CN104109734B - Liquid steel refining dephosphorizing agent and application thereof - Google Patents
Liquid steel refining dephosphorizing agent and application thereof Download PDFInfo
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Abstract
The present invention relates to liquid steel refining dephosphorizing agent and application thereof, belong to metallurgical technology field.Liquid steel refining dephosphorizing agent of the present invention, is made up of the component of following weight part: the calcium oxide of 51 ~ 60 parts, the iron scale of 15 ~ 20 parts and 10 ~ 14 parts of sodium after Passivation Treatment.Liquid steel refining dephosphorizing agent of the present invention can be used for liquid steel refining process, by the combination of the sodium after calcium oxide, iron scale and Passivation Treatment, effectively can remove phosphorus in refining process, reduces molten steel phosphorus content.
Description
Technical field
The present invention relates to liquid steel refining dephosphorizing agent and application thereof, belong to metallurgical technology field.
Background technology
Phosphorus is a kind of harmful element in most of steel, and it has adverse influence to the surface quality, tensile strength, stress corrosion resistant etc. of steel, and it is easily at grain boundary segregation, causes steel " cold short ", significantly reduces the low-temperature impact toughness of steel.In recent years, along with people require more and more stricter to steel performance, the phosphorus content of a lot of steel grade is had higher requirement.As a large amount of high-quality steel requires that finished product phosphorus content is lower than 0.015%, Cryogenic Steel pipe, special deep drawing steel, tin plate require that phosphorus is lower than 0.010%; Some aviations, nuclear power, corrosion-resistant pipeline steel require that finished product phosphorus is lower than 0.005%.Therefore, the difficult problem that phosphorus content in molten steel becomes low-phosphorous, ultra-low phosphoretic steel is produced how is reduced.
Patent documentation CN101423879 discloses smelting method of low-phosphorus steel, comprises converter smelting and ladle refining, liquid steel temperature>=1680 DEG C of its converter smelting, and in molten steel, phosphorus content is less than 0.012%, and in molten steel, oxygen activity controls 0.1% ~ 0.13%; Before converter tapping, first in ladle, load deep dephosphorization agent; Pushing off the slag control is carried out, the lower quantity of slag≤3k in converter tapping process
g/ ton steel, and weak deoxidation treatment is carried out to the molten steel in ladle; After tapping terminates, then drop into deep dephosphorization agent in ladle; Then carry out steel ladle bottom argon blowing gas agitating, finally remove the slag in ladle with ladle device for removing slag.After the method process, the P content of molten steel is lower than 0.005%, and the quantity of slag reduces more than 20% compared with other method, converter smelting cycle time more than 5%.But the method complex process, need in ladle, to add deep dephosphorization agent in advance, this controls there is strict requirement to Oxygen Content in Liquid Steel, if tapping too high oxygen level, ladle may be there is after tapping process or tapping and " blow out " phenomenon, there is certain potential safety hazard, and all will in ladle, add deep dephosphorization agent and weak deoxidation treatment be carried out to molten steel before and after tapping, the process treatment time is long, affects rhythm of production.
Patent CN101696462A discloses a kind of production method of low phosphorus steel by smelting semisteel, mainly realize the control to converter terminal phosphorus content by the slag making parameter of adjustment single slag process converter smelting, BOF Steelmaking Endpoint P can control within 0.006% by the method, control ladle slag return P within 0.002%, alloy increases P within 0.002%, can the stably manufactured finished product phosphorus content low-phosphorous steel grade that is less than 0.010%.But the method has the following disadvantages: adopt single slag process to be difficult to terminal phosphorus to control within 0.006% when entering stove phosphorus content and being higher, and under tapping process, the quantity of slag very difficult control rephosphorization of molten steel is serious.
