Process method for producing soft magnetic stainless steel material by adopting argon-oxygen refining furnace in low-oxygen and sulfur-control manner

Abstract

The invention provides a process method for producing a soft magnetic stainless steel material by adopting an argon-oxygen refining furnace in a low-oxygen and sulfur-control manner. The process method for producing the soft magnetic stainless steel material through the argon-oxygen refining furnace in the low-oxygen and sulfur-control mode comprises the following steps that S1, high-alkalinity slag making and deep desulfurization and deoxidation are conducted in the early stage of refining, specifically, 1.5 tons of lime is added into the argon-oxygen refining furnace, the high-alkalinity slag making is conducted in the early stage, and deep desulfurization and deoxidation are conducted, so that the oxygen content is reduced to be smaller than or equal to 30 ppm, and the sulfur content is reduced to be smaller than or equal to 0.003%; according to the process method for producing the soft magnetic stainless steel material in a low-oxygen and sulfur-control mode through the argon-oxygen refining furnace, the requirements for free cutting machining and corrosion resistance of the material can be met, meanwhile, control over the S element in the soft magnetic stainless steel is completed by continuously adjusting smelting operation key points on site, and the production efficiency is improved. And the S element in the soft magnetic stainless steel is reasonably controlled, so that the corrosion resistance and the machining performance of the material are greatly improved, the efficiency of a precision automatic lathe is improved by more than 1.5 times, and the corrosion resistance is improved by more than 50%.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of stainless steel smelting, and particularly relates to a process method for producing soft magnetic stainless steel material by adopting an argon-oxygen refining furnace low-oxygen sulfur control. BACKGROUND

[0002] Soft magnetic iron is a kind of magnetic material, and its name is derived from its easy magnetization and demagnetization characteristics, rather than the softness in physical hardness. Compared with permanent magnets, soft magnetic iron has lower coercivity and higher magnetic permeability, and can quickly change the magnetization state under the action of an external magnetic field.

[0003] Ferrite soft magnetic stainless steel is a general material for electromagnetic valves at present. The material has obvious corrosion resistance compared with pure iron and silicon steel, has higher saturation magnetic induction intensity and higher magnetic permeability, and is suitable for producing electromagnetic valves and air valve products with corrosion resistance. At present, the production process is basically high-speed walking machine production, and the surface finish and turning speed of the material have higher requirements. The turning resistance of ordinary stainless steel without sulfur is too large, and it is very difficult to break the chip, resulting in burrs on the surface, poor surface finish, difficult turning, and frequent replacement of tools. The oxygen content of high-sulfur product material is also very high, and its corrosion resistance is poor, which is not suitable for corrosion-resistant environments.

[0004] Since ferritic stainless steel is a high-chromium alloy, the material can only be desulfurized at high temperature and high alkalinity. If high-alkalinity slag is used for desulfurization, the sulfur in the material is basically ≤0.005%. How to ensure the sulfur content in the material: 0.020-0.030%. If deep desulfurization is not performed, the oxygen content in the steel is very high, resulting in poor material purity, easy material processing fracture, and poor magnetic performance.

[0005] Therefore, it is necessary to provide a process method for producing soft magnetic stainless steel material by adopting an argon-oxygen refining furnace low-oxygen sulfur control to solve the above technical problems. SUMMARY

[0006] The present application provides a process method for producing soft magnetic stainless steel material by adopting an argon-oxygen refining furnace low-oxygen sulfur control, which solves the problem that ferritic stainless steel is a high-chromium alloy material that can only be desulfurized at high temperature and high alkalinity, and the existing desulfurization process easily causes high oxygen content in the steel, thereby affecting the material purity.

[0007] To solve the above technical problems, the process method for producing soft magnetic stainless steel material by adopting an argon-oxygen refining furnace low-oxygen sulfur control provided by the present application includes the following process method:

[0008] S1: High basicity slag is formed in the early stage of refining, and deep desulfurization and deoxidation is performed: 1.5 tons of lime is added to the argon-oxygen refining furnace to form high basicity slag, and deep desulfurization and deoxidation is performed, so that the oxygen content is reduced to ≤30 ppm, and the sulfur content is reduced to ≤0.003%;

[0009] S2: Deep reduction with aluminum and further reduction of oxygen content: deep reduction is performed using aluminum to further reduce the oxygen content in the molten steel to ≤20 ppm;

[0010] S3: High basicity slag is removed and secondary slag is formed: after the first reduction, the high basicity slag is removed, and then lime and fluorite are added for secondary slag formation. After sufficient stirring, the secondary slag is removed completely;

[0011] S4: Quartz sand is added to adjust the slag basicity to 1.0-1.5: after the second reduction, quartz sand is added to reduce the basicity of the slag, and the basicity is controlled at 1.0-1.5;

[0012] S5: The temperature is controlled at about 1550°C and ferrous sulfate is added: the temperature of the molten steel is controlled at about 1550°C, and ferrous sulfate is added to the ladle to make sulfur react with manganese to form MnS;

