CN108796173A - Improve the smelting process of heavy rail steel cleanness - Google Patents
Improve the smelting process of heavy rail steel cleanness Download PDFInfo
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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
- C21C7/0056—Treating molten ferrous alloys, e.g. steel, not covered by groups C21C1/00 - C21C5/00 using cored wires
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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
- C21C5/28—Manufacture of steel in the converter
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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
- C21C7/0006—Adding metallic additives
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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
- C21C7/06—Deoxidising, e.g. killing
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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
- C21C7/064—Dephosphorising; Desulfurising
- C21C7/0645—Agents used for dephosphorising or desulfurising
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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
- C21C7/076—Use of slags or fluxes as treating agents
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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
- C21C7/10—Handling in a vacuum
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- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
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- Treatment Of Steel In Its Molten State (AREA)
Abstract
The invention discloses a kind of smelting processes improving heavy rail steel cleanness, belong to technical field of ferrous metallurgy.Present invention solves the technical problem that being that existing domestic heavy rail steel cleanness is difficult to meet the requirement of high-speed railway.This method includes molten iron pretreatment, converter smelting, LF refining, RH refinings and continuous casting, wherein being blown to molten iron using double slag process in converter steelmaking process, first time slag making materials active lime dosage is 5~20kg/t molten iron；Quartz sand dosage is 5~10kg/t molten iron；Dolomitic lime dosage is 5~10kg/t molten iron；Second of slag making materials active lime dosage is 5~10kg/t molten iron；Quartz sand dosage is 5~10kg/t molten iron；Dolomitic lime dosage is 5~10kg/t molten iron.The method of the present invention can control P+S+O+N+H≤160ppm, all kinds of grading≤1.0 grade of field trash to significantly improve heavy rail steel cleanness, have certain social benefit.
Description
Technical field
The invention belongs to technical field of ferrous metallurgy, and in particular to a kind of smelting process improving heavy rail steel cleanness.
Background technology
Properties of Heavy Rail Steel is the chief component of railroad track, and in railway transport course, rail provides effectively branch to locomotive
Support and guiding, are subjected to the huge lateral pressure from wheel.Based on China's infrastructure growth requirement, railway transportation is just with fast
Violent speed development, and constantly tend to high speed, heavy loading.This undoubtedly proposes the quality of rail more harsh requirement.
When rail is contacted with wheel, the reciprocal and changeable load of locomotive winding is subject, cleanliness factor is to rail
Service life important, steel inclusion are to cause heavy rail internal injury, generate the main reason for endurance failure.It is mingled in steel
Object is to the successional inhibition of steel matrix so that steel are in rolling processing, heat treatment and during use and folder
Sundries detaches, and gap is caused to generate, and negative influence is generated to indexs such as steel mechanics performance, corrosion resistancies.For rail
Production, the series of influence factors such as deflection rolling, complicated heat treatment process, special stress condition and climatic environment
It is unfavorable to the grading of rail field trash.
With the fast development of China's high ferro and the speed-raising of heavy-rail railway, the demand of seamed high-speed steel rail is increasing, high-speed iron
Road is very high to fatigue behaviour requirement, and the cleanliness factor of Properties of Heavy Rail Steel can largely influence its fatigue behaviour, tired to improve
Labor performance needs the cleanliness factor for controlling Properties of Heavy Rail Steel.In general, cleanliness factor includes P+S+O+N+H and field trash.In this technology
Before exploitation, domestic heavy rail steel cleanness P+S+O+N+H≤200ppm, all kinds of grading≤1.5 grade of field trash.To meet high-speed railway
Requirement, further increase Cleanliness of Molten Steel, need develop P+S+O+N+H≤160ppm, all kinds of grading≤1.0 grade of field trash
High-speed rail production technology.
Patent CN104975130A disclose it is a kind of control heavy rail steel cleanness method, this method include converter smelting,
LF refining, RH application of vacuum and continuous casting, wherein using the essence of active lime, silicon carbide and quartz sand slag making in LF refining process
Refining, controls heavy rail steel continuous casting billet sulfur content≤0.006% being prepared, and it is 1.5~2.0 grades to obtain steel inclusion A classes, B
Class, C classes, D classes are 0.5 grade, it is difficult to meet the requirement of high-speed railway.
