CN113528758A - Method for alloying ultralow-carbon and degassed titanium steel of RH furnace - Google Patents
Method for alloying ultralow-carbon and degassed titanium steel of RH furnace Download PDFInfo
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- CN113528758A CN113528758A CN202110885313.XA CN202110885313A CN113528758A CN 113528758 A CN113528758 A CN 113528758A CN 202110885313 A CN202110885313 A CN 202110885313A CN 113528758 A CN113528758 A CN 113528758A
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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
- C21C5/30—Regulating or controlling the blowing
- C21C5/32—Blowing from above
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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
- C21C7/0006—Adding metallic additives
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- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
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- C22C33/00—Making ferrous alloys
- C22C33/04—Making ferrous alloys by melting
- C22C33/06—Making ferrous alloys by melting using master alloys
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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
- C21C2007/0093—Duplex process; Two stage processes
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Abstract
The invention provides a method for alloying ultralow-carbon and degassed steel and titanium of an RH furnace, which comprises the steps of LD-LF-RH-CC which are sequentially carried out, and comprises the following steps: in the LD stage, the control of nitrogen increase from the converter blowing carbon pulling to the end point is reduced; in the RH stage, flaw detection is carried out on a welding seam at the butt joint welding position of the vacuum chamber body and the inserted pipe steel structure by adopting a penetration method, and the connection mode of the vacuum chamber and the inserted pipe steel structure is a plug-in type; titanium alloying is carried out by adopting titanium sponge alloy. The nitrogen increasing amount of each step is strictly controlled, so that the phenomenon that the nitrogen content of partial heat molten steel is higher due to nitrogen in the alloy is restrained, and the nitrogen increasing amount in the RH process is controlled to be 6 multiplied by 10 on average‑6The above is reduced to 2 x 10‑6WithinThe nitrogen increasing amount is stably controlled to 2 x 10‑6The following; the nitrogen content in the steel after RH treatment of the degassing (plate) high-grade steel represented by the IF steel and X80 of the automobile panel class is stably controlled, and the process quality control requirement is completely met.
Description
Technical Field
The invention relates to the technical field of vanadium-containing semisteel smelting, in particular to a titanium alloying method for ultra-low carbon and degassing steel of an RH furnace.
Background
For the class of IF steels of the automobile panel class, high-grade steels of the degassed class (plates) represented by X80, nitrogen is a harmful element which causes a reduction in the plasticity and impact toughness of the steel and, like phosphorus, causes cold embrittlement of the steel; meanwhile, nitrogen also forms nitride inclusions with elements such as titanium and aluminum in the steel, which causes deterioration of the surface quality of the steel and reduction of the yield. With the increasing demand for steel quality, how to control the nitrogen content in steel to be lower becomes one of the focuses of attention. The high-grade steel grade of degassing class (plate) represented by the IF steel and X80 of automobile panel class generally requires that the nitrogen content of the finished product is 30X 10-6The nitrogen content of the ladle steel in domestic advanced enterprises (such as Wu steel) can be controlled to be 20 x 10-6Within. Some manufacturers produce high-grade steel grades (plates) represented by automobile panel IF steel and X80, and because semisteel is adopted for steelmaking, the initial carbon content in the semisteel is lower, the difficulty of converter denitrification is higher than that of other steel mills, and meanwhile, the nitrogen increasing amount in the RH and continuous casting steel casting process is higher; the nitrogen content of the molten steel in the degassing high-grade steel (plate) represented by the IF steel and X80 of the automobile panel class is as high as 37 multiplied by 10-6It is not satisfactory for the production of high-grade steel such as IF steel for automobile panels and X80. Therefore, the problem of controlling the nitrogen content has become a bottleneck for restricting the development and production of degassing (plate) high-grade steel represented by automobile panel IF steel and X80, and becomes an important restriction factor for comprehensively utilizing vanadium and titanium resources in Panxi areas.