[0013] High basicity slag is formed in the early stage of refining, and deep desulfurization and deoxidation is performed: lime is the core component of high basicity slag, which can enhance the adsorption and reaction ability of sulfur, and the high temperature condition can improve the driving force of desulfurization reaction. At the same time, the oxygen content in the molten steel is reduced, which can initially control the oxygen and sulfur at a low level of oxygen ≤30 ppm and sulfur ≤0.003%, reducing the interference factors in the subsequent sulfur control process, creating conditions for precise sulfur control. Deep reduction with aluminum and further reduction of oxygen content: aluminum reacts with oxygen in the molten steel: 2Al + 3[O] = Al2O3, and the generated Al2O3 can enter the slag, thereby significantly reducing the oxygen content of the molten steel to ≤20 ppm, providing a low-oxygen environment for the reaction of sulfur and manganese after the addition of ferrous sulfate, avoiding the interference of oxygen on the reaction, and ensuring the stable retention of sulfur in the molten steel. High basicity slag is removed and secondary slag is formed: secondary slag formation maintains a certain basicity by adding CaO with lime, and fluorite reduces the melting point of the slag, improves the fluidity, and enhances the adsorption ability of the slag to residual sulfur and oxygen. Stirring promotes the full contact of molten steel and slag, improves the removal efficiency, and can completely remove the residual sulfur and oxygen products, avoiding their interference with the subsequent low basicity slag environment, ensuring the stability of sulfur in the subsequent sulfur control process. Quartz sand is added to adjust the slag basicity to 1.0-1.5: SiO2 in quartz sand is an acidic oxide, which increases the concentration of acidic oxides in the slag after addition, reduces the basicity of the slag, and weakens the desulfurization ability of the slag, so that the slag is in a low desulfurization activity state, providing an environment for the retention of sulfur after the addition of ferrous sulfate.

[0014] Preferably, the adding quartz sand to adjust the slag basicity to 1.0-1.5 comprises the following processes: detecting the initial slag basicity after secondary slagging, adding quartz sand in stages and monitoring the basicity in real time, and stirring the slag to ensure uniform basicity;

[0015] The main component of quartz sand is silicon dioxide, which is an acidic oxide, and the basicity calculation formula of the slag is basicity = calcium oxide content + silicon dioxide content. After adding quartz sand, the concentration of acidic oxides in the slag will increase, thereby reducing the basicity of the slag.

[0016] Preferably, the detection of the initial slag basicity after secondary slagging is used to avoid excessive or insufficient addition of quartz sand, ensure accurate basicity adjustment, reduce material waste and process fluctuations, the addition of quartz sand in stages and real-time monitoring of the basicity is used to smoothly reduce the slag basicity to the target range of 1.0-1.5, ensure good slag flowability, and avoid excessive reduction of the basicity leading to abnormal slag performance, and the stirring of the slag to ensure uniform basicity avoids local high basicity areas from continuing desulfurization, ensuring the consistency of the sulfur retention environment.

[0017] Preferably, the process comprises the following processes: monitoring and adjusting the temperature of the molten steel to 1550°C ± 10°C, calculating the addition amount of pyrite according to the target sulfur content and adding it in batches, and stirring the molten steel to promote the reaction of sulfur and manganese to generate MnS.

[0018] From the perspective of temperature control, a temperature of about 1550°C can effectively reduce the consumption of pyrite, because at high temperatures, the sulfur in pyrite is prone to volatilization and reacts with residual oxygen in the molten steel to generate gas, resulting in increased sulfur loss.

[0019] Preferably, the monitoring and adjustment of the temperature of the molten steel to 1550°C ± 10°C reduces the consumption of pyrite while ensuring that sulfur can efficiently enter the molten steel to participate in the reaction, the calculation of the addition amount of pyrite according to the target sulfur content and the addition in batches achieve precise control of the sulfur content and avoid uneven distribution of sulfur in the molten steel, and the stirring of the molten steel to promote the reaction of sulfur and manganese to generate MnS allows sulfur to remain in the steel in the form of stable MnS, achieving the goal of sulfur control and avoiding the existence of free sulfur affecting material performance, while improving the uniformity of the microstructure of soft magnetic stainless steel.

[0020] The argon-oxygen refining furnace used in the process of producing soft magnetic stainless steel material by low-oxygen sulfur control in an argon-oxygen refining furnace comprises an adjusting base frame;

[0021] The argon-oxygen refining furnace body is installed on the top of the adjusting base frame, the top of the argon-oxygen refining furnace body is provided with a top cover, the top of the top cover is provided with an injection pipe with a first valve, the top of the top cover is provided with a monitoring assembly, and the monitoring assembly comprises a fixed base and a monitoring component;

[0022] The first valve is an electromagnetic valve, which can automatically open and close.

[0023] Preferably, the top of the adjusting base is provided with an oxygen supply structure, the outlet of the oxygen supply structure is provided with an oxygen supply pipe, the top of the adjusting base is provided with an argon supply structure, the outlet of the argon supply structure is provided with an argon supply pipe, the other end of the oxygen supply pipe and the argon supply pipe is respectively provided with a second flow meter and a first flow meter through a second valve, the other end of the second flow meter and the first flow meter is respectively provided with a one-way valve through a fixed pipe, and the other end of the two one-way valves is connected with two inlets of a three-way head.

[0024] The first flow meter can monitor the argon supply amount, and the second flow meter can monitor the oxygen supply amount, the outlet of the three-way head is connected with the first valve, and the argon supply structure and the oxygen supply structure comprise a tank body for storing oxygen and argon and a pump for conveying gas.

