CN101215618A - Method for smelting ultra-low-carbon steel - Google Patents
Method for smelting ultra-low-carbon steel Download PDFInfo
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- CN101215618A CN101215618A CNA2007101592247A CN200710159224A CN101215618A CN 101215618 A CN101215618 A CN 101215618A CN A2007101592247 A CNA2007101592247 A CN A2007101592247A CN 200710159224 A CN200710159224 A CN 200710159224A CN 101215618 A CN101215618 A CN 101215618A
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Abstract
The invention relates to a process for smelting ultra-low-carbon steel, which comprises melted iron pretreatment desulfuration, converter smelt, LF furnace refining, RH vacuum process and continuous casting procedure in turn. Converter smelt tapping adopts non deoxidization tapping, steel which is tapped off is refined by LF ladle furnace before carried out melt iron vacuum decarburization processing, wherein refining is mainly used to proceed modifying property processing and further desulfuration and heating for top slag of melted iron, and the melted iron is reinforced with positive oxygen blowing decarburization after shifted into a RH vacuum container. The process can control carbon, nitrogen and sulfur in steel to preset objects which are required, and has excellent castability when a casting machine casted, thereby realizing casting by several furnaces.
Description
Technical field:
The present invention relates to a kind of method of smelting suprelow carbon steel.
Background technology:
Ultra low-carbon steel is meant that carbon content accounts for the special steel below 0.01% of steel gross weight, and existing smelting technology can drop to carbon content desired degree.Carbon is a not only easy but also cheap method that increases hardness of steel, but when the content of carbon in steel increased, some performances such as the formability of steel, weldability and toughness also can weaken thereupon.Along with basic role and the secondary action of micro alloying element in steel, the notion of " austenite adjusting " has been proposed, control adds micro alloying element in the steel consciously, with expansionary can better steel grade, ultra low-carbon steel adopts micro-alloying technology to obtain high strength exactly in soft steel, the steel grade that has desired performance again simultaneously.
The name of No. 101037716 bulletins of Chinese patent is called the object lesson that " short-flow super low carbon steel ultra-low sulphur smelting control method " provides a kind of smelting special steel.This kind smelting control method comprises desulfurizing iron pre-treatment, converter smelting, RH powder injection desulphurization, continuous casting working procedure successively, and in the desulfurizing iron pretreatment process, adopts secondary to skim and step such as stirring, so that its desulfurization better.This method is not taked deoxygenation step at converter smelting, and directly molten steel is changed over to RH vacuum cycle device and utilized vacuum decarburization or utilize oxygen blast to force decarbonization, desulfuration by converter.Carbon and sulphur can be reduced to desired indicator though utilize this kind method, but, owing to directly enter the RH vacuum circulation degassing after its converter smelting step is finished, directly enter the continuous caster rolled plate then, in entering the continuous caster process, molten steel need arrive crystallizer through submerged nozzle, and through the stopper dominant discharge, and in the molten steel that RH handled, also contain impurity such as aluminium sesquioxide, if these impurity particularly aluminium sesquioxide do not carry out denaturing treatment and fall, can directly stop up stopper, also can make the molten steel secondary oxidation simultaneously, influence the quality of steel, in addition, the RH ladle top slag also has very strong oxidisability, and it is undesirable to handle the aluminium sesquioxide effect with calcium, and used up calcium can cause the raising of smelting cost.
Summary of the invention:
Task of the present invention provides a kind of method of adjusting the smelting order and the smelting suprelow carbon steel of the mode workout cost of controlling molten steel composition and problems such as stopper and mouth of a river passage obstruction of utilizing.
The method of smelting suprelow carbon steel proposed by the invention may further comprise the steps:
Hot metal pretreatment: adopt pretreatment unit blowing desulfurization pulvis in molten iron, when sulphur weight content in the molten iron≤0.004%, change it over to converter smelting; Converter smelting: the molten iron after the desulfurization is carried out the oxygen blast carbon drop in converter it is smelted into molten steel, oxygen blow duration is 12 minutes-18 minutes, in converter steelmaking process, in it, add slag making materials, the weight quota of the weight quota of carbon≤0.035%, oxygen≤0.05～0.09% in molten steel in the converter, and in the ladle of tapping when liquid steel temperature reaches 1680 ℃-1720 ℃ in the converter, adopt the pushing off the slag operation in its tapping process; External refining: is to carry out refining in the LF stove with the molten steel handling in the ladle to the external refining stove, adopt the heating of electrode pair molten steel and in ladle, add lime and reductor simultaneously, top slag modification is handled and the further desulfurization of molten steel is reached except that inclusion, molten steel is stirred the composition and the temperature of even molten steel with steel ladle bottom argon blowing, treat free oxygen weight content≤0.0005% in the molten steel, weight content≤5% of ferric oxide o'clock in the slag of molten steel top changes the vacuum refinement operation over to; RH vacuum refinement: adopt the decarburization of RH vacuum cycle device, the degassing, with to further refining of LF stove molten steel after refining and alloying, carbon content in steel is less than or equal to 0.0050%, when the composition that each composition satisfies steel in the molten steel requires, changes molten steel over to the cast steel program.
