6-3 is reserved above the furnace body of the heat treatment device. The exhaust system 3 is connected to the above one centralized exhaust port 6-3. The exhaust system 3 includes: a cooler 3-2, an intelligent pressure gauge 3-3, a check valve 3-4, a glass rotor flow meter 3-5, an automatic stop valve 3-6; and the check valve 3-4 controls the gas to flow from the heat treatment device to the automatic stop valve 3-6.

[0061] The described atmosphere uniform stirring system 4 is inside the furnace body 6 of the heat treatment equipment. The stirring fan 4-1 of the atmosphere uniform stirring system is located above the furnace body of the heat treatment equipment. The atmosphere uniform stirring system 4 consists of an atmosphere equalizing and air guiding device 4-2 and a high-temperature resistant high-speed stirring fan 4-1. The lower end of the high-temperature resistant stirring fan 4-1 is docked with the in-furnace atmosphere equalizing and air guiding device 4-2. The atmosphere equalizing and air guiding device 4-2 is composed of an upper air guiding device 4-2-1, a multi-component flow sheet 4-2-2, a side air guiding device 4-2-3, a bottom arc-shaped air guiding device 4-2-4, and an air guiding channel 4-2-5. The internal atmosphere circulation of the heat treatment equipment is achieved in the following way: The protective atmosphere gas inside the heat treatment equipment is sucked into the channels of the top air guiding device 4-2-1 and the top 6-4 of the heat treatment equipment under the suction of the high-temperature resistant high-speed stirring fan 4-1. At this time, the protective atmosphere gas is evenly divided by the multi-component flow sheet 4-2-2 into the channels formed by the side air guiding device 4-2-3 and the inner side 6-5 of the heat treatment equipment, and then enters the inside of the air guiding device through the bottom arc-shaped air guiding device 4-2-4 and the air guiding channel 4-2-5 on the side air guiding device 4-2-3.

[0062] The heated component is heated in the following way: The high-temperature resistant high-speed stirring fan 4-1 pumps the protective atmosphere gas inside the air guiding device (where the workpiece to be heated is located) to the upper part, divides the gas sent by the stirring fan through the multi-component flow sheet 4-2-2 and the top 6-4 of the heat treatment equipment, and guides it into the channels formed by the side air guiding device 4-2-3 and the inner side 6-5 of the heat treatment equipment. At this time, the gas contacts the heating element 5-1, heats the gas to the preset temperature, enters the inside of the air guiding device through the bottom arc-shaped air guiding device 4-2-4 and the side air guiding device 4-2-3, impacts the heated component, and exchanges heat with the heated component until the heated component is heated to the ideal temperature.

[0063] The described three-dimensional heating system 5 is inside the furnace body 6 of the heat treatment equipment. The three-dimensional heating system consists of multiple groups of heating elements 5-1. Heating elements 5-1 are arranged above the internal atmosphere heating pipeline 2-1 of the three-dimensional gas filling system equipment. The number of the multiple groups of heating elements is equal to the number of the internal atmosphere heating pipelines of the equipment. The multiple groups of heating elements are above the internal atmosphere heating pipelines of the equipment, with a distance greater than 300 mm, a distance greater than 200 mm from the side of the atmosphere equalizing and air guiding device, and a distance greater than 50 mm from the furnace lining of the heat treatment equipment.

[0064] A first detection air outlet 2-12 is provided on the main air supply pipeline of the three-dimensional inflatable system 2, and a second detection air outlet 3-7 is provided on the exhaust pipeline of the exhaust system 3. The detection air outlet 2-12 on the main pipeline is connected to the detection air outlet 3-7 on the exhaust pipeline through a transition pipeline 7-1 to form a gas collection port 7-2. An automatic cut-off valve 7-3 and a check valve 7-4 are successively provided on the transition pipeline from the detection air outlet 2-12 to the gas collection port 7-2. A detection pipeline 7-5 is provided after the gas collection port, and a hydrocarbon analyzer 7-6, a dew point meter 7-7 and a trace oxygen analyzer 7-8 are provided on the detection pipeline. A check valve 7-9 is provided from the detection air outlet 3-7 to the gas collection port 7-2.