Invention content
The technical problem to be solved by the present invention is to existing domestic heavy rail steel cleanness to be difficult to meet high-speed railway P+S+O+N+H
≤ 160ppm, the requirement of all kinds of grading≤1.0 grade of field trash.
The present invention is to solve its technical problem the technical solution adopted is that providing a kind of smelting improving heavy rail steel cleanness
Smelting method, this method comprises the following steps：
A, molten iron pre-processes：Using active lime and deactivating magnesium powder as desulfurizing agent to desulfurizing iron, obtain S contents≤
0.003%, the desulfurized molten iron that P content is 0.080%~0.120%；
B, converter smelting：Step a desulfurized molten irons are added into converter, are with active lime, quartz sand and dolomitic lime
The dosage of slag making materials double slag dephosphorization, first time slag making materials active lime is 5~20kg/t molten iron；The dosage of quartz sand is
5~10kg/t molten iron；The dosage of dolomitic lime is 5~10kg/t molten iron；The dosage of second of slag making materials active lime be 5~
10kg/t molten iron；The dosage of quartz sand is 5~10kg/t molten iron；The dosage of dolomitic lime is 5~10kg/t molten iron, while with oxygen
Rifle oxygen supply is blown, and the molten steel of P content≤0.003% is obtained after finishing blowing, low nitrogen alloy is added in molten steel tapping process；
C, LF refining：Molten steel obtained by step b is sent to LF ladle furnaces, is heated after calcium carbide and high alkalinity refining slag is added,
After refining 20~30min, it is added quartz sand into molten steel, after refining 5~10min, molten steel Calcium treatment, molten steel is outbound after Argon；
D, RH is refined：After the completion of LF refining, molten steel is transferred to RH ladle furnaces and is vacuum-treated, low nitrogen alloy is added, very
After the completion of the reason of vacancy, Calcium treatment is carried out to molten steel, molten steel is outbound after Argon processing；
E, continuous casting：Continuous casting is carried out to molten steel obtained by step d.
Wherein, in the smelting process of above-mentioned raising heavy rail steel cleanness, in step b, first time slag making materials blowing 8 is added
Second of slag making materials is added after~10min deslagging continues 5~8min of blowing, deslagging tapping.
Wherein, in the smelting process of above-mentioned raising heavy rail steel cleanness, in step a, the dosage of the active lime is 4~
6kg/t molten iron；The dosage of deactivating magnesium powder is 1~3kg/t molten iron.
Wherein, in the smelting process of above-mentioned raising heavy rail steel cleanness, in step a and b, the active lime contains
CaO90% or more, remaining is impurity；The quartz sand contains SiO295% or more, remaining is impurity；The dolomitic lime contains MgO30%
~40%, CaO50%~60%, remaining is impurity.
Wherein, in the smelting process of above-mentioned raising heavy rail steel cleanness, in step b, in the molten steel tapping process, when going out
Low nitrogen alloy is added for 1/2 or more in steel amount.
Wherein, in the smelting process of above-mentioned raising heavy rail steel cleanness, in step b, in the converting process, oxygen rifle is blown
Rifle position control is refined in 1.5~2.5m.
Wherein, in the smelting process of above-mentioned raising heavy rail steel cleanness, in step b, in the converting process, temperature control
At 1640~1670 DEG C.
Wherein, in the smelting process of above-mentioned raising heavy rail steel cleanness, in step c, the dosage of the calcium carbide is 0.2~
0.8kg/t molten steel；The dosage of the high alkalinity refining slag is 1~5kg/t molten steel；The dosage of the quartz sand be 0.2~
0.8kg/t molten steel.
Wherein, in the smelting process of above-mentioned raising heavy rail steel cleanness, in step c and d, the LF and RH are refined at Argon
The flow of reason is 50~80NL/min, and the duration is 5~10min.
Wherein, in the smelting process of above-mentioned raising heavy rail steel cleanness, calcium carbide described in step c contains CaC295% or more,
Remaining is impurity；The high alkalinity refining slag is containing CaO60%~70%, Al2O30~10%, SiO220%~30%, remaining is
Impurity.
Wherein, in the smelting process of above-mentioned raising heavy rail steel cleanness, in step c, the LF refining temperature be 1580~
1595℃。
Wherein, in the smelting process of above-mentioned raising heavy rail steel cleanness, in step c, LF refining process Calcium treatment is to steel
The iron calcium line of 1~3m/t molten steel is added in water；In step d, RH refining process Calcium treatments are addition 3~5m/t molten steel into molten steel
Iron calcium line.