The vanadium titano-magnetite in Panxi area is a composite ore which mainly contains iron and contains multiple metal elements such as titanium, vanadium, chromium and the like. The titanomagnetite is prepared by adopting a blast furnace ironmaking-converter vanadium extraction process. The existing process only recycles iron and vanadium, and a large amount of titanium enters blast furnace slag and has low content (TiO in the slag)2Content about 22%). The ore raw material of Xichang steel vanadium company is vanadium-titanium magnetite oreThe molten iron is rich in a large amount of vanadium elements, after the molten iron is subjected to a vanadium extraction process, vanadium is removed in the form of vanadium slag and then enters a vanadium product process for recycling, and the rest is called semi-steel; the converter raw material of the steel plant adopts 'semi-steel' smelting, and the remarkable characteristics are that the smelting heat source is insufficient: in order to extract vanadium and titanium in molten iron, the original carbon content of a converter is lower than that of the molten iron, and the converter denitrification rate is lower than that of a molten iron smelting process, which is a difficulty in controlling the nitrogen content of the molten steel in a semisteel smelting process. During semisteel smelting, the content of carbon entering a converter is low, the denitrification time is shortened, and the nitrogen content at the end point is high, which is a common problem in semisteel smelting. Compared with other domestic plants, the smelting of high-grade steel grades such as automobile panel IF steel and X80, which are represented by vanadium semisteel, from vanadium semisteel at Xichang is influenced by a heat source for introducing semisteel into a furnace, and the nitrogen content of end-point molten steel is higher due to insufficient end-point temperature of the converter, which easily causes the overoxidation of the end-point molten steel. The nitrogen content of the molten steel of the continuous casting billet after the converter tapping is in an ascending trend, the RH treatment and the steel pouring process are nitrogen increasing processes, and particularly the nitrogen increasing process of the RH procedure is serious.
The high-grade steel of degassing class (plate) represented by automobile panel IF steel and X80 generally adopts LD-LF-RH-CC process flow, because of adopting semisteel to make steel, the initial carbon content in the semisteel is lower, the converter denitrification difficulty is large, and an LF process is added in the process flow, so that the nitrogen absorption probability of molten steel is increased, and simultaneously, the nitrogen increase amount in the RH and continuous casting steel casting process is higher. Data statistics show that: the nitrogen content in the semi-steel is basically stable and is 41 multiplied by 10 on average-6(ii) a After oxygen blowing is started in converter smelting, the nitrogen content in the molten steel begins to decrease, the nitrogen content in the molten steel reaches the minimum when carbon is drawn, and the molten steel absorbs nitrogen to different degrees from carbon drawing to smelting end point; the average denitrification rate of the converter from charging to carbon drawing can reach 75.4 percent, the denitrification rate of the converter from charging to end point is reduced to 57.8 percent, and the average nitrogen of the molten steel is only 11 multiplied by 10 during the carbon drawing-6The average nitrogen of the end-point molten steel reaches 17 multiplied by 10-6The above. Therefore, the nitrogen content of the molten steel is at a lower level during carbon drawing, and the nitrogen absorption of the molten steel is more serious from the carbon drawing to the end point of the converter. Compared with other domestic plants, the semi-steel smelting of high-grade steel grades such as automobile panel IF steel and X80 is influenced by the heat source of semi-steel entering the converter, and the end temperature of the converter is insufficientAnd the nitrogen content of the end-point molten steel is higher due to over oxidation of the end-point molten steel. The nitrogen content of the molten steel of the continuous casting billet after the converter tapping is in an ascending trend, the RH treatment and the steel pouring process are nitrogen increasing processes, and particularly the nitrogen increasing process of the RH procedure is serious.
Disclosure of Invention
The invention aims to provide a method for alloying ultralow-carbon and degassed titanium steel of an RH furnace, which can reduce the nitrogen increase amount in the RH process.
In view of the above, the application provides a method for alloying ultra-low carbon and degassed titanium of steel in an RH furnace, which includes sequential LD-LF-RH-CC, and is characterized by including the following steps:
in the LD stage, the control of nitrogen increase from the converter blowing carbon pulling to the end point is reduced;
in the RH stage, flaw detection is carried out on a welding seam at the butt joint welding position of the vacuum chamber body and the inserted pipe steel structure by adopting a penetration method, and the connection mode of the vacuum chamber and the inserted pipe steel structure is a plug-in type; titanium alloying is carried out by adopting titanium sponge alloy.
Preferably, the method for reducing the converter blowing carbon pull to end point carburetion control comprises one of the following modes:
A) adopts a bottom blowing air supply mode, and the strength of the bottom blowing air supply is 0.03m3More than/min. t steel, argon is adopted for bottom blowing gas;
B) controlling the consumption of scrap steel within 40 kg/ton steel;
C) the low lance position mode is adopted in the later stage of converting, and the end point carbon is 0.04-0.05%;
D) and adding a slag foaming agent in the later smelting stage.
