A silicon steel sheet annealing test furnace and a process method thereof

Abstract

The application belongs to the technical field of silicon steel sheet annealing test furnace and belongs to the green manufacturing plan of ultra-high-grade oriented silicon steel, and specifically discloses a silicon steel sheet annealing test furnace and a process method thereof, which comprises an inlet section, a heating section, a connecting section and an outlet section, the inlet section, the heating section, the connecting section and the outlet section constitute a furnace body structure, the furnace body structure is fixedly installed on the workshop floor through two H-shaped steels, the furnace body structure is provided with three cooling air discharge pipes, and the cooling air discharge pipes are led out of the factory building for discharge. The silicon steel sheet annealing test furnace and the process method thereof, three independent heating sections, namely heating section one, heating section two and heating section three, and three independent connecting sections, namely connecting section one, connecting section two and connecting section three, are arranged in the application, and the independent online oxygen analyzer, the sampling port and the atmosphere supply system are matched, so that the intermediate annealing scene, the non-oriented silicon steel finished product annealing scene and the oriented silicon steel high-temperature annealing and other multi-scene requirements can be matched respectively.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of silicon steel sheet annealing furnace, in particular to a silicon steel sheet annealing test furnace and process method thereof, and belongs to the field of green manufacturing of ultra-high grade oriented silicon steel. BACKGROUND

[0002] As the core magnetic material of electrical equipment such as motors and transformers, the magnetic properties, surface quality and structural consistency of silicon steel directly determine the energy efficiency and service life of the end product, and the annealing process of silicon steel processing is the key link to optimize the performance of silicon steel.

[0003] Existing equipment is mostly designed for specific types of silicon steel, and it is difficult to meet the different process requirements of intermediate annealing and oriented silicon steel finished product annealing. Most of the equipment adopts a unified power regulation mode, lacks a segmented independent temperature control mechanism, and is difficult to adapt to the annealing needs of silicon steel of different specifications. SUMMARY

[0004] The purpose of the present application is to provide a silicon steel sheet annealing test furnace and process method thereof to solve the problem of existing equipment being difficult to adapt to the annealing needs of silicon steel of different specifications as described in the background.

[0005] To achieve the above-mentioned purpose, the present application provides the following technical scheme: a silicon steel sheet annealing test furnace and process method thereof, comprising an inlet section, a heating section, a connecting section and an outlet section, the inlet section, the heating section, the connecting section and the outlet section constitute a furnace body structure, the furnace body structure is fixedly installed on the floor of the workshop through two H-shaped steel, the furnace body structure is provided with three cooling air discharge pipes, and the cooling air discharge pipes are led out of the factory building for discharge;

[0006] The heating section is provided with three heating sections, namely heating section one, heating section two and heating section three; the connecting section is provided with three connecting sections, namely connecting section one, connecting section two and connecting section three; the connecting section three and the outlet section constitute an integral whole, the inlet section, the connecting section one, the connecting section two and the connecting section three and the outlet section are respectively provided with independent gas collecting hoods and exhaust pipes, and the exhaust pipes are led out of the factory building for discharge;

[0007] Preferably, one side of the inlet section is provided with the heating section one, the outlet end of the heating section one is provided with the heating section two, the other side of the heating section two is provided with the connecting section one, the other side of the connecting section one is provided with the heating section three, the other side of the heating section three is provided with the connecting section two, the connecting section two is connected with the connecting section three, and the connecting section three and the outlet section are an integral structure.

[0008] By adopting the above technical scheme, the furnace body structure is sequentially connected, and can adapt to multiple scene annealing processes.

[0009] Preferably, the connecting section one is a connecting transition section between the heating section two and the heating section three, and the lower part of the connecting section one is provided with an electric heating body; the connecting section two is a connecting transition section between the heating section three and the connecting section three and the outlet section, and the lower part of the connecting section two is provided with an electric heating body.

[0010] By using the above technical scheme, the temperature can be controlled by the electric heating body, so as to avoid too large temperature difference of the silicon steel sheet and reduce thermal stress.

[0011] Preferably, the connecting section three is a cooling section, and the connecting section three sprays and cools the silicon steel sheet by using mixed gas of nitrogen and hydrogen through a spray pipe, and the ratio of the nitrogen and the hydrogen is 3:7.

[0012] By using the above technical scheme, the silicon steel sheet can be prevented from being oxidized by using the nitrogen-hydrogen mixed gas, so as to guarantee the surface quality.

[0013] Preferably, the heating section one, the heating section two and the heating section three are respectively provided with independent on-line oxygen analyzers, the heating section one, the heating section two and the heating section three are respectively provided with sampling ports, and the heating section three is provided with an atmosphere supply system.