Wherein, in the smelting process of above-mentioned raising heavy rail steel cleanness, the ingredient of the iron calcium line is calculated in mass percent
Include the Ca of 68% Fe and 30%, remaining is impurity；The specification of the iron calcium line is 200g/m；The iron calcium line it is a diameter of
10mm。
Wherein, in the smelting process of above-mentioned raising heavy rail steel cleanness, in step d, the RH refining temperatures be 1535~
1550℃。
Wherein, in the smelting process of above-mentioned raising heavy rail steel cleanness, in step d, the RH refining controllings vacuum degree≤
100Pa is vacuum-treated 15~20min.
Wherein, in the smelting process of above-mentioned raising heavy rail steel cleanness, in step b and d, the converter smelting and RH refinings
Nitrogen content≤0.01% for the low nitrogen alloy being added.
Wherein, in the smelting process of above-mentioned raising heavy rail steel cleanness, the low nitrogen alloy includes that nitrogen content is 0.005%
Ferrosilicon, nitrogen content be 0.003% silicomanganese, nitrogen content be 0.002% ferrosilicon, nitrogen content be 0.001% ferromanganese.
Wherein, in the smelting process of above-mentioned raising heavy rail steel cleanness, Antaciron that the nitrogen content is 0.005%
Composition is calculated in mass percent as 75%Si, 24%Fe, 0.005%N, and remaining is impurity；The silicomanganese that the nitrogen content is 0.003%
The composition of alloy is calculated in mass percent as 28%Si, 70%Mn, 0.003%N, and remaining is impurity；The nitrogen content is 0.002%
The composition of Antaciron be calculated in mass percent as 75%Si, 24%Fe, 0.002%N, remaining is impurity；The nitrogen content is
The composition of 0.001% manganeisen is 75%Mn, 24%Fe, 0.001%N by percentage to the quality, and remaining is impurity.
Wherein, in the smelting process of above-mentioned raising heavy rail steel cleanness, it is 0.005% that nitrogen content, which is added, in the smelting process
The amount of Antaciron be 10~15kg/t molten steel, it is 15~20kg/t that the amount of silicomangan that nitrogen content is 0.003%, which is added,
Molten steel；The amount that the Antaciron that nitrogen content is 0.002% is added in the RH refining process is 1~3kg/t molten steel, and nitrogen content is added
Amount for 0.001% manganeisen is 1~3kg/t molten steel.
Wherein, in the smelting process of above-mentioned raising heavy rail steel cleanness, in step e, the casting process uses bloom
Continuous casting is produced into the generous continuous casting billet product that cross section is 250mm × 250mm or more.
The beneficial effects of the invention are as follows：
The method of the present invention improves the cleanliness factor of Properties of Heavy Rail Steel, controls P+S+O+N+H≤160ppm in rail, and field trash is all kinds of
≤ 1.0 grades of grading, meets the requirement at present to seamed high-speed steel rail, directly enhances the fatigue behaviour and mechanical property of rail, be
The production of next-generation rail provides strong technical support, has significant social benefit.The method of the present invention can control weight
P≤0.0060%, S≤0.0030%, O≤0.0010%, N≤0.0050% and H≤0.00015% in rail steel, applicable P, S,
O, N and H individual elements have the steel grade that control requires.The method of the present invention uses double slag process by slag making materials activity stone in converter smelting
Ash, quartz sand and dolomitic lime are added in two portions in converter and blow to molten iron, and the control of converter terminal P content is existed
Within 0.003%.When tapping after the method for the present invention smelting process, when tap be 1/2 or more when be added low nitrogen alloy into
Row deoxidation inhibits nitrogen to enter in molten steel, effectively controls nitrogen content in molten steel.
Specific implementation mode
Based on cleanliness factor P+S+O+N+H≤200ppm of existing domestic Properties of Heavy Rail Steel, all kinds of grading≤1.5 grade of field trash are difficult
To meet the requirement of high-speed railway, in order to find the method for improving heavy rail steel cleanness, inventor is provided by numerous studies
A method of heavy rail steel cleanness is improved, cleanliness factor P+S+O+N+H≤160ppm, all kinds of grading≤1.0 grade of field trash can be made.