Preferably, the life of the vacuum chamber insertion tube is not more than 50 times when the vacuum chamber insertion tube is used for treating the IF steel of automobile panels and the high-grade steel of outgas type X80 in the RH stage.
Preferably, in the LD stage, the nitrogen content of the molten steel at the end point of the converter is reduced to 13 x 10-6Within.
Preferably, in the RH phase, the nitrogen increase is reduced to 2 x 10-6Within.
Preferably, the RH arrival molten steel temperature is 1630-1650 ℃, [ C ]: 0.03% -0.04%, in steel [ O ]: 500 to 600 ppm.
Preferably, the RH stage treatment time is 30-40 min/furnace.
The application provides a method for preparing ultra-low carbon and degassing steel-titanium alloy of an RH furnace, which comprises LD-LF-RH-CC which is carried out in sequence, and in the LD and RH stages, the nitrogen increasing amount of each step is strictly controlled, so that the phenomenon that the nitrogen content of partial furnace molten steel is higher due to nitrogen in the alloy is restrained, and the nitrogen increasing amount in the RH process is from 6 multiplied by 10 on average-6The above is reduced to 2 x 10-6The nitrogen increasing amount is stably controlled within 2 x 10-6Below, the fluctuation range is smaller; the nitrogen content in the steel after RH treatment of the degassing (plate) high-grade steel represented by the IF steel and X80 of the automobile panel class is stably controlled, and the process quality control requirement is completely met.
Detailed Description
For a further understanding of the invention, reference will now be made to the preferred embodiments of the invention by way of example, and it is to be understood that the description is intended to further illustrate features and advantages of the invention, and not to limit the scope of the claims.
The embodiment of the invention discloses a method for alloying ultralow-carbon and degassed steel and titanium of an RH furnace, which comprises the following steps of sequentially performing LD-LF-RH-CC:
in the LD stage, the control of nitrogen increase from the converter blowing carbon pulling to the end point is reduced;
in the RH stage, flaw detection is carried out on a welding seam at the butt joint welding position of the vacuum chamber body and the inserted pipe steel structure by adopting a penetration method, and the connection mode of the vacuum chamber and the inserted pipe steel structure is a plug-in type; titanium alloying is carried out by adopting titanium sponge alloy.
In the process, the nitrogen content in the molten steel is firstly controlled at the end point of the converter, and the specific measures are as follows:
1) the bottom blowing air supply mode special for smelting of degassing (plate) high-grade steel represented by automobile panel IF steel and X80 is formulated, and the bottom blowing air supply strength is ensured to be 0.03m3Over/min. t steel, argon is used for bottom blowing gas in the whole smelting process;
2) strictly controlling the consumption of the scrap steel within 40 kg/ton steel;
3) the control of the terminal point is enhanced, the low lance position operation is adopted in the later stage of blowing, the hit rate of primary carbon drawing is improved, the complementary blowing is reduced, the deep blowing is avoided, and the terminal point carbon is controlled according to 0.04-0.05%;
4) and a slag foaming agent is added in the later stage of smelting, so that the nitrogen removal in the later stage of smelting is promoted, and the nitrogen increase of molten steel from carbon drawing to the end point is reduced.
Through the regulation and control, the application effects of the degassing (plate) high-grade steel smelting technology represented by the IF steel and the X80 of the automobile panel are as follows: the nitrogen content of the molten steel at the end point of the converter is controlled by 19 multiplied by 10 on average-6Reduced to 13X 10-6The fluctuation range is smaller, and the control is more stable.
The application then relates to a nitrogen increasing control and titanium alloying technology in the RH process, which specifically comprises the following steps:
1) flaw detection repair welding is carried out on the welding seam at the butt welding position of the vacuum chamber body and the insert tube steel structure by a standardized penetration method, the unwelded solid welding seam at the butt welding position is eliminated and reduced as much as possible before use, and the air tightness of a vacuum chamber system is improved;
2) the service life of the vacuum chamber insert tube is required to be less than or equal to 50 times (the accumulated service time is less than or equal to 1000 minutes) when RH is used for treating IF steel of automobile panels and degassing (plate) high-grade steel represented by X80;
3) the 'plug-in type' masonry technology optimizes a refractory 'neck ring' at the joint of a front vacuum chamber and an insert pipe as a flange plane, and the 'plane' connection mode of the vacuum chamber and the insert pipe is changed into a 'plug-in type' connection mode, so that the steel penetration at the neck ring is reduced, the probability of adsorbing air outside the vacuum chamber is reduced, and the probability of increasing nitrogen before and during use of the vacuum chamber is reduced;
4) the titanium alloying is carried out by adopting high-purity titanium low-nitrogen alloy (sponge titanium) in a standardized way.
