CN104109734A - Molten steel refining and dephosphorizing agent and application thereof - Google Patents
Molten steel refining and dephosphorizing agent and application thereof Download PDFInfo
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- CN104109734A CN104109734A CN201410339908.5A CN201410339908A CN104109734A CN 104109734 A CN104109734 A CN 104109734A CN 201410339908 A CN201410339908 A CN 201410339908A CN 104109734 A CN104109734 A CN 104109734A
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Abstract
The invention relates to a molten steel refining and dephosphorizing agent and an application thereof and belongs to the technical field of metallurgy. The molten steel refining and dephosphorizing agent comprises the following components in parts by weight: 51-60 parts of calcium oxide, 15-20 parts of oxidized scale and 10-14 parts of sodium subjected to passivation treatment. The molten steel refining and dephosphorizing agent can be used in a molten steel refining process; by combining calcium oxide, oxidized scale and sodium subjected to passivation treatment, phosphorus can be effectively removed in the refining process, and phosphorous content of molten steel is reduced.
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 its surface quality to steel, tensile strength, stress corrosion resistant etc. have adverse influence, and it causes steel " cold short " easily at grain boundary segregation, significantly reduces the low-temperature impact toughness of steel.In recent years, along with people are more and more stricter to steel performance requirement, the phosphorus content of a lot of steel grades is had higher requirement.As a large amount of high-quality steel require finished product phosphorus content lower than 0.015%, Cryogenic Steel pipe, special deep drawing steel, tin plate require phosphorus lower than 0.010%; Some aviations, nuclear power, corrosion-resistant pipeline require finished product phosphorus lower than 0.005% with steel.Therefore, how to reduce phosphorus content in molten steel and become a difficult problem low-phosphorous, that ultra-low phosphoretic steel is produced.
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 is controlled at 0.1%～0.13%; Before converter tapping, first in ladle, pack deep dephosphorization agent into; In converter tapping process, carry out pushing off the slag control, the lower quantity of slag≤3k
g/ ton steel, and the molten steel in ladle is carried out to weak deoxidation treatment; After tapping finishes, 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.The method is processed the P content of rear molten steel lower than 0.005%, and the quantity of slag reduces more than 20% compared with other method, and the converter smelting cycle shortens more than 5%.But the method complex process, need in ladle, to add in advance deep dephosphorization agent, to Oxygen Content in Liquid Steel, control has strict requirement for this, if tapping too high oxygen level, after tapping process or tapping, may there is ladle and " blow out " phenomenon, have certain potential safety hazard, and all will in ladle, add deep dephosphorization agent and molten steel is carried out to weak deoxidation treatment 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 to realize the control to converter terminal phosphorus content by the slag making parameter of adjustment single slag process converter smelting, the method can be controlled at BOF Steelmaking Endpoint P in 0.006%, control ladle slag return P in 0.002%, alloy increases P in 0.002%, can stably manufactured the finished product phosphorus content low-phosphorous steel grade that is less than 0.010%.But the method has the following disadvantages: adopt when higher single slag process to be difficult to terminal phosphorus to be controlled in 0.006% when entering stove phosphorus content, and under tapping process the quantity of slag to be difficult to control rephosphorization of molten steel serious.
Patent CN103205536A discloses a kind of semi-steel dephosphorizing agent and semi-steel dephosphorizing method, and semi-steel dephosphorizing agent is to be made up of the lime of 35～50 parts, the iron scale of 25～45 parts and the sodium oxide of 15～25 parts by weight.Its semi-steel dephosphorizing method is in the time of tapping, semi-steel dephosphorizing agent is evenly added in the molten steel having flowed out, and the add-on of semi-steel dephosphorizing agent is controlled at 10～20k
gbetween/t half steel; After tapping completes, to molten steel bottom blowing nitrogen; After finishing, nitrogen flushing pulls out slag processing.Can effectively the phosphorus content in half steel be removed 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 the lower molten steel of phosphorus content after smelting, 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 is to reduce 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 that contains more than 90% iron.
In liquid steel refining process, because the half steel of the fluidity molten steel after converter smelting after compared with vanadium extraction is better, go out steel reinforced concrete impulsion mechanical condition better, be more conducive to the carrying out of dephosphorisation reaction, therefore must the strict content of controlling the each component of liquid steel refining dephosphorizing agent of the present invention.The CaO of 51～60 weight parts is mainly the basicity in order to improve the rear ladle top slag of tapping; And iron scale is mainly the oxidisability in order to improve slag, to cross and can cause at most molten steel temperature drop large as add-on, add-on does not reach the object that improves 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 the sodium of Passivation Treatment be mainly with molten steel in phosphorus reaction dephosphorization, excessive can the reaction of add-on too acutely causes molten steel to turn over greatly, seriously can cause the accident, as add-on poor effect at least, therefore, need be controlled at 10～14 weight parts through the sodium add-on of Passivation Treatment.
Further, preferably formed by 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 comprising the steps: after steel-making converter tapping, liquid steel refining dephosphorizing agent is added to 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.Wherein, phosphorus content when molten steel converter tapping is higher than 0.015%, obtains after refining molten steel phosphorus content for not higher than 0.010% by the method.
Also can adopt the method comprising the steps: after steel-making converter tapping, liquid steel refining dephosphorizing agent is added to ladle with steel stream, 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 when molten steel converter tapping is higher than 0.015%, obtains after refining molten steel phosphorus content for not higher than 0.008% by the method.
Can also adopt the method comprising the steps: after steel-making converter tapping, liquid steel refining dephosphorizing agent is added to ladle with steel stream, add-on is 3～4kg/t steel, and in the time of vacuum-treat, adds liquid steel refining dephosphorizing agent 2～4kg/t steel.Wherein, phosphorus content when molten steel converter tapping is higher than 0.015%, by molten steel phosphorus content after the method refining for not higher than 0.007%.
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, reduces 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 is to reduce 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 that contains more than 90% iron.
In liquid steel refining process, because the half steel of the fluidity molten steel after converter smelting after compared with vanadium extraction is better, go out steel reinforced concrete impulsion mechanical condition better, be more conducive to the carrying out of dephosphorisation reaction, therefore must the strict content of controlling the each component of liquid steel refining dephosphorizing agent of the present invention.The CaO of 51～60 weight parts is mainly the basicity in order to improve the rear ladle top slag of tapping; And iron scale is mainly the oxidisability in order to improve slag, to cross and can cause at most molten steel temperature drop large as add-on, add-on does not reach the object that improves 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 the sodium of Passivation Treatment be mainly with molten steel in phosphorus reaction dephosphorization, excessive can the reaction of add-on too acutely causes molten steel to turn over greatly, seriously can cause the accident, as add-on poor effect at least, therefore, need be controlled at 10～14 weight parts through the sodium add-on of Passivation Treatment.
Further, preferably formed by 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 comprising the steps: after steel-making converter tapping, liquid steel refining dephosphorizing agent is added to 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.Wherein, phosphorus content when molten steel converter tapping is higher than 0.015%, obtains after refining molten steel phosphorus content for not higher than 0.010% by the method.
Also can adopt the method comprising the steps: after steel-making converter tapping, liquid steel refining dephosphorizing agent is added to ladle with steel stream, 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 when molten steel converter tapping is higher than 0.015%, obtains after refining molten steel phosphorus content for not higher than 0.008% by the method.
Can also adopt the method comprising the steps: after steel-making converter tapping, liquid steel refining dephosphorizing agent is added to ladle with steel stream, add-on is 3～4kg/t steel, and in the time of vacuum-treat, adds liquid steel refining dephosphorizing agent 2～4kg/t steel.Wherein, phosphorus content when molten steel converter tapping is higher than 0.015%, by molten steel phosphorus content after the method vacuum-treat refining for not higher than 0.007%.
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, after preliminary refining finishes, obtaining molten steel phosphorus content 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, after preliminary refining finishes, obtaining molten steel phosphorus content 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, after preliminary refining finishes, obtaining molten steel phosphorus content 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, after LF refining finishes, obtaining molten steel phosphorus content 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, after LF refining finishes, obtaining molten steel phosphorus content 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), when molten steel vacuum-treat, add dephosphorizing agent ton steel 4kg liquid steel refining dephosphorizing agent, after vacuum-treat refining finishes, obtaining molten steel phosphorus content 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, after vacuum-treat refining finishes, obtaining molten steel phosphorus content 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, after preliminary refining finishes, obtaining molten steel phosphorus content is 0.012%, and when tapping molten steel seethe acutely, 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 adding a ton steel 4kg liquid steel refining dephosphorizing agent at refining process, after LF refining finishes, obtaining molten steel phosphorus content is 0.011%, and when tapping and refining add sweetening agent moment molten steel to 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), when molten steel vacuum-treat, add dephosphorizing agent ton steel 4kg liquid steel refining dephosphorizing agent, after vacuum-treat refining finishes, obtaining molten steel phosphorus content is 0.012%.When tapping and vacuum add sweetening agent moment molten steel to seethe acutely, and because the low ladle slag basicity that causes of sweetening agent CaO content is on the low side, dephosphorization effect is poor.
Claims (8)
1. liquid steel refining dephosphorizing agent, is characterized in that being made up of the component of following weight part: the calcium oxide of 51～60 parts, the iron scale of 15～20 parts and 10～14 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. liquid steel refining dephosphorizing agent according to claim 1 and 2, 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.
4. the application of the liquid steel refining dephosphorizing agent described in claim 1～3 any one in liquid steel refining.
5. the application of liquid steel refining dephosphorizing agent according to claim 4 in liquid steel refining, it is characterized in that: described liquid steel refining comprises the steps: after steel-making converter tapping, liquid steel refining dephosphorizing agent is added to 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.
6. the application of liquid steel refining dephosphorizing agent according to claim 4 in liquid steel refining, it is characterized in that: described liquid steel refining comprises the steps: after steel-making converter tapping, liquid steel refining dephosphorizing agent is added to 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.
7. the application of liquid steel refining dephosphorizing agent according to claim 4 in liquid steel refining, it is characterized in that: described liquid steel refining comprises the steps: after steel-making converter tapping, liquid steel refining dephosphorizing agent is added to ladle with steel stream, add-on is 3～4kg/t steel, and in the time of vacuum-treat, adds liquid steel refining dephosphorizing agent 2～4kg/t steel.
8. the application in liquid steel refining according to the liquid steel refining dephosphorizing agent described in claim 5～7 any one, 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 (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| 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 |
| 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 |
| JP2012012680A (en) * | 2010-07-02 | 2012-01-19 | Osaka Kohai Kk | Lime-based flux and method of manufacturing the same |
| 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 |
-
2014
- 2014-07-17 CN CN201410339908.5A patent/CN104109734B/en active Active
Patent Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| 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 |
| 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 |
| JP2012012680A (en) * | 2010-07-02 | 2012-01-19 | Osaka Kohai Kk | Lime-based flux and method of manufacturing the same |
| 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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