CN105886700B - Utilize the method for the direct alloy smelting variety steel of prepurging steel - Google Patents
Utilize the method for the direct alloy smelting variety steel of prepurging steel Download PDFInfo
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- CN105886700B CN105886700B CN201610472103.7A CN201610472103A CN105886700B CN 105886700 B CN105886700 B CN 105886700B CN 201610472103 A CN201610472103 A CN 201610472103A CN 105886700 B CN105886700 B CN 105886700B
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- C—CHEMISTRY; METALLURGY
- C21—METALLURGY OF IRON
- C21C—PROCESSING OF PIG-IRON, e.g. REFINING, MANUFACTURE OF WROUGHT-IRON OR STEEL; TREATMENT IN MOLTEN STATE OF FERROUS ALLOYS
- C21C5/00—Manufacture of carbon-steel, e.g. plain mild steel, medium carbon steel or cast steel or stainless steel
- C21C5/52—Manufacture of steel in electric furnaces
- C21C5/54—Processes yielding slags of special composition
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- C—CHEMISTRY; METALLURGY
- C21—METALLURGY OF IRON
- C21C—PROCESSING OF PIG-IRON, e.g. REFINING, MANUFACTURE OF WROUGHT-IRON OR STEEL; TREATMENT IN MOLTEN STATE OF FERROUS ALLOYS
- C21C7/00—Treating molten ferrous alloys, e.g. steel, not covered by groups C21C1/00 - C21C5/00
- C21C7/04—Removing impurities by adding a treating agent
- C21C7/072—Treatment with gases
-
- C—CHEMISTRY; METALLURGY
- C21—METALLURGY OF IRON
- C21C—PROCESSING OF PIG-IRON, e.g. REFINING, MANUFACTURE OF WROUGHT-IRON OR STEEL; TREATMENT IN MOLTEN STATE OF FERROUS ALLOYS
- C21C7/00—Treating molten ferrous alloys, e.g. steel, not covered by groups C21C1/00 - C21C5/00
- C21C7/10—Handling in a vacuum
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- Engineering & Computer Science (AREA)
- Materials Engineering (AREA)
- Metallurgy (AREA)
- Organic Chemistry (AREA)
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- Treatment Of Steel In Its Molten State (AREA)
Abstract
The method that the present invention relates to the use of the direct alloy smelting variety steel of prepurging steel, belongs to EAF steelmaking technology field.The technical problem that this method solves is to provide the method using the direct alloy smelting variety steel of prepurging steel, this method includes electric furnace steel making, LF refining and VD applications of vacuum, wherein, the electric furnace steel making controls out content of MgO≤3.5% in slag, and the LF refining time is 60~80min；VD vacuum processing times 15~20min, VD application of vacuum terminates that rear molten steel is quiet to blow the time >=12min.Using the inventive method, it can newly repair body of heater in electric furnace or change the direct alloy smelting variety steel of the 1st~3 stove steel of slag line body of heater smelting, both be suitable for steel enterprise breed structure readjustment needs, and can is that enterprise brings preferable benefit.
Description
Technical field
The method that the present invention relates to the use of the direct alloy smelting variety steel of prepurging steel, and in particular to electric furnace is newly repaiied body of heater or changed
Slag line body of heater smelts the control of prepurging steel purity of steel, belongs to EAF steelmaking technology field.
Background technology
The most common Wear mechanism of electric furnace body refractory material is to corrode, wash away, melting, peeling off and aquation, this five kinds because
Most importantly corrode and wash away in element.The carbon component of refractory material is etched due to iron oxide or oxygen, is occurred following anti-
Should：FeO+C=Fe+CO, O2+ 2C=2CO.Graphite or tar/resin reaction in the hot face of iron oxide and bricking in slag, or
Oxygen corrodes the graphite or carbon binding agent of bricking huyashi-chuuka (cold chinese-style noodles).Now the surface strength of refractory brick reduces and causes to peel off.And wash away be by
In molten steel or slag flow through refractory surface and physically wear or wash away furnace lining and result in physics damage.
When electric furnace newly repaiies body of heater or changes slag line body of heater and begin to use, because refractory material contacts with molten steel or clinker for the first time
When, CaO, SiO in clinker2, Fe, Si, Al, Mn, C in FeO and molten steel etc. penetrate into the capillary channel of refractory material, therefore
By rapid etching, the refractory surface being then etched forms one layer of fine and close sinter layer, hinders on refractory material top layer
Molten steel or clinker further permeate into the capillary channel of refractory material, and etch rate decreases.Therefore electric furnace newly repaiies body of heater
Or change the smelting of slag line body of heater the probability that is polluted by refractory material of the 1st stove molten steel it is higher.In addition, in initial stage fire resisting material of furnace body
Moisture is also absorbed by molten steel, the hydrogen content increase of molten steel.Therefore, all regulation electric furnace newly repaiies body of heater or changes slag line substantially for domestic steel enterprise
The 1st~3 stove steel (common name " prepurging steel ") that body of heater is smelted can only produce low-end product (such as straight carbon steel), and reason is exactly to produce " to wash
The refractory material being etched during stove steel " is difficult to be removed after entering molten steel, causes the hydrogen in steel, oxygen content and B, D, Ds class to be mingled with
Thing is higher, and purity of steel is poor.We were once sampled to " prepurging steel ", found hydrogen content >=4.5 × 10 in steel-6, oxygen
Content >=38 × 10-6, the grading of B, D, Ds type impurity is higher more than 2.5 grades of probability, does not possess production alloy variety steel
Condition.
As steel market in recent years is weak and the impact of bof process low cost steel billet, electric furnace can only using alloy variety steel as
Developing direction, when electric furnace newly repaiies body of heater or changes slag line body of heater, often it is forced loss of capital production low-end product (such as straight carbon steel).Cause
This, if the non-metallic inclusion and gas content of energy stability contorting " prepurging steel ", can newly repair body of heater in electric furnace or change slag line stove
Direct alloy smelting variety steel during body.
In terms of current existing technology, do not find electric furnace newly repair body of heater or change the smelting of slag line body of heater the 1st~3 stove steel it is straight
Connect the relevant report of alloy smelting variety steel.
The content of the invention
The technical problem that this method solves is to provide the method using the direct alloy smelting variety steel of prepurging steel, using the party
Method, it can newly repair body of heater in electric furnace or change the 1st~3 stove steel of slag line body of heater smelting with regard to direct alloy smelting variety steel.
The method that the present invention utilizes the direct alloy smelting variety steel of prepurging steel, including electric furnace steel making, LF refining and VD vacuum
Processing, wherein, the electric furnace steel making controls out content of MgO≤3.5wt% in slag, and the LF refining time is 60~80min；VD
Vacuum processing time 15~20min, VD application of vacuum terminates that rear molten steel is quiet to blow the time >=12min.
Preferably, vacuum≤67Pa of VD applications of vacuum.
Further, after VD applications of vacuum terminate, preferably molten steel is kept under conditions of 40~80Nl/min of argon flow amount
It is quiet to blow.
Heretofore described prepurging steel is preferably the 1st~3 stove steel that electric furnace newly repaiies body of heater or changes the smelting of slag line body of heater.
Preferably, it is 2.5~3.4wt% that the electric furnace steel making, which controls out the content of MgO in slag, during LF refining
Between be 62~78min；VD 16~18min of vacuum processing time, vacuum are 37~65Pa, and it is quiet that VD applications of vacuum terminate rear molten steel
Blow 13~17min of time.
Using the inventive method, it can newly repair body of heater at electric furnace or change the 1st~3 stove steel that slag line body of heater is smelted and directly smelt conjunction
Golden variety steel, had both been suitable for steel enterprise breed structure readjustment needs, and and can is that enterprise brings preferable benefit.With prior art phase
Than the present invention has the advantages that：
1st, this method can newly repair body of heater in electric furnace or change the direct alloy smelting kind of the 1st~3 stove steel of slag line body of heater smelting
Steel.
2nd, it at electric furnace can newly repair body of heater by this method or change the 1st~3 stove steel that slag line body of heater is smelted and produce [H] ＜ 2
×10-6, [O] ＜ 25 × 10-6Continuous casting billet, nonmetallic inclusionsin steel rating result meet standard requirement.
Embodiment
The method that the present invention utilizes the direct alloy smelting variety steel of prepurging steel, including electric furnace steel making, LF refining and VD vacuum
Processing, wherein, the electric furnace steel making controls out content of MgO≤3.5% in slag, and the LF refining time is 60~80min；VD is true
Empty 15~20min of processing time, VD applications of vacuum terminate that rear molten steel is quiet to blow the time >=12min.
