CN114107610B - Vacuum nitrogen increasing refining method - Google Patents
Vacuum nitrogen increasing refining method Download PDFInfo
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- CN114107610B CN114107610B CN202111419672.2A CN202111419672A CN114107610B CN 114107610 B CN114107610 B CN 114107610B CN 202111419672 A CN202111419672 A CN 202111419672A CN 114107610 B CN114107610 B CN 114107610B
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- C—CHEMISTRY; METALLURGY
- C21—METALLURGY OF IRON
- C21C—PROCESSING OF PIG-IRON, e.g. REFINING, MANUFACTURE OF WROUGHT-IRON OR STEEL; TREATMENT IN MOLTEN STATE OF FERROUS ALLOYS
- C21C7/00—Treating molten ferrous alloys, e.g. steel, not covered by groups C21C1/00 - C21C5/00
- C21C7/10—Handling in a vacuum
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- C—CHEMISTRY; METALLURGY
- C21—METALLURGY OF IRON
- C21C—PROCESSING OF PIG-IRON, e.g. REFINING, MANUFACTURE OF WROUGHT-IRON OR STEEL; TREATMENT IN MOLTEN STATE OF FERROUS ALLOYS
- C21C5/00—Manufacture of carbon-steel, e.g. plain mild steel, medium carbon steel or cast steel or stainless steel
- C21C5/28—Manufacture of steel in the converter
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- C—CHEMISTRY; METALLURGY
- C21—METALLURGY OF IRON
- C21C—PROCESSING OF PIG-IRON, e.g. REFINING, MANUFACTURE OF WROUGHT-IRON OR STEEL; TREATMENT IN MOLTEN STATE OF FERROUS ALLOYS
- C21C7/00—Treating molten ferrous alloys, e.g. steel, not covered by groups C21C1/00 - C21C5/00
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- C—CHEMISTRY; METALLURGY
- C21—METALLURGY OF IRON
- C21C—PROCESSING OF PIG-IRON, e.g. REFINING, MANUFACTURE OF WROUGHT-IRON OR STEEL; TREATMENT IN MOLTEN STATE OF FERROUS ALLOYS
- C21C7/00—Treating molten ferrous alloys, e.g. steel, not covered by groups C21C1/00 - C21C5/00
- C21C7/04—Removing impurities by adding a treating agent
- C21C7/06—Deoxidising, e.g. killing
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- C—CHEMISTRY; METALLURGY
- C21—METALLURGY OF IRON
- C21C—PROCESSING OF PIG-IRON, e.g. REFINING, MANUFACTURE OF WROUGHT-IRON OR STEEL; TREATMENT IN MOLTEN STATE OF FERROUS ALLOYS
- C21C7/00—Treating molten ferrous alloys, e.g. steel, not covered by groups C21C1/00 - C21C5/00
- C21C7/04—Removing impurities by adding a treating agent
- C21C7/064—Dephosphorising; Desulfurising
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Abstract
The invention relates to a method for vacuum nitrogen increasing refining, which comprises the following steps: (1) smelting at a low S content of the converter, wherein the S content of the furnace entering station at the end point S, LF of the converter is less than or equal to 0.005 percent; (2) converter and LF low-C smelting, wherein the station (C) of the LF furnace is less than or equal to 0.07%; (3) converter and LF low Si smelting, wherein the [ Si ] discharged from the LF furnace is less than or equal to 0.08%; (4) mn and Cr alloying process for converter and LF furnace; (5) the steel is subjected to deep deoxidation and deep desulfurization refining, the discharge station [ S ] of the LF furnace is less than or equal to 0.002%, the discharge station [ O ] is less than or equal to 5ppm, and the temperature of the steel liquid is 1630-; (6) RH furnace gas nitrogen increasing process; the vacuum degree of the RH furnace is 3KPa-8KPa, the RH furnace is driven by nitrogen, the flow rate of a nitrogen main pipe is 2000-2080L/min, the vacuum cycle time is 15-22min, the temperature is 1615-1640 ℃, and the RH cycle process realizes the increase of the nitrogen in the molten steel by 120-180 ppm; (7) when the nitrogen content reaches a set value, C, Si and other elements are added into a control standard range according to the steel component design to finish the smelting of the nitrogen-containing steel, and the molten steel is transferred to the next procedure for continuous casting; the method has the advantages of simple and convenient operation, stable nitrogen recovery rate, strong operability and easy control.
Description
Technical Field
The invention relates to the technical field of metal material manufacturing, in particular to a method for vacuum nitrogen increasing refining.
