Experimental annealing furnace suitable for ultrathin strip annealing process research and use method

Abstract

The invention relates to an experimental annealing furnace suitable for ultrathin strip annealing process research and a use method, belongs to the technical field of ultrathin strip heat treatment, and solves the problems that in the prior art, the tension of an ultrathin strip in an annealing process is difficult to control accurately, and a tension applying device of an annealing furnace is complex in structure and lacks of partitioned temperature control and continuous switching functions. The invention discloses an experimental annealing furnace suitable for research on an annealing process of an ultrathin strip. The experimental annealing furnace comprises a furnace tube, a furnace body mounted on a base through a supporting column, a lifting system and a tension applying assembly, the lifting system comprises a driving assembly arranged at the top of the furnace body and a lifting assembly connected with the driving assembly; the lifting assembly comprises a metal pull rod and a heat-resistant baffle, the metal pull rod penetrates through the top of the furnace tube and is connected with the driving assembly, and the lower part of the heat-resistant baffle is connected with a test sample through a second holder; and the tension applying assembly comprises a standard weight molybdenum column which is connected below the test sample through a second clamp holder. And the working efficiency and the experiment success rate of the heat treatment of the ultrathin strip are improved.

Description

Technical Field

[0001] The invention relates to the technical field of ultra-thin strip heat treatment, and in particular to an experimental annealing furnace suitable for ultra-thin strip annealing process research and a use method thereof. Background Art

[0002] Strips with a thickness of ≤0.10mm are usually called ultra-thin strips, which are mainly used in some high-precision instruments.

[0003] During the high-temperature annealing process of ultra-thin strips, tension has a significant effect on the microstructure and texture evolution of the ultra-thin strips, so the continuous annealing tension value of the thin strip must be accurately set. However, the domestic experience in the precise control technology of ultra-thin strip preparation and the performance testing of thin strips is relatively insufficient. Especially in the preparation of ultra-thin strips, there is a lack of theoretical and practical basis for the tensile force during atmosphere annealing. Since the ultra-thin strips are relatively soft during the annealing process, their structure and properties are easily deteriorated due to stress. At present, the specific influence mechanism of stress has not been clearly explained in public information at home and abroad. Therefore, in industrial production, the setting of tension annealing parameters for ultra-thin strips lacks a scientific basis, resulting in a series of problems such as the failure to meet the standards for the mechanical properties or magnetic properties of the strips, reduced production efficiency, and poor product quality consistency, which need to be solved urgently. Summary of the invention

[0004] In view of the above analysis, an embodiment of the present invention aims to provide an experimental annealing furnace and a method of use suitable for the research of ultra-thin strip annealing process, so as to solve at least one of the problems that the tension of the existing ultra-thin strip in the atmosphere-protected annealing process is difficult to accurately control, the tension applying device of the annealing furnace has a complex structure, and the annealing furnace lacks zoned temperature control and continuous switching functions.

[0005] On the one hand, an embodiment of the present invention provides an experimental annealing furnace suitable for ultra-thin strip annealing process research, including a furnace tube 2, a furnace body 1 mounted on a base 14 through a support column 13, and a lifting system and a tension applying assembly;

[0006] The furnace tube 2 comprises a heating section embedded in the furnace body and a cooling section suspended below the furnace body, wherein an exhaust port is provided at the top of the heating section and an air supply port is provided at the bottom of the cooling section;

[0007] The lifting system includes a driving assembly placed on the top of the furnace body and a lifting assembly connected to the driving assembly; the lifting assembly includes a metal tie rod 7 and a heat-resistant baffle 10 connected to the bottom of the metal tie rod 7 through a first clamp, wherein the metal tie rod 7 passes through the top of the furnace tube 2 and is connected to the driving assembly, and the bottom of the heat-resistant baffle 10 is connected to the test sample 11 through a second clamp;

[0008] The tension applying assembly includes a weighted molybdenum column 12 connected below the test sample 11 via a second clamp.

[0009] Specifically, the test sample 11 and the standard weight molybdenum column 12 are located in the furnace tube 2 .

[0010] Exemplarily, the length of the heating section of the furnace tube 2 is ≥350 mm, the space corresponding to the heating section of the furnace tube 2 is a constant temperature zone, and the space corresponding to the cooling section is a cooling zone.

[0011] Furthermore, the driving assembly includes a column 5, a lifting block 6, a rocker 3 and a screw 4. The upper end of the screw is vertically fixedly connected to the top of the column. The rocker 3 is connected to the lower end of the screw 4 through a gear transmission mechanism. The lifting block 6 is connected to the screw 4 through a spiral transmission mechanism and can move vertically along the axial direction of the screw.