The present invention provides a kind of methods improving heavy rail steel cleanness, and this method comprises the following steps：
A, molten iron pre-processes：Using active lime and deactivating magnesium powder as desulfurizing agent to desulfurizing iron, obtain S contents≤
0.003%, the desulfurized molten iron that P content is 0.080%~0.120%；
B, converter smelting：Step a desulfurized molten irons are added into converter, are with active lime, quartz sand and dolomitic lime
The dosage of slag making materials double slag dephosphorization, first time slag making materials active lime is 5~20kg/t molten iron；The dosage of quartz sand is
5~10kg/t molten iron；The dosage of dolomitic lime is 5~10kg/t molten iron；The dosage of second of slag making materials active lime be 5~
10kg/t molten iron；The dosage of quartz sand is 5~10kg/t molten iron；The dosage of dolomitic lime is 5~10kg/t molten iron, while with oxygen
Rifle oxygen supply is blown, and the molten steel of P content≤0.003% is obtained after finishing blowing, low nitrogen alloy is added in molten steel tapping process；
C, LF refining：Molten steel obtained by step b is sent to LF ladle furnaces, is heated after calcium carbide and high alkalinity refining slag is added,
After refining 20~30min, it is added quartz sand into molten steel, after refining 5~10min, molten steel Calcium treatment, molten steel is outbound after Argon；
D, RH is refined：After the completion of LF refining, molten steel is transferred to RH ladle furnaces and is vacuum-treated, low nitrogen alloy is added, very
After the completion of the reason of vacancy, Calcium treatment is carried out to molten steel, molten steel is outbound after Argon processing；
E, continuous casting：Continuous casting is carried out to molten steel obtained by step d.
Wherein, in the smelting process of above-mentioned raising heavy rail steel cleanness, in step b, first time slag making materials blowing 8 is added
Second of slag making materials is added after~10min deslagging continues 5~8min of blowing, deslagging tapping.
Wherein, in the smelting process of above-mentioned raising heavy rail steel cleanness, in step a, the dosage of the active lime is 4~
6kg/t molten iron；The dosage of deactivating magnesium powder is 1~3kg/t molten iron.Molten iron pretreatment is using inert gas by active lime powder and blunt
Change magnesium powder mixing, sprayed into molten iron using rotary desulfurization spray gun, the injection time is 15~30min, and desulfurization is obtained after the completion of injection
Molten iron afterwards, wherein S content≤0.003%, P content are 0.080%~0.120%.Molten iron is steel-making one before desulfurization in the present invention
As molten iron, molten iron S content ranges can also be implemented more than 0.012% 0.060%~0.120%, but can extended de-
The sulphur time, influence manufacturing schedule.
Wherein, in the smelting process of above-mentioned raising heavy rail steel cleanness, in step a and b, the active lime contains
CaO90% or more, remaining is impurity；The quartz sand contains SiO295% or more, remaining is impurity；The dolomitic lime contains MgO30%
~40%, CaO50%~60%, remaining is impurity.Active lime, quartz sand, dolomitic lime are added in batches in the present invention, first divide
Not Jia Ru active lime, quartz sand and dolomitic lime, after slag melting, then be separately added into active lime, quartz sand and high magnesium
Lime, it is multiple batches of to be added to whole additions.The slag making materials chemical composition of active lime, quartz sand and dolomitic lime composition is equal
It is even, stable, slugging in advance can be played, is shortened the heat, the effect of effective dephosphorization.
Wherein, in the smelting process of above-mentioned raising heavy rail steel cleanness, in step b, in the converting process, oxygen rifle is blown
Rifle position control is refined in 1.5~2.5m.
Wherein, in the smelting process of above-mentioned raising heavy rail steel cleanness, in step b, in the converting process, temperature control
At 1640~1670 DEG C.Temperature is not to be exceeded 1670 DEG C, and temperature is excessively high, is unfavorable for the progress of dephosphorisation reaction.
Wherein, in the smelting process of above-mentioned raising heavy rail steel cleanness, in step b, in order to ensure lower nitrogen in molten steel
Content, in molten steel tapping process, when tap is 1/2 or more low nitrogen alloy is added is diffused deoxidation and molten steel alloying,
Ensure that tapping molten steel oxygen activity early period is higher, to inhibit nitrogen to enter molten steel.