Background
Nitrogen is harmful gas to most steel types, but is a beneficial alloy element in tool steel, die steel and some high-toughness structural steel, nitrogen increase of nitrogen-containing steel is generally realized by adding nitriding alloy, but when nitriding alloying is added, the recovery rate of nitrogen in steel is unstable, the purity of nitriding alloy is generally high, and the influence on molten steel purity is large.
Disclosure of Invention
The invention aims to solve the problems that: the method provided by the invention has the advantages that the problems that the existing nitrogen-containing steel needs to realize the nitrogen recovery rate by adding the nitralloy, but the nitralloy has large influence on the purity of the molten steel and the nitrogen recovery rate is unstable are solved, and the method for vacuum nitrogen increasing refining is provided.
The invention relates to a method for vacuum nitrogen increasing refining, which comprises the following steps:
(1) smelting in a converter with low S content: the method comprises the following steps of deeply desulfurizing the molten iron until S is less than or equal to 0.002%, thoroughly slagging off after desulfurization, feeding low-sulfur steel scrap into a converter, wherein S is less than or equal to 0.005%, controlling the molten iron and the steel scrap, and lowering the initial S content in an LF furnace through low-S smelting at a converter terminal point S, LF, so as to create conditions for deep desulfurization of LF molten steel;
(2) converter and LF low-C smelting: in order to avoid the high influence of molten steel [ C ] on the gas nitrogen increasing efficiency of the RH furnace, the converter adopts a low-carbon tapping process, the tapping [ C ] is less than or equal to 0.05 percent, carbon is not added to an argon station after the tapping of the converter, carbon is not added in the refining process of the LF furnace, the power transmission process is controlled to increase carbon, and the tapping [ C ] of the LF furnace is less than or equal to 0.07 percent;
(3) converter and LF low Si smelting: in order to avoid the influence of high [ Si ] of molten steel on the gas nitrogen increasing efficiency of the RH furnace, no silicon-containing alloy is added in the converter and the LF alloying, and the [ Si ] of the LF furnace is less than or equal to 0.08%;
(4) the Mn and Cr alloying process of the converter and the LF furnace comprises the following steps: according to the actual component design of the steel grade, the converter finishes the first alloying of Mn and Cr, the LF realizes the accurate control of Mn and Cr components, Mn in the molten steel is added to the target value of the component design requirement of the steel grade before the LF is out of the station, Cr in the molten steel is added to the target value of the component design requirement of the steel grade before the LF is out of the station, and Cr is added to the steel without Cr and is controlled according to 0.10-0.20%;
(5) deep deoxidation and deep desulfurization refining of steel: adding 1Kg/t of pure metal aluminum into the molten steel in a converter for deoxidation alloying, quickly reducing the content of molten steel [ O ] to be within 30ppm, adding 12-13Kg/t of lime and 2-2.2Kg/t of calcium iron powder for diffusion deoxidation of slag when the LF furnace enters a station for deep deoxidation, wherein the dosage of the simple substance aluminum is 3.0-3.3Kg/t of steel, the temperature of the molten steel discharged from the LF furnace is controlled at 1630-;
(6) RH furnace gas nitrogen increasing process: the vacuum degree of the RH furnace vacuum circulation process is controlled according to 3KPa-8KPa, the driving gas in the vacuum circulation process is driven by nitrogen, the flow rate of a nitrogen header pipe is 2080L/min in 2000-one, 16 driving gas branch pipes embedded in the vacuum insertion pipe are adopted to increase the dispersion degree of the driving gas nitrogen when the driving gas nitrogen is blown into the molten steel, the flow rate of a single pipe is 130L/min in 125-one, the vacuum circulation time (namely the nitrogen increasing time) is controlled according to 15-22min, the temperature in the vacuum circulation process is 1640 ℃ in 1615-one, and the RH circulation process realizes 180ppm of the nitrogen increase of the molten steel in 120-one;
(7) after the vacuum nitrogen increasing is finished, when the nitrogen content reaches a set value, C, Si elements and the like are added into a control standard range according to the steel type component design, the nitrogen-containing steel smelting is finished, and the molten steel is transferred to the next procedure for continuous casting.
