CN111349758A - Method for improving castability of non-oriented silicon steel molten steel of CSP production line - Google Patents
Method for improving castability of non-oriented silicon steel molten steel of CSP production line Download PDFInfo
- Publication number
- CN111349758A CN111349758A CN202010319651.2A CN202010319651A CN111349758A CN 111349758 A CN111349758 A CN 111349758A CN 202010319651 A CN202010319651 A CN 202010319651A CN 111349758 A CN111349758 A CN 111349758A
- Authority
- CN
- China
- Prior art keywords
- steel
- molten steel
- added
- top slag
- slag
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
Links
Classifications
-
- 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
-
- 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
- C21C1/00—Refining of pig-iron; Cast iron
- C21C1/02—Dephosphorising or desulfurising
- C21C1/025—Agents used for dephosphorising or desulfurising
-
- 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
-
- 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
-
- 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
- C21C7/0645—Agents used for dephosphorising or desulfurising
-
- 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
- C21C7/068—Decarburising
-
- 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
-
- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22C—ALLOYS
- C22C38/00—Ferrous alloys, e.g. steel alloys
- C22C38/002—Ferrous alloys, e.g. steel alloys containing In, Mg, or other elements not provided for in one single group C22C38/001 - C22C38/60
-
- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22C—ALLOYS
- C22C38/00—Ferrous alloys, e.g. steel alloys
- C22C38/004—Very low carbon steels, i.e. having a carbon content of less than 0,01%
-
- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22C—ALLOYS
- C22C38/00—Ferrous alloys, e.g. steel alloys
- C22C38/02—Ferrous alloys, e.g. steel alloys containing silicon
-
- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22C—ALLOYS
- C22C38/00—Ferrous alloys, e.g. steel alloys
- C22C38/04—Ferrous alloys, e.g. steel alloys containing manganese
-
- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22C—ALLOYS
- C22C38/00—Ferrous alloys, e.g. steel alloys
- C22C38/06—Ferrous alloys, e.g. steel alloys containing aluminium
-
- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22C—ALLOYS
- C22C38/00—Ferrous alloys, e.g. steel alloys
- C22C38/14—Ferrous alloys, e.g. steel alloys containing titanium or zirconium
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
- Y02P10/00—Technologies related to metal processing
- Y02P10/20—Recycling
Landscapes
- Chemical & Material Sciences (AREA)
- Engineering & Computer Science (AREA)
- Materials Engineering (AREA)
- Metallurgy (AREA)
- Organic Chemistry (AREA)
- Mechanical Engineering (AREA)
- Manufacturing & Machinery (AREA)
- Treatment Of Steel In Its Molten State (AREA)
Abstract
The invention provides a method for improving the castability of non-oriented silicon steel molten steel of a CSP production line, compared with the prior art, the invention adopts a double additive method, aluminum-containing top slag modifier is added after tapping to reduce the oxidability of top slag and inhibit the secondary oxidation of the molten steel, a desulfurizer is blown after RH alloying to carry out certain desulfurization on the molten steel and inhibit the desulfurization reaction of reductive top slag on the molten steel, so that the reaction between the top slag and the molten steel is inhibited from the two points, the generation of high-melting-point inclusions is reduced, and the castability of the molten steel is improved. CaO/Al of RH outbound top slag of the invention2O3The content of TFe is stably controlled to be 1.3-1.9, the content of RH end point S is stably controlled to be 15-40ppm, the position of a stopper rod in the continuous casting process is stable, and the number of continuous casting furnaces is increased to more than 13.
Description
Technical Field
The invention belongs to the field of ferrous metallurgy, and particularly relates to a method for improving the castability of non-oriented silicon steel molten steel of a CSP production line.