Theoretically, when the alloy is added into molten steel, the nitrogen content in the alloy can directly enter the molten steel, so that nitrogen is added to the molten steel, and the nitrogen content in raw materials needs to be controlled in order to control the nitrogen content of the molten steel.
At present, in the production process of degassing (plate) high-grade steel represented by automobile panel IF steel and X80, ferrotitanium is generally adopted for titanium alloying, and the ferrotitanium mainly comprises 40 ferrotitanium and 70 ferrotitanium, but in actual production, the adoption of both alloys has certain problems. The applicant initially used 40 ferrotitanium, which has a higher silicon content (above 3.5%), and in some high-grade IF steel production had silicon content exceeding the upper limit, and then replaced 70 ferrotitanium, which has a higher nitrogen content although its silicon content is significantly reduced (less than or equal to 0.2%),
the production of ferrotitanium usually adopts aluminothermic reduction method, and the nitrogen content of 70 ferrotitanium produced by said method is higher. The titanium alloying uses 70 ferrotitanium, the nitrogen increasing amount of the 70 ferrotitanium reaches 2 x 10-6When RH processing IF steel of automobile panel class and degassing class (plate) high-grade steel represented by X80 are treated at 100kg, IF the adding amount of ferrotitanium of 70 kg per furnace steel is 250kg, the nitrogen increasing amount reaches 5 multiplied by 10-6. The problem of nitrogen increase is brought about, especially, the nitrogen content of the IF steel of automobile panels with extremely high requirement on the nitrogen content and the degassing (plate) high-grade steel represented by X80, such as part of steel for automobile panels, is required to be within 20ppm, the nitrogen content is difficult to control after 70 ferrotitanium is adopted, and 40 ferrotitanium is not suitable due to the problem of high silicon content, so that a new titanium alloy is needed. Titanium alloying with titanium alloy with low nitrogen content is an effective measure for controlling RH nitrogen increase.
The titanium iron ore is changed into titanium tetrachloride, then the titanium tetrachloride is put into a sealed stainless steel tank, argon is filled, the titanium sponge is obtained after the titanium iron ore and the titanium sponge react with metal magnesium, magnesium chloride and excess magnesium in the titanium sponge are removed by vacuum distillation, and the titanium sponge alloy for industrial application is obtained, and the nitrogen content of the titanium sponge alloy is extremely low. Wherein the purity (mass) of the sponge titanium (namely the sponge metal titanium produced by the metallothermic reduction method) is generally 99.1-99.7, the total mass of impurity elements is 0.3-0.9, and the mass of oxygen of the impurity elements is 0.06-0.20.
Titanium sponge is used for titanium alloying, and the nitrogen increasing amount of the titanium sponge is only 0.5 multiplied by 10 in theoretical calculation-6Per 100kg, RH processing of automobile panel IF steel, X80 as representative degassing (plate) high grade steel, each furnace steel sponge titanium adding amount is 200kg, theoretical calculation nitrogen increasing amount is only 1X 10-6. The mass production practice shows that: adopts high-purity titanium low-nitrogen alloy (titanium sponge) titanium alloying, RH nitrogen increasing is stabilized at 2 x 10-6Within. Now Xichang steelVanadium production of IF steel for automobile panels and high-grade steel for degassing (plate) represented by X80 have all adopted high-purity titanium with titanium component (titanium alloying).