The invention is characterized in that: the difficulty of increasing nitrogen by adopting gas is how to improve the solubility of nitrogen in molten steel. From the thermodynamic analysis, 3 nitrogen solubilities in molten steel are influenced, the temperature, the nitrogen partial pressure and the content of alloy elements in the molten steel are improved, the nitrogen partial pressure and the temperature are both favorable for absorbing nitrogen by the molten steel, the solubility of nitrogen can be improved by the alloy elements such as [ Cr ] and [ Mn ] in the molten steel, the solubility of nitrogen is reduced by [ C ] [ O ] [ S ] [ Si ], and the nitrogen adsorption reaction speed is greatly reduced when the content of [ O ] [ S ] in the molten steel is higher, so that the nitrogen solubility of the molten steel with good deoxidation and deep desulfurization is greatly improved. From the aspect of dynamics, the mass transfer speed of nitrogen in molten steel can be obviously improved by increasing the stirring of the molten steel, the nitrogen flow of nitrogen blowing does not directly influence the nitrogen absorption speed of the molten steel, but influences the stirring strength of the molten steel and the dispersion degree of nitrogen bubbles in the molten steel, obviously, the higher the dispersion degree of the nitrogen bubbles in the molten steel is, the higher the contact interface of the nitrogen in the molten steel is, and the higher the nitrogen absorption speed of the molten steel is.
According to the invention, through researching the nitrogen increasing mechanism of the molten steel from the thermodynamic and kinetic angles, the RH vacuum refining has good nitrogen increasing conditions, and firstly, the partial pressure of nitrogen is high under the vacuum condition, the temperature of the molten steel is high, and the basic conditions of nitrogen increasing thermodynamics are met; secondly, the stirring condition is good in the vacuum treatment process, and nitrogen can be increased by introducing argon into the ascending pipe of the insertion pipe in the circulation process; thirdly, before the molten steel is subjected to RH vacuum, the molten steel can be subjected to deep deoxidation and deep desulfurization in an LF ladle furnace, and reasonable control of components such as Cr, Mn, C, Si and the like is realized, so that favorable thermodynamic conditions are created for vacuum nitrogen increase. Based on the method, nitrogen is added into the RH furnace by using nitrogen, and the smelting process route is designed to be 'molten iron deep desulphurization-converter low carbon, low smelting-LF low carbon, low Si, deep desulphurization, deep deoxidation refining-RH vacuum gas nitrogen addition'.
The beneficial effects of the invention are:
(1) by adopting gas nitrogen increase under the vacuum condition, the purity of the molten steel is high, and the nitrogen increase process realizes the smelting targets of cleanness, greenness and environmental protection.
(2) The method adopts gas for increasing nitrogen, can avoid using high-price nitrogen-containing alloy, has low production cost, and does not increase smelting production cost.
(3) The method has the advantages of simple and convenient operation, stable nitrogen recovery rate, strong operability and easy control.
Detailed Description
In order to better explain the technical solution of the present invention, the technical solution of the present invention is further described below with reference to specific examples, which are only exemplary to illustrate the technical solution of the present invention and do not limit the present invention in any way.
The method of the invention is explained in detail by the smelting of certain nitrogen-containing steel grades. The content of the finished product w (N) of the nitrogenous steel is 160-220ppm, and the smelting component standard is as follows: w (C) content of 0.13-0.18%, w (Mn) content of 1.40-1.60%, w (Si) content of 0.25-0.35%, w (Cr) content of 0.30-0.45%, w (S) content less than or equal to 0.003%, and the others are Fe, Nb, V, Mo and other impurity elements, and the specific embodiment is as follows:
example 1
The smelting furnace number 1 comprises the following specific embodiments:
(1) smelting in a converter with low S content: the iron water is deeply desulfurized to S0.002%, desulfurized slag is thoroughly removed after desulfurization, low sulfur is added into converter scrap steel, the S content of the scrap steel is 0.005%, and the S content of LF furnace entering stations is 0.005% at the end point of the converter;
(2) converter and LF low-C smelting: in order to avoid the influence of the high molten steel [ C ] on the gas nitrogen increasing efficiency of the RH furnace, the converter adopts a tapping low-carbon tapping process, the tapping [ C ] is 0.05 percent, carbon is not added to an argon station after the tapping of the converter, carbon is not added in the refining process of the LF furnace, the power transmission process is controlled to increase the carbon, and the tapping rate of the LF furnace is 0.07 percent;
(3) converter and LF low Si smelting: in order to avoid the high influence of the [ Si ] of the molten steel on the gas nitrogen increasing efficiency of the RH furnace, no silicon-containing alloy is added in the converter and the LF alloying, and the [ Si ] discharged from the LF furnace is 0.08%;
(4) the Mn and Cr alloying process of the converter and the LF furnace comprises the following steps: the converter finishes the first alloying of Mn and Cr, the LF realizes the accurate control of Mn and Cr components, and the [ Mn ] is added to 1.40% and the [ Cr ] is added to 0.30% in the molten steel before the LF is out of the station;