Wherein, in the smelting process of above-mentioned raising heavy rail steel cleanness, in step c, the dosage of the calcium carbide is 0.2~
0.8kg/t molten steel；The dosage of the high alkalinity refining slag is 1~5kg/t molten steel；The dosage of the quartz sand be 0.2~
0.8kg/t molten steel.
Wherein, in the smelting process of above-mentioned raising heavy rail steel cleanness, in step c, the calcium carbide contains CaC295% with
On, remaining is impurity；The high alkalinity refining slag is containing CaO60%~70%, Al2O30~10%, SiO220%~30%, remaining
For impurity.The purpose of addition calcium carbide and high alkalinity refining slag can equably reduce the oxidisability of slag in LF stoves, reduce it
Fusing point, the field trash being conducive in absorption molten steel, is diffused deoxidation, controls oxygen activity≤0.0015% in molten steel, is on the one hand
Control field trash prevents the elements such as Al, Si that casting process aoxidizes in molten steel；On the other hand it is to improve receiving for Ca
Rate, reduction iron calcium line are added after molten steel and are oxidized to CaO by the O in molten steel.
Wherein, in the smelting process of above-mentioned raising heavy rail steel cleanness, in step c, during LF refining, in order to alloy
In a small amount of metallic aluminium for bringing into aoxidized after the dystectic brittleness Al of bulky grain that generates2O3Field trash becomes the calcium aluminium of low melting point
Hydrochlorate field trash effectively facilitates the floating of field trash, improves the cleanliness factor of molten steel, and the iron of 1~3m/t molten steel is added into ladle
Calcium line carries out Calcium treatment.
Wherein, in the smelting process of above-mentioned raising heavy rail steel cleanness, in step c, during LF refining, in order to promote steel
The substance between chemical reaction, acceleration slag between slag transmits, conducive to the progress of deoxidation of molten steel and desulphurization reaction, Calcium treatment knot
With 50~80NL/min Argons, 5~10min in Shu Houxiang LF stoves.
Wherein, in the smelting process of above-mentioned raising heavy rail steel cleanness, in step c, the LF refining temperature be 1580~
1595℃.LF refining can be with depth deoxidation, the cleanliness factor for desulfurization, reducing foreign substance in molten steel, improving molten steel.
Wherein, in the smelting process of above-mentioned raising heavy rail steel cleanness, in step d, RH refining controllings vacuum degree≤
100Pa is vacuum-treated 15~20min.
Wherein, in the smelting process of above-mentioned raising heavy rail steel cleanness, in step d, RH refining temperatures are 1535~1550
℃。
Wherein, in the smelting process of above-mentioned raising heavy rail steel cleanness, in step d, in order to make molten steel alloying, ensure steel
Water constituent meets target call, and molten steel, which enters after RH ladle furnaces are vacuum-treated 8min, is initially added into low nitrogen alloy, controls in molten steel
Nitrogen content≤0.0050% controls oxygen activity≤0.0010% in molten steel.
Wherein, in the smelting process of above-mentioned raising heavy rail steel cleanness, in step d, in order to ensure in molten steel remaining S with
Ca can be combined effectively, need have certain calcium content in molten steel, to avoid the formation of a large amount of MnS Large Inclusions, to ladle
The interior iron calcium line that 3~5m/t molten steel is added carries out Calcium treatment.
Wherein, in the smelting process of above-mentioned raising heavy rail steel cleanness, in step d, in order to ensure that calcium can be evenly distributed on
With 5~10min of argon flow blowing argon gas of 50~80NL/min in molten steel.
Wherein, in the smelting process of above-mentioned raising heavy rail steel cleanness, the ingredient of the iron calcium line is calculated in mass percent
Include the Ca of 68% Fe and 30%, remaining is impurity；The specification of the iron calcium line is 200g/m；The iron calcium line it is a diameter of
10mm。
Wherein, in the smelting process of above-mentioned raising heavy rail steel cleanness, the low nitrogen of the converter smelting and RH refining additions
Nitrogen content≤0.01% of alloy.