[0014] By using the above technical scheme, the atmosphere sample can be conveniently collected through the sampling port, and the atmosphere parameters of the heating section three can be accurately controlled.

[0015] Preferably, 16 sets of independent driving first furnace roller groups and second furnace roller groups are arranged in the furnace body structure, and each of the first furnace roller groups and the second furnace roller groups includes two roller bodies, wherein two sets of the first furnace roller groups are arranged, the first furnace roller groups are made of stainless steel, 14 sets of the second furnace roller groups are arranged, the second furnace roller groups are made of ceramic sleeve material, the two sets of the first furnace roller groups made of stainless steel are arranged at the inlet section and the outlet section respectively, and the remaining 14 sets of the second furnace roller groups made of ceramic sleeve material are arranged in the heating section, the connecting section and the outlet section in sequence; the second furnace roller groups made of ceramic sleeve material are modularly arranged and have mutual replaceability; independent chains and sprockets are arranged in each of the first furnace roller groups and the second furnace roller groups, and the two roller bodies in each of the first furnace roller groups and the second furnace roller groups are independently connected through the independent chains and sprockets, and each of the first furnace roller groups and the second furnace roller groups is powered by a driving motor.

[0016] By using the above technical scheme, the first furnace roller groups and the second furnace roller groups can be independently controlled by the independent driving motors, so as to realize single control of each processing section of the silicon steel sheet.

[0017] Preferably, the process method comprises the following steps:

[0018] Step one, feed and preheating section; the silicon steel sheet enters the furnace body structure through the stainless steel No. 1 furnace roller group in the inlet section, the initial volatile gas is discharged through the independent gas collecting cover and exhaust pipe, the strip steel centering accuracy is ensured, the silicon steel sheet enters the early stage of the heating section, is indirectly heated through convection and radiation of the furnace gas, the temperature is controlled to be lower than the ignition point of the rolling oil on the surface of the silicon steel sheet, the surface rolling oil, emulsion residue and moisture are removed, and the volatile oil gas is discharged out of the plant through the exhaust pipe;

[0019] Step two, heating and soaking section; the silicon steel sheet sequentially passes through heating section one, heating section two and heating section three, each heating section is independently temperature controlled and is provided with an online oxygen analyzer and a sampling port, is indirectly heated through a radiation pipe, a nitrogen-hydrogen mixed protective atmosphere is introduced and the gas ratio is adjusted, the heating temperature is controlled according to the type of silicon steel, and the control of the heating temperature is specifically as follows:

[0020] If it is an intermediate annealing scene, the control temperature is 800-900℃;

[0021] If it is an annealing scene for non-oriented silicon steel finished product, the control temperature is 800-950℃;

[0022] If it is an oriented silicon steel high-temperature annealing scene, the control temperature is up to 1200℃ or above;

[0023] Step three, slow cooling section; the silicon steel sheet first passes through connecting section one and connecting section two, is heat preserved through the built-in electric heating body in the connecting section one and the connecting section two, is cooled from the annealing temperature to 550-650℃ at a controlled rate, carbonization is promoted, and thermal stress is avoided;

[0024] Step four, fast cooling section; the silicon steel sheet enters the connecting section three, a mixed gas of nitrogen and hydrogen is sprayed and cooled through a spray pipe, the strip steel is cooled to below 150℃, and oxidation is prevented;

[0025] Step five, discharging and post-processing section; the cooled silicon steel sheet is discharged through the stainless steel No. 1 furnace roller group in the outlet section, enters a subsequent water quenching tank for strengthening treatment according to process requirements, and the waste gas generated in each section is discharged out of the plant through independent exhaust pipes and cooling air exhaust pipes.

[0026] By adopting the above technical scheme, the whole process of silicon steel sheet annealing can be controlled through the above steps, and multiple scene requirements can be adapted.

[0027] Preferably, the hydrogen content in the nitrogen-hydrogen mixed protective atmosphere in step two is 5%-20%;

[0028] In the high-temperature annealing scene of the oriented silicon steel in step two, the heat preservation time of the heating section three is set according to the secondary recrystallization requirement, the {110} <001> Goss texture is formed, the MgO release agent coated on the surface of the silicon steel sheet reacts with the matrix to form a magnesium silicate glass film;

[0029] In the annealing scene of the non-oriented silicon steel product in the second step, the nitrogen-hydrogen mixed atmosphere in the third heating section is a decarburizing atmosphere, which removes harmful impurity elements such as carbon, nitrogen and sulfur in the silicon steel sheet, and optimizes the grain size to be uniform equiaxed grains.