Patent CN103205536A discloses a kind of semi-steel dephosphorizing agent and semi-steel dephosphorizing method, and semi-steel dephosphorizing agent is be made up of the sodium oxide of the lime of 35 ~ 50 parts, the iron scale of 25 ~ 45 parts and 15 ~ 25 parts by weight.Its semi-steel dephosphorizing method is when tapping, and semi-steel dephosphorizing agent evenly added in the molten steel flowed out, and the add-on of semi-steel dephosphorizing agent controls at 10 ~ 20k
gbetween/t half steel; After tapping completes, to molten steel bottom blowing nitrogen; Carry out after nitrogen flushing terminates pulling out Slag treatment.Can effectively be removed by the phosphorus content in half steel by the method, dephosphorization rate can reach more than 40%.But this dephosphorizing agent is mainly used in the converter smelting of half steel, for smelting the lower molten steel of rear phosphorus content, the dephosphorization effect in refining process is limited.
Summary of the invention
The technical problem that the present invention solves is to provide liquid steel refining dephosphorizing agent.
Liquid steel refining dephosphorizing agent of the present invention, is made up of the component of following weight part: the calcium oxide of 51 ~ 60 parts, the iron scale of 15 ~ 20 parts and 10 ~ 14 parts of sodium after Passivation Treatment.
Wherein, the object of passivation reduces speed of reaction, and the sodium after Passivation Treatment is the product that sodium Metal 99.5 obtains after physical-chemical reaction, is preferably sodium carbonate and sodium oxide.
Described iron scale is preferably the oxide compound of the iron containing more than 90%.
In liquid steel refining process, because the fluidity molten steel after converter smelting is better compared with the half steel after vanadium extraction, go out steel reinforced concrete impulsion mechanical condition better, be more conducive to the carrying out of dephosphorisation reaction, therefore must the strict content controlling each component of liquid steel refining dephosphorizing agent of the present invention.The CaO of 51 ~ 60 weight parts is mainly in order to improve the basicity of the rear ladle top slag of tapping; And iron scale is mainly in order to improve the oxidisability of slag, cross as add-on and molten steel temperature drop can be caused at most large, add-on does not reach the object improving oxidisability at least, and dephosphorization effect is not good, and therefore, the add-on of iron scale is advisable at 15 ~ 20 weight parts; Through Passivation Treatment sodium mainly with the phosphorus reaction dephosphorization in molten steel, add-on is excessive, can react and too acutely cause molten steel to turn over greatly, seriously namely can cause the accident, as add-on poor effect at least, therefore, the sodium add-on through Passivation Treatment need control at 10 ~ 14 weight parts.
Further, be preferably made up of the component of following weight part: the calcium oxide of 51 parts, the iron scale of 15 parts and 14 parts of sodium after Passivation Treatment.
The present invention also provides the application of liquid steel refining dephosphorizing agent in liquid steel refining.
Liquid steel refining can adopt the method comprised the steps: steel-making converter tapping after, liquid steel refining dephosphorizing agent is added ladle with steel stream, and add-on is 3 ~ 5kg/t steel, and after stove ar blowing refining, BOTTOM ARGON BLOWING intensity is 0.001 ~ 0.005m
3/ (mint steel), the time is not less than 8min.Wherein, phosphorus content during molten steel converter tapping is not higher than 0.015%, and after obtaining refining by the method, molten steel phosphorus content is not higher than 0.010%.
Also the method comprised the steps can be adopted: after steel-making converter tapping, liquid steel refining dephosphorizing agent is added ladle with steel stream, and add-on is 2 ~ 3kg/t steel, and molten steel enters LF refining, and adds liquid steel refining dephosphorizing agent 2 ~ 4kg/t steel at refining process.Wherein, phosphorus content during molten steel converter tapping is not higher than 0.015%, and after obtaining refining by the method, molten steel phosphorus content is not higher than 0.008%.
The method comprised the steps can also be adopted: after steel-making converter tapping, liquid steel refining dephosphorizing agent is added ladle with steel stream, and add-on is 3 ~ 4kg/t steel, and adds liquid steel refining dephosphorizing agent 2 ~ 4kg/t steel when vacuum-treat.Wherein, phosphorus content during molten steel converter tapping, not higher than 0.015%, is not higher than 0.007% by molten steel phosphorus content after the method refining.
Liquid steel refining dephosphorizing agent of the present invention, can be used for liquid steel refining process, by the combination of the sodium after calcium oxide, iron scale and Passivation Treatment, can ensure normally carrying out of reaction, and effectively remove phosphorus in refining process, reduce molten steel phosphorus content.