Wherein, in the smelting process of above-mentioned raising heavy rail steel cleanness, the low nitrogen alloy includes that nitrogen content is 0.005%
Ferrosilicon, nitrogen content be 0.003% silicomanganese, nitrogen content be 0.002% ferrosilicon, nitrogen content be 0.001% ferromanganese.
Wherein, in the smelting process of above-mentioned raising heavy rail steel cleanness, Antaciron that the nitrogen content is 0.005%
Composition is calculated in mass percent as 75%Si, 24%Fe, 0.005%N, and remaining is impurity；The silicomanganese that the nitrogen content is 0.003%
The composition of alloy is calculated in mass percent as 28%Si, 70%Mn, 0.003%N, and remaining is impurity；The nitrogen content is 0.002%
The composition of Antaciron be calculated in mass percent as 75%Si, 24%Fe, 0.002%N, remaining is impurity；The nitrogen content is
The composition of 0.001% manganeisen is 75%Mn, 24%Fe, 0.001%N by percentage to the quality, and remaining is impurity.
Wherein, in the smelting process of above-mentioned raising heavy rail steel cleanness, it is 0.005% that nitrogen content, which is added, in the smelting process
The amount of Antaciron be 10~15kg/t molten steel, it is 15~20kg/t that the amount of silicomangan that nitrogen content is 0.003%, which is added,
Molten steel；The amount that the Antaciron that nitrogen content is 0.002% is added in the RH refining process is 1~3kg/t molten steel, and nitrogen content is added
Amount for 0.001% manganeisen is 1~3kg/t molten steel.
Wherein, in the smelting process of above-mentioned raising heavy rail steel cleanness, in step e, the casting process open pour before it is right
Tundish carries out Argon 5min~10min；Long nozzle is sealed using seal washer；Be produced into cross section be 250mm × 250mm with
On generous continuous casting billet product.
The present invention will be explained in detail by specific embodiment below.
Embodiment 1
Molten iron pre-processes：Using molten iron as raw material, using carrier gas by the blunt of the active lime of 4kg/t molten iron and 1kg/t molten iron
Change magnesium powder mixing, sprayed into molten iron using rotary desulfurization spray gun, the injection time is 15min, and low-sulfur molten iron, S are obtained after desulfurization
Content：0.001%, P content：0.082%.
Converter smelting：Desulfurized molten iron is added into converter, the active stone of first time slag making materials 7kg/t molten iron is added
The dolomitic lime of ash, the quartz sand of 8kg/t molten iron and 10kg/t molten iron, while being blown with oxygen supply by lance, the blowing of oxygen rifle
In 1.5~2.5m, converting process temperature is 1655 DEG C for rifle position control, and second of slag making materials is added after 8min deslagging of blowing
The dolomitic lime of the active lime of 10kg/t molten iron, the quartz sand and 10kg/t molten iron of 10kg/t molten iron, after continuing blowing 5min,
Deslagging is tapped again, P content 0.0024%.It taps after converter smelting, 10kg/t steel is added when tap is 1/2 or more
The silicomanganese that 15kg/t molten steel nitrogen contents are 0.003% is added in the ferrosilicon that water nitrogen content is 0.005%.
LF refining：The molten steel that converter smelting obtains is sent into LF stove ladles and is refined, before LF stove heats, into ladle
The calcium carbide of 0.2kg/t molten steel, the high alkalinity refining slag of 1kg/t molten steel is added, is heated to 1580 DEG C, after refining 20min, Xiang Gang
The quartz sand of 0.2kg/t molten steel is added in packet, continues after refining 5min, the iron calcium line that 1m/t molten steel is added into ladle carries out calcium
Processing, Calcium treatment terminate after into LF stoves with the flow Argon 5min of 50NL/min, molten steel is outbound.
RH is refined：After the completion of the refining of LF stoves, molten steel is transferred to RH stove ladles and is vacuum-treated, control vacuum degree is
70Pa, refining temperature are 1535 DEG C, and molten steel, which enters after RH ladle furnaces are vacuum-treated 8min, is initially added into 2.5kg/t molten steel nitrogen contents
For 0.002% ferrosilicon, the ferromanganese that 2.5kg/t molten steel nitrogen contents are 0.001% is added.After being vacuum-treated 18min, into ladle
The iron calcium line that 3m/t molten steel is added carries out Calcium treatment, is gone out with the flow blowing argon gas 5min of 50NL/min, molten steel after Calcium treatment
It stands.