Described molten iron is through molten iron pretreatment desulfurizing, and its sweetening agent is to be made of magnesium powder and lime powder, and the weight ratio between magnesium powder and the lime powder is 1: 2.5-3.5.
Described converter smelting, converter tapping when weight quota≤0.035%, weight quota≤0.05～0.09% of oxygen, the temperature of carbon in the steel reach 1680 ℃-1720 ℃, deoxidation alloying is not carried out in tapping, but must the pushing off the slag tapping.
Mainly be earlier molten steel top slag to be carried out carrying out vacuum decarburization again after modification is handled in the described external refining step, promptly before the RH vacuum decarburization, must carry out modification to molten steel top slag through the LF stove and handle, make the content (weight)≤2% of ferric oxide in the slag of molten steel top.
In the method for smelting suprelow carbon steel proposed by the invention behind LF stove liquid steel refining, the content of ferric oxide in the slag of molten steel top can be reduced to below 2% (being preferably below 1%), the secondary oxidation in the molten steel steel pouring process can be reduced like this, and then steel quality can be improved.The RH vacuum forces decarburization the carbon in the steel can be taken off to below 0.0050%, the standard that meets ultra low-carbon steel fully, and do not contain or contain aluminium sesquioxide and other impurity of minute quantity, so, this kind smelting process can avoid stopper and mouth of a river passage to stop up, and can realize that the company of ultra low-carbon steel waters and sequence casting.
Embodiment:
Embodiment 1:
This method comprises: molten iron pretreatment desulfurizing, skim → converter smelting, pushing off the slag, not deoxidation tapping → LF furnace roof slag upgrading, desulfurization → RH vacuum is forced decarburization, alloying, temperature adjustment → casting machine casting.
At first the molten iron in the hot metal pretreatment device being carried out desulfurization handles, promptly add the sweetening agent that constitutes by magnesium powder and lime powder toward molten iron, weight ratio between magnesium powder and the lime powder is 1: 3, and adopt conventional steps such as stir, skim, when sulphur weight content in the molten iron≤0.004%, change it over to converter smelting;
Converter smelting: the molten iron after the desulfurization is carried out the oxygen blast carbon drop smelt into molten steel in converter, oxygen blow duration is usually between 12-18 minute, in converter steelmaking process, in converter, add slag making materials such as lime it is carried out dephosphorization and further desulfurization and other harmful element, detect through sampling, the weight quota of the weight quota of carbon≤0.035%, oxygen≤0.05～0.09% in molten steel in the converter, and when liquid steel temperature reaches 1680 ℃-1720 ℃ in the converter, finish the converter smelting of molten steel, tap in the ladle, tapping process must adopt the pushing off the slag tapping;
External refining: the molten steel behind the converter smelting is sent into ladle, is to carry out refining in the LF stove with the molten steel handling in the ladle to external refining equipment, when the refining of LF stove, adopt the heating of electrode pair molten steel and in ladle, add slag making materialses such as lime and reductor aluminium simultaneously, to top slag upgrading with to the further desulfurization of molten steel and except that being mingled with, molten steel is stirred the composition and the temperature of even molten steel with steel ladle bottom argon blowing, reinforcement is discharged molten steel desulfurizing and inclusion floating, treat the free oxygen level (weight)≤0.0005% in the molten steel, in the slag of molten steel top during the content (weight)≤5% (being preferably below 2%) of ferric oxide external refining finish, change molten steel over to next process;
The RH vacuum refinement: the RH vacuum refinement is for molten steel being forced decarburization, the degassing, temperature adjustment and microalloying, in the vacuum refinement process, detect through sampling, carbon content in molten steel is less than or equal to 0.0050% (generally at 0.0010%-0.0020%), other composition in the molten steel satisfies the predefined composition requirement of steel, the temperature of molten steel satisfy the continuous caster routine water steel bar spare the time, then the RH vacuum refinement is finished, molten steel changes continuous caster over to and carries out cast steel.
Claims (3)
1. the method for a smelting suprelow carbon steel is characterized in that may further comprise the steps:
Hot metal pretreatment: adopt pretreatment unit blowing desulfurization pulvis in molten iron, when sulphur weight content in the molten iron≤0.004%, change it over to converter smelting;
Converter smelting: the molten iron after the desulfurization is carried out the oxygen blast carbon drop in converter it is smelted into molten steel, oxygen blow duration is 12 minutes-18 minutes, in converter steelmaking process, in it, add slag making materials, the weight quota of the weight quota of carbon≤0.035%, oxygen≤0.05～0.09% in molten steel in the converter, and in the ladle of tapping when liquid steel temperature reaches 1680 ℃-1720 ℃ in the converter, adopt the pushing off the slag operation in its tapping process;
External refining: is to carry out refining in the LF stove with the molten steel handling in the ladle to the external refining stove, adopt the heating of electrode pair molten steel and in ladle, add lime and reductor simultaneously, top slag modification is handled and the further desulfurization of molten steel is reached except that inclusion, molten steel is stirred the composition and the temperature of even molten steel with steel ladle bottom argon blowing, treat free oxygen weight content≤0.0005% in the molten steel, weight content≤5% of ferric oxide o'clock in the slag of molten steel top changes the vacuum refinement operation over to;
RH vacuum refinement: adopt the decarburization of RH vacuum cycle device, the degassing, with to further refining of LF stove molten steel after refining and alloying, carbon content in steel is less than or equal to 0.0050%, when the composition that each composition satisfies steel in the molten steel requires, changes molten steel over to the cast steel program.
2. method according to claim 1 is characterized in that: described sweetening agent is to be made of magnesium powder and lime powder, and the weight ratio between magnesium powder and the lime powder is 1: 2.5-3.5.
3. method according to claim 1 is characterized in that: in the described external refining step, and through the LF stove carries out the modification processing to molten steel top slag after, weight content≤2% of ferric oxide in the slag of molten steel top.
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| Application Number | Priority Date | Filing Date | Title |
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| CNA2007101592247A CN101215618A (en) | 2007-12-27 | 2007-12-27 | Method for smelting ultra-low-carbon steel |
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| CNA2007101592247A CN101215618A (en) | 2007-12-27 | 2007-12-27 | Method for smelting ultra-low-carbon steel |
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| CN101550516B (en) * | 2009-03-06 | 2011-01-05 | 攀钢集团研究院有限公司 | Method for revolving furnace smelting 45CrMnMo steel |
| CN101941021A (en) * | 2010-08-13 | 2011-01-12 | 济南钢铁股份有限公司 | Method for producing extra-deep drawing cold-rolled steel plate based on ASP process |
| CN101993974A (en) * | 2009-08-10 | 2011-03-30 | 鞍钢股份有限公司 | Method for preparing pure iron with extremely low gas content |
| CN101760581B (en) * | 2009-12-30 | 2011-04-20 | 首钢总公司 | Production process for smelting high-level low-carbon steel at low cost |
| CN101948980B (en) * | 2009-07-10 | 2012-03-21 | 攀钢集团研究院有限公司 | Method for producing industrial pure iron |
| CN102453830A (en) * | 2010-10-25 | 2012-05-16 | 攀钢集团钢铁钒钛股份有限公司 | Preparation method of cast steel |
| CN102719593A (en) * | 2011-03-29 | 2012-10-10 | 鞍钢股份有限公司 | Method for smelting ultra-low carbon steel |
| CN103160648A (en) * | 2013-03-18 | 2013-06-19 | 马钢(集团)控股有限公司 | Method of smelting ultra-low carbon steel in LF (Ladle Furnace) |
| CN103911487A (en) * | 2012-12-31 | 2014-07-09 | 攀钢集团攀枝花钢钒有限公司 | Method for smelting of ultra-low carbon steel and continuous casting method for ultra-low carbon steel |
| CN104988271A (en) * | 2015-08-07 | 2015-10-21 | 武汉钢铁(集团)公司 | Method for smelting ultra-low carbon steel with carbon lower than or equal to 20 PPm |
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| TWI576311B (en) * | 2015-10-14 | 2017-04-01 | 國立清華大學 | A molten iron-assisted method for producing aluminum nitride (aln) and facility thereof |
| CN106929630A (en) * | 2017-03-10 | 2017-07-07 | 共享铸钢有限公司 | A kind of method that EAF stoves smelt low Cr abrasion-resistant stees |
| CN107354269A (en) * | 2017-05-26 | 2017-11-17 | 内蒙古包钢钢联股份有限公司 | The method that RH complex deoxidizations produce ultra-low-carbon steel |
| CN107699654A (en) * | 2017-09-25 | 2018-02-16 | 南京钢铁股份有限公司 | A kind of smelting process of ultra-low-carbon steel desulfurization rapidly |
| CN108149133A (en) * | 2017-12-08 | 2018-06-12 | 安泰科技股份有限公司 | A kind of plus boron high-carbon, the high intensity carbon clean steel of microalloying and preparation method |
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| CN110106316A (en) * | 2019-05-14 | 2019-08-09 | 鞍钢股份有限公司 | A kind of method of duplex production carbon aluminium-killed steel |
| CN110684883A (en) * | 2019-11-18 | 2020-01-14 | 马鞍山钢铁股份有限公司 | Steelmaking method for reducing tapping temperature of vacuum decarburization steel converter |
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2007
- 2007-12-27 CN CNA2007101592247A patent/CN101215618A/en active Pending
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| CN115044820A (en) * | 2022-05-30 | 2022-09-13 | 鞍钢股份有限公司 | Smelting method of ultra-low carbon and ultra-low sulfur pure iron |
| CN115044820B (en) * | 2022-05-30 | 2023-09-26 | 鞍钢股份有限公司 | Smelting method of ultralow-carbon ultralow-sulfur pure iron |
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