[0065] A temperature sensor 6-6, a flow sensor 6-7, a pressure sensor 6-8, etc. are provided on the furnace body 6 of the heat treatment equipment.

[0066] As Figure 2 shown, a control method for a protective atmosphere heat treatment equipment includes the following steps:

[0067] (1) Start air extraction: The furnace body temperature sensor 6-6 and the pressure sensor 6-8 automatically detect. When the heat treatment equipment is in a preset ready state, start the pre-vacuum pumping system 1. Under the action of the vacuum pump 1-5 and the check valve 1-3, extract the initial air in the furnace body of the heat treatment equipment until the vacuum degree in the furnace body of the heat treatment equipment reaches 10 -2 Torr.

[0068] (2) Start exhaust: When the pressure sensor 6-8 of the heat treatment equipment furnace body detects that the vacuum degree in the furnace body of the heat treatment equipment reaches 10 -2 Torr, close the pre-vacuum pumping system 1 through the automatic cut-off valve 1-2, and then open the exhaust system 2 through the automatic cut-off valve 3-6.

[0069] (3) Start inflation: When the pressure sensor 6-8 of the heat treatment equipment furnace body detects that the vacuum degree in the furnace body of the heat treatment equipment reaches 10 -2 Torr, detect that the pre-vacuum pumping system 1 has been closed and the exhaust system 2 has been opened, and the hydrocarbon analyzer 7-6 detects that the carbon atoms and hydrogen atoms in the argon gas source 2-9 meet the inflation atmosphere requirements, and the dew point meter 7-7 and the trace oxygen analyzer 7-8 detect that the water vapor and oxygen in the argon gas source 2-9 meet the inflation atmosphere requirements. At this time, start to inflate argon into the heat treatment equipment from bottom to top by the three-dimensional inflatable system 3; when the inflation step starts, the automatic cut-off valve 7-3 is closed, and the hydrocarbon analyzer 7-6, the dew point meter 7-7 and the trace oxygen analyzer 7-8 are connected through the check valve 7-9 and the detection air outlet 3-7 to detect the atmosphere filled into the furnace body of the heat treatment equipment.

[0070] (4) Start heating: When the oxygen content and water vapor content in the discharged gas detected by the exhaust system reach the preset values, start the three-dimensional heating system 5; at the same time, automatically reduce the three-dimensional inflation system 3 and the exhaust system 2 slightly to maintain the pressure in the furnace at a state of 4000 - 6000P; in the step of starting heating, when the atmosphere filled into the furnace body of the heat treatment equipment reaches the preset value detected by the intelligent pressure gauge 3-3, the hydrocarbon analyzer 7-6, the dew point meter 7-7 and the micro oxygen analyzer 7-8, start heating. On this basis, through the intelligent pressure gauge 2-4 and the intelligent mass flowmeter 2-6, adjust the automatic cut-off valve 3-6 and the automatic cut-off valve 2-3 to make the protective atmosphere in the heat treatment equipment enter a dynamic stable state of "slightly in and slightly out" pressure maintenance.

[0071] (5) Start stirring: When the temperature sensor 6-6 of the furnace body of the heat treatment equipment detects that the atmosphere temperature reaches the preset temperature, start the atmosphere uniform stirring system 4, contact the gas in the heated protective atmosphere with the pre-heated component, and the gas and the heated component automatically exchange heat, so as to heat the heated component.

[0072] In a certain actual heat treatment equipment, based on the present invention patent technology, the oxygen content in the atmosphere in the furnace body of the heat treatment equipment is 22 ppm, and the water vapor content is 18 ppm. The temperature uniformity in the furnace body of the heat treatment equipment is controlled within ±5. At the same time, the numerical simulation results show that by adopting the present invention patent technology, the heating time can be shortened by 30%.