Continuous casting：Molten steel is sent to continuous casting working procedure, is opened and is carried out Argon 5min to tundish before pouring；Long nozzle is close using seal washer
Envelope is produced into the generous continuous casting billet product that cross section is 280mm × 380mm.
By obtained continuous casting billet milling at 60kg rail, the rail P+S+O+N+H=0.0144% that is produced, wherein P
0.0060%, S 0.0030%, O 0.0010%, N 0.0043%, H 0.0001%.All kinds of gradings of field trash：1.0 grades of A classes,
B classes, C classes, D classes are 0 grade.
Embodiment 2
Molten iron pre-processes：Using molten iron as raw material, using carrier gas by the blunt of the active lime of 6kg/t molten iron and 3kg/t molten iron
Change magnesium powder mixing, sprayed into molten iron using rotary desulfurization spray gun, the injection time is 30min, and low-sulfur molten iron, S are obtained after desulfurization
Content：0.001%, P content：0.120%.
Converter smelting：Desulfurized molten iron is added into converter, the active stone of first time slag making materials 10kg/t molten iron is added
The dolomitic lime of ash, the quartz sand of 7kg/t molten iron and 9kg/t molten iron, while being blown with oxygen supply by lance, the blowing rifle of oxygen rifle
In 1.5~2.5m, converting process temperature is 1658 DEG C for position control, and second of slag making materials is added after 10min deslagging of blowing
The dolomitic lime of the active lime of 10kg/t molten iron, the quartz sand and 10kg/t molten iron of 10kg/t molten iron, after continuing blowing 8min,
Deslagging is tapped again, P content 0.0022%.It taps after converter smelting, 15kg/t steel is added when tap is 1/2 or more
The silicomanganese that 20kg/t molten steel nitrogen contents are 0.003% is added in the ferrosilicon that water nitrogen content is 0.005%.
LF refining：The molten steel that converter smelting obtains is sent into LF stove ladles and is refined, before LF stove heats, into ladle
The calcium carbide of 0.8kg/t molten steel, the high alkalinity refining slag of 5kg/t molten steel is added, is heated to 1595 DEG C, after refining 30min, Xiang Gang
The quartz sand of 0.8kg/t molten steel is added in packet, continues after refining 10min, the iron calcium line that 3m/t molten steel is added into ladle carries out
Calcium treatment, Calcium treatment terminate after into LF stoves with the flow Argon 10min of 60NL/min, molten steel is outbound.
RH is refined：After the completion of the refining of LF stoves, molten steel is transferred to RH stove ladles and is vacuum-treated, control vacuum degree is
60Pa, refining temperature are 1550 DEG C, and molten steel, which enters after RH ladle furnaces are vacuum-treated 8min, to be initially added into 1kg/t molten steel nitrogen contents and be
The ferromanganese that 1kg/t molten steel nitrogen contents are 0.001% is added in 0.002% ferrosilicon.After being vacuum-treated 19min, it is added into ladle
The iron calcium line of 5m/t molten steel carries out Calcium treatment, and with the flow blowing argon gas 10min of 60NL/min after Calcium treatment, molten steel is outbound.
Continuous casting：Molten steel is sent to continuous casting working procedure, is opened and is carried out Argon 10min to tundish before pouring；Long nozzle uses seal washer
Sealing is produced into the generous continuous casting billet product that cross section is 280mm × 380mm.
By obtained continuous casting billet milling at 60kg rail, the rail P+S+O+N+H=0.0127% that is produced, wherein P
0.0050%, S 0.0030%, O 0.0006%, N 0.0040%, H 0.0001%.All kinds of gradings of field trash：0.5 grade of A classes,
B classes, C classes, D classes are 0 grade.
Embodiment 3
Molten iron pre-processes：Using molten iron as raw material, using carrier gas by the blunt of the active lime of 5kg/t molten iron and 2kg/t molten iron
Change magnesium powder mixing, sprayed into molten iron using rotary desulfurization spray gun, the injection time is 20min, and low-sulfur molten iron, S are obtained after desulfurization
Content：0.0006%, P content：0.105%.