(5) deep deoxidation and deep desulfurization refining of steel: adding 1Kg/t of pure metal aluminum into the molten steel in a converter for deoxidation alloying, detecting that the content of the molten steel [ O ] is 30ppm, adding Al for deep deoxidation when an LF furnace enters a station, adding 3.0Kg/t of steel into the amount of the pure metal aluminum, adding 12Kg/t of lime for realizing deep desulfurization, adding 2Kg/t of calcium iron powder for slag diffusion deoxidation, controlling the temperature of the molten steel discharged from the LF furnace to be 1630.0020 percent and 5 ppm;
(6) RH furnace gas nitrogen increasing process; controlling the vacuum degree of the RH furnace in a vacuum circulation process according to 3KPaPa, driving gas in the vacuum circulation process by adopting nitrogen, controlling the flow rate of a nitrogen header pipe according to 2000L/min, controlling the flow rate of a single pipe at 125L/min, controlling the vacuum circulation time (namely the nitrogen increasing time) according to 15min, controlling the temperature in the vacuum circulation process at 1615 ℃ and realizing the nitrogen increase of the molten steel by 120ppm in the RH circulation process, wherein 16 driving gas branch pipes embedded in vacuum insertion pipes are adopted to increase the dispersion degree of the driving gas nitrogen blown into the molten steel;
(7) after the vacuum nitrogen increasing is finished, the original nitrogen content of the molten steel is 40ppm, the RH gas nitrogen increasing value is 120ppm, the nitrogen content of the molten steel after the nitrogen increasing is 160ppm meets the smelting component standard, C, Si is respectively added to 0.13 percent and 0.25 percent, and other elements are added to the range of the control standard according to the steel component design, so that the smelting of the furnace nitrogen-containing steel is finished.
And (3) analyzing a smelting result, wherein after the furnace number 1 adopts gas nitrogen increasing, the nitrogen content is 160ppm, and the standard of the smelting component of the steel grade is met.
Example 2
The smelting furnace number 2 comprises the following specific embodiments:
(1) smelting in a converter with low S content: the iron is deeply desulfurized to S0.001%, desulfurized slag is thoroughly removed after desulfurization, low sulfur is adopted to enter converter steel scraps, the S content of the steel scraps is 0.004%, and S0.004% is achieved at the end point of the converter when an LF furnace enters a station;
(2) converter and LF low-C smelting: in order to avoid the high content of the molten steel [ C ] from influencing the gas nitrogen increasing efficiency of the RH furnace, the converter adopts a tapping low-carbon tapping process, the tapping [ C ] is 0.04 percent, carbon is not added to an argon station after the tapping of the converter, carbon is not added in the refining process of the LF furnace, the carbon increasing is controlled in the power transmission process, and the tapping [ C ] of the LF furnace is 0.06 percent;
(3) converter and LF low Si smelting: in order to avoid the influence of high [ Si ] of molten steel on the gas nitrogen increasing efficiency of the RH furnace, no silicon-containing alloy is added in the converter and the LF alloying, and the [ Si ] of the LF furnace is 0.07%;
(4) the Mn and Cr alloying process of the converter and the LF furnace comprises the following steps: the converter finishes the first alloying of Mn and Cr, the LF realizes the accurate control of Mn and Cr components, and the [ Mn ] is added to 1.50% and the [ Cr ] is added to 0.40% in the molten steel before the LF is out of the station;
(5) deep deoxidation and deep desulfurization refining of steel: adding 1Kg/t of pure metal aluminum into the molten steel by converter deoxidation alloying, detecting that the content of the molten steel [ O ] is 28ppm, adding Al to perform deep deoxidation when an LF furnace enters a station, wherein the dosage of the pure metal aluminum is 3.1Kg/t of the steel, adding 12.5Kg/t of lime for realizing deep desulfurization, adding 2.1Kg/t of calcium iron powder for slag diffusion deoxidation, controlling the outlet [ S ] of the LF furnace to be 0.0015 percent and the outlet [ O ] to be 4ppm, and controlling the outlet molten steel temperature of the LF furnace to be 1640 ℃;
(6) RH furnace gas nitrogen increasing process; controlling the vacuum degree of the RH furnace in the vacuum circulation process according to 6KPaPa, driving gas in the vacuum circulation process by adopting nitrogen, controlling the flow rate of a nitrogen header pipe according to 2032L/min, controlling the flow rate of a single pipe at 127L/min, controlling the vacuum circulation time (namely the nitrogen increasing time) according to 18min, controlling the temperature in the vacuum circulation process at 1630 ℃, and increasing the nitrogen content in the molten steel in the RH circulation process by 160ppm, wherein 16 driving gas branch pipes embedded in a vacuum insertion pipe are adopted;
(7) after the vacuum nitrogen increasing is finished, the original nitrogen content of the molten steel is 40ppm, the RH gas nitrogen increasing value is 160ppm, the nitrogen content of the molten steel after the nitrogen increasing is 200ppm meets the smelting component standard, C, Si is respectively added to 0.16 percent and 0.30 percent, and other elements are added to the control standard range according to the steel component design, so that the smelting of the furnace nitrogen-containing steel is finished.