[0030] In the second step, nitrogen-hydrogen mixed gas is introduced as a protective atmosphere for several hours, and the internal stress generated during the forming process of the silicon steel sheet is eliminated through the slow cooling treatment of the first connecting section and the second connecting section without changing the material texture and grain size.

[0031] By adjusting the atmosphere and holding parameters, the product performance can be stabilized.

[0032] Preferably, in the first step to the fifth step, the running speed of the silicon steel sheet is adjusted by 16 sets of independent transmission of the first furnace roller group and the second furnace roller group, wherein 14 sets of the second furnace roller group with ceramic sleeve can be replaced with each other, and the processing time of the silicon steel sheet in each process section is adjusted by controlling the running speed of the first furnace roller group and the second furnace roller group.

[0033] By adjusting the processing time of the silicon steel sheet in each process section, the annealing requirements of multiple scenes can be met.

[0034] Preferably, in the third step, the cooling rate of the first connecting section and the second connecting section is realized by adjusting the circulation speed of the protective gas in the furnace body structure and the temperature of the electric heating body, and the spraying cooling rate of the third connecting section is controlled according to the CCT curve of the silicon steel sheet.

[0035] By adjusting the cooling rate of each slow cooling and rapid cooling stage, thermal stress and oxidation can be avoided, and the stability of carbide spheroidization and product performance can be ensured.

[0036] Compared with the prior art, the present application has the following advantages:

[0037] 1. In the present application, three independent heating sections, i.e., the first heating section, the second heating section and the third heating section, and three independent connecting sections, i.e., the first connecting section, the second connecting section and the third connecting section, are provided, which are matched with an independent online oxygen analyzer, a sampling port and an atmosphere supply system, so as to meet the requirements of multiple scenes such as intermediate annealing scene, non-oriented silicon steel product annealing scene and oriented silicon steel high-temperature annealing.

[0038] By adjusting the segmented temperature above 800-1200℃, the nitrogen-hydrogen protective atmosphere with a proportion of 5%-20%, and the cooling rate, the formation of {110} <001> Goss texture of oriented silicon steel and the generation of magnesium silicate glass film can be realized, and the impurity removal and uniform equiaxed grain optimization of non-oriented silicon steel can also be realized, thereby avoiding the problems of single adaptation and large performance fluctuation of traditional equipment process.

[0039] 2. In this invention, silicon wafers are conveyed by 16 sets of independently driven No. 1 and No. 2 furnace roller groups. The two No. 1 furnace roller groups are made of stainless steel and are respectively set in the inlet and outlet sections. The stainless steel No. 1 furnace roller groups in the inlet and outlet sections are matched with the normal temperature feeding and discharging scenarios. Stainless steel has good corrosion resistance and structural stability. The No. 2 furnace roller groups with ceramic sleeves are used in high-temperature areas such as the heating section and the connecting section. The ceramic sleeves have the characteristics of high temperature resistance, high temperature deformation resistance and atmospheric corrosion resistance. They can cope with high temperature annealing environments above 800-1200℃, avoid damage to the furnace roller groups under extreme working conditions, and avoid the problem that a single furnace roller group cannot adapt to multiple temperature ranges in the whole process.

[0040] By adjusting the speed of the No. 1 and No. 2 furnace roller groups, the processing time of silicon steel sheets in each process stage can be controlled. Combined with segmented cooling of slow and fast cooling, experimental efficiency can be improved while ensuring the accuracy of experimental data, providing reliable data support for subsequent large-scale production and reducing the risk of technology transfer. Attached Figure Description

[0041] Figure 1 This is a schematic diagram of the furnace body layout structure of the present invention;

[0042] Figure 2 This is a schematic diagram of the gas collection hood structure of the present invention;

[0043] Figure 3 This is a schematic diagram of the furnace roller assembly structure of the present invention;

[0044] Figure 4 This is a schematic diagram of the process structure of the present invention.

[0045] In the diagram: 1. Inlet section; 2. Heating section one; 3. Heating section two; 4. Heating section three; 5. Connecting section one; 6. Connecting section two; 7. Connecting section three; 8. Outlet section; 9. Gas collection hood; 10. No. 1 furnace roller group; 11. No. 2 furnace roller group. Detailed Implementation

[0046] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0047] Please see Figures 1-4 The present invention provides a technical solution: a test furnace for annealing silicon steel sheets and its process, comprising an inlet section 1, a heating section 1 2, a heating section 2 3, a heating section 3 4, a connecting section 1 5, a connecting section 2 6, a connecting section 3 7, an outlet section 8, a gas collecting hood 9, a first furnace roller group 10, and a second furnace roller group 11.