Background
Non-oriented silicon steel belongs to ultra-low carbon aluminum killed steel, and the steelmaking process route is molten iron pretreatment → converter → RH → continuous casting, the converter is difficult to ensure oxidizing slag to enter a steel ladle even if sliding plates are used for slag stopping, the converter highly oxidizing slag is difficult to be fully reduced like an LF route by adopting RH refining, so that the oxidizing (TFe) content in top slag after RH refining is higher, and oxygen in the top slag is continuously transferred to the steel in the casting process and reacts with Al in the steel to generate Al2O3，Al2O3The method is easy to bond on the nozzle wall, and simultaneously, as the caliber of the CSP casting nozzle is small and the operation of argon blowing by a stopper rod cannot be carried out, once the oxidizability of RH station-exiting top slag is higher, the nozzle flow accumulation is easy to occur, so that the number of continuous casting furnaces is reduced and the proportion of metallurgical defects is increased. In order to reduce the oxidability of the top slag, a great deal of work is carried out at home and abroad, the main idea is top slag modification, some steel mills adopt an aluminum-containing top slag modifier to be added into the top slag during RH treatment or after RH treatment is finished, and some steel mills adopt lime and the aluminum-containing top slag modifier to be added into the slag surface after converter tapping to reduce the oxidability of the top slag. Both top slag modification modes can reduce the oxygen content of top slag and improve the castability of molten steel to a certain extent, but on the other hand, because the converter slag discharging amount and the top slag oxidability are difficult to measure accurately, the top slag oxidability control has certain fluctuation. The top slag after modification has high oxidability and cannot achieve the purpose of modificationThe top slag has low oxidability, and a desulfurization reaction is possibly generated between the top slag and molten steel after RH is broken due to the fact that the content of S at the end point of the converter is higher, so that CaS-type inclusions are generated, and the inclusions are easy to adhere to the wall surface of a water gap to form water gap accumulation.
At present, the method for improving the castability of the molten steel of the CSP non-oriented silicon steel mainly carries out top slag modification so as to reduce the secondary oxidation of the top slag on the molten steel and reduce Al2O3And the generation of inclusions is performed, so that the castability of the molten steel is improved. The top slag modification method mainly comprises two methods, one method is that an aluminum-containing modifier is added to the slag surface after steel tapping is finished, argon is blown, and the reaction of the modifier and the top slag is promoted to reduce the TFe content of the top slag; and the other is that after the RH treatment is finished, an aluminum-containing top slag modifier or aluminum iron powder is manually or mechanically fed into the top slag surface, argon blowing or calcium feeding lines are carried out to promote the reaction between the top slag and aluminum and calcium so as to reduce the content of TFe in the top slag. However, the former method has the problems that the control fluctuation of the top slag oxidability and the over-low top slag oxidability can generate a desulfurization reaction, and the generated CaS-type inclusions are easy to generate water gap flow accumulation and the like; the latter method mainly has the defects that the top slag is difficult to effectively reduce, secondary oxidation is easy to occur in the stirring or calcium wire feeding process, and the generated inclusions are difficult to remove.
Disclosure of Invention
The invention aims to provide a method for improving the castability of molten steel of non-oriented silicon steel on a CSP production line, which designs a novel process idea for inhibiting the reaction of top slag and molten steel from the CSP casting and flow storage mechanism of the non-oriented silicon steel.
The specific technical scheme of the invention is as follows:
a method for improving the castability of molten non-oriented silicon steel of a CSP production line comprises the following steps:
1) carrying out pretreatment desulfurization on molten iron;
2) smelting in a converter;
3) adding a high-aluminum top slag modifier into an argon blowing station;
4) RH is decarbonized and deoxidized and alloyed, Al particles are added for deoxidation after the decarbonization is finished, then alloying treatment is carried out, and a desulfurizer is added for desulfurization after the alloying treatment;
5) and (4) calming the molten steel, and performing protective casting in the whole process before casting and in the casting process.
The S content after desulfurization in the step 1) is below 20 ppm;
further, the bright surface of slag skimming before and after desulfurization in the step 1) is more than 90%;
and 2) smelting by adopting low-sulfur steel scrap and low-sulfur auxiliary materials in the transfer furnace.
And 2) in the step 2), the steel tapping adopts a sliding plate to block slag, and 3-5kg/t of steel lime is added according to different slag discharging amounts in the steel tapping process.
Step 2), controlling the content of the end point C of the transfer furnace to be 0.02-0.06 percent, controlling the end point oxygen to be 400-1000ppm and controlling the end point temperature to be 1650-1700 ℃;
in the step 3), 1.8-3.6kg/t of high-aluminum top slag modifier is added according to the slag discharging condition of the converter and the oxygen determination result of the molten steel; the high-aluminum top slag modifier contains more than 45% of metallic aluminum.
Opening bottom blowing argon in the step 3) to promote reduction of top slag; controlling the TFe content in the RH top slag to be 1-4% after modifying the top slag;
the oxygen content at the decarburization end in the step 4) is controlled to be 200-400 ppm.
Adding Al particles for deoxidation after decarburization is finished in the step 4), and circulating for 3-5min after Al particles are added according to different oxygen contents at the decarburization end point and then carrying out alloying treatment;
further, after alloying in the step 4), a top gun is utilized to spray a desulfurizing agent according to different S contents in molten steel.