[0012] Furthermore, the lifting block 6 includes a column sliding guide seat 601, a spiral transmission connecting seat 602 and a traction part 603 arranged in sequence along the horizontal direction; the column sliding guide seat is connected to the column 5, the spiral transmission connecting seat is connected to the spiral screw 4, the height of the column sliding guide seat and the spiral transmission connecting seat are consistent, and when the lifting block 6 performs lifting and lowering movements, the two move synchronously; the traction part is connected to the metal pull rod 7 through a first clamp.

[0013] Specifically, the column 5 and the screw 4 are used to support the rocking wheel 3 and the lifting block 6. The rocking wheel 3 is rotated to drive the screw 4 to rotate through the gear transmission mechanism. The rotation of the screw 4 is converted into the vertical movement of the lifting block 6 along the axial direction of the screw 4 through the screw transmission mechanism; the metal pull rod 7 moves up and down in the vertical direction with the lifting of the lifting block 6, and its moving range covers the constant temperature zone and cooling zone of the furnace tube 2.

[0014] Preferably, a retractable metal hose 8 is sleeved on the outer side of the portion of the metal pull rod 7 between the lifting block 6 and the furnace tube 2 ; the retractable metal hose 8 is used to provide sealing at the connection between the metal pull rod 7 and the furnace tube 2 .

[0015] Preferably, the experimental annealing furnace further comprises a gas supply system 15, which is connected to the gas supply interface of the furnace tube 2 and comprises 3 to 4 gas cylinders connected to the gas supply port on the furnace tube through a pressure reducing valve and a flow meter, a hose and a gas valve respectively.

[0016] Preferably, the experimental annealing furnace further comprises an exhaust system 9, which is connected to the exhaust interface of the furnace tube 2 and comprises a gas pipe, a three-way valve, a gas filtering device and an exhaust gas ignition device.

[0017] On the other hand, an embodiment of the present invention further provides a method for using an experimental annealing furnace suitable for studying an annealing process of an ultra-thin strip. The method is applied to the annealing furnace and comprises the following steps:

[0018] S1, heating the constant temperature zone of furnace tube 2 to annealing temperature through the furnace body;

[0019] S2, after the heat-resistant baffle 10, the ultra-thin strip test sample 11, and the standard weight molybdenum column 12 are connected to the metal pull rod 7 in sequence through the clamp, they are loaded into the furnace from the lower end of the furnace tube 2, and the metal pull rod is driven by the driving component to move to the cooling zone and hover;

[0020] S3, after introducing high-purity nitrogen to exhaust the air in the furnace tube, switch to the atmosphere required by the experiment;

[0021] S4. After the furnace is filled with experimental atmosphere, the ultra-thin strip test sample is moved to the constant temperature zone for heat preservation by the lifting system;

[0022] S5. After the insulation is completed, the ultra-thin strip test sample is moved to the cooling zone by the lifting system, and ventilation is continued. After the test sample is cooled, it is unloaded from the furnace port at the lower end of the furnace tube 2.

[0023] Compared with the prior art, the present invention can achieve at least one of the following beneficial effects:

[0024] 1. The annealing furnace of the present invention controls the tensile stress of the thin strip by hanging a weighted molybdenum column. The tension can be adjusted by simply replacing the molybdenum column. There is no need to use tension applying motors, sensors and other equipment. The operation is flexible and simple, and the cost and maintenance difficulty are reduced.

[0025] 2. The present invention selects molybdenum columns as components for applying tension. On the one hand, molybdenum is a refractory metal with a high melting point and extremely high creep resistance and high-temperature stability. In the high-temperature environment of the annealing furnace, the molybdenum column can maintain stable physical properties and will not be deformed or damaged due to high temperature. Its internal structure is uniform and can provide a stable tension control effect. On the other hand, molybdenum has a low thermal expansion coefficient. Under high-temperature conditions, the size of the molybdenum column changes little, which can ensure the accuracy of tension control.

[0026] 3. The present invention uses the design of the lifting component and the driving component to ensure that the test sample is always suspended in the air without friction with the furnace body, and the sample can be switched between the heating constant temperature zone and the cooling zone in a closed state, which provides great help for accurately controlling the annealing process of the sample, ensuring that the sample can be heated evenly in the constant temperature zone and cooled evenly in the cooling zone, and a uniform ambient temperature can be obtained, so that the organization and material properties of the annealed sample are evenly distributed. It can be used for related research on the influence of various process parameters such as annealing temperature, annealing time, annealing atmosphere, and annealing tension on the ultra-thin strip version and performance.

[0027] 4. The present invention designs a heat-resistant baffle for the annealing furnace and optimizes its size, which is coordinated with the position design of the gas supply interface and the exhaust interface. When in use, the gas enters from the bottom of the furnace tube and is discharged from the top. When the test sample is in the heating constant temperature zone, the heat-resistant baffle assists in controlling the direction of the airflow, making the airflow more stable and slowing down its flow speed, effectively blocking the rapid discharge of a part of the gas, thereby slowing down the gas outflow speed, and further reducing the heat loss, ensuring the temperature uniformity of the constant temperature zone of the furnace tube; when the test sample is in the cooling zone, the heat-resistant baffle mainly acts as a heat insulator, blocking the heat in the insulation zone of the furnace tube from radiating to the cooling section, and playing an auxiliary role in cooling.