Electric furnace newly repaiies body of heater or changes (mainly magnesia carbon refractory) when slag line body of heater begins to use, and smelts the 1st~3 stove
1~3 times of heat after the etch rate of refractory material is about during steel, wherein larger-size MgO particles are entered by floating
In slag, MgO particles roll up in slag.And about 2800 DEG C of MgO fusing point, fusing point are higher, with MgO increase, slag
Mobility be deteriorated therewith, delay the chemical reaction between slag steel, reduce the ability of slag dross inclusion adsorption.And size is less
Then the long period is suspended in molten steel MgO particles, and is combined into complex inclusion with Al2O3, SiO2 of steel grade etc..Therefore must be strict
Control electric furnace steel tapping when slag in MgO content.All it is mainly by stove from current control electric furnace steel tapping slag in terms of MgO technology
Content of MgO in slag is controlled 5~12%, and furnace life is improved with this.When electric furnace newly repaiies body of heater or changes slag line body of heater and begin to use, by
Do not form one layer of fine and close sinter layer also in refractory surface, though by the content of MgO control in clinker 5~
12%, the etch of refractory material at initial stage can not be slowed down, therefore should be to control field trash as main purpose.Electric furnace smelting is taken on one side
Slag charge is supplemented, flows the operator scheme of slag on one side, body of heater will be newly repaiied or changes refractory material that slag line body of heater is etched initial stage with clinker
Outflow.Found through lot of experiments, content of MgO≤3.5% can repair body of heater or change slag line stove as new in clinker using before electric furnace steel tapping
The foundation that the refractory material that body is etched initial stage is excluded substantially.
It is in increase trend to the field trash in molten steel that electric furnace, which is newly repaiied body of heater or changed when slag line body of heater smelts the 1st~3 stove steel, quilt
After the refractory material of etch enters molten steel, larger-size to be removed soon by floating, size is less, needs longer
Time could float removal.Therefore extend the time of LF refining furnace, then fully float and inhaled beneficial to the field trash in molten steel
Attached removal.Through experiment, within LF refining furnace time 80min, the field trash in molten steel increases with refining time and gradually reduced,
From not only ensure purity of steel but also do not influence rhythm of production consider, by LF refining furnace time control be 60~80min be suitable.
When electric furnace newly repaiies body of heater or changes slag line body of heater and begin to use, because puzzle joint material and refractory brick have all remained part water in itself
Part (H2O), therefore electric furnace newly repaiies body of heater or changes the 1st~3 stove steel capital of slag line body of heater smelting and the problem of hydrogenation be present.Take molten steel vacuum
The measure of (i.e. vacuum dehydrogenation) is handled, effectively prevent molten steel hydrogenation.By it was verified that VD vacuum drying ovens vacuum≤
During 67Pa, the molten steel vacuum retention time ensures that hydrogen content≤2.0ppm in steel more than 15min.But the vacuum retention time is unsuitable
Long, overlong time then increases energy consumption and production cost.Therefore 15~20min of molten steel vacuum processing time is preferably to select.
In molten steel VD applications of vacuum, because molten steel is stirred vigorously, part slag is inevitably involved in molten steel, therefore
Need to remove indrawn slag by quiet blow of molten steel.It was verified that protected under conditions of 40~80Nl/min of argon flow amount
Hold that molten steel is quiet to be blown more than time 12min, can effective cleaning molten steel.
Prepurging steel of the present invention is that electric furnace newly repaiies body of heater or changes the 1st~3 stove steel of slag line body of heater smelting.
Preferably, it is 2.5~3.4% that the electric furnace steel making, which controls out the content of MgO in slag, the LF refining time
For 62~78min；VD 16~18min of vacuum processing time, vacuum are 37~65Pa, and VD applications of vacuum terminate that rear molten steel is quiet to be blown
13~17min of time.
The steel-making step do not mentioned in the present invention is prior art, be will not be described here.
The embodiment of the present invention is further described with reference to embodiment, therefore not limited the present invention
System is among described scope of embodiments.
The new stove of body of heater the 1st of the electric furnace of embodiment 1 smelts 27MnCr production technology
The new stove of body of heater the 1st of electric furnace smelts 27MnCr steel, controls following parameter：
[1] electric furnace steel tapping [C]=0.06%, (MgO)=2.7% in slag, 1634 DEG C of tapping temperature.
[2] LF refining furnace time 75min, 1647 DEG C of tapping temperature.
[3] the vacuum 65Pa of molten steel VD stoves application of vacuum, processing time 17min.
[4] VD applications of vacuum terminate that rear molten steel is quiet to blow time 13min, argon flow amount 65Nl/min.
[5] it is cast into ∮ 280mm continuous casting billets, sampling analysis, as a result：[H]=1.1 × 10-6, [O]=20 × 10-6。
[6] non-metallic inclusion rating result is shown in Table 1 after continuous casting billet tube rolling.
The new stove of body of heater the 3rd of the electric furnace of embodiment 2 smelts 37Mn2 production technology
The new stove of body of heater the 3rd of electric furnace smelts 37Mn2 steel, controls following parameter：
[1] electric furnace steel tapping [C]=0.09%, (MgO)=3.2% in slag, 1628 DEG C of tapping temperature.