In the step 4), the adding amount of the desulfurizer is 1.8-4.0kg/t steel;
carrying out clean circulation for 6-10min after desulfurization in the step 4), and then carrying out molten steel discharge;
the desulfurizer in the step 4) is selected from RH high-efficiency desulfurizer or CaO + Al2O3Mixed powder of wherein RH is highThe effective desulfurizer contains CaO and CaF2CaO mass fraction is not less than 48%, CaF2The mass fraction is 12-30%, and the proportion of the granularity less than or equal to 1mm reaches more than 95%; the CaO + Al2O3Mixed powder of CaO/Al2O3The mass percentage of the CaO is 3.0 to 4.0, the CaO particle size is less than or equal to 0.125mm, and Al2O3The proportion of the granularity of less than or equal to 0.075mm is more than or equal to 90 percent, the proportion of the granularity of CaO more than or equal to 0.15mm is less than or equal to 5 percent, and Al2O3The proportion of the particle size of more than or equal to 0.10mm is 0 percent.
And 5), calming the molten steel for 10-20min after the molten steel is placed on a continuous casting table.
Compared with the prior art, the novel CSP silicon steel casting accumulation control method adopted by the invention is characterized in that lime and a high-aluminum top slag modifier are added into the converter tapping to modify the ladle top slag and optimize the RH process, and the RH outbound top slag is CaO/Al2O3The control is 1.3-1.9, the TFe content is stably controlled to be 1-4%, the secondary oxidation of ladle top slag on molten steel can be effectively reduced, RH is subjected to powder injection desulfurization, the RH end point S content is stably controlled to be 15-40ppm, the desulfurization reaction between the top slag and the molten steel can be effectively prevented, the generation of CaS impurities is prevented, the stable position of a stopper rod in the continuous casting process is ensured, and the number of continuous casting furnaces is increased to more than 13.
Detailed Description
Example 1
A method for improving the castability of molten non-oriented silicon steel of a CSP production line comprises the following steps:
1) the process for producing the non-oriented silicon steel W800 and improving the castability of molten steel comprises the following steps of: c: less than or equal to 0.0050%, Si: 0.85% -1.05%, Mn: 0.20% -0.45%, P: 0.040% -0.070%, S: less than or equal to 0.0060 percent, Als: 0.15% -0.30%, Ti: less than or equal to 0.0040 percent, and the balance of Fe and inevitable impurities;
2) pretreating molten iron: slagging off the slag before the ladle until the exposed area of the molten iron is more than or equal to 90 percent before starting the treatment, desulfurizing the molten iron by a magnesium powder and lime injection mode, controlling the S content in the treated molten iron to be 15ppm, and slagging off the slag after the treatment until the exposed area of the molten iron is more than or equal to 90 percent;
3) converter steelmaking: pouring molten iron subjected to pretreatment and desulfurization of molten iron into a converter, and adding auxiliary materials such as low-sulfur scrap steel and low-sulfur lime to carry out converter steelmaking, wherein the content of C at the end point of the converter is controlled to be 0.035%, the content of oxygen at the end point is controlled to be 621ppm, the temperature at the end point is controlled to be 1684 ℃, a sliding plate is adopted for slag blocking in the tapping process, and 3.5kg/t of steel small granular lime is added into a steel ladle when the steel is tapped to 1/3;
4) and (3) argon blowing station: after the molten steel of the converter enters an argon blowing station, 2.5kg/t of steel high-aluminum top slag modifier is uniformly added on the slag surface, and bottom argon blowing is opened to keep the exposed diameter area of the molten steel at 400mm2The slag is discharged after the top slag is melted;
5) RH refining: after molten steel in an argon blowing station enters RH, the insertion depth of a dip pipe is kept at 500mm, the vacuum degree is 96Pa, the decarburization time is 12min, the oxygen content at the end point of decarburization is 276ppm, aluminum particles are added for deoxidation after the decarburization is finished, the cycle time is 3min after the aluminum particles are added for alloying, the S content is 42ppm after the alloying, 1.8kg/t of steel RH high-efficiency desulfurizer is sprayed by a top gun for desulfurization, 7min of net circulation is carried out after powder spraying is finished, then the steel is discharged, and when the steel is discharged, top slag comprises the following components in percentage by weight: CaO: 48.2% of SiO2:4.9％，Al2O334.1%, MgO: 7.5%, TFe: 2.5% and other unavoidable elements of Mn, P, Ti;
6) continuous casting: after the molten steel is fed onto a continuous casting platform, the molten steel is calmed for 10min, and the continuous casting tundish components are controlled as follows: c: 0.0015%, Si: 0.98%, Mn: 0.32%, P: 0.057%, S: 0.0021%, Als: 0.25%, Ti: 0.0028 percent, the balance of Fe and inevitable impurities, protective casting is carried out before casting and in the casting process, water gap accumulation does not occur in the casting process, the stopper rod position is stable, and the inclusion defect rate of hot rolling reaction is 1.3 percent.