[0028] 5. The method for using the experimental annealing furnace provided by the present invention has few process steps and is simple and practical. The sample can be switched between the heating constant temperature zone and the cooling zone in a closed state. It can be used for related research on the influence of various process parameters such as annealing temperature, annealing time, annealing atmosphere, and annealing tension on the ultra-thin strip version and performance, which greatly improves the work efficiency of heat treatment and the success rate of experiments, saves a lot of time and energy, and realizes the function of one furnace for multiple uses.

[0029] 6. The annealing furnace of the present invention controls the appropriate gas flow rate when in use, effectively reducing the disturbance of the airflow to the suspension system, thereby reducing the risk of tension fluctuations; and the design of the heat-resistant baffle not only assists in controlling the direction of the airflow to make it more stable, but also slows down the outflow speed of the gas, reduces heat loss, and further stabilizes the temperature in the furnace tube, thereby indirectly improving the stability of the tension.

[0030] 7. The method for using the experimental annealing furnace of the present invention adopts a process design of one furnace experiment corresponding to a single tension, that is, each test sample corresponds to a specific tension value, annealing temperature and annealing time during the annealing process, and each set of annealing process parameters corresponds to the experimental sample one by one, avoiding the complicated tension adjustment process, simplifying the experimental operation flow, and significantly improving the experimental efficiency; when replacing the test sample and the weighted molybdenum column, there is no need to stop the furnace or interrupt the experimental process. The temperature in the furnace is maintained by introducing a protective atmosphere, and the experimental environment is maintained stable, thereby ensuring the continuity and stability of the experiment and reducing the interruption time of the experiment.

[0031] In the present invention, the above-mentioned technical solutions can also be combined with each other to achieve more preferred combination solutions. Other features and advantages of the present invention will be described in the subsequent description, and some advantages can become obvious from the description, or can be understood by practicing the present invention. The purpose and other advantages of the present invention can be realized and obtained through the contents particularly pointed out in the description and the drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] The drawings are only for the purpose of illustrating specific embodiments and are not to be considered limiting of the present invention. Like reference symbols denote like components throughout the drawings.

[0033] Figure 1 The figure is a schematic diagram of the overall structure of an experimental annealing furnace suitable for ultra-thin strip annealing process research according to the present invention.

[0034] Reference numerals:

[0035] 1-furnace body; 2-furnace tube; 3-rocker; 4-screw; 5-column; 6-lifting block; 601-column sliding guide seat; 602-screw transmission connecting seat; 603-traction part; 7-metal pull rod; 8-retractable metal hose; 9-exhaust system; 10-heat-resistant baffle; 11-thin strip steel; 12-standard weight molybdenum column; 14-base; 15-gas supply system. DETAILED DESCRIPTION

[0036] The preferred embodiments of the present invention are described in detail below in conjunction with the accompanying drawings, wherein the accompanying drawings constitute a part of this application and are used together with the embodiments of the present invention to illustrate the principles of the present invention, but are not used to limit the scope of the present invention.

[0037] On the one hand, a specific embodiment of the present invention discloses an experimental annealing furnace suitable for ultra-thin strip annealing process research, such as Figure 1 As shown, it includes a furnace tube 2, a furnace body 1 mounted on a base 14 through a support column 13, and a lifting system and a tension applying assembly;

[0038] The furnace tube 2 comprises a heating section embedded in the furnace body and a cooling section suspended below the furnace body, wherein an exhaust port is provided at the top of the heating section and an air supply port is provided at the bottom of the cooling section;

[0039] The lifting system includes a driving assembly placed on the top of the furnace body and a lifting assembly connected to the driving assembly; the lifting assembly includes a metal tie rod 7 and a heat-resistant baffle 10 connected to the bottom of the metal tie rod 7 through a first clamp, wherein the metal tie rod 7 passes through the top of the furnace tube 2 and is connected to the driving assembly, and the bottom of the heat-resistant baffle 10 is connected to the test sample 11 through a second clamp;

[0040] The tension applying assembly includes a weighted molybdenum column 12 connected below the test sample 11 via a second clamp.

[0041] The weighted molybdenum column 12 is located below the test sample 11 and is used to control the tensile stress of the thin strip without the need for a tension applying motor or other equipment. The operation is flexible and simple, and the tension of the ultra-thin strip steel during the annealing process can be changed by controlling the mass of the weighted molybdenum column.

[0042] Specifically, the tension T applied to the test sample is ((m 钼柱 +m 样品 )×g) / S; where m 钼柱 is the mass of the standard weight molybdenum column, m 样品is the mass of the test sample, S is the cross-sectional area of ​​the test sample, and g is the gravitational acceleration.