[0025] Preferably, the top of the adjusting base is provided with a filter assembly, and the top of the adjusting base is provided with an exhaust assembly, the filter assembly comprises a filter box and an intercepting part, and the exhaust assembly comprises a protective shell, an exhaust pipe, an exhaust part and a mounting pipe, the mounting pipe is used for connecting the inlet of the exhaust part with the filter assembly.

[0026] The exhaust part provides suction force to assist in exhausting harmful gas.

[0027] Preferably, the top of the top cover is provided with an exhaust pipe with a connecting head, the other end of the exhaust pipe is provided with a docking pipe, and the top of the top cover is provided with a plurality of hooks.

[0028] Preferably, the adjusting base comprises a bottom plate, an adjusting structure and a mounting structure, the mounting structure is used for mounting the adjusting structure at the bottom of the bottom plate, the top of the adjusting base is provided with a control box with a box door, and the front surface of the control box is provided with an operation panel.

[0029] The operation panel can control the operation of the equipment on the top of the adjusting base.

[0030] Compared with the related art, the process method for producing soft magnetic stainless steel material by using the argon-oxygen refining furnace to control sulfur under low oxygen provided by the application has the following beneficial effects:

[0031] The application provides a process method for producing soft magnetic stainless steel material by using argon-oxygen refining furnace low-oxygen sulfur control, in order to improve the purity of the production of soft magnetic stainless steel material, the process for producing soft magnetic stainless steel material by using argon-oxygen refining furnace low-oxygen sulfur control is carried out in sequence according to accurate steps, and each link is closely connected, in the early stage of refining, first, 1.5 tons of lime is added to the furnace to form high-alkalinity slag, according to the desulfurization reaction [S]+(CaO)=(CaS)+[O], the high-alkalinity slag can promote the reaction to proceed to the right, and the high-temperature environment is also beneficial to desulfurization, in this process, deep desulfurization and deoxidation can be realized, the oxygen content is reduced to ≤30ppm, and the sulfur content is reduced to ≤0.003%, which can lay a foundation for low-oxygen and low-sulfur for subsequent sulfur control, reduce the interference of subsequent process, after completing the slagging, aluminum is used for deep reduction, since aluminum is a strong deoxidizer, it can react with oxygen in the molten steel 2Al+3[O]=Al2O3, the generated Al2O3 enters the slag, thereby further reducing the oxygen content to ≤20ppm, in this way, in the low-oxygen environment, the reaction of oxygen with the reactant of the subsequently added sulfur can be avoided, which creates favorable conditions for the reaction of sulfur and manganese, next, the high-alkalinity slag is removed after the first reduction, the slag contains a large amount of desulfurization and deoxidation products, if the products are not removed, they will affect the subsequent process, then lime and fluorite are added for secondary slagging, fluorite can improve the fluidity of the slag and enhance the exchange between the molten steel and the slag, and then the slag is removed completely, in this process, the harmful products are completely removed through twice slagging, so as to avoid the interference of the products on the subsequent process, after the second reduction, quartz sand is added to adjust the alkalinity of the slag to 1.0-1.5, so that the high-alkalinity slag continuously desulfurizes, which is not conducive to the retention of subsequent sulfur, and the quartz sand as an acidic oxide can increase the concentration of acidic oxides in the slag and reduce the alkalinity "alkalinity=CaO / SiO2", the principle is to weaken the desulfurization ability by changing the composition of the slag, so that the slag is in a low desulfurization activity state, which solves the difficulty of sulfur retention, finally, the temperature of the molten steel is controlled at about 1550℃, at this time, iron sulfide is added, because high temperature will cause serious burning loss of iron sulfide, and about 1550℃ can reduce the consumption of iron sulfide, at the same time, in the low-alkalinity slag environment, sulfur will react with manganese to generate MnS, the principle is that low temperature and low alkalinity conditions work together to reduce the consumption of iron sulfide and promote the generation of MnS, realizing accurate control of sulfur, meeting the production requirements of soft magnetic ferrite stainless steel, through the process method, the S content in the composition of the molten steel can be finally controlled in the range of 0.020-0.030%, which can meet the requirements of easy cutting and corrosion resistance of the material, at the same time, through continuous adjustment of the operation points of smelting on site, the control of S element in soft magnetic stainless steel is completed, and through reasonable control of S element in soft magnetic stainless steel, the corrosion resistance and machining performance of the material are greatly improved, the efficiency of the broaching machine is increased by more than 1.5 times, and the corrosion resistance is increased by more than 50%. BRIEF DESCRIPTION OF DRAWINGS

[0032] Figure 1The structural schematic diagram of the first embodiment of the process method for producing the soft magnetic stainless steel material by using the argon-oxygen refining furnace low-oxygen sulfur control provided by the application is shown in the figure.

[0033] Figure 2 The flow chart of adding quartz sand to adjust the slag basicity to 1.0-1.5 is provided by the application.

[0034] Figure 3 The flow chart of controlling the temperature to about 1550 DEG C and adding sulfur iron is provided by the application.