By adopting the method of example 1, the number of continuous casting furnaces reaches 15.
Example 2
A method for improving the castability of molten non-oriented silicon steel of a CSP production line comprises the following steps:
1) the process for producing the non-oriented silicon steel W800 and improving the castability of molten steel comprises the following steps of: c: less than or equal to 0.0050%, Si: 0.85% -1.05%, Mn: 0.20% -0.45%, P: 0.040% -0.070%, S: less than or equal to 0.0060 percent, Als: 0.15% -0.30%, Ti: less than or equal to 0.0040 percent, and the balance of Fe and inevitable impurities;
2) pretreating molten iron: slagging off the slag before the ladle until the exposed area of the molten iron is more than or equal to 90 percent before starting the treatment, desulfurizing the molten iron by a magnesium powder and lime injection mode, controlling the S content in the treated molten iron to be 12ppm, and slagging off the slag after the treatment until the exposed area of the molten iron is more than or equal to 90 percent;
3) converter steelmaking: pouring molten iron subjected to pretreatment and desulfurization of molten iron into a converter, and adding auxiliary materials such as low-sulfur scrap steel and low-sulfur lime to carry out converter steelmaking, wherein the end point C content of the converter is controlled to be 0.030%, the end point oxygen content is controlled to be 645ppm, the end point temperature is controlled to be 1686 ℃, a sliding plate is adopted for slag blocking in the tapping process, and 3.6kg/t of steel small granular lime is added into a steel ladle when the tapping reaches 1/3;
4) and (3) argon blowing station: after the molten steel of the converter enters an argon blowing station, 2.8kg/t of steel high-aluminum top slag modifier is uniformly added on the slag surface, and bottom argon blowing is opened to keep the exposed diameter area of the molten steel at 400mm2The slag is discharged after the top slag is melted;
5) RH refining: after molten steel in an argon blowing station enters RH, the insertion depth of a dip pipe is kept at 600mm, the vacuum degree is 102Pa, the decarburization time is 13min, the oxygen content at the end point of decarburization is 305ppm, aluminum particles are added for deoxidation after the decarburization is finished, the circulation time is 4min after the aluminum particles are added for alloying, the S content is 32ppm after the alloying, 2.8kg/t steel CaO + Al is sprayed by a top lance2O3And desulfurizing the mixed powder, and performing clean circulation for 6min after powder spraying is finished, wherein during the leaving, the top slag comprises the following components in percentage by weight: CaO: 49.1% of SiO2:5.0％，Al2O332.4%, MgO: 7.2%, TFe: 2.2% and other unavoidable elements of Mn, P, Ti;
6) continuous casting: after the molten steel is fed onto a continuous casting platform, the molten steel is calmed for 15min, and the continuous casting tundish components are controlled as follows: c: 0.0014%, Si: 0.99%, Mn: 0.31%, P: 0.055%, S: 0.0019%, Als: 0.24%, Ti: 0.0026 percent and the balance of Fe and inevitable impurities, protective casting is carried out before casting and in the casting process, water gap accumulation does not occur in the casting process, the stopper rod position is stable, and the inclusion defect rate of hot rolling reaction is 1.4 percent.
By adopting the method of the embodiment 2, the number of continuous casting furnaces reaches 15.