[0043] It should be noted that when the experimental annealing furnace of the present invention is used, a process design of one furnace experiment corresponding to a single tension is adopted, that is, each test sample corresponds to a specific tension value, annealing temperature and annealing time during the annealing process, and each set of annealing process parameters corresponds to the experimental sample one by one; when replacing the test sample and the weighted molybdenum column, there is no need to stop the furnace or interrupt the experimental process. It is only necessary to introduce a protective atmosphere (such as argon or nitrogen) into the furnace to maintain a constant temperature in the furnace to ensure a stable experimental environment. After the sample replacement is completed, the experimental process can be resumed immediately and subsequent experimental operations can be continued.

[0044] Molybdenum columns are selected as components for applying tension. On the one hand, molybdenum is a refractory metal with a high melting point and extremely high creep resistance and high-temperature stability. In the high-temperature environment of the annealing furnace, the molybdenum column can maintain stable physical properties and will not be deformed or damaged due to high temperature. Its internal structure is uniform and can provide a stable tension control effect. On the other hand, molybdenum has a low thermal expansion coefficient. Under high temperature conditions, the size of the molybdenum column changes little, which can ensure the accuracy of tension control.

[0045] In a possible design, the portion where the first clamp is connected to the metal rod 7 is designed with an annular clamping portion, the inner surface of which is provided with serrations, which can fit tightly with the outer surface of the metal rod, and effectively improve the stability of the clamping by increasing the friction. The portion where the second clamp is connected to the test sample includes an upper clamp, a lower clamp and a fixing screw. When in use, a part of the test sample is placed between the upper clamp and the lower clamp, and the fixing screw is tightened to complete the fixed connection. The use of the first clamp and the second clamp enhances the rigidity of the suspension system, making the sample more stable when subjected to tension, avoiding tension changes caused by structural deformation, and the fixing effect of the clamp further improves the overall stability of the system.

[0046] Specifically, the space corresponding to the heating section of the furnace tube 2 is a constant temperature zone, and the space corresponding to the cooling section is a cooling zone.

[0047] Preferably, the metal pull rod is made of heat-resistant steel, which is heat-resistant and easy to move.

[0048] It should be noted that the test sample 11 and the weighted molybdenum column 12 are located in the furnace tube 2 .

[0049] Specifically, the length of the heating section of the furnace tube 2 is ≥350 mm.

[0050] It is worth noting that the heat-resistant baffle is a cylindrical thin plate with a thickness of 1 to 3 mm, and the diameter of the heat-resistant baffle is 0.9 to 0.95 times the diameter of the furnace tube; when the experimental annealing furnace of the present invention is used, the protective gas is introduced from the bottom of the furnace tube 2 and discharged from the top of the furnace tube. The heat-resistant baffle plays multiple roles: on the one hand, the heat-resistant baffle assists in controlling the direction of the airflow, making the airflow more stable and slowing down its flow speed; on the other hand, since the protective gas will take away part of the heat during the circulation and discharge process in the furnace tube, the heat-resistant baffle can effectively block the rapid discharge of part of the gas, thereby slowing down the gas outflow speed and reducing the loss of heat. In this way, the heat-resistant baffle ensures the temperature uniformity of the furnace tube during the insulation stage.

[0051] Furthermore, the driving assembly includes a column 5, a lifting block 6, a rocker 3, and a screw 4. The upper end of the screw 4 is vertically fixedly connected to the top of the column 5, the rocker 3 is connected to the lower end of the screw 4 through a gear transmission mechanism, and the lifting block 6 is connected to the screw 4 through a spiral transmission mechanism, and can move vertically along the axial direction of the screw.

[0052] Preferably, the lifting block 6 includes a column sliding guide seat 601, a spiral transmission connecting seat 602 and a traction part 603 arranged in sequence along the horizontal direction; the column sliding guide seat 601 is connected to the column 5, the spiral transmission connecting seat 602 is connected to the spiral screw 4, the column sliding guide seat 601 and the spiral transmission connecting seat 602 have the same height, and when the lifting block 6 performs a lifting movement, the two move synchronously; the traction part 603 is connected to the metal pull rod 7 through a first clamp.

[0053] The column 5 and the screw 4 are used to support the rocking wheel 3 and the lifting block 6. The rocking wheel 3 is rotated to drive the screw 4 to rotate through the gear transmission mechanism. The rotation of the screw 4 is converted into the vertical movement of the lifting block 6 along the axial direction of the screw 4 through the screw transmission mechanism; the metal pull rod 7 moves up and down in the vertical direction with the lifting of the lifting block 6, and its moving range covers the constant temperature zone and cooling zone of the furnace tube 2, ensuring that the test sample 11 switches between the constant temperature zone and cooling zone of the furnace tube 2.

[0054] The ultra-thin strip test samples are switched between the constant temperature zone and the cooling zone while tension is applied, achieving continuous processing during the annealing process, reducing material loss during the transfer process, avoiding frequent operations by staff during actual operations, and effectively improving heat treatment efficiency and experimental success rate.