[0048] The inlet section 1, the heating section, the connecting section and the outlet section 8 constitute a furnace structure, the furnace structure is fixedly installed on the floor in the workshop through two H-shaped steels, the furnace structure is provided with three cooling air discharge pipes, the cooling air discharge pipes are led out of the factory building for discharge; the heating section is provided with three, the three heating sections are heating section one 2, heating section two 3 and heating section three 4; the connecting section is provided with three, the three connecting sections are connecting section one 5, connecting section two 6 and connecting section three 7; the connecting section three 7 and the outlet section 8 constitute an integral whole, the inlet section 1, the connecting section one 5, the connecting section two 6 and the connecting section three 7 and the outlet section 8 are respectively provided with independent gas collecting hoods 9 and exhaust pipes, the exhaust pipes are led out of the factory building for discharge; one side of the inlet section 1 is provided with the heating section one 2, the outlet end of the heating section one 2 is provided with the heating section two 3, the other side of the heating section two 3 is provided with the connecting section one 5, the other side of the connecting section one 5 is provided with the heating section three 4, the other side of the heating section three 4 is provided with the connecting section two 6, the connecting section two 6 is connected with the connecting section three 7, and the connecting section three 7 and the outlet section 8 are an integral structure; the connecting section one 5 is a connecting transition section between the heating section two 3 and the heating section three 4, the lower part of the connecting section one 5 is provided with an electric heating body, the connecting section two 6 is a connecting transition section between the heating section three 4 and the connecting section three 7 and the outlet section 8, and the lower part of the connecting section two 6 is provided with an electric heating body; the connecting section three 7 is a cooling section, the connecting section three 7 sprays and cools the silicon steel sheet by using a mixed gas of nitrogen and hydrogen through a spray pipe, and the ratio of the nitrogen and the hydrogen is 3:7; the heating section one 2, the heating section two 3 and the heating section three 4 are respectively provided with independent online oxygen analyzers, the heating section one 2, the heating section two 3 and the heating section three 4 are respectively provided with sampling ports, and the heating section three 4 is provided with an atmosphere supply system;

[0049] The furnace structure is provided with 16 sets of independently driven first furnace roller groups 10 and second furnace roller groups 11, each of the first furnace roller groups 10 and the second furnace roller groups 11 includes two roller bodies, one of the first furnace roller groups 10 is provided with two sets, the first furnace roller group 10 is made of stainless steel, 14 sets of the second furnace roller groups 11 are provided with the second furnace roller group 11, the second furnace roller group 11 is made of ceramic sleeve pipe, the two sets of first furnace roller groups 10 made of stainless steel are arranged in the inlet section 1 and the outlet section 8 respectively, and the remaining 14 sets of second furnace roller groups 11 made of ceramic sleeve pipe are arranged in the heating section, the connecting section and the outlet section 8 in sequence; the ceramic sleeve second furnace roller group 11 is modularly arranged and has mutual replaceability; each of the first furnace roller groups 10 and the second furnace roller groups 11 is respectively provided with an independent chain and a sprocket, the two roller bodies in each of the first furnace roller groups 10 and the second furnace roller groups 11 are independently connected through the independent chain and the sprocket, and each of the first furnace roller groups 10 and the second furnace roller groups 11 is respectively powered by a driving motor;

[0050] As 1, Figure 2 and Figure 3As shown, the furnace body structure is assembled in sequence by the inlet section 1, the heating section one 2, the heating section two 3, the heating section three 4, the connecting section one 5, the connecting section two 6, the connecting section three 7 and the outlet section 8, wherein the connecting section three 7 and the outlet section 8 are fixed as a whole structure by welding process, the furnace body structure is horizontally fixed and installed on the concrete foundation preset on the workshop floor by taking H-shaped steel as a support piece, three cooling air discharge pipes are symmetrically installed on the top of the furnace body structure, one end of the discharge pipe is communicated with the inside of the furnace body, the other end is connected to the outside of the factory building through a flange, extends to the inlet of the waste gas treatment device outside the factory building, and the independent gas collecting hoods 9 are respectively installed on the top of the inlet section 1, the connecting section one 5, the connecting section two 6 and the connecting section three 7 and the outlet section 8, the gas collecting hoods 9 are formed by welding with stainless steel material, the inner wall is smooth without dead angle, one gas collecting hood 9 corresponds to one exhaust pipe, and the exhaust pipes are finally collected to the waste gas discharge system outside the factory building;

[0051] Radiant tube heating devices are respectively installed in the heating section one 2, the heating section two 3 and the heating section three 4, the radiant tubes are made of high-temperature resistant alloy material, the radiant tubes are uniformly distributed in each heating section, and an oxygen analyzer is respectively installed in each heating section, and the detection probe of the oxygen analyzer extends into the furnace; sampling ports are arranged on the side surfaces of each heating section, the sampling ports are provided with sealing covers, so that the atmosphere samples in the furnace can be collected in real time; and an atmosphere supply system is installed on one side of the heating section three 4;

[0052] Electric heating bodies are installed at the lower parts of the connecting section one 5 and the connecting section two 6, the connecting section three 7 is used as a cooling section, a plurality of groups of spray pipes are installed in the connecting section three 7, the spray pipes are connected with nitrogen-hydrogen mixed gas supply pipelines, and flow regulating valves are installed on the supply pipelines, so that the blowing pressure and flow can be adjusted.

[0053] Sixteen sets of independent drive one furnace roller groups 10 and two furnace roller groups 11 are installed in the furnace body structure, wherein two sets of the one furnace roller groups 10 are made of stainless steel and are respectively installed in the inlet section 1 and the outlet section 8, and the remaining fourteen sets of the two furnace roller groups 11 are made of ceramic sleeve material, each set of the one furnace roller group 10 and the two furnace roller group 11 is provided with an independent drive motor, a chain and a sprocket.

[0054] Step one, feeding and preheating section; the silicon steel sheet enters the furnace body structure through the stainless steel one furnace roller group 10 of the inlet section 1, the initial volatile gas is discharged from the inlet section 1 through the independent gas collecting hood 9 and the exhaust pipe, the strip steel centering accuracy is ensured, the silicon steel sheet enters the early stage area of the heating section, is indirectly heated through convection and radiation of the furnace gas, the temperature is controlled to be lower than the ignition point of the rolling oil on the surface of the silicon steel sheet, the surface rolling oil, emulsion residue and moisture are removed, and the volatile oil gas is discharged from the factory building through the exhaust pipe;

[0055] Step two, heating and soaking section; silicon steel sheet passes through heating section one 2, heating section two 3 and heating section three 4 in turn, each heating section is independently temperature controlled and is equipped with an online oxygen analyzer and a sampling port, indirect heating is performed through a radiation tube, nitrogen-hydrogen mixed protective atmosphere is introduced and the gas ratio is adjusted, the heating temperature is controlled according to the type of silicon steel, and the control of the heating temperature is specifically as follows:

[0056] If it is an intermediate annealing scene, the control temperature is 800-900℃;

[0057] If it is a non-oriented silicon steel finished product annealing scene, the control temperature is 800-950℃;

[0058] If it is an oriented silicon steel high-temperature annealing scene, the control temperature is up to 1200℃ or above;

[0059] Step three, slow cooling section; the silicon steel sheet first passes through connecting section one 5 and connecting section two 6, and is heated by the built-in electric heating body in the connecting section one 5 and the connecting section two 6 to cool the strip steel from the annealing temperature to 550-650℃ at a controlled rate, promote the spheroidization of carbides and avoid the generation of thermal stress;

[0060] Step four, fast cooling section; the silicon steel sheet enters connecting section three 7, and is cooled to below 150℃ by spraying and blowing cooling with a mixture of nitrogen and hydrogen gas through a spray pipe to prevent oxidation;

[0061] Step five, discharging and post-processing section; the cooled silicon steel sheet is discharged through the stainless steel No. 1 furnace roller group 10 of the outlet section 8, and enters the subsequent water quenching tank for strengthening treatment according to process requirements, and the waste gas generated in each section is discharged outside the plant through independent exhaust pipes and cooling air exhaust pipes;

[0062] The hydrogen content in the nitrogen-hydrogen mixed protective atmosphere in step two is 5%-20%;

[0063] In the oriented silicon steel high-temperature annealing scene in step two, the holding time of the heating section three 4 is set according to the secondary recrystallization requirement to ensure the formation of {110} <001> Goss texture, so that the MgO release agent coated on the surface of the silicon steel sheet reacts with the matrix to form a magnesium silicate glass film;

[0064] In the non-oriented silicon steel finished product annealing scene in step two, the nitrogen-hydrogen mixed atmosphere of the heating section three 4 is a decarburization atmosphere, which removes harmful impurity elements such as carbon, nitrogen and sulfur in the silicon steel sheet, and optimizes the grain size to be uniform equiaxed grains;

[0065] In step two, nitrogen-hydrogen mixed gas is introduced as a protective atmosphere for several hours, and the internal stress generated during the forming process of the silicon steel sheet is eliminated through the slow cooling treatment of the connecting section one 5 and the connecting section two 6, without changing the material texture and grain size;

[0066] In steps one to five, the running speed of the silicon steel sheet is adjusted by 16 sets of independently driven first furnace roller group 10 and second furnace roller group 11, wherein 14 sets of second furnace roller group 11 with ceramic sleeve can be replaced with each other, and the processing time of the silicon steel sheet in each process section is regulated by controlling the running speed of the first furnace roller group 10 and the second furnace roller group 11;

[0067] In step three, the cooling rate of the connection section one 5 and the connection section two 6 is realized by adjusting the circulating speed of the protective gas in the furnace body structure and the temperature of the electric heating body, and the spraying cooling rate of the connection section three 7 is controlled according to the CCT curve of the silicon steel sheet;

[0068] As shown in Figure 1 and Figure 4 , the stainless steel first furnace roller group 10 of the starting inlet section 1 is started, the furnace roller group rotating speed is adjusted, the silicon steel sheet is sent into the furnace body structure through the inlet section 1, and the strip steel centering accuracy is ensured. The independent gas collecting cover 9 and the exhaust pipeline of the inlet section 1 are opened, and the initial volatile gas carried by the silicon steel sheet when entering is discharged. After the silicon steel sheet enters the pre-stage area of the heating section, it is indirectly heated by convection and radiation of the furnace gas, and the temperature of this area is controlled to be lower than the ignition point of the rolling oil on the surface of the silicon steel sheet. The rolling oil, emulsion residue and moisture on the surface of the silicon steel sheet are removed at this temperature for 30 minutes, and the oil gas generated by volatilization is discharged from the exhaust pipeline to the waste gas treatment device outside the factory building;

[0069] The silicon steel sheet continues to be conveyed by the second furnace roller group 11 and enters the heating section one 2, the heating section two 3 and the heating section three 4 in turn. Each heating section is independently temperature-controlled according to the preset temperature, indirectly heated by the radiation pipe, and the atmosphere supply system is started at the same time. Nitrogen-hydrogen mixed protective atmosphere is introduced, wherein the hydrogen content is controlled at 5%-20%, and the specific proportion is adjusted according to the type of silicon steel. If it is the annealing scene of non-oriented silicon steel product, the nitrogen-hydrogen mixed atmosphere of the heating section three 4 is decarburization atmosphere, the hydrogen content is adjusted to 15%-20%, the harmful impurity elements of carbon, nitrogen and sulfur in the silicon steel sheet are removed by atmosphere adjustment, and the grain size is optimized to uniform equiaxed grains. If it is the high-temperature annealing scene of oriented silicon steel, the holding time of the heating section three 4 is set according to the secondary recrystallization requirement, so as to ensure the formation of {110} <001> Goss texture, and at the same time, the MgO release agent coated on the surface of the silicon steel sheet reacts with the matrix to form a magnesium silicate glass film. During the process, the furnace atmosphere samples can be collected regularly through the sampling ports of each heating section for composition analysis, and the atmosphere supply parameters can be adjusted slightly according to the analysis results;

[0070] After the silicon steel sheet passes through the heating and soaking section, it enters the connecting section one 5 and the connecting section two 6, the electric heating bodies in the two connecting sections are started, the silicon steel sheet is cooled from the annealing temperature to 550-650℃ at a controlled rate through the electric heating bodies, the specific cooling end temperature is determined according to the type of silicon steel, and the cooling rate is realized by adjusting the circulating speed of the protective gas in the furnace body structure and the temperature of the electric heating body, so as to ensure the smoothness of the cooling process, promote the spheroidization of carbides and avoid the generation of thermal stress;

[0071] The silicon steel sheet enters the connecting section three 7, the nitrogen-hydrogen mixed gas supply system is started, the mixed gas with a nitrogen-hydrogen ratio of 3:7 is introduced, the mixed gas is sprayed and cooled on the silicon steel sheet through the spray pipe, the silicon steel sheet is rapidly cooled to below 150℃, the surface of the silicon steel sheet is prevented from being oxidized, the spraying and cooling rate of the connecting section three 7 is accurately controlled according to the CCT curve of the silicon steel sheet, and the performance of the silicon steel sheet after cooling is stable by adjusting the gas flow and pressure of the spray pipe.

[0072] The cooled silicon steel sheet is discharged through the stainless steel No. 1 furnace roller group 10 of the outlet section 8, and according to the process requirement, the silicon steel sheet after discharge is sent into the subsequent water quenching tank for strengthening treatment, if no water quenching treatment is required, it is directly sent into the winding device, and the waste gas generated in each section is discharged from the factory building through independent exhaust pipe and cooling air exhaust pipe, and is discharged after treatment by the waste gas treatment device.