Example 3
A method for improving the castability of molten non-oriented silicon steel of a CSP production line comprises the following steps:
1) the process for producing the non-oriented silicon steel W800 and improving the castability of molten steel comprises the following steps of: c: less than or equal to 0.0050%, Si: 0.85% -1.05%, Mn: 0.20% -0.45%, P: 0.040% -0.070%, S: less than or equal to 0.0060 percent, Als: 0.15% -0.30%, Ti: less than or equal to 0.0040 percent, and the balance of Fe and inevitable impurities;
2) pretreating molten iron: slagging off the slag before the ladle until the exposed area of the molten iron is more than or equal to 90 percent before starting the treatment, desulfurizing the molten iron by a magnesium powder and lime injection mode, controlling the S content in the treated molten iron to be 16ppm, and slagging off the slag after the treatment until the exposed area of the molten iron is more than or equal to 90 percent;
3) converter steelmaking: pouring molten iron subjected to pretreatment and desulfurization of molten iron into a converter, and adding auxiliary materials such as low-sulfur scrap steel and low-sulfur lime to carry out converter steelmaking, wherein the end point C content of the converter is controlled to be 0.041%, the end point oxygen content is controlled to be 526ppm, the end point temperature is controlled to be 1672 ℃, a sliding plate is adopted for slag blocking in the tapping process, and 3.2kg/t of steel small granular lime is added into a steel ladle when the tapping reaches 1/3;
4) and (3) argon blowing station: after the molten steel of the converter enters an argon blowing station, 1.8kg/t of steel high-aluminum top slag modifier is uniformly added on the slag surface, and bottom argon blowing is opened to keep the exposed diameter area of the molten steel at 400mm2The slag is discharged after the top slag is melted;
5) RH refining: after molten steel in an argon blowing station enters RH, the insertion depth of a dip pipe is kept at 400mm, the vacuum degree is 84Pa, the decarburization time is 13min, the oxygen content at the end point of decarburization is 242ppm, aluminum particles are added for deoxidation after the decarburization is finished, the cycle time is 3min after the aluminum particles are added for alloying, the S content is 39ppm after alloying, and 3.5kg/t steel CaO + Al is sprayed by a top lance2O3And desulfurizing the mixed powder, carrying out 8min net circulation after powder spraying is finished, and then leaving the station, wherein the top slag comprises the following components in percentage by weight: CaO: 50.1% of SiO2:5.1％，Al2O334.6 percent, MgO: 7.1%, TFe: 1.9% and other unavoidable elementsOxides of elemental Mn, P, Ti;
6) continuous casting: after the molten steel is fed into a continuous casting platform, the molten steel is calmed for 18min, and the continuous casting tundish components are controlled as follows: c: 0.0013%, Si: 0.97%, Mn: 0.34%, P: 0.059%, S: 0.0021%, Als: 0.26%, Ti: 0.0032 percent, the balance being Fe and inevitable impurities, protective casting is carried out before casting and in the casting process, water gap flow accumulation does not occur in the casting process, the stopper rod position is stable, and the inclusion defect rate of hot rolling reaction is 1.7 percent.
By adopting the method of example 3, the number of continuous casting furnaces reaches 13.
Comparative example 1
A method for improving the castability of molten non-oriented silicon steel of a CSP production line comprises the following steps:
1) the process for producing the non-oriented silicon steel W800 and improving the castability of molten steel comprises the following steps of: c: less than or equal to 0.0050%, Si: 0.85% -1.05%, Mn: 0.20% -0.45%, P: 0.040% -0.070%, S: less than or equal to 0.0060 percent, Als: 0.15% -0.30%, Ti: less than or equal to 0.0040 percent, and the balance of Fe and inevitable impurities;
2) pretreating molten iron: slagging off the slag before the ladle until the exposed area of the molten iron is more than or equal to 90 percent before starting the treatment, desulfurizing the molten iron by a magnesium powder and lime injection mode, controlling the S content in the treated molten iron to be 14ppm, and slagging off the slag after the treatment until the exposed area of the molten iron is more than or equal to 90 percent;
3) converter steelmaking: pouring molten iron subjected to pretreatment and desulfurization of molten iron into a converter, and adding auxiliary materials such as low-sulfur scrap steel and low-sulfur lime to carry out converter steelmaking, wherein the end point C content of the converter is controlled to be 0.042%, the end point oxygen content is controlled to be 601ppm, the end point temperature is controlled to be 1687 ℃, a sliding plate is adopted for slag blocking in the tapping process, and 3.4kg/t of steel small granular lime is added into a steel ladle when the tapping reaches 1/3;
4) and (3) argon blowing station: after the converter molten steel enters an argon blowing station, opening bottom argon blowing, and discharging after top slag is well melted;
5) RH refining: after molten steel in an argon blowing station enters RH, the insertion depth of a dip pipe is kept at 500mm, the vacuum degree is 97Pa, the decarburization time is 14min, the oxygen content at the end point of decarburization is 278ppm, aluminum particles are added for deoxidation after the decarburization is finished, and the circulation time is 3min after the aluminum particles are addedAlloying, wherein the S content is 41ppm after alloying, spraying 2.0kg/t steel RH high-efficiency desulfurizer by a top gun for desulfurization, carrying out 7min net circulation after powder spraying is finished, and then leaving the station, wherein top slag comprises the following components in percentage by weight: CaO: 47.8% of SiO2:6.9％，Al2O327.9%, MgO: 6.8%, TFe: 9.2% and other unavoidable elements of Mn, P, Ti;
6) continuous casting: after the molten steel is fed onto a continuous casting platform, the molten steel is calmed for 10min, and the continuous casting tundish components are controlled as follows: c: 0.0018%, Si: 1.01%, Mn: 0.33%, P: 0.054%, S: 0.0023%, Als: 0.25%, Ti: 0.0021 percent, protective casting is well carried out before casting and in the casting process, the water gap accumulation occurs in the casting process, the stopper rod position is lifted, and the inclusion defect rate of the hot rolling reaction is 6.2 percent.