[0055] Furthermore, a retractable metal hose 8 is sleeved on the outer side of the part of the metal pull rod 7 located between the lifting block 6 and the furnace tube 2; the retractable metal hose 8 is used to provide sealing at the connection between the metal pull rod 7 and the furnace tube 2, ensuring the airtightness of the system, especially the airtightness inside the furnace tube when the metal pull rod 7 moves.

[0056] Specifically, the experimental annealing furnace also includes a gas supply system 15, which is connected to the gas supply interface of the furnace tube 2, including 3 to 4 gas cylinders connected to the gas supply port on the furnace tube through a pressure reducing valve and a flow meter, a hose and a gas valve, respectively. The gas cylinders store protective gases such as hydrogen, nitrogen, and argon. The gas valve switch can simultaneously ensure that 3 to 4 protective gases are introduced at a constant flow rate.

[0057] The protective gas is introduced from the gas supply interface at the lower end of the furnace tube 2. Due to the presence of the heat-resistant baffle and the airflow, a cooling zone with a length of not less than 350 mm and a temperature below 80° C. can be ensured in the lower half of the furnace tube.

[0058] Furthermore, the experimental annealing furnace also includes an exhaust system 9, which is connected to the exhaust interface of the furnace tube 2 and includes a gas pipe, a three-way valve, a gas filter device and an exhaust gas ignition device, and can handle combustible and hazardous gases by ignition.

[0059] It should be noted that when the experimental annealing furnace of the present invention is in use, the heat-resistant baffle moves with the movement of the test sample, and is transferred to the cooling section along with the sample during the cooling process. The heat-resistant baffle mainly serves as heat insulation, blocking the heat from the insulation zone of the furnace tube from radiating to the cooling section, and plays an auxiliary role in cooling. The cooling section is mainly cooled by gas, and the cooling temperature is determined according to the cooling rate and cooling time of different gases.

[0060] On the other hand, a specific embodiment of the present invention further discloses a method for using an experimental annealing furnace suitable for studying an ultra-thin strip annealing process, comprising the following steps:

[0061] S1, heating the constant temperature zone of furnace tube 2 to annealing temperature through the furnace body;

[0062] S2, after the heat-resistant baffle 10, the ultra-thin strip test sample 11, and the standard weight molybdenum column 12 are connected to the metal pull rod 7 in sequence through the clamp, they are loaded into the furnace from the lower end of the furnace tube 2, and the metal pull rod is driven by the driving component to move to the cooling zone and hover;

[0063] S3, after introducing high-purity nitrogen to exhaust the air in the furnace tube, switch to the atmosphere required by the experiment;

[0064] S4. After the furnace is filled with experimental atmosphere, the ultra-thin strip test sample is moved to the constant temperature zone for heat preservation by the lifting system;

[0065] S5. After the insulation is completed, the ultra-thin strip test sample is moved to the cooling zone by the lifting system, and ventilation cooling is continued. After the test sample is cooled, it is unloaded from the furnace port at the lower end of the furnace tube 2.

[0066] It should be noted that during the entire annealing process, the ultra-thin strip test sample was always suspended in the air without friction with the furnace body.

[0067] In a possible design, the annealing atmosphere is 30% hydrogen + 70% nitrogen, and the gas flow rate is 1.5 mol / L hydrogen and 3.5 mol / L nitrogen. During the annealing process, the appropriate gas flow rate is controlled to maintain the stability of the suspension system, thereby ensuring the accuracy of tension application.

[0068] In summary, the annealing furnace of the present invention controls the tensile stress of the thin strip by hanging a weighted molybdenum column. The tension adjustment can be achieved by simply replacing the molybdenum column. There is no need to use tension applying motors, sensors and other equipment. The operation is flexible and simple, and the cost and maintenance difficulty are reduced. When the annealing furnace is used, the appropriate gas flow rate is controlled to effectively reduce the disturbance of the airflow to the suspension system, thereby reducing the risk of tension fluctuations. And the design of the heat-resistant baffle not only assists in controlling the direction of the airflow to make it more stable, but also can slow down the outflow speed of the gas, reduce heat loss, and further stabilize the temperature in the furnace tube, thereby indirectly improving the stability of the tension.

[0069] The experimental annealing furnace and the method of using the present invention applicable to the research of the annealing process of ultra-thin strips are described in detail below in conjunction with specific embodiments.

[0070] Example 1

[0071] This embodiment provides an experimental annealing furnace suitable for research on ultra-thin strip annealing technology.