The method comprises the steps of heating or rhythm adjusting through an LF furnace procedure (or not through the LF furnace procedure), deoxidizing and decarburizing through an RH furnace procedure under a vacuum (negative pressure) condition, and reducing the carbon-oxygen reaction of initial carbon [ C ] (about 0.03-0.05%) in steel to be less than 0.0030% or less under the vacuum condition, wherein the ferrotitanium alloy material cannot be added for titanium alloying because the ferrotitanium alloy material is not deoxidized and killed in molten steel before the carbon in the steel is decarburized to be less than 0.0030% or less, so that the yield of the ferrotitanium alloy is low and unstable (the yield of the titanium alloy material is about 40-50%), the ferrotitanium alloy material is not economic, and free oxygen in the steel is consumed to influence the decarburization reaction under the vacuum condition of the RH furnace procedure. The ultra-low carbon steel titanium alloying operation is carried out after vacuum decarburization in an RH process is finished and a final deoxidation material is added for deoxidation and sedation, at the moment, the titanium alloy material is added for titanium alloy, the yield of the titanium alloy is about 90-95 percent, the control of titanium components is stable, and the titanium alloying is economical.
By optimizing the use of the degassing type (plate) high-grade steel titanium alloy represented by the automobile panel IF steel and X80, the phenomenon that partial heat molten steel is high in nitrogen due to nitrogen in the alloy is restrained, and the nitrogen content in the degassing type (plate) high-grade steel represented by the automobile panel IF steel and X80 after RH treatment is stably controlled, so that the process quality control requirement is completely met. The nitrogen increasing amount in the RH process is from 6 multiplied by 10 on average-6The above is reduced to 2 x 10-6The nitrogen increasing amount is stably controlled within 2 x 10-6Hereinafter, the fluctuation range is smaller.
In order to further understand the present invention, the following will explain the method for alloying titanium in ultra-low carbon and degassing steel of RH furnace in detail with reference to the following examples, and the scope of the present invention is not limited by the following examples.
The invention can be widely applied, and particularly provides an effective solution for realizing mass production of high-grade steel grades and low-cost production in steel mills which are supposed to try to manufacture or produce the IF steel of automobile panels and the high-grade steel grades (plates) represented by X80.
As further explained below.
Example 1
The Xichang steel vanadium limited steel plant of Pan Steel group smelts a certain heat of ultra-low carbon phosphorus strengthened high manganese steel, the RH arrival molten steel temperature is 1630-1640 ℃, and [ C ]]Percent: 0.02% -0.05% of steel [ O ]]500-600 ppm, performing LD blowing, LF furnace process temperature and rhythm adjustment, and then performing RH furnace process treatment, wherein the service life of an RH vacuum chamber insertion tube is in the early and middle stages, the service life (the number of use times) is less than or equal to 50 times (the accumulated use time is less than or equal to 1000 minutes), and the RH treatment time furnace for the steel grade is about 31 minutes/furnace; the specific control conditions are as follows: when the phosphorus-iron alloy and the manganese-iron alloy are added to the steel at the early stage of RH molten steel treatment for phosphorus and manganese alloying, and the decarburization treatment cycle time lasts to about 16-18 minutes (decarburization end), the temperature and oxygen of the molten steel are measured at the moment, aluminum particles are added for final deoxidation alloying, the low-nitrogen sponge titanium alloy is added to the aluminum particles after 3 minutes for titanium alloying and homogenization cycle treatment, after the homogenization cycle treatment lasts for more than or equal to 5 minutes, the treatment is completed, the system is broken empty, and the temperature and oxygen of the molten steel are measured and sampled. After the treatment, the components and the temperature of the molten steel meet the requirements of the continuous casting in the subsequent working procedure. RH off-station nitrogen 18X 10-6Finished product nitrogen 21X 10-6. And (5) lifting the molten steel out of the station to a casting machine for casting. The control method realizes green low-energy production, reduces the treatment cost of molten steel per ton of steel, and has good environmental protection implementation effect.
Example 2
The Xichang steel vanadium limited company of Pan Steel group smelts IF series ultra-low carbon steel of a certain heat, RH arrives at the station molten steel temperature 1630 ~ 1650 ℃, [ C ℃]Percent: 0.03% -0.04% of steel [ O ]]500-700 ppm, after LD blowing and LF furnace process temperature and rhythm adjustment, the steel is treated in an RH furnace process, the service life of an RH vacuum chamber insert tube is in the early and middle period, the service life (the number of use times) is less than or equal to 50 times (the accumulated use time is less than or equal to 1000 minutes), and the RH treatment time furnace for the steel grade is about 31 minutes/furnace; the specific control conditions are as follows: when the ferromanganese alloy is added in the early stage of RH molten steel treatment of the steel grade for manganese alloying, and the decarburization treatment cycle time is continued to aboutAnd (3) measuring the temperature and determining the oxygen of the molten steel at the end of decarburization within 16-18 minutes, adding aluminum particles for final deoxidation alloying, adding low-nitrogen sponge titanium alloy for titanium alloying and homogenization circulation treatment after the aluminum particles are added for 3 minutes, breaking a system after the treatment is finished and the temperature and the oxygen of the molten steel are measured and sampled after the duration is more than or equal to 5 minutes. After the treatment, the components and the temperature of the molten steel meet the requirements of the continuous casting in the subsequent working procedure. RH off-station nitrogen 17X 10-6Finished product nitrogen 20X 10-6. And (5) lifting the molten steel out of the station to a casting machine for casting. The control method realizes green low-energy production, reduces the treatment cost of molten steel per ton of steel, and has good environmental protection implementation effect.