The method of comparative example 1 was used, and the number of continuous casting furnaces was 5.
Comparative example 2
A method for improving the castability of molten non-oriented silicon steel of a CSP production line comprises the following steps:
1) the process for producing the non-oriented silicon steel W800 and improving the castability of molten steel comprises the following steps of: c: less than or equal to 0.0050%, Si: 0.85% -1.05%, Mn: 0.20% -0.45%, P: 0.040% -0.070%, S: less than or equal to 0.0060 percent, Als: 0.15% -0.30%, Ti: less than or equal to 0.0040 percent, and the balance of Fe and inevitable impurities;
2) pretreating molten iron: slagging off the slag before the ladle until the exposed area of the molten iron is more than or equal to 90 percent before starting the treatment, desulfurizing the molten iron by a magnesium powder and lime injection mode, controlling the S content in the treated molten iron to be 13ppm, and slagging off the slag after the treatment until the exposed area of the molten iron is more than or equal to 90 percent;
3) converter steelmaking: pouring molten iron subjected to pretreatment and desulfurization of molten iron into a converter, and adding auxiliary materials such as low-sulfur scrap steel and low-sulfur lime to carry out converter steelmaking, wherein the end point C content of the converter is controlled to be 0.032%, the end point oxygen content is controlled to be 634ppm, the end point temperature is controlled to be 1679 ℃, a sliding plate is adopted for slag stopping in the tapping process, and 3.4kg/t of steel small granular lime is added into a steel ladle when the tapping reaches 1/3;
4) and (3) argon blowing station: after the converter molten steel enters the argon blowing station, the converter molten steel is uniform on the slag surface2.7kg/t of steel aluminum-containing top slag modifier is added, bottom blowing argon is opened, and the exposed diameter area of the molten steel is kept at 400mm2The slag is discharged after the top slag is melted;
5) RH refining: after molten steel in an argon blowing station enters RH, the insertion depth of a dip pipe is kept at 500mm, the vacuum degree is 87Pa, the decarburization time is 12min, the oxygen content at the decarburization end point is 349ppm, aluminum particles are added for deoxidation after the decarburization is finished, the cycle time is 4min after the aluminum particles are added for alloying, the S content is 43ppm after the alloying, the molten steel is taken out after 6min net cycle after the alloying, and top slag comprises the following components in percentage by weight: CaO: 46.9% of SiO2:5.6％，Al2O336.4%, MgO: 7.3%, TFe: 2.3% and other unavoidable elements of Mn, P, Ti;
6) continuous casting: after the molten steel is fed onto a continuous casting platform, the molten steel is calmed for 20min, and the continuous casting tundish components are controlled as follows: c: 0.0018%, Si: 0.98%, Mn: 0.33%, P: 0.060%, S: 0.0037%, Als: 0.25%, Ti: 0.0033 percent, protective casting is well carried out before casting and in the casting process, water gap accumulation occurs in the casting process, the stopper rod position is lifted, and the inclusion defect rate of hot rolling reaction is 5.4 percent.
The method of comparative example 2 was used, and the number of continuous casting furnaces reached 7.
Claims (10)
1. A method for improving the castability of non-oriented silicon steel molten steel of a CSP production line is characterized by comprising the following steps:
1) carrying out pretreatment desulfurization on molten iron;
2) smelting in a converter;
3) adding a high-aluminum top slag modifier into an argon blowing station;
4) RH is decarbonized and deoxidized and alloyed, Al particles are added for deoxidation after the decarbonization is finished, then alloying treatment is carried out, and a desulfurizer is added for desulfurization after the alloying treatment;
5) and (4) calming the molten steel, and performing protective casting in the whole process before casting and in the casting process.
2. The method according to claim 1, wherein the S content after desulfurization in step 1) is 20ppm or less.
3. The method as claimed in claim 1 or 2, wherein the tapping in step 2) is carried out by using a sliding plate for slag blocking, and 3-5kg/t steel lime is added during the tapping.