Embodiment
Liquid steel refining dephosphorizing agent of the present invention, is made up of the component of following weight part: the calcium oxide of 51 ~ 60 parts, the iron scale of 15 ~ 20 parts and 10 ~ 14 parts of sodium after Passivation Treatment.
Wherein, the object of passivation reduces speed of reaction, and the sodium after Passivation Treatment is the product that sodium Metal 99.5 obtains after physical-chemical reaction, is preferably sodium carbonate and sodium oxide.
Described iron scale is preferably the oxide compound of the iron containing more than 90%.
In liquid steel refining process, because the fluidity molten steel after converter smelting is better compared with the half steel after vanadium extraction, go out steel reinforced concrete impulsion mechanical condition better, be more conducive to the carrying out of dephosphorisation reaction, therefore must the strict content controlling each component of liquid steel refining dephosphorizing agent of the present invention.The CaO of 51 ~ 60 weight parts is mainly in order to improve the basicity of the rear ladle top slag of tapping; And iron scale is mainly in order to improve the oxidisability of slag, cross as add-on and molten steel temperature drop can be caused at most large, add-on does not reach the object improving oxidisability at least, and dephosphorization effect is not good, and therefore, the add-on of iron scale is advisable at 15 ~ 20 weight parts; Through Passivation Treatment sodium mainly with the phosphorus reaction dephosphorization in molten steel, add-on is excessive, can react and too acutely cause molten steel to turn over greatly, seriously namely can cause the accident, as add-on poor effect at least, therefore, the sodium add-on through Passivation Treatment need control at 10 ~ 14 weight parts.
Further, be preferably made up of the component of following weight part: the calcium oxide of 51 parts, the iron scale of 15 parts and 14 parts of sodium after Passivation Treatment.
The present invention also provides the application of liquid steel refining dephosphorizing agent in liquid steel refining.
Liquid steel refining can adopt the method comprised the steps: steel-making converter tapping after, liquid steel refining dephosphorizing agent is added ladle with steel stream, and add-on is 3 ~ 5kg/t steel, and after stove ar blowing refining, BOTTOM ARGON BLOWING intensity is 0.001 ~ 0.005m
3/ (mint steel), the time is not less than 8min.Wherein, phosphorus content during molten steel converter tapping is not higher than 0.015%, and after obtaining refining by the method, molten steel phosphorus content is not higher than 0.010%.
Also the method comprised the steps can be adopted: after steel-making converter tapping, liquid steel refining dephosphorizing agent is added ladle with steel stream, and add-on is 2 ~ 3kg/t steel, and molten steel enters LF refining, and adds liquid steel refining dephosphorizing agent 2 ~ 4kg/t steel at refining process.Wherein, phosphorus content during molten steel converter tapping is not higher than 0.015%, and after obtaining refining by the method, molten steel phosphorus content is not higher than 0.008%.
The method comprised the steps can also be adopted: after steel-making converter tapping, liquid steel refining dephosphorizing agent is added ladle with steel stream, and add-on is 3 ~ 4kg/t steel, and adds liquid steel refining dephosphorizing agent 2 ~ 4kg/t steel when vacuum-treat.Wherein, phosphorus content during molten steel converter tapping, not higher than 0.015%, is not higher than 0.007% by molten steel phosphorus content after the method vacuum-treat refining.
Below in conjunction with embodiment, the specific embodiment of the present invention is further described, does not therefore limit the present invention among described scope of embodiments.Percentage ratio in the present invention is mass percent.
Embodiment 1
Endpoint molten steel phosphorus content is 0.014%, tapping process adds a ton steel 3kg liquid steel refining dephosphorizing agent (CaO of 51 weight parts, the iron scale of 15 weight parts, the sodium of 14 weight parts after Passivation Treatment) with steel stream, and after stove ar blowing refining, BOTTOM ARGON BLOWING intensity control is at 0.003m
3/ (mint steel), the preliminary refining time is 10min, and obtaining molten steel phosphorus content after preliminary refining terminates is 0.0010%.
Embodiment 2
Endpoint molten steel phosphorus content is 0.014%, tapping process adds a ton steel 5kg liquid steel refining dephosphorizing agent (CaO of 60 weight parts, the iron scale of 20 weight parts, the sodium after Passivation Treatment of 10 weight parts) with steel stream, and after stove ar blowing refining, BOTTOM ARGON BLOWING intensity control is at 0.001m
3/ (mint steel), the preliminary refining time is 9min, and obtaining molten steel phosphorus content after preliminary refining terminates is 0.009%.
Embodiment 3
Endpoint molten steel phosphorus content is 0.011%, tapping process adds a ton steel 4kg liquid steel refining dephosphorizing agent (CaO of 55 weight parts, the iron scale of 18 weight parts, the sodium after Passivation Treatment of 14 weight parts) with steel stream, and after stove ar blowing refining, BOTTOM ARGON BLOWING intensity control is at 0.005m
3/ (mint steel), the preliminary refining time is 11min, and obtaining molten steel phosphorus content after preliminary refining terminates is 0.007%.
Embodiment 4
Endpoint molten steel phosphorus content is 0.014%, tapping process adds a ton steel 2kg liquid steel refining dephosphorizing agent (CaO for 51 weight parts with steel stream, the iron scale of 15 weight parts, the sodium after Passivation Treatment of 10 weight parts), molten steel enters LF refining, and adding a ton steel 4kg liquid steel refining dephosphorizing agent at refining process, obtaining molten steel phosphorus content after LF refining terminates is 0.007%.
Embodiment 5
Endpoint molten steel phosphorus content is 0.013%, tapping process adds a ton steel 3kg liquid steel refining dephosphorizing agent (CaO for 60 weight parts with steel stream, the iron scale of 15 weight parts, the sodium after Passivation Treatment of 14 weight parts), molten steel enters LF refining, and adding a ton steel 2kg liquid steel refining dephosphorizing agent at refining process, obtaining molten steel phosphorus content after LF refining terminates is 0.008%.
Embodiment 6
Endpoint molten steel phosphorus content is 0.014%, tapping process adds a ton steel 3kg liquid steel refining dephosphorizing agent (CaO for 51 weight parts with steel stream, the iron scale of 15 weight parts, the sodium after Passivation Treatment of 10 weight parts), during molten steel vacuum-treat, add dephosphorizing agent ton steel 4kg liquid steel refining dephosphorizing agent, obtaining molten steel phosphorus content after vacuum-treat refining terminates is 0.006%.
Embodiment 7
Endpoint molten steel phosphorus content is 0.015%, tapping process adds a ton steel 4kg liquid steel refining dephosphorizing agent (CaO for 60 weight parts with steel stream, the iron scale of 15 weight parts, the sodium after Passivation Treatment of 14 weight parts), molten steel enters LF refining, and adding a ton steel 2kg liquid steel refining dephosphorizing agent at refining process, obtaining molten steel phosphorus content after vacuum-treat refining terminates is 0.006%.
Comparative example 1
Endpoint molten steel phosphorus content is 0.014%, tapping process adds a ton steel 3kg liquid steel refining dephosphorizing agent (lime of 50 weight parts, the iron scale of 25 weight parts, the sodium oxide of 25 weight parts) with steel stream, and after stove ar blowing refining, BOTTOM ARGON BLOWING intensity control is at 0.003m
3/ (mint steel), the preliminary refining time is 10min, and obtaining molten steel phosphorus content after preliminary refining terminates is 0.012%, and during tapping, molten steel seethes acutely, and part molten steel overflows ladle.
Comparative example 2
Endpoint molten steel phosphorus content is 0.014%, tapping process adds a ton steel 2kg liquid steel refining dephosphorizing agent (CaO for 50 weight parts with steel stream, the iron scale of 25 weight parts, the sodium oxide of 25 weight parts), molten steel enters LF refining, and add a ton steel 4kg liquid steel refining dephosphorizing agent at refining process, obtaining molten steel phosphorus content after LF refining terminates is 0.011%, and tapping time and refining add sweetening agent moment molten steel seethe acutely.