[0073] In addition to adopting the above technical measures to obtain a highly clean, highly uniform temperature and highly efficient protective atmosphere in this specific embodiment, there are other safeguard measures, which are summarized as follows:

[0074] (1) Strengthen the furnace body sealing. The furnace body of the heat treatment equipment adopts welded sealing to fully ensure the sealing of the furnace chamber.

[0075] (2) Enhance the furnace lining heat preservation effect. Thick heat preservation cotton is arranged on the furnace lining of the heat treatment equipment and at the system connection parts. The thick heat preservation cotton can effectively enhance the furnace lining heat preservation effect.

[0076] (3) Arrange heating elements in a three-dimensional manner. The heating elements in the heat treatment equipment are evenly distributed in multiple layers on the furnace lining, and multiple independent controllable heating zones are designed along the height direction of the furnace body.

[0077] (4) Design a reasonable hot air circulation structure to form a large hot air circulation in the furnace. This is also the key to ensuring high temperature uniformity and high efficiency heating of the heat treatment temperature in the protective atmosphere heat treatment equipment.

[0078] (5) Heating power segmentation limitation. By adjusting the total power output of the heat treatment equipment, the furnace temperature can be prevented from overshooting. For example, in an actual heat treatment process, in the 20℃-180℃ stage, the output power is limited to 20% of the total power; in the 180℃-350℃ stage, the output power is limited to 40% of the total power; in the 350℃-650℃ stage, the output power is limited to 80% of the total power.

[0079] (6) Segmented adjustment of the frequency of the variable frequency fan. By adjusting the frequency of the high temperature resistant stirring fan, the temperature operation performance and heating efficiency can be improved. For example, in an actual heat treatment process, during the heating stage, the operating frequency of the high temperature resistant stirring fan is 45HZ, and during the insulation stage, the operating frequency of the high temperature resistant stirring fan is 20HZ.

[0080] (7) PID precise temperature control. Intelligent PID control algorithm is used, that is, through proportional, integral and differential regulators, and self-tuning mode, precise furnace temperature control is achieved.

[0081] The words "first, second, third, etc." or module A, module B, module C and other similar terms in the specification and claims are only used to distinguish similar objects and do not represent a specific ordering of the objects. It is understandable that the specific order or sequence can be interchanged where permitted so that the embodiments of the present application described herein can be implemented in an order other than that illustrated or described herein.

[0082] In the above description, the numbers representing the steps, such as S110, S120, etc., do not necessarily mean that the steps will be executed in this manner. If permitted, the order of the steps can be interchanged or they can be executed simultaneously.

[0083] The term "comprising" as used in the description and claims should not be interpreted as being limited to what is listed thereafter; it does not exclude other elements or steps. Therefore, it should be interpreted as specifying the presence of the features, integers, steps or components mentioned, but does not exclude the presence or addition of one or more other features, integers, steps or components and groups thereof. Therefore, the expression "a device comprising means A and B" should not be limited to a device consisting of components A and B only.

[0084] References to "one embodiment" or "an embodiment" in this specification mean that a particular feature, structure, or characteristic described in conjunction with the embodiment is included in at least one embodiment of the present application. Therefore, the phrases "in one embodiment" or "in an embodiment" appearing in various places in this specification do not necessarily refer to the same embodiment, but may refer to the same embodiment. In addition, in one or more embodiments, the particular features, structures, or characteristics can be combined in any appropriate manner, as would be apparent to one of ordinary skill in the art from this disclosure.

[0085] Note that the above is only a preferred embodiment of the present application and the applied technical principles. Those skilled in the art will understand that the present application is not limited to the specific embodiments described herein, and various obvious changes, re-adjustments, and substitutions can be made by those skilled in the art without departing from the protection scope of the present application. Therefore, although the present application has been described in more detail through the above embodiments, the present application is not limited to the above embodiments only. Without departing from the concept of the present application, more other equivalent embodiments can also be included, all of which fall within the protection scope of the present application.