[0072] The annealing furnace system includes: a furnace tube 2, a furnace body 1 installed on a base 14 through a support column 13, a lifting system and a tension applying component; the furnace tube 2 includes a heating section embedded in the furnace body and a cooling section suspended below the furnace body, wherein an exhaust interface is provided at the top of the heating section, and an air supply interface is provided at the bottom of the cooling section; the lifting system includes a driving component placed on the top of the furnace body, and a lifting component connected to the driving component; the lifting component includes a metal pull rod 7 and a heat-resistant baffle 10 connected to the bottom of the metal pull rod 7 through a first clamp, wherein the metal pull rod 7 passes through the top of the furnace tube 2 and is connected to the driving component, and the bottom of the heat-resistant baffle 10 is connected to a test sample 11 through a second clamp; the tension applying component includes a weighted molybdenum column 12 connected to the bottom of the test sample 11 through a second clamp.

[0073] The driving assembly includes a column 5, a lifting block 6, a rocking wheel 3, and a spiral screw 4. The upper end of the spiral screw 4 is vertically fixedly connected to the top of the column 5. The rocking wheel 3 is connected to the lower end of the spiral screw 4 through a gear transmission mechanism. The lifting block 6 is connected to the spiral screw 4 through a spiral transmission mechanism and can move vertically along the axial direction of the spiral screw.

[0074] The lifting block 6 includes a column sliding guide seat, a spiral transmission connection seat and a traction part arranged in sequence in the horizontal direction; the column sliding guide seat is connected to the column 5, the spiral transmission connection seat is connected to the spiral screw 4, the column sliding guide seat and the spiral transmission connection seat are at the same height, and when the lifting block 6 is lifted and lowered, the two move synchronously; the traction part is connected to the metal pull rod 7 through the first clamp;

[0075] The column 5 and the screw 4 are used to support the rocking wheel 3 and the lifting block 6. The rocking wheel 3 is rotated to drive the screw 4 to rotate through the gear transmission mechanism. The rotation of the screw 4 is converted into the vertical movement of the lifting block 6 along the axial direction of the screw 4 through the screw transmission mechanism; the metal pull rod 7 moves up and down in the vertical direction with the lifting of the lifting block 6, and its moving range covers the constant temperature zone and cooling zone of the furnace tube 2.

[0076] A retractable metal hose 8 is sleeved on the outer side of the metal pull rod 7 between the lifting block 6 and the furnace tube 2; the retractable metal hose 8 is used to provide sealing at the connection between the metal pull rod 7 and the furnace tube 2;

[0077] The experimental annealing furnace also includes a gas supply system 15, which is connected to the gas supply interface of the furnace tube 2, including two gas cylinders connected to the gas supply port on the furnace tube through a pressure reducing valve and a flow meter, a hose and a gas valve, respectively, and hydrogen and nitrogen are stored in the gas cylinders respectively. The gas valve switch can ensure that a constant flow of hydrogen and nitrogen can be simultaneously introduced;

[0078] The experimental annealing furnace also includes an exhaust system 9, which is connected to the exhaust interface of the furnace tube 2 and includes a gas pipe, a three-way valve, a gas filter device and an exhaust gas ignition device, and can handle combustible and dangerous gases by ignition.

[0079] The thickness of the heat-resistant baffle is 3 mm, and the diameter of the heat-resistant baffle is 0.95 times the diameter of the furnace tube.

[0080] Application Example 1

[0081] This application example provides a method for using the experimental annealing furnace described in Example 1.

[0082] The annealing experiment object is: 0.08mm ultra-thin oriented silicon steel.

[0083] Annealing experiment process parameters: annealing atmosphere is 30% hydrogen + 70% nitrogen; at 800 ° C, after keeping warm for 1 hour, cool for 3 minutes in a mixed atmosphere of 1.5 mol / L hydrogen and 3.5 mol / L nitrogen flow rate.

[0084] The method of using the experimental annealing furnace includes the following steps:

[0085] S1, heating the constant temperature zone of furnace tube 2 to the annealing temperature of 800°C through the furnace body;

[0086] S2, after the heat-resistant baffle 10, the ultra-thin strip test sample 11, and the 0.5 kg standard weight molybdenum column 12 are connected to the metal pull rod 7 in sequence through the clamp, they are loaded into the furnace from the lower end of the furnace tube 2, and the metal pull rod is driven by the driving assembly to move to the cooling zone and hover;

[0087] S3, after introducing high-purity nitrogen to exhaust the air in the furnace tube, switch to the atmosphere required by the experiment: 30% hydrogen + 70% nitrogen, with a gas flow rate of 1.5 mol / L hydrogen and 3.5 mol / L nitrogen;

[0088] S4. After the furnace is filled with experimental atmosphere, the ultra-thin strip test sample is moved to the constant temperature zone by the lifting system and kept warm for 60 minutes;

[0089] S5. After the insulation is completed, the ultra-thin strip test sample is moved to the cooling zone by pulling through the lifting system, and ventilation is continued for 3 minutes, with a flow rate of 1.5 mol / L hydrogen and 3.5 mol / L. The temperature in the cooling zone is 80°C. After the test sample is cooled, it is unloaded from the furnace port at the lower end of furnace tube 2.