4. The method as claimed in claim 1, wherein the end point C content of the transfer furnace in step 2) is controlled to be 0.02% -0.06%, the end point oxygen is controlled to be 1000ppm, and the end point temperature is controlled to be 1650-1700 ℃.
5. The method of claim 1, wherein 1.8-3.6kg/t steel of high aluminum top slag modifier is added in step 3).
6. The method of claim 1, wherein the content of TFe in the RH top dross after upgrading in step 3) is controlled to be 1-4%.
7. The method as set forth in claim 1, wherein the decarburization end oxygen in the step 4) is controlled to 200-400 ppm.
8. The method as claimed in claim 1, wherein the alloying treatment is performed after 3-5min of the cycle after the Al particles are added in the step 4).
9. The method according to claim 1 or 8, characterized in that the desulfurizing agent is added in step 4) in an amount of 1.8-4.0kg/t steel.
10. The method as claimed in claim 1, wherein the desulfurizing agent in step 4) is selected from RH high-efficiency desulfurizing agent or CaO + Al2O3And (4) mixing the powder.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202010319651.2A CN111349758B (en) | 2020-04-22 | 2020-04-22 | Method for improving castability of non-oriented silicon steel molten steel of CSP production line |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202010319651.2A CN111349758B (en) | 2020-04-22 | 2020-04-22 | Method for improving castability of non-oriented silicon steel molten steel of CSP production line |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN111349758A true CN111349758A (en) | 2020-06-30 |
| CN111349758B CN111349758B (en) | 2022-08-09 |
Family
ID=71193318
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202010319651.2A Active CN111349758B (en) | 2020-04-22 | 2020-04-22 | Method for improving castability of non-oriented silicon steel molten steel of CSP production line |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN111349758B (en) |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN113088792A (en) * | 2021-03-25 | 2021-07-09 | 武汉钢铁有限公司 | Method for improving castability of high-aluminum non-oriented silicon steel produced by continuous casting of thin slab |
| CN114085956A (en) * | 2021-11-30 | 2022-02-25 | 马鞍山钢铁股份有限公司 | RH top gun powder injection desulfurization process for non-oriented silicon steel |
| CN115287407A (en) * | 2022-08-10 | 2022-11-04 | 柳州钢铁股份有限公司 | Method for controlling slag splashing of continuous casting residue recovery |
Citations (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH0995726A (en) * | 1995-09-29 | 1997-04-08 | Nippon Steel Corp | Method for reforming slag |
| CN101736133A (en) * | 2009-12-22 | 2010-06-16 | 马鞍山钢铁股份有限公司 | Pre-melted type RH vacuum refining desulfurizing agent and using method thereof |
| CN102296157A (en) * | 2010-06-23 | 2011-12-28 | 宝山钢铁股份有限公司 | Very low Ti control method of ultralow-carbon aluminum-silicon killed steel |
| CN103451349A (en) * | 2013-08-16 | 2013-12-18 | 河北钢铁股份有限公司邯郸分公司 | Control method for preventing nozzle clogging in casting process of ultra-low carbon-aluminium deoxidized molten steel |
| CN107299196A (en) * | 2017-07-28 | 2017-10-27 | 江苏省沙钢钢铁研究院有限公司 | A kind of non-orientation silicon steel RH vacuum drying ovens molten steel and clinker synchronized desulfuring method |
| CN108998613A (en) * | 2018-08-08 | 2018-12-14 | 鞍钢股份有限公司 | Free oxygen control method in a kind of low aluminum steel of Ultra-low carbon |
| CN110283962A (en) * | 2019-07-26 | 2019-09-27 | 马鞍山钢铁股份有限公司 | A kind of technique of non-orientation silicon steel aluminium deoxidation product denaturation |
| CN110643779A (en) * | 2019-11-08 | 2020-01-03 | 马鞍山钢铁股份有限公司 | Ultra-low carbon steel top slag control production method |
-
2020
- 2020-04-22 CN CN202010319651.2A patent/CN111349758B/en active Active
Patent Citations (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH0995726A (en) * | 1995-09-29 | 1997-04-08 | Nippon Steel Corp | Method for reforming slag |
| CN101736133A (en) * | 2009-12-22 | 2010-06-16 | 马鞍山钢铁股份有限公司 | Pre-melted type RH vacuum refining desulfurizing agent and using method thereof |