And (4) analyzing a smelting result, wherein after the furnace number 2 adopts gas nitrogen increasing, the nitrogen content is 200ppm, and the standard of the smelting component of the steel grade is met.
Example 3
The smelting furnace number 3 comprises the following specific embodiments:
(1) smelting in a converter with low S content: the iron is deeply desulfurized to S0.001%, desulfurized slag is thoroughly removed after desulfurization, low sulfur is added into converter scrap steel, the S content of the scrap steel is 0.003%, and the S content of LF furnace entering stations is 0.003% at the end point of the converter;
(2) converter and LF low-C smelting: in order to avoid the influence of the high molten steel [ C ] on the gas nitrogen increasing efficiency of the RH furnace, the converter adopts a tapping low-carbon tapping process, the tapping [ C ] is 0.03 percent, carbon is not added to an argon station after the tapping of the converter, carbon is not added in the refining process of the LF furnace, the power transmission process is controlled for carbon increasing, and the tapping rate of the LF furnace is 0.05 percent;
(3) converter and LF low Si smelting: in order to avoid the influence of high [ Si ] of molten steel on the gas nitrogen increasing efficiency of the RH furnace, no silicon-containing alloy is added in the converter and the LF alloying, and the station outlet [ Si ] of the LF furnace is 0.05 percent;
(4) the Mn and Cr alloying process of the converter and the LF furnace comprises the following steps: the converter finishes the first alloying of Mn and Cr, the LF realizes the accurate control of Mn and Cr components, and the [ Mn ] and the [ Cr ] in the molten steel are added to 1.60% and 0.45% respectively before the LF leaves the station;
(5) deep deoxidation and deep desulfurization refining of steel: adding 1Kg/t of pure metal aluminum into the molten steel in a converter for deoxidation alloying, quickly reducing the content of the molten steel [ O ] to 25ppm, adding Al to perform deep deoxidation when an LF furnace enters a station, wherein the consumption of the pure metal aluminum is 3.3Kg/t of steel, adding 13Kg/t of lime, adding 2.2Kg/t of calcium iron powder for slag diffusion deoxidation, controlling the temperature of the molten steel discharged from the LF furnace to be 0.0010 percent and 3ppm when the LF furnace is discharged from the station, and controlling the temperature of the molten steel discharged from the LF furnace to be 1650 ℃;
(6) RH furnace gas nitrogen increasing process; the vacuum degree of the RH furnace in the vacuum circulation process is controlled according to 8KPa, the driving gas in the vacuum circulation process is driven by nitrogen, the flow rate of a nitrogen header pipe is 2080L/min, in order to increase the dispersion degree of the driving gas nitrogen when the driving gas nitrogen is blown into the molten steel, 16 driving gas branch pipes embedded in vacuum insertion pipes are adopted, the flow rate of a single pipe is 130L/min, the vacuum circulation time (namely nitrogen increasing time) is controlled according to 22min, the temperature in the vacuum circulation process is controlled at 1640 ℃, and the RH circulation process can realize the nitrogen increase of the molten steel by 180 ppm;
(7) after the vacuum nitrogen increasing is finished, the original nitrogen content of the molten steel is 40ppm, the RH gas nitrogen increasing value is 180ppm, the nitrogen content of the molten steel after the nitrogen increasing is 220ppm meets the smelting component standard, C, Si is respectively added to 0.18 percent and 0.35 percent, and other elements are added to the range of the control standard according to the steel type component design, thus completing the smelting of the furnace nitrogen-containing steel.