Claims

1. A protective atmosphere heat treatment equipment, characterized in that: include: Three-dimensional inflation system, three-dimensional heating system, uniform atmosphere stirring system, pre-vacuum system and exhaust system; The pre-vacuum system is arranged on the four sides of the bottom of the heat treatment equipment, and is gathered to one end through four branch pipes, and is connected one by one to form a manifold, and then connected to the vacuum pump. Automatic stop valves (1-2) and one-way valves (1-3) are respectively arranged on the four branch pipes; The three-dimensional gas filling system is arranged on the inner linings on four sides of the heat treatment equipment, the atmosphere pipelines in the equipment are arranged in parallel and the air holes are evenly distributed, and the gas delivery pipelines outside the equipment and the argon gas source are arranged around the outside of the heat treatment equipment. The atmosphere pipelines in the equipment and the gas delivery pipelines outside the equipment are connected to the argon gas source through multi-stage intersections; The exhaust system is arranged on one side above the furnace body of the heat treatment equipment, and a cooler (3-2), a second detection air outlet (3-7), an intelligent pressure gauge (3-3), a one-way valve (3-4), a glass rotor flowmeter (3-5), and an automatic stop valve (3-6) are arranged in sequence from the end of the heat treatment equipment through an exhaust pipe; The atmosphere uniform stirring system is arranged inside the furnace body of the heat treatment equipment, and is composed of a high-temperature resistant high-speed stirring fan located at the furnace top and a butt joint with an atmosphere uniform gas guide device at the upper end. The high-temperature resistant high-speed stirring fan circulates argon gas up and down and makes the heated argon gas act uniformly on the components through the atmosphere uniform gas guide device. The three-dimensional heating system comprises a plurality of groups of heating elements which are evenly arranged on the inner walls around the furnace body of the heat treatment equipment. The heating elements are evenly arranged in strips in a horizontal and parallel manner up and down.

2. The protective atmosphere heat treatment equipment according to claim 1, characterized in that: The gas transmission pipeline outside the equipment is composed of a main gas supply pipeline, a plurality of gas supply side-branch pipelines, and a plurality of gas supply trunk and branch pipelines. The main gas supply pipeline is connected to the argon gas source and the plurality of gas supply side-branch pipelines; the plurality of gas supply side-branch pipelines are further connected to the plurality of gas supply trunk and branch pipelines; the plurality of gas supply trunk and branch pipelines are connected in sequence from the vertical midlines of the four sides outside the heat treatment equipment to the atmosphere pipelines inside the equipment of equal diameter and quantity.

3. The protective atmosphere heat treatment equipment according to claim 2, characterized in that: The main gas supply pipeline is provided with an automatic stop valve (2-10) and a filter (2-11), and the plurality of trunk and branch pipelines are provided with automatic stop valves (2-3), intelligent pressure gauges (2-4), one-way valves (2-5), intelligent mass flow meters (2-6), and pressure reducing and stabilizing valves (2-7) from the furnace body end.

4. A protective atmosphere heat treatment equipment according to claim 1 or 3, characterized in that: The main gas supply pipeline is provided with a first detection gas outlet (2-12), the first detection gas outlet (2-12) and the second detection gas outlet (3-7) are connected via a transition pipeline to form a gas collecting port, an automatic stop valve (7-3) and a one-way valve (7-4) are sequentially arranged on the transition pipeline from the detection gas outlet (2-12) to the gas collecting port; and a carbon hydrogen analyzer (7-6), a dew point meter (7-7), a trace oxygen analyzer (7-8), and an automatic stop valve (7-9) are sequentially arranged behind the gas collecting port.