Comparative example 3
Endpoint molten steel phosphorus content is 0.014%, tapping process adds a ton steel 3kg liquid steel refining dephosphorizing agent (CaO for 35 weight parts with steel stream, the iron scale of 45 weight parts, the sodium oxide of 20 weight parts), during molten steel vacuum-treat, add dephosphorizing agent ton steel 4kg liquid steel refining dephosphorizing agent, obtaining molten steel phosphorus content after vacuum-treat refining terminates is 0.012%.During tapping and vacuum add sweetening agent moment molten steel seethe acutely, and due to the low ladle slag basicity that causes of sweetening agent CaO content on the low side, dephosphorization effect is poor.
Claims (7)
1. liquid steel refining dephosphorizing agent, is characterized in that being made up of the component of following weight part: the calcium oxide of 51 parts, the iron scale of 15 parts and 14 parts of sodium after Passivation Treatment.
2. liquid steel refining dephosphorizing agent according to claim 1, is characterized in that: the sodium after Passivation Treatment is sodium carbonate or sodium oxide.
3. the application of liquid steel refining dephosphorizing agent in liquid steel refining described in claim 1 or 2.
4. the application of liquid steel refining dephosphorizing agent according to claim 3 in liquid steel refining, it is characterized in that: after described liquid steel refining comprises the steps: steel-making converter tapping, liquid steel refining dephosphorizing agent is added ladle with steel stream, add-on is 3 ~ 5kg/t steel, and after stove ar blowing refining, BOTTOM ARGON BLOWING intensity is 0.001 ~ 0.005m
3/ (mint steel), the time is not less than 8min.
5. the application of liquid steel refining dephosphorizing agent according to claim 3 in liquid steel refining, it is characterized in that: after described liquid steel refining comprises the steps: steel-making converter tapping, liquid steel refining dephosphorizing agent is added ladle with steel stream, add-on is 2 ~ 3kg/t steel, molten steel enters LF refining, and adds liquid steel refining dephosphorizing agent 2 ~ 4kg/t steel at refining process.
6. the application of liquid steel refining dephosphorizing agent according to claim 3 in liquid steel refining, it is characterized in that: after described liquid steel refining comprises the steps: steel-making converter tapping, liquid steel refining dephosphorizing agent is added ladle with steel stream, add-on is 3 ~ 4kg/t steel, and adds liquid steel refining dephosphorizing agent 2 ~ 4kg/t steel when vacuum-treat.
7. the application of liquid steel refining dephosphorizing agent in liquid steel refining according to any one of claim 4 ~ 6, is characterized in that: the molten steel phosphorus content after steel-making converter tapping is not higher than 0.015wt%.
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Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101104876A (en) * | 2006-12-07 | 2008-01-16 | 首钢总公司 | Method for producing ultra-low phosphoretic steel by molten steel dephosphorising outside furnace |
| CN103205536A (en) * | 2013-04-26 | 2013-07-17 | 攀钢集团攀枝花钢铁研究院有限公司 | Semi-steel dephosphorizing agent and semi-steel dephosphorizing method |
| CN103540711A (en) * | 2013-10-23 | 2014-01-29 | 攀钢集团攀枝花钢铁研究院有限公司 | Method for simultaneously removing sulfur and phosphorus from semi-steel |
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| Publication number | Priority date | Publication date | Assignee | Title |
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| JPH11172314A (en) * | 1997-12-04 | 1999-06-29 | Nippon Steel Corp | Method for dephosphorizing and desulfurizing molten iron |
| JP2002285217A (en) * | 2001-03-23 | 2002-10-03 | Kobe Steel Ltd | Dephosphorizing agent and desulfurizing agent for molten iron and molten steel |
| JP5525939B2 (en) * | 2010-07-02 | 2014-06-18 | 大阪鋼灰株式会社 | Lime-based flux and its manufacturing method |
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Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101104876A (en) * | 2006-12-07 | 2008-01-16 | 首钢总公司 | Method for producing ultra-low phosphoretic steel by molten steel dephosphorising outside furnace |
| CN103205536A (en) * | 2013-04-26 | 2013-07-17 | 攀钢集团攀枝花钢铁研究院有限公司 | Semi-steel dephosphorizing agent and semi-steel dephosphorizing method |
| CN103540711A (en) * | 2013-10-23 | 2014-01-29 | 攀钢集团攀枝花钢铁研究院有限公司 | Method for simultaneously removing sulfur and phosphorus from semi-steel |
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