[0035] Figure 4 The structural schematic diagram of the second embodiment of the process method for producing the soft magnetic stainless steel material by using the argon-oxygen refining furnace low-oxygen sulfur control provided by the application is shown in the figure.

[0036] Figure 5 The structural schematic diagram of the filter assembly provided by the application is shown in the figure.

[0037] Figure 6 The structural schematic diagram of the filter assembly provided by the application is shown in the figure. Figure 5 The enlarged view of A shown in the figure.

[0038] Figure 7 The structural schematic diagram of the exhaust component provided by the application is shown in the figure.

[0039] The figure shows that: 1, the adjusting chassis, 101, the bottom plate, 102, the adjusting structure, 103, the mounting structure, 2, the control box, 3, the operation panel, 4, the box door, 5, the argon-oxygen refining furnace body, 6, the oxygen supply structure, 7, the hook, 8, the top cover, 9, the monitoring assembly, 901, the fixed base, 902, the monitoring component, 10, the injection pipe, 11, the first valve, 12, the exhaust pipe, 13, the connecting head, 14, the butt joint pipe, 15, the exhaust assembly, 151, the protective shell, 152, the exhaust pipe, 153, the exhaust component, 154, the mounting pipe, 16, the filter assembly, 161, the filter box, 162, the intercepting component, 17, the argon supply structure, 18, the oxygen supply pipe, 19, the argon supply pipe, 20, the first flowmeter, 21, the second valve, 22, the second flowmeter, 23, the tee, 24, the check valve, 25, the fixed pipe. DETAILED DESCRIPTION

[0040] The application will be further described below in combination with the figures and embodiments.

[0041] Please refer to Figure 1 , Figure 2 , Figure 3 Among them, Figure 1 The structural schematic diagram of the first embodiment of the process method for producing the soft magnetic stainless steel material by using the argon-oxygen refining furnace low-oxygen sulfur control provided by the application is shown in the figure. Figure 2 The flow chart of adding quartz sand to adjust the slag basicity to 1.0-1.5 is provided by the application. Figure 3The process flow chart for controlling the temperature to about 1550℃ and adding ferrous sulfide is provided for the present application. The process method for producing soft magnetic stainless steel material by low oxygen control sulfur in argon oxygen refining furnace includes the following process methods:

[0042] S1: High basicity slag making, deep desulfurization and deoxidization before refining: 1.5 tons of lime is added into the argon oxygen refining furnace to make high basicity slag, and deep desulfurization and deoxidization is carried out, so that the oxygen content is reduced to ≤30ppm, and the sulfur content is reduced to ≤0.003%;

[0043] S2: Deep reduction with aluminum, further reducing oxygen content: deep reduction is carried out using aluminum to further reduce the oxygen content in the molten steel to ≤20ppm;

[0044] S3: Removing high basicity slag and removing secondary slag: after the first reduction, the high basicity slag is removed, then lime and fluorite are added for the second slag making, and after sufficient stirring, the secondary slag is removed completely;

[0045] S4: Adding quartz sand to adjust the slag basicity to 1.0-1.5: after the second reduction, quartz sand is added to reduce the basicity of the slag, and the basicity is controlled to 1.0-1.5;

[0046] S5: Controlling the temperature to about 1550℃ and adding ferrous sulfide: the temperature of the molten steel is controlled to about 1550℃, and ferrous sulfide is added into the ladle to make the sulfur react with manganese to generate MnS;

[0047] High basicity slag in early refining stage, deep desulphurization and deoxidation: lime is the core component of high basicity slag, high basicity slag can enhance the adsorption and reaction capacity of sulfur, and the driving force of desulfurization reaction is improved under high temperature conditions, at the same time, the oxygen content in the molten steel is reduced, which can preliminarily control the oxygen and sulfur at a low level, oxygen≤30ppm, sulfur≤0.003%, reduce the interference factors in the subsequent sulfur control process, create conditions for precise sulfur control, deep reduction of aluminum, further reduce the oxygen content: aluminum reacts with oxygen in the molten steel: 2Al+3[O]=Al2O3, the generated Al2O3 can enter the slag, thereby significantly reducing the oxygen content of the molten steel, and the oxygen content is reduced to≤20ppm, providing a low-oxygen environment for the reaction of sulfur and manganese after the addition of ferrous sulfate, avoiding the interference of oxygen on the reaction, ensuring that the sulfur is stably retained in the molten steel, and removing the high basicity slag and removing it after secondary slagging: secondary slagging maintains a certain basicity by supplementing CaO with lime, reduces the melting point of the slag with fluorite, improves the fluidity, and enhances the adsorption capacity of the slag to residual sulfur and oxygen; stirring promotes the full contact of the molten steel and the slag, improves the removal efficiency, and can completely remove the residual sulfur and oxygen products, avoiding their interference with the subsequent low basicity slag environment, ensuring the stability of sulfur in the subsequent sulfur control process, adding quartz sand to adjust the slag basicity to 1.0-1.5: SiO2 in quartz sand is an acidic oxide, which increases the concentration of acidic oxides in the slag after addition, reduces the basicity of the slag, and weakens the desulfurization capacity of the slag, so that the slag is in a low desulfurization activity state, providing an environment for the retention of sulfur after the addition of ferrous sulfate;

[0048] The desulfurization and deoxidation are carried out in an argon-oxygen refining furnace, and how to produce the material with reduced oxygen content for sulfur control is the key process: [S]+(CaO)=(CaS)+[O]It is well known that the desulfurization process must be preceded by deoxidation to make the above reaction proceed to the right, and the desulfurization reaction in stainless steel requires an increase in the content of calcium oxide, and high basicity slag is used to perform desulfurization and deoxidization at high temperature, the oxygen content is reduced to≤30ppm, and the sulfur content is reduced to≤0.003%, by adding quartz sand to change the basicity of the slag to about 1.0-1.5, so that the slag is in a low basicity and low temperature condition, and the sulfur and manganese react to produce MnS under the condition of the ladle at about 1550℃, so as to achieve the purpose of sulfur control.

[0049] The addition of quartz sand to adjust the slag basicity to 1.0-1.5 comprises the following processes: detecting the initial basicity of the slag after secondary slagging, adding quartz sand in stages and monitoring the basicity in real time, and stirring the slag to ensure uniform basicity;

[0050] The main component of quartz sand is silicon dioxide, which is an acidic oxide, and the basicity calculation formula of the slag is basicity=calcium oxide content, silicon dioxide content, after adding quartz sand, the concentration of acidic oxides in the slag is increased, thereby reducing the basicity of the slag.

[0051] The detection of the initial slag basicity after secondary slagging: for avoiding excessive or insufficient addition of quartz sand, ensuring accurate basicity adjustment, reducing material waste and process fluctuation, the staged addition of quartz sand and real-time monitoring of basicity: for smoothly reducing the slag basicity to the target range of 1.0-1.5, ensuring good slag fluidity, and avoiding excessive reduction of basicity to cause abnormal slag performance, the stirring of the slag ensures uniform basicity: uniform and stable slag basicity, avoiding continued desulfurization in the local high basicity area, and ensuring the consistency of the sulfur retention environment.

[0052] The process of controlling the temperature to about 1550 DEG C and adding sulfur iron includes monitoring and adjusting the molten steel temperature to 1550 DEG C ± 10 DEG C, calculating the sulfur iron addition amount according to the target sulfur content and adding in batches, and stirring the molten steel to promote the reaction of sulfur and manganese to generate MnS;

[0053] From the temperature control, the temperature of about 1550 DEG C can effectively reduce the consumption of sulfur iron, because when the temperature is too high, the sulfur in the sulfur iron is easy to volatilize, and will react with the residual oxygen in the molten steel to generate gas and escape, resulting in increased sulfur loss; and when the temperature is too low, the dissolution rate of sulfur iron in the molten steel is reduced, affecting the reaction efficiency of sulfur and manganese, this temperature range can control the loss of sulfur at the lowest level while ensuring sufficient dissolution of sulfur iron, reducing production cost.

[0054] The monitoring and adjustment of the molten steel temperature to 1550 DEG C ± 10 DEG C: reduce the consumption of sulfur iron, while ensuring that sulfur can enter the molten steel efficiently to participate in the reaction, the calculation of the sulfur iron addition amount according to the target sulfur content and the batch addition: realize accurate control of sulfur content, avoid uneven distribution of sulfur in the molten steel, the stirring of the molten steel to promote the reaction of sulfur and manganese to generate MnS: make sulfur remain in the steel in the form of stable MnS, realize the control of sulfur to avoid the existence of free sulfur affecting the material performance, and improve the uniformity of the microstructure of the soft magnetic stainless steel.

[0055] The working principle of the process method for producing soft magnetic stainless steel material by adopting argon-oxygen refining furnace low-oxygen sulfur control provided by the application is as follows:

[0056] First, 1.5 tons of lime is added to the furnace to produce high basicity slag, which can promote the reaction to the right according to the desulfurization reaction [S]+(CaO)=(CaS)+[O], and the high temperature environment is also conducive to desulfurization. In this process, deep desulfurization and deoxidation can be achieved, reducing the oxygen content to ≤30ppm and the sulfur content to ≤0.003%, which can lay the foundation for low oxygen and low sulfur in subsequent sulfur control, reduce the interference of subsequent processes, and complete slagging. After slagging, aluminum is used for deep reduction. Since aluminum is a strong deoxidizer, it can react with oxygen in the steel liquid 2Al+3[O]=Al2O3, and the generated Al2O3 enters the slag, thereby further reducing the oxygen content to ≤20ppm. Next, the high basicity slag is removed after the first reduction, and the slag contains a large amount of desulfurization and deoxidation products, which will affect the subsequent process if not removed. Subsequently, lime and fluorite are added for secondary slagging, and fluorite can improve the fluidity of the slag and enhance the exchange between the steel liquid and the slag liquid. After being removed again, the harmful products are completely removed through two times of slagging to avoid interference with the subsequent process. After the second reduction, quartz sand is added to adjust the basicity of the slag to 1.0-1.5, so that the high basicity slag can continue to desulfurize, which is not conducive to the retention of sulfur in the subsequent process. Quartz sand, as an acidic oxide, can increase the concentration of acidic oxides in the slag and reduce the basicity "basicity=CaO / SiO2". Finally, the temperature of the steel liquid is controlled at about 1550°C, at which point sulfur iron is added. High temperature can cause serious burning of sulfur iron, while a temperature of about 1550°C can reduce sulfur iron consumption. In addition, in a low basicity slag environment, sulfur will react with manganese to form MnS.

[0057] Compared with the related art, the process method for producing soft magnetic stainless steel material by low-oxygen sulfur control in an argon-oxygen refining furnace provided by the present application has the following beneficial effects:

[0058] In order to improve the purity of soft magnetic stainless steel material production, the process of producing soft magnetic stainless steel material by low oxygen control sulfur in argon oxygen refining furnace, according to the accurate steps in turn, each link closely, in the early stage of refining, first need to add 1.5 tons of lime to the furnace to build high basicity slag, can according to the desulfurization reaction [S]+(CaO)=(CaS)+[O], high basicity slag can promote the reaction to the right, at the same time, high temperature environment is also conducive to desulfurization, in this process can realize deep desulfurization and deoxidation, the oxygen content is reduced to ≤30ppm, the sulfur content is reduced to ≤0.003%, can lay the foundation of low oxygen and low sulfur for subsequent sulfur control, reduce the interference of subsequent process, after completing the slag building, use aluminum for deep reduction, because aluminum is a strong deoxidizer, can react with the oxygen in the molten steel 2Al+3[O]=Al2O3, the generated Al2O3 enters the slag, thereby further reducing the oxygen content to ≤20ppm, in this way, in the low oxygen environment, the reaction of oxygen with the subsequent added sulfur reactant can be avoided, creating favorable conditions for the reaction of sulfur and manganese, next, after the first reduction, the high basicity slag is removed, the slag contains a large amount of desulfurization and deoxidation products, if not removed, it will affect the subsequent process, then add lime and fluorite for secondary slag building, fluorite can improve the fluidity of the slag, enhance the exchange between the molten steel and the slag, then remove it again, in this process, through two times of slagging, the harmful products are completely removed, avoiding the interference of these products on the subsequent process, after the second reduction, add quartz sand to adjust the basicity of the slag to 1.0-1.5, so that the high basicity slag continues to desulfurize, which is not conducive to the retention of sulfur in the subsequent process, while quartz sand as an acidic oxide can increase the concentration of acidic oxide in the slag, reducing the basicity "basicity=CaO / SiO2", the principle is to weaken the desulfurization ability by changing the composition of the slag, so that the slag is in a low desulfurization activity state, solving the difficulty of sulfur retention, finally, control the temperature of the molten steel at about 1550℃, at this time, add sulfur iron, because high temperature will cause serious burning loss of sulfur iron, while 1550℃ can reduce the consumption of sulfur iron, at the same time, in the low basicity slag environment, sulfur will react with manganese to generate MnS, the principle is that low temperature and low basicity conditions work together to reduce sulfur iron consumption and promote the generation of MnS, realizing accurate control of sulfur, meeting the production requirements of soft magnetic ferrite stainless steel, through this process, the S content in the molten steel composition can be finally controlled in the range of 0.020-0.030%, which can meet the requirements of easy cutting and corrosion resistance of the material, at the same time, through continuous adjustment of the smelting operation points on site, the control of S element in soft magnetic stainless steel is completed, and through reasonable control of S element in soft magnetic stainless steel, the corrosion resistance and machining performance of the material are greatly improved, the efficiency of the broaching machine is increased by more than 1.5 times, and the corrosion resistance is increased by more than 50%.

[0059] Second embodiment

[0060] Please refer to Figures 4-5 - Figure 6 andFigure 7 , Figure 4 This is a schematic diagram of the second embodiment of the present invention, which uses an argon-oxygen refining furnace to produce soft magnetic stainless steel material with low oxygen and controlled sulfur. Figure 5 A schematic diagram of the structure of the filter assembly is provided for this invention; Figure 6 Provided for the present invention Figure 5 An enlarged view of point A shown; Figure 7 This invention provides a structural schematic diagram of an exhaust component. Based on the process method for producing soft magnetic stainless steel using an argon-oxygen refining furnace with low oxygen and controlled sulfur, provided in the first embodiment of this application, the second embodiment of this application proposes another process method for producing soft magnetic stainless steel using an argon-oxygen refining furnace with low oxygen and controlled sulfur. The second embodiment is merely a preferred embodiment of the first embodiment, and the implementation of the second embodiment will not affect the separate implementation of the first embodiment.

[0061] Specifically, the difference between the process method for producing soft magnetic stainless steel material using an argon-oxygen refining furnace with low oxygen and sulfur control provided in the second embodiment of this application is that the argon-oxygen refining furnace used in the process method for producing soft magnetic stainless steel material using an argon-oxygen refining furnace with low oxygen and sulfur control includes: an adjustable base frame 1.

[0062] Argon-oxygen refining furnace body 5, the argon-oxygen refining furnace body 5 is installed on the top of the adjusting base frame 1, the top of the argon-oxygen refining furnace body 5 is equipped with a top cover 8, the top of the top cover 8 is equipped with an injection pipe 10 with a first valve 11, the top of the top cover 8 is equipped with a monitoring component 9, the monitoring component 9 includes a fixed base 901 and a monitoring component 902.

[0063] The first valve 11 is a solenoid valve that can open and close automatically. The monitoring component 902 can monitor the carbon dioxide gas content, temperature and pressure changes inside the argon-oxygen refining furnace body 5.

[0064] An oxygen supply structure 6 is installed on the top of the adjusting base frame 1, and an oxygen supply pipe 18 is installed at the outlet of the oxygen supply structure 6. An argon supply structure 17 is installed on the top of the adjusting base frame 1, and an argon supply pipe 19 is installed at the outlet of the argon supply structure 17. The other ends of the oxygen supply pipe 18 and the argon supply pipe 19 are respectively connected to a second flow meter 22 and a first flow meter 20 through a second valve 21. The other ends of the second flow meter 22 and the first flow meter 20 are each connected to a one-way valve 24 through a fixed pipe 25. The other ends of the two one-way valves 24 are connected to the two inlets of the three-way head 23.

[0065] The first flow meter 20 can monitor the argon supply, while the second flow meter 22 can monitor the oxygen supply. The outlet of the three-way connector 23 is connected to the first valve 11. The argon supply structure 17 and the oxygen supply structure 6 include tanks for storing oxygen and argon and pumps for delivering the gases.

[0066] The top of the adjusting base 1 is provided with a filtering assembly 16, and the top of the adjusting base 1 is provided with an exhaust assembly 15, the filtering assembly 16 comprises a filtering box 161 and an intercepting part 162, the exhaust assembly 15 comprises a protective shell 151, an exhaust pipe 152, an exhaust part 153 and a mounting pipe 154, the mounting pipe 154 is used for connecting the inlet of the exhaust part 153 and the filtering assembly 16;

[0067] The exhaust part 153 provides suction force, and the exhaust part 153 assists in discharging harmful gas, and the intercepting part 162 can adsorb dust and harmful gas.

[0068] The top of the top cover 8 is provided with an exhaust pipe 12 with a connecting head 13, the other end of the exhaust pipe 12 is provided with a docking pipe 14, and the top of the top cover 8 is provided with a plurality of hooks 7.

[0069] The hook 7 is convenient for lifting the top cover 8, and the other end of the docking pipe 14 is connected with one side of the filtering assembly 16.

[0070] The adjusting base 1 comprises a bottom plate 101, an adjusting structure 102 and a mounting structure 103, the mounting structure 103 is used for mounting the adjusting structure 102 at the bottom of the bottom plate 101, the top of the adjusting base 1 is provided with a control box 2 with a box door 4, and the front of the control box 2 is provided with an operation panel 3.

[0071] The operation panel 3 can control the operation of the equipment on the top of the adjusting base 1, the box door 4 is provided with a handle, and the inside of the control box 2 is provided with a power switch and a controller for assisting the operation of the equipment.

[0072] Compared with the related art, the process method for producing soft magnetic stainless steel material by using the argon-oxygen refining furnace to control sulfur at low oxygen has the following beneficial effects:

[0073] In order to improve the efficiency and effect of decarburization, deoxidation and desulfurization, an injection pipe 10 with a first valve 11 is installed on the top of the top cover 8, then only two one-way valves 24 with fixed pipes 25 are connected with the first flow meter 20 and the second flow meter 22 through the three-way joint 23, then the corresponding proportion of oxygen and argon mixed gas can be injected into the inside of the argon-oxygen refining furnace body 5 through the cooperation of the argon supply structure 17 and the oxygen supply structure 6 with the second flow meter 22 and the first flow meter 20, in actual use, the refining process of the argon-oxygen refining furnace body 5 is divided into multiple stages, in the first stage, the decarburization operation is mainly carried out, the higher oxygen flow and the appropriate argon-oxygen ratio are adopted, the carbon content in the molten steel is quickly reduced, when the carbon content is reduced to a certain extent, the second stage is entered, the oxygen flow is reduced, the argon flow is increased, and appropriate deoxidizing agent and desulfurizing agent are added, the deoxidation and desulfurization operations are carried out, through the segmented refining, the smelting process can be more targeted controlled, the efficiency and effect of decarburization, deoxidation and desulfurization are improved, the carbon, oxygen and sulfur contents of the produced soft magnetic stainless steel material are lower, the quality is better, and the performance is more stable.

[0074] The above is only an embodiment of the present application, and does not limit the patent range of the present application, any equivalent structure or equivalent process transformation using the content of the specification and drawings, or direct or indirect application in other related technical fields, are also included in the patent protection range of the present application.

Claims

1. A process for producing soft magnetic stainless steel materials using an argon-oxygen refining furnace with low oxygen and controlled sulfur content, characterized in that, The following processes are included: S1: High-alkalinity slag formation and deep desulfurization and deoxidation in the early stage of refining: 1.5 tons of lime are added to the argon-oxygen refining furnace to form high-alkalinity slag in the early stage, and deep desulfurization and deoxidation are carried out to reduce the oxygen content to ≤30ppm and the sulfur content to ≤0.003%. S2: Deep aluminum reduction, further reducing oxygen content: Using aluminum for deep reduction, the oxygen content in the molten steel is further reduced to ≤20ppm; S3: Remove high-alkalinity slag and then remove slag after secondary slag formation: After the first reduction, remove the high-alkalinity slag, then add lime and fluorite for the second slag formation, and after thorough mixing, remove the secondary slag completely. S4: Add quartz sand to adjust the slag basicity to 1.0-1.5: After the secondary reduction, add quartz sand to reduce the slag basicity and control it at 1.0-1.5; S5: Control the temperature to about 1550℃ and add ferrous sulfate: Control the temperature of the molten steel to about 1550℃, add ferrous sulfate to the ladle, so that sulfur reacts with manganese to generate MnS.