| CN102296157A (en) * | 2010-06-23 | 2011-12-28 | 宝山钢铁股份有限公司 | Very low Ti control method of ultralow-carbon aluminum-silicon killed steel |
| CN103451349A (en) * | 2013-08-16 | 2013-12-18 | 河北钢铁股份有限公司邯郸分公司 | Control method for preventing nozzle clogging in casting process of ultra-low carbon-aluminium deoxidized molten steel |
| CN107299196A (en) * | 2017-07-28 | 2017-10-27 | 江苏省沙钢钢铁研究院有限公司 | A kind of non-orientation silicon steel RH vacuum drying ovens molten steel and clinker synchronized desulfuring method |
| CN108998613A (en) * | 2018-08-08 | 2018-12-14 | 鞍钢股份有限公司 | Free oxygen control method in a kind of low aluminum steel of Ultra-low carbon |
| CN110283962A (en) * | 2019-07-26 | 2019-09-27 | 马鞍山钢铁股份有限公司 | A kind of technique of non-orientation silicon steel aluminium deoxidation product denaturation |
| CN110643779A (en) * | 2019-11-08 | 2020-01-03 | 马鞍山钢铁股份有限公司 | Ultra-low carbon steel top slag control production method |
Non-Patent Citations (1)
| Title |
|---|
| 高海潮等: "RH处理超低碳铝镇静钢技术的优化 ", 《安徽冶金》 * |
Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN113088792A (en) * | 2021-03-25 | 2021-07-09 | 武汉钢铁有限公司 | Method for improving castability of high-aluminum non-oriented silicon steel produced by continuous casting of thin slab |
| CN114085956A (en) * | 2021-11-30 | 2022-02-25 | 马鞍山钢铁股份有限公司 | RH top gun powder injection desulfurization process for non-oriented silicon steel |
| CN114085956B (en) * | 2021-11-30 | 2023-11-03 | 马鞍山钢铁股份有限公司 | Non-oriented silicon steel RH top gun powder spraying desulfurization process |
| CN115287407A (en) * | 2022-08-10 | 2022-11-04 | 柳州钢铁股份有限公司 | Method for controlling slag splashing of continuous casting residue recovery |
| CN115287407B (en) * | 2022-08-10 | 2023-10-20 | 柳州钢铁股份有限公司 | Method for controlling continuous casting surplus recovery slag splashing |
Also Published As
| Publication number | Publication date |
|---|---|
| CN111349758B (en) | 2022-08-09 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US7901482B2 (en) | Removal method of nitrogen in molten steel | |
| CN111349758B (en) | Method for improving castability of non-oriented silicon steel molten steel of CSP production line | |
| RU2476604C2 (en) | Method for obtaining molten steel with manganese content of up to 30% | |
| JPWO2002022891A1 (en) | Refining agent and refining method | |
| CN101768656B (en) | Method for refining ultra-low carbon ferritic stainless steel under vacuum | |
| CN113249639B (en) | Production method for improving castability of silicon-manganese killed silicon steel | |
| CN111206137B (en) | Method for stably controlling low titanium content in high-grade non-oriented silicon steel produced by high-titanium molten iron | |
| CN112921148B (en) | Ultra-low sulfur silicon steel smelting process | |
| CN108893576B (en) | Smelting method of welding rod steel H08A | |
| AU2009279363A1 (en) | Low cost making of a low carbon, low sulfur, and low nitrogen steel using conventional steelmaking equipment | |
| JP2012012648A (en) | Method for applying desulfurize-treatment to molten steel | |
| EP2663662B1 (en) | Method of desulfurizing steel | |
| KR101449799B1 (en) | Method of producing steel | |
| CN105483501A (en) | Method for smelting phosphorus-containing ultra-low carbon steel | |
| CN112899437A (en) | Oxygen content control method of aluminum-free low-alloy non-oriented silicon steel | |
| CN108796173A (en) | Improve the smelting process of heavy rail steel cleanness | |
| CN110484808B (en) | Method for improving castability of phosphorus-containing ultra-low carbon steel | |
| WO2018216660A1 (en) | Method for manufacturing high manganese steel ingot | |
| CN113584259B (en) | Method for washing RH furnace | |
| CN108796172A (en) | Improve the smelting process of heavy rail steel cleanness | |
| CN114535525A (en) | Ultra-low sulfur non-oriented electrical steel and production method thereof | |
| KR101045972B1 (en) | Refining method of highly clean ultra low carbon steel for soft two-piece can | |
| CN108754073A (en) | Improve the smelting process of heavy rail steel cleanness | |
| JP3339982B2 (en) | Converter steelmaking method | |
| JP2006152368A (en) | Method for melting low carbon high manganese steel |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |