CN104060045B - A kind of vanadium-titanium-iron-water smelts the method for the low carbon IF steel of hypoxia - Google Patents
A kind of vanadium-titanium-iron-water smelts the method for the low carbon IF steel of hypoxia Download PDFInfo
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Abstract
The invention discloses a kind of method that vanadium-titanium-iron-water smelts the low carbon IF steel of hypoxia, the method comprises the following steps: 1) is blended into by hot metal containing V-Ti in No. 1 converter, carries out extraction smelting of vanadium；2) half steel obtained after vanadium extraction is carried out desulfurization process；3) half steel obtained after desulfurization is carried out oxygen blast slag making, then carry out slag-stopping tapping, obtain the first molten steel；4) described first molten steel is carried out LF stove refine, obtain the second molten steel；5) make described second molten steel enter RH and process station, under vacuum condition, carry out decarburization deoxidation treatment；6) in the molten steel obtained after deoxidation treatment, add the second slag adjusting agent in aluminum, obtain the 3rd molten steel, then described 3rd molten steel is carried out continuous casting.The method is while effectively extracting vanadium resource, and connected applications slag adjusting agent can produce the IF steel of hypoxia low-carbon (LC).
Description
Technical field
The present invention relates to a kind of method that vanadium-titanium-iron-water smelts the low carbon IF steel of hypoxia.
Background technology
IF steel is widely used in car panel, and in order to meet the performance requirement of IF steel, it is desirable to its carbon component is of a sufficiently low, special requirement T [O] (oxygen content)≤0.0020% and steel are pure, have bigger difficulty in actual smelting process.
CN101760583A discloses a kind of method controlling impurity in ultra low carbon IF steel, and the method is mainly by 1) determine the span of control step of converter terminal C, T and a [O] (molten steel oxygen activity)；2) ladle top slag modifying process step；3) step of RH endpoint molten steel T [O] is reduced；4) in continuous casting, bag uses double-deck coverture to carry out the step and 5 of molding casting) use the step of stopper gon technics to control the content of impurity in IF steel.Although this invention provides the production technology of ultra low carbon IF steel, but can not reach the purpose that in the IF steel controlling to produce, carbon oxygen content is low.
CN102108430A discloses a kind of ultra-low-carbon steel steel slag modification agent and Adding Way thereof, turbulence level when this invention is by adding steel slag modification agent to reach to alleviate the cast of IF steel in ultra-low-carbon steel production process, reduce IF steel slag oxidisability, reduce molten steel in casting process produced secondary oxidation, avoid nozzle blocking, improve the pourability of molten steel and guarantee the purpose of quality of molten steel.But, extra effect can not be brought when this invention is by adding steel slag modification agent and reaching above-mentioned purpose, it is thus impossible to be reached for meeting the carbon required by the performance requirement of IF steel, oxygen content, thus cannot be used for producing the low carbon IF steel of hypoxia.
Summary of the invention
It is an object of the invention to provide a kind of method that vanadium-titanium-iron-water smelts the low carbon IF steel of hypoxia, the method is by using vanadium-bearing hot metal as raw material, while effectively extracting vanadium resource, connected applications slag adjusting agent also controls the oxidisability of ladle slag in IF steel production process, to produce the IF steel of hypoxia low-carbon (LC).
To achieve these goals, the invention provides a kind of method that vanadium-titanium-iron-water smelts the low carbon IF steel of hypoxia, the method comprises the following steps:
1) hot metal containing V-Ti is blended in No. 1 converter, under oxygen supply condition, in converter, is sequentially added into oxides-containing iron and magnesia carries out extraction smelting of vanadium；
2) half steel obtained after vanadium extraction is carried out desulfurization process；
3) half steel obtained after desulfurization is blended in No. 2 converters, in converter, adds slag making materials carry out oxygen blast slag making, then carry out slag-stopping tapping, and after slag-stopping tapping, on the top of the slag of gained molten steel, add the first slag adjusting agent in aluminum, obtain the first molten steel；
4) described first molten steel is carried out LF stove refine, obtain the second molten steel；
5) make described second molten steel enter RH and process station, start evacuation and control lift gas flow, carrying out decarburization and deoxidation treatment the most successively；
6) in the molten steel obtained after deoxidation treatment, add the second slag adjusting agent in aluminum, obtain the 3rd molten steel, then described 3rd molten steel is carried out continuous casting.
In the vanadium-titanium-iron-water of present invention offer smelts the method for the low carbon IF steel of hypoxia, by using vanadium-bearing hot metal as raw material, can be while effectively extracting vanadium resource, connected applications slag adjusting agent also controls the oxidisability of ladle slag in IF steel production process, is of value to the IF steel producing hypoxia low-carbon (LC).
Other features and advantages of the present invention will be described in detail in detailed description of the invention part subsequently.
Accompanying drawing explanation
Fig. 1 is the process chart that the vanadium-titanium-iron-water that the present invention provides smelts the method for the low carbon IF steel of hypoxia.
Detailed description of the invention
Hereinafter the detailed description of the invention of the present invention is described in detail.It should be appreciated that detailed description of the invention described herein is merely to illustrate and explains the present invention, it is not limited to the present invention.
A of the present invention [O] is the concentration of free oxygen in molten steel；Described T [O] is the concentration of total oxygen in molten steel, and it includes oxygen contained in free oxygen and oxide；" gas " in described control lift gas flow is " argon "；Described " vacuum " is absolute pressure；Described " molten iron " is ferrous metal liquation title before No. 1 converter tapping；Described " half steel " be molten metal after No. 1 converter tapping to the title before No. 2 converter tappings；Described " molten steel " is molten metal title after No. 2 converter tappings.
A kind of vanadium-titanium-iron-water of the present invention is smelted the method for the low carbon IF steel of hypoxia and can be operated by process chart as shown in Figure 1, in 1# converter, i.e. carry out extraction smelting of vanadium, then go out converter and use winding-up or KR method to carry out desulfurization, dephosphorization and first step decarburization is carried out subsequently into 2# converter, then slag-stopping tapping, and during slag-stopping tapping, add ladle dreg modifying agent (being of the present invention containing aluminum slag adjusting agent), in proceeding to LF stove again, heat temperature raising carries out refine, then tap after proceeding to RH application of vacuum and carrying out second step decarburization and deoxidation, and in tapping process, again add ladle dreg modifying agent, and carry out continuous casting to produce continuous casting billet.
The invention provides a kind of method that vanadium-titanium-iron-water smelts the low carbon IF steel of hypoxia, the method comprises the following steps:
1) hot metal containing V-Ti is blended in No. 1 converter, under oxygen supply condition, in converter, is sequentially added into oxides-containing iron and magnesia carries out extraction smelting of vanadium；
2) half steel obtained after vanadium extraction is carried out desulfurization process；
3) half steel obtained after desulfurization is blended in No. 2 converters, in converter, adds slag making materials carry out oxygen blast slag making, then carry out slag-stopping tapping, and after slag-stopping tapping, on the top of the slag of gained molten steel, add the first slag adjusting agent in aluminum, obtain the first molten steel；
4) described first molten steel is carried out LF stove refine, obtain the second molten steel；
5) make described second molten steel enter RH and process station, start evacuation and control lift gas flow, carrying out decarburization and deoxidation treatment the most successively；
6) in the molten steel obtained after deoxidation treatment, add the second slag adjusting agent in aluminum, obtain the 3rd molten steel, then described 3rd molten steel is carried out continuous casting.
In converter of the present invention, oxygen supply condition includes that employing arranges oxygen rifle and realizes, and oxygen lance position is 1.5-2.5m, and described rifle position is the liquid steel level distance to oxygen rifle muzzle.
Under preferable case, in the step 1) of the method for the invention, in converter, add oxides-containing iron and magnesia carry out the method for extraction smelting of vanadium and may include that at oxygen-supplying amount per minute be 20000-25000Nm3Under conditions of, in converter extracting vanadium, add oxides-containing iron in continuing oxygen supply 1-3 minute, add magnesia in continuing 3-5 minute backward converter extracting vanadium of oxygen supply and carry out vanadium extraction.
Under preferable case, slag making materials in the step 3) of the method for the invention can be active lime, quartz sand, dolomitic lime and sludge ball of steel smelting, and the addition of active lime be 15-20kg/ ton half steel, the addition of quartz sand be 10-15kg/ ton half steel, the addition of dolomitic lime be the addition of 10-15kg/ ton half steel and sludge ball of steel smelting be 2-3kg/ ton half steel.In the case of Jin Yibuyouxuan, described slag making materials all adds in the 0-8min after oxygen rifle starts oxygen supply.Wherein, on the basis of the addition of described slag making materials is the total amount of the half steel after desulfurization.
Preferably, in stove, add the dolomitic lime of 4-6kg/ ton half steel after slag making materials adds 3-8min in the step 3) of the method for the invention, and utilize argon to blow stirring 1-3min again.Wherein, on the basis of the addition of described dolomitic lime is the total amount of the half steel after desulfurization.
Under preferable case, the step 2 in the method for the invention) in the method that processes of desulfurization can be composite blowing doctor treatment or KR doctor treatment.
Preferably, described composite blowing sulfur method includes that the composite blowing time is 30-40min；Desulfurizing agent is deactivating magnesium powder and Calx, and lime consumption amount is 4.0-6.0kg/ ton half steel；Deactivating magnesium powder consumption is 1.2-1.5kg/ ton half steel.Described KR method includes that mixing time is 40-50min；Desulfurizing agent is deactivating magnesium powder and Calx, and lime consumption amount is 4.0-6.0kg/ ton half steel；Deactivating magnesium powder consumption is 1.2-1.5kg/ ton half steel.Wherein, on the basis of the addition of described desulfurizing agent is the total amount of the half steel after desulfurization.
Under preferable case, when carrying out slag-stopping tapping in the step 3) of the method for the invention, tapping process adds in the ladle containing molten steel at least one in mid-carbon fe-mn 2-4kg/ ton molten steel, active lime 4-8kg/ ton molten steel and fluorite 0.5-2kg/ ton molten steel.Wherein, on the basis of the addition of described mid-carbon fe-mn, active lime and fluorite is the total amount of the half steel after desulfurization.
Under preferable case, described in the step 3) of the method for the invention, first containing containing 25-40 weight %Al in aluminum slag adjusting agent2O3, 30-45 weight %CaO and 30-45 weight %Al, the described first addition containing aluminum slag adjusting agent can be 1-3kg/ ton molten steel.Wherein, the described first slag adjusting agent addition in aluminum is on the basis of the total amount of the first molten steel.
Under preferable case, in the step 3) of the method for the invention, the temperature of the first molten steel of gained is 1600-1630 DEG C, on the basis of the total amount of the first molten steel, being mainly composed of of described first molten steel: 0.02-0.06 weight %C, 0.15-0.25 weight %Mn, 0.005-0.015 weight %P, 0.001-0.015 weight %S, 0.030-0.080 weight %a [O], Fe and inevitable impurity.
Under preferable case, the step 4) of the method for the invention is refined to temperature in LF stove and is 1630-1650 DEG C.
Under preferable case, in the step 5) of the method for the invention, the operation carrying out decarburization and deoxidation treatment the most successively includes: the second measuring temp of molten steel entering RH process station is determined oxygen, determines oxygen demand during molten steel decarburization according to the carbon oxygen relation recorded.If carbon content is more than oxygen activity, then needing to carry out oxygen decarburization, wherein blowing oxygen quantity can be carried out the selection of routine by those skilled in the art according to phosphorus content.Such as, when No. 2 converters producing IF steel are 210 tons of converters, the blowing oxygen quantity in oxygen decarburization operation can calculate according to following formula (1).After oxygen blast completes, quickly reduce vacuum, within ensureing, in 3min, vacuum is reduced to 100Pa, then under conditions of vacuum is within 100Pa, process molten steel 1-15min, (meet IF carbon content of steel to require) when sample analysis carbon content is for≤0.003%, carrying out thermometric again and determine oxygen, and carry out deoxidation according to the second oxygen activity addition aluminum shot obtained, wherein aluminum shot addition can be carried out the selection of routine by those skilled in the art according to the second oxygen activity.Such as, when No. 2 converters producing IF steel are 210 tons of converters, aluminum shot addition can calculate according to following formula (2).
Formula (1): blowing oxygen quantity (Nm3)=1.2 × [C] × W；
Formula (2): aluminum shot addition (kg)=1.4 × a [O] × W；
Wherein, W is the weight of the second molten steel, and unit is kg；[C] is for needing the carbon content reduced；A [O] is the second oxygen activity of molten steel.
In the case of Jin Yibuyouxuan, in the step 5) of the method for the invention, the method controlling lift gas flow is timing when evacuation starts, in 0-3min, lift gas flow is 1600-1800NL/min, in 4-18min, lift gas flow is that at the end of 2000-2500NL/min, 19min-RH process, lift gas flow is 1800-2000NL/min.
Under preferable case, in the step 5) of the method for the invention, when gas flow to be hoisted is 2000-2500NL/min, vacuum is 60-300Pa, carry out deoxidation treatment, the method of described deoxidation treatment includes adding aluminum shot deoxidizer in molten steel, and the addition of described aluminum shot deoxidizer is 0.31-0.51kg/ ton molten steel.And after deoxidation terminates, in molten steel, preferably add alloyed feedstock 0.1-6kg/ ton molten steel, at least one in manganese metal and middle carbon duriron of described alloyed feedstock.Wherein, the addition of described alloyed feedstock is on the basis of the total amount of the second molten steel.
Under preferable case, in the step 6) of the method for the invention, described second containing containing 25-40 weight %Al in aluminum slag adjusting agent2O3, 30-45 weight %CaO and 30-45 weight %Al, the described second addition containing aluminum slag adjusting agent is 0.8-1.2kg/ ton molten steel.Wherein, the described second addition containing aluminum slag adjusting agent is on the basis of the total amount of the second molten steel.
Under preferable case, in the step 6) of the method for the invention, described in molten steel, addition second is containing also including after the operation of aluminum slag adjusting agent the ladle of splendid attire molten steel is carried out BOTTOM ARGON BLOWING process, and described BOTTOM ARGON BLOWING flow is 50-150NL/min, and argon blowing time is 8-20min.
A preferred embodiment of the invention, the method producing the low carbon IF steel of hypoxia comprises the following steps:
1) hot metal containing V-Ti is blended in No. 1 converter, oxygen rifle is set, and oxygen lance position is 1.5-2.5m, is 20000-25000Nm at oxygen-supplying amount per minute3Under conditions of, in converter, add oxides-containing iron in continuing oxygen supply 1-3 minute, add magnesia in continuing oxygen supply backward converter in 3-5 minute and carry out vanadium extraction.
2) use composite blowing doctor treatment or KR doctor treatment that the half steel obtained after vanadium extraction is carried out desulfurization process.Described composite blowing sulfur method includes that the composite blowing time is 30-40min；Desulfurizing agent is deactivating magnesium powder and Calx, and lime consumption amount is 4.0-6.0kg/ ton half steel；Deactivating magnesium powder consumption is 1.2-1.5kg/ ton half steel.Described KR method includes that mixing time is 40-50min；Desulfurizing agent is deactivating magnesium powder and Calx, and lime consumption amount is 4.0-6.0kg/ ton half steel；Deactivating magnesium powder consumption is 1.2-1.5kg/ ton half steel.
3) half steel obtained after desulfurization is blended in No. 2 converters, in converter, adds slag making materials carry out oxygen blast slag making.Described slag making materials is active lime, quartz sand, dolomitic lime and sludge ball of steel smelting, and the addition of active lime be 15-20kg/ ton half steel, the addition of quartz sand be 10-15kg/ ton half steel, the addition of dolomitic lime be the addition of 10-15kg/ ton half steel and sludge ball of steel smelting be 2-3kg/ ton half steel.In the case of Jin Yibuyouxuan, described slag making materials all adds in the 0-8min after oxygen rifle starts oxygen supply.Slag making materials adds the dolomitic lime of 4-6kg/ ton half steel in stove after adding 3-8min, and utilizes argon to blow stirring 1-3min again.Then carry out slag-stopping tapping, tapping process adds in the ladle containing molten steel at least one in mid-carbon fe-mn 2-4kg/ ton molten steel, active lime 4-8kg/ ton molten steel and fluorite 0.5-2kg/ ton molten steel.And after slag-stopping tapping, on the top of the slag of gained molten steel, add the first slag adjusting agent in aluminum, and obtain the first molten steel, described first containing containing 25-40 weight %Al in aluminum slag adjusting agent2O3, 30-45 weight %CaO and 30-45 weight %Al, the described first addition containing aluminum slag adjusting agent can be 1-3kg/ ton molten steel.The temperature of described first molten steel is 1600-1630 DEG C, on the basis of the total amount of the first molten steel, being mainly composed of of first molten steel: 0.02-0.06 weight %C, 0.15-0.25 weight %Mn, 0.005-0.015 weight %P, 0.001-0.015 weight %S, 0.030-0.080 weight %a [O], Fe and inevitable impurity.
4) described first molten steel is carried out LF stove refine, obtain the second molten steel.
5) make described second molten steel enter RH and process station, start evacuation and control lift gas flow, carrying out decarburization and deoxidation treatment the most successively；
The operation carrying out decarburization and deoxidation treatment the most successively includes: the second measuring temp of molten steel entering RH process station is determined oxygen, determines oxygen demand during molten steel decarburization according to the carbon oxygen relation recorded.If carbon content is more than oxygen activity, then needing to carry out oxygen decarburization, wherein blowing oxygen quantity can be carried out the selection of routine by those skilled in the art according to phosphorus content.Such as, when No. 2 converters producing IF steel are 210 tons of converters, the blowing oxygen quantity in oxygen decarburization operation can calculate according to following formula (1).After oxygen blast completes, quickly reduce vacuum, within ensureing, in 3min, vacuum is reduced to 100Pa, then under conditions of vacuum is within 100Pa, process molten steel 1-15min, (meet IF carbon content of steel to require) when sample analysis carbon content is for≤0.003%, carrying out thermometric again and determine oxygen, and carry out deoxidation according to the second oxygen activity addition aluminum shot obtained, wherein aluminum shot addition can be carried out the selection of routine by those skilled in the art according to the second oxygen activity.Such as, when No. 2 converters producing IF steel are 210 tons of converters, aluminum shot addition can calculate according to following formula (2).
Formula (1): blowing oxygen quantity (Nm3)=1.2 × [C] × W；
Formula (2): aluminum shot addition (kg)=1.4 × a [O] × W；
Wherein, W is the weight of the second molten steel, and unit is kg；[C] is for needing the carbon content reduced；A [O] is the second oxygen activity of molten steel.
The method of described lift gas flow is timing when evacuation starts, in 0-3min, lift gas flow is 1600-1800NL/min, in 4-18min, lift gas flow is that at the end of 2000-2500NL/min, 19min-RH process, lift gas flow is 1800-2000NL/min；
The opportunity of described deoxidation treatment be gas flow to be hoisted be 2000-2500NL/min, when vacuum is 60-300Pa.The method of described deoxidation treatment includes adding aluminum shot deoxidizer in molten steel, and the addition of described aluminum shot deoxidizer is 0.31-0.51kg/ ton molten steel.And after deoxidation terminates, in molten steel, add alloyed feedstock 0.1-6kg/ ton molten steel, at least one in mid-carbon fe-mn and ferrosilicon of described alloyed feedstock.
6) in the molten steel obtained after deoxidation treatment, add the second slag adjusting agent in aluminum, obtain the 3rd molten steel, the ladle containing the 3rd molten steel is carried out BOTTOM ARGON BLOWING process, then described 3rd molten steel is carried out continuous casting；
Described second is identical containing aluminum slag adjusting agent and the first slag adjusting agent composition in aluminum, and the second addition containing aluminum slag adjusting agent is 0.8-1.2kg/ ton molten steel.Described BOTTOM ARGON BLOWING flow is 50-150NL/min, and argon blowing time is 8-20min.
Hereinafter will be described the present invention by embodiment.Raw material used in following example is purchased from Panzhihua Steel City Group Co., Ltd. in case of no particular description, and concrete composition is:
The composition of mid-carbon fe-mn is: the Mn and the Fe of 21 weight % of 77 weight %, and remaining is impurity.
The composition of middle carbon duriron is: the Si and the Fe of 21 weight % of 78 weight %, and remaining is impurity.
The composition of carbon dust is: the C of 94 weight %, the ash of 3.5 weight %, the sulfur of 0.15 weight %, the volatile matter of 1.1 weight % and the water of 0.5 weight %, and granularity is 3-15mm.
The composition of aluminum shot is: the Al of 99.9 weight %, and remaining is trace element and impurity.
Embodiment 1
With hot metal containing V-Ti as raw material, it is mainly composed of: 4.03 weight %C, 0.26% weight V, 0.18% weight Mn, 0.071 weight %S, 0.072 weight %P, 0.22 weight %Si, 0.16 weight %Ti and a small amount of inevitably impurity；This molten iron is blended into 210t blowing vanadium extracting bessemerize, the amount of being blended into is 238t, then in converter extracting vanadium, add coolant, and use 339 oxygen rifles to carry out oxygen supply to blow vanadium, in the 3min blowing vanadium, in stove, add 2t iron scale, after oxygen supply 4.5min, adding 300kg magnesia in stove and carry out residue adjustment, then oxygen supply carries out pushing off the slag for 40 seconds and goes out half steel and vanadium slag, blowing end point temperature is 1437 DEG C.Half composition of steel obtained is: 3.41 weight %C, 0.07 weight %Mn, 0.065 weight %P, 0.067 weight %S, 0.027 weight %V, surplus is Fe and inevitable impurity.
Half steel after vanadium extraction is delivered to desulfurization station and carries out desulfurization, use KR method desulfurization.Desulfurization time is 38min；Desulfurizing agent is deactivating magnesium powder and Calx, and lime consumption amount is 5.5kg/ ton half steel；Deactivating magnesium powder consumption is 1.35kg/ ton half steel.Half composition of steel obtained after desulfurization is: 3.36 weight %C, 0.06 weight %Mn, 0.062 weight %P, 0.003 weight %S, 0.026 weight %V, surplus is Fe and inevitable impurity.
Half steel after desulfurization is blended into 210t blow again steel converter blowing, the amount of being blended into is 235t, and use 536 oxygen rifles to carry out oxygen supply slag making dephosphorization decarburization, starting oxygen blown while, carry out steelmaking slagging, slag making materials active lime, quartz sand, dolomitic lime and sludge ball of steel smelting is added in stove, and open blow oxygen supply 6min in slag making materials is all added, the addition of slag making materials active lime, quartz sand, dolomitic lime and sludge ball of steel smelting is respectively 18kg/ ton half steel, 11kg/ ton half steel, 13.5kg/ ton half steel and 2.2kg/ ton half steel；During oxygen supply time 874 seconds, oxygen feeding stop promotes oxygen rifle, now converter slag basicity is 3.1, obtain the molten steel that temperature is 1687 DEG C, the main component of molten steel: 0.036 weight %C, 0.06 weight %Mn, 0.007 weight %P, 0.0024 weight %S, the a [O] of 0.083 weight %, surplus is Fe and inevitable impurity.In stove, the dolomitic lime of 4.5kg/ ton half steel is added after 4min, argon is utilized to blow stirring 2min again, carry out slag-stopping tapping, in ladle, mid-carbon fe-mn 2.8kg/ ton molten steel is added in tapping process, active lime 5.0kg/ ton molten steel, adds the first slag adjusting agent 3kg/ ton molten steel in aluminum on the ladle top of the slag after having gone out steel.Obtaining 215 tons of first molten steel of alloying, temperature is 1601 DEG C, and its composition is 0.008 weight %P, 0.0036 weight %S, 0.034 weight %C, 0.151 weight %Mn, 0.075 weight %a [O], and surplus is Fe and inevitable impurity.
First molten steel is sent to LF process again, by molten steel by LF stove electrical heating and refine.When ladle is to LF electrical heating, after the process time is 25min, stops heating, obtain the second molten steel.By the second molten steel departures after soft blow argon 5min, LF out-station temperature is 1641 DEG C.
RH application of vacuum delivered to by the second molten steel after being processed by LF, and now temperature is 1621 DEG C, and carbon content is 0.035 weight %, and a [O] is 0.084 weight %, it is not necessary to oxygen blast.Starting evacuation, lift gas (argon) flow is 1600NL/min.3min final vacuum degree is reduced to 290Pa, adjusts lift gas (argon) flow to 2500NL/min, vacuum be the process time of 290Pa be 12min；After processing 12min, keeping vacuum, recording oxygen activity is 0.021 weight %, and then in vacuum chamber, molten steel adds aluminum shot 0.31kg/ ton molten steel, carries out deoxidation.After deoxidation aluminum shot adds 2min, in vacuum chamber, add ferrosilicon 1.5kg/ ton molten steel and manganese metal 0.375kg/ ton molten steel, after ferrosilicon and manganese metal add, adjust lift gas (argon) flow to 1800NL/min, after continuing with 7min, vacuum breaker, RH process terminates.In ladle, the top of the slag adds the second slag adjusting agent 1kg/ ton molten steel in aluminum, the 3rd molten steel is obtained after argon flow amount BOTTOM ARGON BLOWING 16min of ladle employing 80NL/min, by the 3rd molten steel departures, 3rd molten steel composition is 0.010 weight %P, 0.004 weight %S, 0.0022 weight %C, and surplus is Fe and inevitable impurity.Then ladle is sent to continuous casting.
By employing continuous casting protection pouring Technology, the 3rd molten steel in this ladle is i.e. obtained section is 200mm × 1080mm hypoxia low carbon IF steel strand product.
The continuous casting billet sample analysis produced is understood, its T [O] average out to 0.0017 weight %, carbon content average out to 0.0029 weight %.
Embodiment 2
With hot metal containing V-Ti as raw material, it is mainly composed of: 4.12 weight %C, 0.25 weight %V, 0.16 weight %Mn, 0.071 weight %S, 0.089 weight %P, 0.17 weight %Si, 0.16 weight %Ti and a small amount of inevitably impurity, this molten iron is blended into 210t blowing vanadium extracting bessemerize, the amount of being blended into is 238t, then in converter extracting vanadium, add coolant, and use 339 oxygen rifles to carry out oxygen supply to blow vanadium, in the 3min blowing vanadium, 2.5t iron scale is added in stove, after oxygen supply 4.6min, in stove, add 280kg magnesia carry out residue adjustment, oxygen supply carries out pushing off the slag for 55 seconds and goes out half steel and vanadium slag again, blowing end point temperature is 1445 DEG C.Half composition of steel obtained is: 3.71 weight %C, 0.05 weight %Mn, 0.082 weight %P, 0.071 weight %S, 0.026 weight %V, surplus is Fe and inevitable impurity.
Half steel after vanadium extraction being delivered to desulfurization station and carries out desulfurization, use KR method desulfurization, mixing time is 42min；Desulfurizing agent is deactivating magnesium powder and Calx, and lime consumption amount is 5.8kg/ ton half steel；Deactivating magnesium powder consumption is 1.42kg/ ton half steel.Half composition of steel obtained after desulfurization is: 3.7 weight %C, 0.04 weight %Mn, 0.085 weight %P, 0.001 weight %S, 0.022 weight %V and inevitable impurity.
Half steel after desulfurization is blended into 210t blow again steel converter blowing, the amount of being blended into is 235t, and use 536 oxygen rifles to carry out oxygen supply slag making dephosphorization decarburization, starting oxygen blown while, carry out steelmaking slagging, slag making materials active lime, quartz sand, dolomitic lime and sludge ball of steel smelting is added in stove, and open blow oxygen supply 7min in slag making materials is all added, the addition of slag making materials active lime, quartz sand, dolomitic lime and sludge ball of steel smelting is respectively 19kg/ ton half steel, 12kg/ ton half steel, 13kg/ ton half steel and 2.5kg/ ton half steel；During oxygen supply time 920 seconds, oxygen feeding stop promotes oxygen rifle, now converter slag basicity is 3.2, obtain the molten steel that temperature is 1675 DEG C, the main component of molten steel: 0.041 weight %C, 0.05 weight %Mn, 0.006 weight %P, 0.0028 weight %S, the a [O] of 0.067 weight %, surplus is Fe and inevitable impurity.In stove, the dolomitic lime of 5kg/ ton half steel is added after 5min, argon is utilized to blow stirring 1.5min again, carry out slag-stopping tapping, in tapping process, in ladle, add active lime 4kg/ ton molten steel, mid-carbon fe-mn 2.95kg/ ton molten steel, on the ladle top of the slag, after having gone out steel, add the first slag adjusting agent 2.5kg/ ton molten steel in aluminum.Obtaining 218 tons of first molten steel of alloying, temperature is 1603 DEG C, and its composition is 0.007 weight %P, 0.004 weight %S, 0.042 weight %C, 0.15 weight %Mn, 0.064 weight %a [O], and surplus is Fe.
First molten steel is sent to LF process again, by the first molten steel by LF stove electrical heating and refine.When ladle is to LF electrical heating, after the process time is 23min, stops heating, obtain the second molten steel.By the second molten steel departures after soft blow argon 6min, LF out-station temperature is 1643 DEG C.
RH application of vacuum delivered to by the second molten steel after being processed by LF, and now temperature is 1621 DEG C, and carbon content is 0.044 weight %, and a [O] is 0.066 weight %, it is not necessary to oxygen blast.Starting evacuation, lift gas (argon) flow is 1800NL/min.3min final vacuum degree is reduced to 295Pa, and adjustment lift gas (argon) flow, to 2400NL/min, maintains this vacuum to process 13min；After processing 13min, keeping vacuum, recording oxygen activity is 0.032 weight %, and then in vacuum chamber, molten steel adds aluminum shot 0.45kg/ ton molten steel, carries out deoxidation.After deoxidation aluminum shot adds 2min, in vacuum chamber, add ferrosilicon 1.2kg/ ton molten steel and manganese metal 0.225kg/ ton molten steel, after ferrosilicon and manganese metal add, adjust lift gas (argon) flow to 2000NL/min, after continuing with 8min, vacuum breaker, RH process terminates.In ladle, the top of the slag adds the second slag adjusting agent 1.1kg/ ton molten steel in aluminum, obtains the 3rd molten steel after argon flow amount BOTTOM ARGON BLOWING 16min of ladle employing 85NL/min, and the 3rd molten steel composition is 0.008 weight %P, 0.005 weight %S, 0.0018 weight %C.Then the 3rd molten steel is sent to continuous casting.
By employing continuous casting protection pouring Technology, the 3rd molten steel in this ladle is i.e. obtained section is 220mm × 1150mm hypoxia low carbon IF steel strand product.
The continuous casting billet sample analysis produced is understood, its T [O] average out to 0.0018 weight %, carbon content average out to 0.0023 weight %.
Embodiment 3
With hot metal containing V-Ti as raw material, it is mainly composed of: 4.32 weight %C, 0.25 weight %V, 0.11 weight weight %Mn, 0.067 weight %S, 0.083 weight %P, 0.12 weight %Si, 0.15 weight %Ti and a small amount of inevitably impurity；This molten iron is blended into 210t blowing vanadium extracting bessemerize, the amount of being blended into is 236t, then in converter extracting vanadium, add coolant, and use 339 oxygen rifles to carry out oxygen supply to blow vanadium, in the 3min blowing vanadium, in stove, add 2.3t iron scale, after oxygen supply 5.1min, adding 320kg magnesia in stove and carry out residue adjustment, then oxygen supply carries out pushing off the slag for 42 seconds and goes out half steel and vanadium slag, blowing end point temperature is 1438 DEG C.Half composition of steel obtained is: 3.80 weight %C, 0.05 weight %Mn, 0.086 weight %P, 0.067 weight %S, 0.023 weight %V, surplus is Fe and inevitable impurity.
Half steel after vanadium extraction being delivered to desulfurization station and carries out desulfurization, use KR method desulfurization, mixing time is 43min；Desulfurizing agent is deactivating magnesium powder and Calx, and lime consumption amount is 5.5kg/ ton half steel；Deactivating magnesium powder consumption is 1.2kg/ ton half steel.Half composition of steel obtained after desulfurization is: 3.8 weight %C, 0.05 weight %Mn, 0.082 weight %P, 0.002 weight %S, 0.022 weight %V and inevitable impurity.
Half steel after desulfurization is blended into 210t blow again steel converter blowing, the amount of being blended into is 237t, and use 536 oxygen rifles to carry out oxygen supply slag making dephosphorization decarburization, starting oxygen blown while, carry out steelmaking slagging, slag making materials active lime, quartz sand, dolomitic lime and sludge ball of steel smelting is added in stove, and open blow oxygen supply 6min in slag making materials is all added, the addition of slag making materials active lime, quartz sand, dolomitic lime and sludge ball of steel smelting is respectively 17kg/ ton half steel, 10kg/ ton half steel, 15kg/ ton half steel and 2.3kg/ ton half steel；During oxygen supply time 810 seconds, oxygen feeding stop promotes oxygen rifle, now converter slag basicity is 3.4, obtain the molten steel that temperature is 1682 DEG C, the main component of molten steel: 0.055 weight %C, 0.05 weight %Mn, 0.004 weight %P, 0.0025 weight %S, the a [O] of 0.047 weight %, surplus is Fe and inevitable impurity.In stove, the dolomitic lime of 6kg/ ton half steel is added after 3min, argon is utilized to blow stirring 3min again, carry out slag-stopping tapping, in tapping process, in ladle, add active lime 4kg/ ton molten steel, mid-carbon fe-mn 2.05kg/ ton molten steel, on the ladle top of the slag, after having gone out steel, add the first slag adjusting agent 1.2kg/ ton molten steel in aluminum.Obtaining 221 tons of first molten steel of alloying, temperature is 1615 DEG C, and its composition is 0.005 weight %P, 0.003 weight %S, 0.056 weight %C, 0.15 weight %Mn, 0.045 weight %a [O], and surplus is Fe and inevitable impurity.
Gained the first molten steel is sent to LF process, by the first molten steel by LF stove electrical heating and refine.When ladle is to LF electrical heating, after the process time is 24min, stop heating.Obtaining the second molten steel after soft blow argon 6min, the second molten steel LF out-station temperature is 1645 DEG C.
RH application of vacuum delivered to by the second molten steel after being processed by LF, and now temperature is 1619 DEG C, and carbon content is 0.058 weight %, and a [O] is 0.048 weight %, needs oxygen blast carbon drop 0.01 weight %.Start evacuation, oxygen blast 26Nm3, after 1min, oxygen blast completes.When application of vacuum starts, lift gas (argon) flow is 1800NL/min.6min final vacuum degree is reduced to 98Pa, and lift gas (argon) flow is adjusted to 2500NL/min, and after maintaining vacuum 98Pa to process 14min, recording oxygen activity is 0.026 weight %, and then in vacuum chamber, molten steel adds aluminum shot 0.36kg/ ton molten steel, carries out deoxidation.After deoxidation aluminum shot adds 2min, in vacuum chamber, add ferrosilicon 1.0kg/ ton molten steel and manganese metal 0.45kg/ ton molten steel, after ferrosilicon and manganese metal add, adjust lift gas (argon) flow to 1800NL/min, after continuing with 7min, vacuum breaker, RH process terminates.In ladle, the top of the slag adds the second slag adjusting agent 0.9kg/ ton molten steel in aluminum, obtains the 3rd molten steel after argon flow amount BOTTOM ARGON BLOWING 18min of ladle employing 85NL/min, and the 3rd molten steel composition is 0.007 weight %P, 0.004 weight %S, 0.0021 weight %C.Then the 3rd molten steel is sent to continuous casting.
By employing continuous casting protection pouring Technology, the 3rd molten steel in this ladle is i.e. obtained section is 230mm × 1850mm hypoxia low carbon IF steel strand product.
The continuous casting billet sample analysis produced is understood, its T [O] average out to 0.0016 weight %, carbon content average out to 0.0026 weight %.
Comparative example 1
The low carbon IF steel of hypoxia is produced according to the method described in embodiment 1, except that do not add the slag adjusting agent in aluminum at converter tapping process and RH departures process, continuous casting billet sample analysis its T [O] average out to 0.0036 weight % to it, carbon content average out to 0.0026 weight %, its T [O] too high (higher than 20ppm), it is impossible to meet following process requirement.
Comparative example 2
The low carbon IF steel of hypoxia is produced according to the method described in embodiment 1, except that molten steel directly sets off without BOTTOM ARGON BLOWING in RH processing procedure, its continuous casting billet T [O] average out to 0.0032 weight % produced, carbon content average out to 0.0031 weight %, its T [O] (higher than 20ppm) and carbon content (higher than 30ppm) are the most too high, it is impossible to meet following process requirement.
Comparative example 3
The low carbon IF steel of hypoxia is produced according to the method described in embodiment 1, except that lift gas flow has been used up 1800NL/min in RH processing procedure, its continuous casting billet T [O] average out to 0.0026 weight % produced, carbon content average out to 0.0052 weight %, its T [O] (higher than 20ppm) and carbon content (higher than 30ppm) are the most too high, it is impossible to meet following process requirement.
Be can be seen that by the result of above example 1-3 and comparative example 1-3, the method producing the low carbon IF steel of hypoxia that the present invention provides is by adding containing aluminum slag adjusting agent in different operations to control the oxidisability of ladle slag, thus to molten steel diffusive deoxidation, reach the T [O] of molten steel is controlled the purpose within 0.0020 weight %.Meanwhile, can be seen that the method for the present invention control to lift gas flow from embodiment and comparative example, it is ensured that the production of qualified low carbon IF steel, it is ensured that carbon content control is within 0.0030 weight %.Use vanadium-bearing hot metal to produce IF steel and there is no this technique report at home, by method of the present invention, both ensure that the abundant extraction of vanadium resource, and also produced high-quality low-carbon (LC) hypoxia IF steel simultaneously.
The preferred embodiment of the present invention described in detail above; but, the present invention is not limited to the detail in above-mentioned embodiment, in the technology concept of the present invention; technical scheme can be carried out multiple simple variant, these simple variant belong to protection scope of the present invention.
It is further to note that, each concrete technical characteristic described in above-mentioned detailed description of the invention, in the case of reconcilable, can be combined by any suitable means, in order to avoid unnecessary repetition, various possible compound modes are illustrated by the present invention the most separately.
Additionally, can also carry out combination in any between the various different embodiment of the present invention, as long as it is without prejudice to the thought of the present invention, it should be considered as content disclosed in this invention equally.
Claims (7)
1. the method that a vanadium-titanium-iron-water smelts the low carbon IF steel of hypoxia, it is characterised in that the method includes
Following steps:
1) hot metal containing V-Ti is blended in No. 1 converter, under oxygen supply condition, is sequentially added in converter
Oxides-containing iron and magnesia carry out extraction smelting of vanadium, and described are sequentially added into oxides-containing iron and magnesium in converter
Sand carries out the method for extraction smelting of vanadium and includes: be 20000-25000Nm at oxygen-supplying amount per minute3Under conditions of,
In converter, add oxides-containing iron in continuing oxygen supply 1-3 minute, continue oxygen supply backward converter in 3-5 minute
Interior addition magnesia carries out vanadium extraction；
2) half steel obtained after vanadium extraction is carried out desulfurization process；
3) half steel obtained after desulfurization is blended in No. 2 converters, in converter, adds slag making materials carry out
Oxygen blast slag making, then carries out slag-stopping tapping, and adds first after slag-stopping tapping on the top of the slag of gained molten steel
Containing aluminum slag adjusting agent, obtaining the first molten steel, the described first addition containing aluminum slag adjusting agent is 1-3kg/ ton molten steel,
Described first containing containing 25-40 weight %Al in aluminum slag adjusting agent2O3, 30-45 weight %CaO and 30-45
Weight %Al；
4) described first molten steel is carried out LF stove refine, obtain the second molten steel；
5) make described second molten steel enter RH and process station, start evacuation and control lift gas stream
Amount, carries out decarburization and deoxidation treatment the most successively；
6) in the molten steel obtained after deoxidation treatment, add the second slag adjusting agent in aluminum, obtain the 3rd steel
Water, then carries out continuous casting by described 3rd molten steel, and the described second addition containing aluminum slag adjusting agent is 0.8-1.2
Kg/ ton molten steel, described second containing containing 25-40 weight %Al in aluminum slag adjusting agent2O3, 30-45 weight %CaO
With 30-45 weight %Al.
Method the most according to claim 1, wherein, in step 2) in, the method that desulfurization processes
For composite blowing doctor treatment or KR doctor treatment.
Method the most according to claim 1, wherein, in step 3) in, described slag making materials is
Active lime, quartz sand, dolomitic lime and sludge ball of steel smelting, and the addition of active lime is 15-20kg/
Ton half steel, the addition of quartz sand be 10-15kg/ ton half steel, the addition of dolomitic lime be 10-15kg/
The addition of ton half steel and sludge ball of steel smelting is 2-3kg/ ton half steel.
Method the most according to claim 1, wherein, in step 3) in, carrying out slag-stopping tapping
During in the ladle containing the first molten steel add mid-carbon fe-mn 2-4kg/ ton molten steel, active lime 4-8
At least one in kg/ ton molten steel and fluorite 0.5-2kg/ ton molten steel.
Method the most according to claim 1, wherein, in step 4) in, refine in LF stove
It is 1630-1650 DEG C to temperature.
Method the most according to claim 1, wherein, in step 5) in, the method for deoxidation treatment
Including adding aluminum shot deoxidizer in molten steel, the addition of described aluminum shot deoxidizer is 0.31-0.51kg/ ton
Molten steel.
Method the most according to claim 1, wherein, in step 6) in, in molten steel, add the
Containing after the operation of aluminum slag adjusting agent, two also include that the ladle to containing molten steel carries out BOTTOM ARGON BLOWING process, described BOTTOM ARGON BLOWING
Flow is 50-150NL/min, and argon blowing time is 8-20min.
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| CN104745766A (en) * | 2015-03-30 | 2015-07-01 | 宣化钢铁集团有限责任公司 | LF refining process for deoxidizing according to colour of furnace slag |
| CN105603156B (en) * | 2016-03-09 | 2018-01-26 | 攀钢集团攀枝花钢铁研究院有限公司 | The production method of super-low sulfur IF steel |
| CN107502704B (en) * | 2017-10-20 | 2020-04-28 | 攀钢集团攀枝花钢铁研究院有限公司 | Method for reducing alumina inclusions in semisteel steelmaking casting blank |
| CN109022664B (en) * | 2018-08-08 | 2020-09-08 | 河钢股份有限公司承德分公司 | Method for smelting Ti-IF steel by using vanadium-titanium-containing molten iron |
| CN111826493B (en) * | 2020-06-30 | 2022-02-01 | 攀钢集团攀枝花钢铁研究院有限公司 | SWRH82B steel and smelting method thereof |
| CN112195312B (en) * | 2020-09-29 | 2022-04-15 | 攀钢集团攀枝花钢铁研究院有限公司 | Method for improving cleanliness of ultra-low carbon steel |
| CN113136479A (en) * | 2021-04-20 | 2021-07-20 | 攀钢集团攀枝花钢铁研究院有限公司 | Method for desulfurizing semi-steel steelmaking converter after furnace |
| CN113337772B (en) * | 2021-05-24 | 2022-09-09 | 河钢股份有限公司承德分公司 | Method for producing IF steel by using vanadium-extracting semisteel |
| CN115433867A (en) * | 2022-08-24 | 2022-12-06 | 攀钢集团西昌钢钒有限公司 | Phosphorus-containing high-strength IF steel smelted from semisteel and preparation method thereof |
Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102011062A (en) * | 2010-11-29 | 2011-04-13 | 攀钢集团钢铁钒钛股份有限公司 | Easy-cutting gear steel and smelting method thereof |
| CN102260822A (en) * | 2011-07-27 | 2011-11-30 | 攀钢集团有限公司 | High-phosphorus low-sulfur non-oriented electrical steel and smelting method thereof |
| CN103194567A (en) * | 2013-04-26 | 2013-07-10 | 攀钢集团攀枝花钢铁研究院有限公司 | Smelting process of iron ore containing vanadium |
-
2013
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Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102011062A (en) * | 2010-11-29 | 2011-04-13 | 攀钢集团钢铁钒钛股份有限公司 | Easy-cutting gear steel and smelting method thereof |
| CN102260822A (en) * | 2011-07-27 | 2011-11-30 | 攀钢集团有限公司 | High-phosphorus low-sulfur non-oriented electrical steel and smelting method thereof |
| CN103194567A (en) * | 2013-04-26 | 2013-07-10 | 攀钢集团攀枝花钢铁研究院有限公司 | Smelting process of iron ore containing vanadium |
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