[0073] Working principle: the furnace body is composed of the inlet section 1, three independent heating sections, three connecting sections and the outlet section 8, and is matched with an independent exhaust and atmosphere control system, the silicon steel sheet is fed through the inlet section 1, first removes impurities such as rolling oil and moisture at low temperature in the preheating section, then passes through the three heating sections in turn, independently controls the temperature according to the annealing scene, introduces the nitrogen-hydrogen protective atmosphere with a hydrogen content of 5%-20%, accurately regulates the atmosphere through the online oxygen analyzer and the sampling port, then slowly cools to 550-650℃ through the two connecting sections to avoid thermal stress, then uses the nitrogen-hydrogen mixed gas with a ratio of 3:7 to spray and rapidly cool to below 150℃ to prevent oxidation in the connecting section three, and finally discharges from the outlet section 8, through the segmented temperature control, atmosphere adjustment and gradient cooling, adapts to the annealing requirements of multiple scenes, optimizes the microstructure and performance of the silicon steel.

[0074] Although the embodiments of the present application have been shown and described, it can be understood by those skilled in the art that various changes, modifications, replacements and variations can be made to the embodiments without departing from the principles and spirits of the present application.

Claims

1. A process for a silicon steel sheet annealing test furnace characterized by: The process method steps are as follows: Step one, feeding and preheating section; the silicon steel sheet enters the furnace body structure through the stainless steel No. 1 furnace roller group (10) of the inlet section (1), the inlet section (1) discharges the initial volatile gas through the independent gas collecting cover (9) and the exhaust pipe, ensures the strip steel centering accuracy, the silicon steel sheet enters the early stage area of the heating section, is indirectly heated through convection and radiation of the furnace gas, the temperature is controlled to be lower than the rolling oil ignition point of the silicon steel sheet surface, the surface rolling oil, emulsion residue and moisture are removed, and the volatile oil gas is discharged out of the plant through the exhaust pipe; Step two, heating and soaking section; the silicon steel sheet sequentially passes through heating section one (2), heating section two (3) and heating section three (4), each heating section is independently temperature controlled and is provided with an online oxygen analyzer and a sampling port, is indirectly heated through a radiation pipe, a nitrogen-hydrogen mixed protective atmosphere is introduced and the gas proportion is adjusted, the heating temperature is controlled according to the silicon steel type, and the control of the heating temperature is specifically as follows: If it is an intermediate annealing scene, the control temperature is 800-900 DEG C; If it is a non-oriented silicon steel finished product annealing scene, the control temperature is 800-950 DEG C; If it is an oriented silicon steel high-temperature annealing scene, the control temperature is up to 1200 DEG C or above; Step three, slow cooling section; the silicon steel sheet first passes through connecting section one (5) and connecting section two (6), is heat preserved through the built-in electric heating body in the connecting section one (5) and the connecting section two (6), and the strip steel is cooled at a controlled rate from the annealing temperature to 550-650 DEG C, so that the carbide spheroidization is promoted and thermal stress is avoided; Step four, fast cooling section; the silicon steel sheet enters the connecting section three (7), a mixed gas of nitrogen and hydrogen is sprayed and blown through a spray pipe to cool the strip steel to below 150 DEG C, and oxidation is prevented; Step five, discharging and post-processing section; the cooled silicon steel sheet is discharged through the stainless steel No. 1 furnace roller group (10) of the outlet section (8), enters a subsequent water quenching tank for strengthening treatment according to process requirements, and the waste gas generated in each section is discharged out of the plant through independent exhaust pipes and cooling air exhaust pipes; The hydrogen content in the nitrogen-hydrogen mixed protective atmosphere in step two is 5%-20%; In the oriented silicon steel high-temperature annealing scene in step two, the heat preservation time of the heating section three (4) is set according to the secondary recrystallization requirement, so that the {110} <001> Goss texture is formed, the MgO release agent coated on the surface of the silicon steel sheet reacts with the matrix to form a magnesium silicate glass film; In the non-oriented silicon steel finished product annealing scene in step two, the nitrogen-hydrogen mixed atmosphere of the heating section three (4) is a decarburization atmosphere, which removes harmful impurity elements such as carbon, nitrogen and sulfur in the silicon steel sheet, and optimizes the grain size to be uniform equiaxed grains; In step two, the nitrogen-hydrogen mixed gas is introduced as a protective atmosphere and is heat preserved for several hours, the internal stress generated in the forming process of the silicon steel sheet is eliminated through the slow cooling treatment of the connecting section one (5) and the connecting section two (6), and the material texture and grain size are not changed.