5. The protective atmosphere heat treatment equipment according to claim 1, characterized in that: A multi-component flow sheet is arranged on the upper part of the atmosphere uniform air guiding device, and atmosphere guide channels are evenly distributed on the side. The high-speed stirring fan draws the protective atmosphere inside the atmosphere uniform air guiding device to the upper part, and evenly guides it to the space formed by the side of the atmosphere uniform air guiding device and the inner wall of the furnace of the heat treatment equipment through the multi-component flow sheet, and then enters the interior of the atmosphere uniform air guiding device through the bottom arc of the atmosphere uniform air guiding device and the atmosphere guide channel, and cyclically impacts the heated components located in the atmosphere uniform air guiding device.

6. A protective atmosphere heat treatment equipment control method, characterized in that: The protective atmosphere heat treatment equipment comprising any one of 1 to 5, wherein the method comprises the following steps: Start the pre-vacuum system to extract the gas in the furnace of the heat treatment equipment to a pressure of 10 -2 The vacuum degree is below 1000 torr; After the equipment reaches a preset vacuum degree, the pre-vacuum system is closed, and then the exhaust system is opened; The exhaust system is turned on, and then the three-dimensional gas filling system is started to fill argon gas into the heat treatment equipment from the bottom of the furnace body of the heat treatment equipment upward; When the exhaust system detects that the oxygen content and water vapor content in the exhaust gas reach the preset value, the three-dimensional heating system is started, and the three-dimensional charging system and the exhaust system are turned off at the same time, so that the pressure in the furnace is maintained at 4000-6000Pa; When the heat treatment equipment reaches a preset temperature, the atmosphere uniform stirring system is started to bring the heated protective atmosphere into contact with the preheated component, thereby heating the heated component.

7. A protective atmosphere heat treatment equipment control method according to claim 6, characterized in that: The control of extracting the gas from the furnace of the heat treatment equipment is performed by the following formula: Where P 极限 is the ultimate vacuum degree of the vacuum pump in the pre-vacuum system; P is the required vacuum degree in the heat treatment equipment, which is 10 -2 Torr or less; Q0 is the total outgassing volume of the heat treatment equipment, in Pa*L / s; Q t is the total air leakage of the heat treatment equipment, in Pa*L / s; S y is the effective exhaust rate of the heat treatment equipment, in L / s; V is the volume of the heat treatment equipment, in m 3 ; t is the required pumping time, in h; K is the vacuum coefficient, generally 1.1 to 1.

25.

8. A protective atmosphere heat treatment equipment control method according to claim 6, characterized in that: The amount of argon gas filled into the heat treatment equipment is calculated by the following formula: V 充标 =(1.5-3)V The V 充标 The amount of argon filled into the heat treatment equipment before heating.

9. A protective atmosphere heat treatment equipment control method according to claim 6, characterized in that: The atmosphere temperature difference when starting the atmosphere uniform stirring system is obtained by the following formula: Q=vA 炉 Where α C It is the surface heat transfer coefficient of the heated component when it is heated in a protective atmosphere heat treatment furnace, in W / m 2 *℃; M is the weight of the heated component, in kg; c is the specific heat capacity of the heated component, in J / kg*℃; A is the surface area of ​​the heated component, in m 2 ; tg is the set temperature of the heat treatment equipment, in °C; ts is the initial temperature of the heated component, in °C; t is the final heating temperature of the heated component, in °C; v is the atmosphere flow rate in the heat treatment equipment, in m / s; Q is the protective atmosphere flow rate in the heat treatment equipment, in m 3 / s; A 炉 is the effective cross-sectional area of ​​the heat treatment equipment, in m 2 ; Heat loss from the top of the heat treatment equipment, in W / m 2 ; S is the heat dissipation area on the top of the heat treatment equipment, in m 2 ; C g is the specific heat of the atmosphere inside the heat treatment equipment, in J / kg*℃; ρ is the atmosphere density inside the heat treatment equipment, in kg / m 3 ; Δt is the temperature difference between the first and last surfaces of the heated component that the protective atmosphere contacts during the circulation process, expressed in °C.

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