[2] LF refining furnace time 62min, 1643 DEG C of tapping temperature.
[3] the vacuum 41Pa of molten steel VD stoves application of vacuum, processing time 16min.
[4] VD applications of vacuum terminate that rear molten steel is quiet to blow time 16min, argon flow amount 60Nl/min.
[5] ∮ 350mm continuous casting billet sampling results are cast into：[H]=0.6 × 10-6, [O]=17 × 10-6。
[6] non-metallic inclusion rating result is shown in Table 1 after continuous casting billet tube rolling.
The electric furnace of embodiment 3 changes the production technology that the stove of slag line body of heater the 1st smelts X42 steel
Electric furnace changes the stove of slag line body of heater the 1st and smelts X42 steel, controls following parameter：
[1] electric furnace steel tapping [C]=0.04%, (MgO)=2.5% in slag, 1651 DEG C of tapping temperature.
[2] LF refining furnace time 67min, 1655 DEG C of tapping temperature.
[3] the vacuum 37Pa of molten steel VD stoves application of vacuum, processing time 18min.
[4] VD applications of vacuum terminate that rear molten steel is quiet to blow time 17min, argon flow amount 40Nl/min.
[5] ∮ 200mm continuous casting billet sampling results are cast into：[H]=0.8 × 10-6, [O]=24 × 10-6。
[6] non-metallic inclusion rating result is shown in Table 1 after continuous casting billet tube rolling.
The electric furnace of embodiment 4 changes the production technology that the stove of slag line body of heater the 2nd smelts L245N
Electric furnace changes the stove of slag line body of heater the 2nd and smelts L245N steel, controls following parameter：
[1] electric furnace steel tapping [C]=0.04%, (MgO)=3.4% in slag, 1649 DEG C of tapping temperature.
[2] LF refining furnace time 78min, 1657 DEG C of tapping temperature.
[3] the vacuum 52Pa of molten steel VD stoves application of vacuum, processing time 16min.
[4] VD applications of vacuum terminate that rear molten steel is quiet to blow time 13min, argon flow amount 80Nl/min.
[5] ∮ 200mm continuous casting billet sampling results are cast into：[H]=0.6 × 10-6, [O]=23 × 10-6。
[6] non-metallic inclusion rating result is shown in Table 1 after continuous casting billet tube rolling.
The new stove of body of heater the 1st of the electric furnace of embodiment 5 smelts 30Mn production technology
The new stove of body of heater the 1st of electric furnace smelts 30Mn steel, controls following parameter：
[1] electric furnace steel tapping [C]=0.06%, (MgO)=3.1% in slag, 1644 DEG C of tapping temperature.
[2] LF refining furnace time 65min, 1645 DEG C of tapping temperature.
[3] the vacuum 45Pa of molten steel VD stoves application of vacuum, processing time 17min.
[4] VD applications of vacuum terminate that rear molten steel is quiet to blow time 15min, argon flow amount 50Nl/min.
[5] ∮ 200mm continuous casting billet sampling results are cast into：[H]=0.9 × 10-6, [O]=19 × 10-6。
[6] non-metallic inclusion rating result is shown in Table 1 after continuous casting billet tube rolling.
The non-metallic inclusion rating result of table 1
Claims (3)
1. using the method for the direct alloy smelting variety steel of prepurging steel, including electric furnace steel making, LF refining and VD applications of vacuum, it is special
Sign is：
The electric furnace steel making controls out content of MgO≤3.5wt% in slag, and the LF refining time is 60~80min；At VD vacuum
Vacuum≤67Pa of reason, after VD vacuum processing times 15~20min, VD application of vacuum terminates, in 40~80Nl/ of argon flow amount
Keep that molten steel is quiet blows under conditions of min, molten steel is quiet to blow the time >=12min.
2. the method according to claim 1 using the direct alloy smelting variety steel of prepurging steel, it is characterised in that：It is described to wash
Stove steel is that electric furnace newly repaiies body of heater or changes the 1st~3 stove steel of slag line body of heater smelting.
3. the method according to claim 1 using the direct alloy smelting variety steel of prepurging steel, it is characterised in that：The electricity
It is 2.5~3.4wt% that stove steel-making, which controls out the content of MgO in slag, and the LF refining time is 62~78min；During VD applications of vacuum
Between 16~18min, vacuum is 37~65Pa, and VD applications of vacuum terminate that rear molten steel is quiet to blow 13~17min of time.
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| CN102021269A (en) * | 2010-11-25 | 2011-04-20 | 攀钢集团钢铁钒钛股份有限公司 | First furnace smelting method for new electric arc furnace |
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