2. The process method for producing soft magnetic stainless steel materials using an argon-oxygen refining furnace with low oxygen and controlled sulfur content according to claim 1, characterized in that, The process of adding quartz sand to adjust the slag alkalinity to 1.0-1.5 includes the following steps: detecting the initial alkalinity of the slag after the second slag removal, adding quartz sand in stages and monitoring the alkalinity in real time, and stirring the slag to ensure uniform alkalinity.

3. The process method for producing soft magnetic stainless steel materials using an argon-oxygen refining furnace with low oxygen and controlled sulfur content according to claim 2, characterized in that, The detection of the initial alkalinity of the slag after the second slag removal is used to avoid adding too much or too little quartz sand, ensure accurate alkalinity adjustment, reduce material waste and process fluctuations. The phased addition of quartz sand and real-time monitoring of alkalinity are used to ensure that the slag alkalinity is steadily reduced to the target range of 1.0-1.5, ensuring good slag fluidity, while avoiding excessive reduction of alkalinity that could lead to abnormal slag performance. The stirring of the slag ensures uniform alkalinity: uniform and stable slag alkalinity prevents continued desulfurization in localized high-alkalinity areas and ensures a consistent sulfur-preserving environment.

4. The process method for producing soft magnetic stainless steel materials using an argon-oxygen refining furnace with low oxygen and controlled sulfur content according to claim 1, characterized in that, The process of controlling the temperature to around 1550℃ and adding ferrous sulfate includes the following steps: monitoring and adjusting the temperature of the molten steel to 1550℃±10℃, calculating the amount of ferrous sulfate to be added according to the target sulfur content and adding it in batches, and stirring the molten steel to promote the reaction of sulfur and manganese to generate MnS.

5. The process method for producing soft magnetic stainless steel material using an argon-oxygen refining furnace with low oxygen and controlled sulfur production according to claim 4, characterized in that, The monitoring and adjustment of the molten steel temperature to 1550℃±10℃ reduces the consumption of ferrous sulfate while ensuring that sulfur can efficiently enter the molten steel to participate in the reaction. The calculation of the amount of ferrous sulfate added according to the target sulfur content and its addition in batches achieves precise control of the sulfur content and avoids uneven distribution of sulfur in the molten steel. The stirring of the molten steel promotes the reaction of sulfur with manganese to generate MnS, so that sulfur remains in the steel in a stable MnS form, achieving the sulfur control target and avoiding the impact of sulfur in a free state on material properties, while improving the microstructure uniformity of soft magnetic stainless steel.

6. The argon-oxygen refining furnace used in the process for producing soft magnetic stainless steel materials with low oxygen and controlled sulfur production according to claim 1, is characterized in that... include: Adjust the base frame; The argon-oxygen refining furnace body is mounted on top of an adjustable base frame. A top cover is installed on the top of the argon-oxygen refining furnace body. An injection pipe with a first valve is installed on the top of the top cover. A monitoring component is installed on the top of the top cover. The monitoring component includes a fixed base and monitoring parts.

7. The method for producing soft magnetic stainless steel material using an argon-oxygen refining furnace with low oxygen and controlled sulfur production according to claim 6, characterized in that, An oxygen supply structure is installed on the top of the adjusting base, and an oxygen supply pipe is installed at the outlet of the oxygen supply structure. An argon supply structure is installed on the top of the adjusting base, and an argon supply pipe is installed at the outlet of the argon supply structure. A second flow meter and a first flow meter are respectively installed at the other end of the oxygen supply pipe and the argon supply pipe through a second valve. A one-way valve is installed at the other end of the second flow meter and the first flow meter through a fixed pipe. The other ends of the two one-way valves are connected to the two inlets of the three-way head.

8. The method for producing soft magnetic stainless steel material using an argon-oxygen refining furnace with low oxygen and controlled sulfur production according to claim 6, characterized in that, A filter assembly is installed on the top of the adjustable base frame, and an exhaust assembly is also installed on the top of the adjustable base frame. The filter assembly includes a filter box and an interception component. The exhaust assembly includes a protective shell, an exhaust pipe, an exhaust component, and an installation pipe. The installation pipe is used to connect the inlet of the exhaust component and the filter assembly.

9. The method for producing soft magnetic stainless steel material using an argon-oxygen refining furnace with low oxygen and controlled sulfur production according to claim 6, characterized in that, The top of the cover is equipped with an exhaust pipe with a connector, the other end of which is equipped with a connecting pipe, and the top of the cover is equipped with multiple hooks.

10. The method for producing soft magnetic stainless steel material using an argon-oxygen refining furnace with low oxygen and controlled sulfur production according to claim 6, characterized in that, The adjustable base frame includes a base plate, an adjusting structure, and a mounting structure. The mounting structure is used to install the adjusting structure at the bottom of the base plate. A control box with a door is installed on the top of the adjustable base frame, and an operation panel is installed on the front of the control box.

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