And (4) analyzing a smelting result, wherein after the furnace number 3 adopts gas nitrogen increasing, the nitrogen content is 220ppm, and the standard of the smelting component of the steel grade is met.
The following table 1 shows the values of the content of N in molten steel in the smelting process in examples 1 to 3 of the present invention, and it can be seen from table 1 that the nitrogen increase by using the pure nitrogen gas of the present invention is stable in nitrogen recovery rate, high in molten steel purity, reduced in impurity elements, and meets the technical requirements of clean steel smelting, compared with the nitrogen increase by alloy.
TABLE 1N content of molten steel in the smelting process of examples 1 to 3 of the present invention
Claims (1)
1. A method for refining nitrogen by vacuum is characterized by comprising the following steps:
(1) smelting in a converter with low S content: the iron is deeply desulfurized to S less than or equal to 0.002 percent, the slag is thoroughly removed after desulfurization, low-sulfur steel scrap is fed into the converter, the S content of the steel scrap is less than or equal to 0.005 percent, and the S content of the steel scrap fed into the converter at the terminal point S, LF is less than or equal to 0.005 percent;
(2) converter and LF low-C smelting: in order to avoid the high influence of molten steel [ C ] on the gas nitrogen increasing efficiency of the RH furnace, the converter adopts a low-carbon tapping process, the tapping [ C ] is less than or equal to 0.05 percent, carbon is not added to an argon station after the tapping of the converter, carbon is not added in the refining process of the LF furnace, the power transmission process is controlled to increase carbon, and the tapping [ C ] of the LF furnace is less than or equal to 0.07 percent;
(3) converter and LF low Si smelting: in order to avoid the high influence of the [ Si ] of the molten steel on the gas nitrogen increasing efficiency of the RH furnace, silicon-containing alloy is not added in the converter and the LF alloying, and the [ Si ] discharged from the LF furnace is less than or equal to 0.08 percent;
(4) the Mn and Cr alloying process of the converter and the LF furnace comprises the following steps: according to the actual component design of the steel grade, the converter finishes the first alloying of Mn and Cr, the LF realizes the accurate control of Mn and Cr components, Mn in the molten steel is added to the target value of the component design requirement of the steel grade before the LF leaves the station, Cr-containing steel is added to the target value of the component design requirement of the steel grade before the LF leaves the station, and the Cr adding amount of Cr-free steel is controlled according to 0.10-0.20%;
(5) deep deoxidation and deep desulfurization refining of steel: converter deoxidation alloying, adding 1Kg/t of metallic pure aluminum into the molten steel, rapidly reducing the content of molten steel [ O ] to within 30ppm, adding Al to deep deoxidation at the station of the LF furnace, adding 12-13Kg/t of lime to realize deep desulfurization when the dosage of simple substance aluminum is 3.0-3.3Kg/t of steel, adding 2-2.2Kg/t of calcium iron powder for diffusion deoxidation of slag, controlling the temperature of the molten steel at the station of the LF furnace at 1630-;
(6) RH furnace gas nitrogen increasing process: the vacuum degree of the RH furnace vacuum circulation process is controlled according to 3KPa-8KPa, the driving gas in the vacuum circulation process is driven by nitrogen, the flow rate of a nitrogen header pipe is 2080L/min in order to increase the dispersion degree of the driving gas nitrogen when being blown into the molten steel, 16 driving gas branch pipes embedded in the vacuum insertion pipe are adopted, the flow rate of a single pipe is 130L/min in 125-;
(7) after the vacuum nitrogen increasing is finished, when the nitrogen content reaches a set value, C, Si elements are added into a control standard range according to the steel component design to finish the smelting of the steel containing nitrogen, and the molten steel is transferred to the next procedure for continuous casting.
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| CN110607413A (en) * | 2019-11-01 | 2019-12-24 | 武汉钢铁集团鄂城钢铁有限责任公司 | Smelting method of low-cost high-nitrogen steel |
| CN111286677A (en) * | 2020-04-03 | 2020-06-16 | 武汉钢铁有限公司 | Ultralow-sulfur low-aluminum high-nitrogen steel and smelting method |
| CN113435114A (en) * | 2021-06-23 | 2021-09-24 | 马鞍山钢铁股份有限公司 | Method for accurately controlling nitrogen content of CV-RH-CC process path steel |
| CN113652511A (en) * | 2021-07-16 | 2021-11-16 | 武汉钢铁有限公司 | Smelting method for controlling nitrogen content in silicon-aluminum killed steel to be less than or equal to 0.0013% |
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