[0090] The experimental object is 0.08mm ultra-thin oriented silicon steel. Under the above annealing process, the magnetic properties reach magnetic induction B 800 ≥1.85T, iron loss P 1.0 / 400 ≤9.5W / kg.

[0091] Comparative Example 1

[0092] The structure of the annealing furnace is basically the same as that of Example 1, except that no heat-resistant baffle is added.

[0093] The experimental method is the same as that of Application Example 1.

[0094] The experimental object is 0.08mm ultra-thin oriented silicon steel. Under the above annealing process, the magnetic properties and magnetic induction B 800 ≤1.80T, iron loss P 1.0 / 400 ≥11W / kg.

[0095] Comparative Example 2

[0096] The structure of the annealing furnace is basically the same as that of Example 1, except that the thickness of the heat-resistant baffle is 0.5 mm.

[0097] The experimental method is the same as that of Application Example 1.

[0098] The experimental object is 0.08mm ultra-thin oriented silicon steel. Under the above annealing process, the magnetic properties and magnetic induction B 800 ≤1.78T, iron loss P 1.0 / 400 ≥11.5W / kg.

[0099] Comparative Example 3

[0100] The structure of the annealing furnace is basically the same as that of Example 1, except that the diameter of the heat-resistant baffle is 0.8 times the diameter of the furnace tube.

[0101] The experimental method is the same as that of Application Example 1.

[0102] The experimental object is 0.08mm ultra-thin oriented silicon steel. Under the above annealing process, the magnetic properties and magnetic induction B 800 ≤1.77T, iron loss P 1.0 / 400 ≥12.3W / kg.

[0103] Comparative Example 4

[0104] The annealing experiment was carried out using the experimental annealing furnace provided in Example 1.

[0105] The experimental method is basically the same as that of Application Example 1, except that the gas flow rates in steps S3 and S5 are 5 mol / L hydrogen and 6.5 mol / L nitrogen.

[0106] The experimental object is 0.08mm ultra-thin oriented silicon steel. Under the above annealing process, the magnetic properties and magnetic induction B 800 ≤1.75T, iron loss P 1.0 / 400 ≥12.9W / kg.

[0107] It can be seen from Comparative Example 1, Example 1 and Application Example 1 that since Comparative Example 1 does not have a heat-resistant baffle, the following results occur: (1) During the insulation process, due to the large gas flow rate and the lack of a heat-resistant baffle to block it, the gas is discharged too quickly and carries away too much temperature, which makes the temperature of the insulation area low and the actual insulation temperature of the sample lower than the set temperature; (2) During the cooling process, since there is no heat-resistant baffle, the furnace will continue to radiate heat to the cooling section, which makes the cooling time calculation inaccurate and the furnace outlet temperature high, which poses a danger to the operator; (3) Since there is no heat-resistant baffle, the actual insulation temperature is low, the structure of the ultra-thin strip is affected, and performance deviation occurs.

[0108] Compared with Example 1 and Application Example 1, the size design of the heat-resistant baffles in Comparative Examples 2 and 3 does not meet the requirements of the present invention and cannot fully play the role of the heat-resistant baffles. The heat-resistant baffles are too thin and the thermal insulation capacity is significantly reduced. The diameter of the heat-resistant baffles is too small, and the thermal insulation and heat insulation capacities are reduced.

[0109] Compared with Application Example 1, Comparative Example 4 has a poor suspension system stability due to excessive gas flow, and the ultra-thin strip experiences a certain degree of disturbance during the annealing and insulation process, resulting in a large actual tension of the strip, which affects the magnetic properties and also affects the surface quality of the ultra-thin strip; on the other hand, too much gas flow leads to too much heat being taken away during the insulation process, and the actual temperature of the sample is lower than the theoretical design temperature, which affects the organization and texture of the sample and the magnetic properties; finally, too much gas flow increases production costs and increases experimental risks, resulting in excessive pressure in the furnace and affecting the service life of the furnace.

[0110] In summary, the annealing furnace of the present invention controls the tensile stress of the thin strip by hanging a weighted molybdenum column. The tension adjustment can be achieved by simply replacing the molybdenum column. There is no need to use tension applying motors, sensors and other equipment. The operation is flexible and simple, and the cost and maintenance difficulty are reduced. When the annealing furnace is used, the appropriate gas flow rate is controlled to effectively reduce the disturbance of the airflow to the suspension system, thereby reducing the risk of tension fluctuations. And the design of the heat-resistant baffle not only assists in controlling the direction of the airflow to make it more stable, but also can slow down the outflow speed of the gas, reduce heat loss, and further stabilize the temperature in the furnace tube, thereby indirectly improving the stability of the tension.

[0111] The above description is only a preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any changes or substitutions that can be easily conceived by any technician familiar with the technical field within the technical scope disclosed by the present invention should be covered within the protection scope of the present invention.