The above description of the embodiments is only intended to facilitate the understanding of the method of the invention and its core idea. It should be noted that, for those skilled in the art, it is possible to make various improvements and modifications to the present invention without departing from the principle of the present invention, and those improvements and modifications also fall within the scope of the claims of the present invention.
The previous description of the disclosed embodiments is provided to enable any person skilled in the art to make or use the present invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other embodiments without departing from the spirit or scope of the invention. Thus, the present invention is not intended to be limited to the embodiments shown herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.
Claims (7)
1. A method for alloying ultralow-carbon and degassed titanium steel of an RH furnace comprises the steps of LD-LF-RH-CC which are sequentially carried out, and is characterized by comprising the following steps:
in the LD stage, the control of nitrogen increase from the converter blowing carbon pulling to the end point is reduced;
in the RH stage, flaw detection is carried out on a welding seam at the butt joint welding position of the vacuum chamber body and the inserted pipe steel structure by adopting a penetration method, and the connection mode of the vacuum chamber and the inserted pipe steel structure is a plug-in type; titanium alloying is carried out by adopting titanium sponge alloy.
2. The method of claim 1, wherein the method of reducing converter blowing carbon pull to endpoint recarburization control comprises one of:
A) adopts a bottom blowing air supply mode, and the strength of the bottom blowing air supply is 0.03m3More than/min. t steel, argon is adopted for bottom blowing gas;
B) controlling the consumption of scrap steel within 40 kg/ton steel;
C) the low lance position mode is adopted in the later stage of converting, and the end point carbon is 0.04-0.05%;
D) and adding a slag foaming agent in the later smelting stage.
3. The method according to claim 1, wherein the life of the vacuum chamber insert tube is less than or equal to 50 times in the RH stage when the IF steel of automobile panel type, the high-grade steel of degassing type represented by X80 are processed.
4. The method according to claim 1, characterized in that the nitrogen content of the molten steel at the end of the converter is reduced to 13 x 10 in the LD phase-6Within.
5. The method of claim 1, wherein the nitrogen increase is reduced to 2 x 10 in the RH phase-6Within.
6. The method according to claim 1, wherein the RH arrival temperature of molten steel is 1630-1650 ℃, [ C ]: 0.03% -0.04%, in steel [ O ]: 500 to 600 ppm.
7. The method according to claim 1, wherein the RH stage is performed for 30-40 min/furnace.
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| Publication number | Priority date | Publication date | Assignee | Title |
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| CN108842038A (en) * | 2018-07-03 | 2018-11-20 | 洛阳利尔耐火材料有限公司 | The building method of circulating pipe is improved in a kind of RH refining furnace |
| CN111394536A (en) * | 2020-05-06 | 2020-07-10 | 攀钢集团西昌钢钒有限公司 | Control method for N content of high-strength high-aluminum high-vanadium plate blank |
| CN111647720A (en) * | 2020-07-29 | 2020-09-11 | 攀钢集团西昌钢钒有限公司 | Control method for N content of high-aluminum high-vanadium plate blank |
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Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN108842038A (en) * | 2018-07-03 | 2018-11-20 | 洛阳利尔耐火材料有限公司 | The building method of circulating pipe is improved in a kind of RH refining furnace |
| CN111394536A (en) * | 2020-05-06 | 2020-07-10 | 攀钢集团西昌钢钒有限公司 | Control method for N content of high-strength high-aluminum high-vanadium plate blank |
| CN111647720A (en) * | 2020-07-29 | 2020-09-11 | 攀钢集团西昌钢钒有限公司 | Control method for N content of high-aluminum high-vanadium plate blank |
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