2. A process for annealing of silicon steel sheets as claimed in claim 1 wherein: The running speed of the silicon steel sheet is adjusted by 16 sets of independent transmission of the first furnace roller group (10) and the second furnace roller group (11), wherein 14 sets of ceramic sleeve pipes of the second furnace roller group (11) can be replaced with each other, and the processing time of the silicon steel sheet in each process section is controlled by controlling the running speed of the first furnace roller group (10) and the second furnace roller group (11).

3. A process for annealing of silicon steel sheets as claimed in claim 1 wherein: In the third step, the cooling rate of the connecting section one (5) and the connecting section two (6) is realized by adjusting the circulating speed of the protective gas in the furnace structure and the temperature of the electric heating body, and the spraying cooling rate of the connecting section three (7) is controlled according to the CCT curve of the silicon steel sheet.

4. A furnace for annealing silicon steel sheets, characterized by: A process method for the silicon steel sheet annealing test furnace according to any one of claims 1-3: comprising an inlet section (1), a heating section, a connecting section and an outlet section (8), the inlet section (1), the heating section, the connecting section and the outlet section (8) constitute a furnace structure, the furnace structure is fixedly installed on the floor in the workshop through two H-shaped steels, the furnace structure is provided with three cooling air discharge pipes, and the cooling air discharge pipes are led out of the factory building for discharge; The heating section is provided with three, and the three heating sections are heating section one (2), heating section two (3) and heating section three (4); the connecting section is provided with three, and the three connecting sections are connecting section one (5), connecting section two (6) and connecting section three (7); the connecting section three (7) and the outlet section (8) constitute an integral whole, and the inlet section (1), the connecting section one (5), the connecting section two (6), the connecting section three (7) and the outlet section (8) are respectively provided with independent gas collecting covers (9) and exhaust pipes, and the exhaust pipes are led out of the factory building for discharge.

5. The annealing test furnace for silicon steel sheets according to claim 4, characterized in that: One side of the inlet section (1) is provided with the heating section one (2), the outlet end of the heating section one (2) is provided with the heating section two (3), the other side of the heating section two (3) is provided with the connecting section one (5), the other side of the connecting section one (5) is provided with the heating section three (4), the other side of the heating section three (4) is provided with the connecting section two (6), the connecting section two (6) is connected with the connecting section three (7), and the connecting section three (7) and the outlet section (8) are in an integral structure.

6. The annealing test furnace for silicon steel sheets according to claim 4, characterized in that: The connecting section one (5) is a connecting transition section between the heating section two (3) and the heating section three (4), and the lower part of the connecting section one (5) is provided with an electric heating body; the connecting section two (6) is a connecting transition section between the heating section three (4) and the connecting section three (7) and the outlet section (8), and the lower part of the connecting section two (6) is provided with an electric heating body.

7. The annealing test furnace for silicon steel sheets according to claim 4, characterized in that: The connecting section three (7) is a cooling section, the connecting section three (7) sprays and cools the silicon steel sheet by a spray pipe using a mixed gas of nitrogen and hydrogen, and the ratio of the nitrogen and hydrogen is 3:

7.

8. The annealing test furnace for silicon steel sheets according to claim 4, characterized in that: The heating section one (2), the heating section two (3) and the heating section three (4) are respectively provided with independent online oxygen analyzers, the heating section one (2), the heating section two (3) and the heating section three (4) are respectively provided with sampling ports, and the heating section three (4) is provided with an atmosphere supply system.

9. The annealing test furnace for silicon steel sheets according to claim 4, characterized in that: The furnace body structure is provided with 16 sets of independently driven No. 1 furnace roller groups (10) and No. 2 furnace roller groups (11), the No. 1 furnace roller groups (10) and the No. 2 furnace roller groups (11) each include two roller bodies, one set of the No. 1 furnace roller groups (10) is provided, the No. 1 furnace roller groups (10) are made of stainless steel, 14 sets of the No. 2 furnace roller groups (11) are provided, the No. 2 furnace roller groups (11) are made of ceramic sleeve material, the two sets of the No. 1 furnace roller groups (10) made of stainless steel are arranged in the inlet section (1) and the outlet section (8) respectively, and the remaining 14 sets of the No. 2 furnace roller groups (11) made of ceramic sleeve material are sequentially arranged in the heating section, the connecting section and the outlet section (8); The ceramic sleeve No. 2 furnace roller groups (11) are modularly arranged and have mutual replaceability; Each of the No. 1 furnace roller groups (10) and the No. 2 furnace roller groups (11) is provided with independent chains and sprockets, the two roller bodies in each of the No. 1 furnace roller groups (10) and the No. 2 furnace roller groups (11) are independently connected through the chains and the sprockets, and each of the No. 1 furnace roller groups (10) and the No. 2 furnace roller groups (11) is provided with one driving motor.

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