Claims

1. An experimental annealing furnace suitable for ultra-thin strip annealing process research, characterized in that: It comprises a furnace tube (2), a furnace body (1) mounted on a base (14) via a support column (13), a lifting system and a tension applying component; The furnace tube (2) comprises a heating section embedded in the furnace body and a cooling section suspended below the furnace body, wherein an exhaust port is provided at the top of the heating section and an air supply port is provided at the bottom of the cooling section; The lifting system comprises a driving assembly placed on the top of the furnace body and a lifting assembly connected to the driving assembly; the lifting assembly comprises a metal tie rod (7) and a heat-resistant baffle (10) connected to the bottom of the metal tie rod (7) via a first clamp, wherein the metal tie rod (7) passes through the top of the furnace tube (2) and is connected to the driving assembly, and the bottom of the heat-resistant baffle (10) is connected to the test sample (11) via a second clamp; The tension applying assembly comprises a weighted molybdenum column (12) connected below the test sample (11) via a second clamp.

2. The annealing furnace according to claim 1, characterized in that: The test sample (11) and the standard weight molybdenum column (12) are located in the furnace tube (2).

3. The annealing furnace according to claim 1, characterized in that: The length of the heating section of the furnace tube (2) is ≥350 mm, the space corresponding to the heating section of the furnace tube (2) is a constant temperature zone, and the space corresponding to the cooling section is a cooling zone.

4. The annealing furnace according to claim 1, characterized in that: The driving assembly comprises a column (5), a lifting block (6), a rocking wheel (3) and a screw (4); the upper end of the screw is vertically fixedly connected to the top of the column; the rocking wheel (3) is connected to the lower end of the screw (4) via a gear transmission mechanism; the lifting block (6) is connected to the screw (4) via a screw transmission mechanism and can move vertically along the axial direction of the screw.

5. The annealing furnace according to claim 4, characterized in that: The lifting block (6) comprises a column sliding guide seat (601), a spiral transmission connection seat (602) and a traction part (603) arranged in sequence along the horizontal direction; the column sliding guide seat is connected to the column (5), the spiral transmission connection seat is connected to the spiral screw (4), the column sliding guide seat and the spiral transmission connection seat have the same height, and when the lifting block (6) performs a lifting movement, the two move synchronously; the traction part is connected to the metal pull rod (7) through a first clamp.

6. The annealing furnace according to claim 4, characterized in that: The column (5) and the screw (4) are used to support the rocking wheel (3) and the lifting block (6). The rocking wheel (3) is rotated to drive the screw (4) to rotate through the gear transmission mechanism. The rotation of the screw (4) is converted into vertical movement of the lifting block (6) along the axial direction of the screw (4) through the screw transmission mechanism; the metal pull rod (7) moves up and down in the vertical direction as the lifting block (6) is raised and lowered, and its moving range covers the constant temperature zone and the cooling zone of the furnace tube (2).

7. The annealing furnace according to claim 5, characterized in that: A retractable metal hose (8) is sleeved on the outer side of the portion of the metal pull rod (7) located between the lifting block (6) and the furnace tube (2); the retractable metal hose (8) is used to provide sealing at the connection between the metal pull rod (7) and the furnace tube (2).

8. The annealing furnace according to claim 1, characterized in that: The experimental annealing furnace also includes a gas supply system (15), which is connected to the gas supply interface of the furnace tube (2) and includes 3 to 4 gas cylinders connected to the gas supply port on the furnace tube through a pressure reducing valve and a flow meter, a hose and a gas valve.

9. The annealing furnace according to claim 1, characterized in that: The experimental annealing furnace also includes an exhaust system (9), which is connected to the exhaust interface of the furnace tube (2) and includes a gas pipe, a three-way valve, a gas filtering device and an exhaust gas ignition device.

10. A method for using an experimental annealing furnace suitable for research on ultra-thin strip annealing technology, characterized in that: The method is applied to the annealing furnace according to any one of claims 1 to 9, comprising the following steps: S1, heating the constant temperature zone of the furnace tube (2) to the annealing temperature through the furnace body; S2, after the heat-resistant baffle (10), the ultra-thin strip test sample (11), and the standard weight molybdenum column (12) are connected to the metal pull rod (7) in sequence through the clamp, they are loaded into the furnace from the lower end of the furnace tube (2), and the metal pull rod is driven by the driving component to move to the cooling zone and hover; S3, after introducing high-purity nitrogen to exhaust the air in the furnace tube, switch to the atmosphere required by the experiment; S4. After the furnace is filled with experimental atmosphere, the ultra-thin strip test sample is moved to the constant temperature zone for heat preservation by the lifting system; S5. After the insulation is completed, the ultra-thin strip test sample is moved to the cooling zone by pulling through the lifting system, and ventilation is continued. After the test sample is cooled, it is unloaded from the furnace opening at the lower end of the furnace tube (2).

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