Converter smelting：Desulfurized molten iron is added into converter, the active stone of first time slag making materials 8kg/t molten iron is added
The dolomitic lime of ash, the quartz sand of 8kg/t molten iron and 8kg/t molten iron, while being blown with oxygen supply by lance, the blowing rifle of oxygen rifle
In 1.5~2.5m, converting process temperature is 1653 DEG C for position control, and second of slag making materials 8kg/ is added after 9min deslagging of blowing
The dolomitic lime of the active lime of t molten iron, the quartz sand and 8kg/t molten iron of 8kg/t molten iron, after continuing blowing 7min, deslagging is again
Tapping, P content 0.0021%.It taps after converter smelting, it is nitrogenous that 12kg/t molten steel is added when tap is 1/2 or more
Amount is 0.005% ferrosilicon, and the silicomanganese that 18kg/t molten steel nitrogen contents are 0.003% is added.
LF refining：The molten steel that converter smelting obtains is sent into LF stove ladles and is refined, before LF stove heats, into ladle
The calcium carbide of 0.6kg/t molten steel, the high alkalinity refining slag of 3kg/t molten steel is added, is heated to 1595 DEG C, after refining 25min, Xiang Gang
The quartz sand of 0.6kg/t molten steel is added in packet, continues after refining 8min, the iron calcium line that 2m/t molten steel is added into ladle carries out calcium
Processing, Calcium treatment terminate after into LF stoves with the flow Argon 8min of 80NL/min, molten steel is outbound.
RH is refined：After the completion of the refining of LF stoves, molten steel is transferred to RH stove ladles and is vacuum-treated, control vacuum degree is
70Pa, refining temperature are 1545 DEG C, and molten steel, which enters after RH ladle furnaces are vacuum-treated 8min, to be initially added into 2kg/t molten steel nitrogen contents and be
The ferromanganese that 2kg/t molten steel nitrogen contents are 0.001% is added in 0.002% ferrosilicon.After being vacuum-treated 18min, it is added into ladle
The iron calcium line of 4m/t molten steel carries out Calcium treatment, and with the flow blowing argon gas 8min of 50NL/min after Calcium treatment, molten steel is outbound.
Continuous casting：Molten steel is sent to continuous casting working procedure, is opened and is carried out Argon 8min to tundish before pouring；Long nozzle is close using seal washer
Envelope is produced into the generous continuous casting billet product that cross section is 280mm × 380mm.
By obtained continuous casting billet milling at 60kg rail, the rail P+S+O+N+H=0.0112% that is produced, wherein P
0.0050%, S 0.0010%, O 0.0008%, N 0.0043%, H 0.0001%.All kinds of gradings of field trash：0.5 grade of A classes,
B classes, C classes, D classes are 0 grade.
Comparative example 1
Molten iron pre-processes：Using molten iron as raw material, using carrier gas by the blunt of the active lime of 5kg/t molten iron and 2kg/t molten iron
Change magnesium powder mixing, sprayed into molten iron using rotary desulfurization spray gun, the injection time is 20min, and low-sulfur molten iron, S are obtained after desulfurization
Content：0.0006%, P content：0.099%.
Converter smelting：Desulfurized molten iron is added into converter, the active stone of first time slag making materials 3kg/t molten iron is added
The dolomitic lime of ash, the quartz sand of 4kg/t molten iron and 6kg/t molten iron, while being blown with oxygen supply by lance, the blowing rifle of oxygen rifle
In 1.5~2.5m, converting process temperature is 1653 DEG C for position control, and second of slag making materials 4kg/ is added after 9min deslagging of blowing
The dolomitic lime of the active lime of t molten iron, the quartz sand and 4kg/t molten iron of 4kg/t molten iron, after continuing blowing 7min, deslagging is again
Tapping, P content 0.0071%.It taps after converter smelting, it is nitrogenous that 12kg/t molten steel is added when tap is 1/2 or more
Amount is 0.005% ferrosilicon, and the silicomanganese that 12kg/t molten steel nitrogen contents are 0.003% is added.
LF refining：The molten steel that converter smelting obtains is sent into LF stove ladles and is refined, before LF stove heats, into ladle
The calcium carbide of 0.6kg/t molten steel, the high alkalinity refining slag of 3kg/t molten steel is added, is heated to 1590 DEG C, after refining 25min, Xiang Gang
The quartz sand of 0.6kg/t molten steel is added in packet, continues after refining 8min, the iron calcium line that 2m/t molten steel is added into ladle carries out calcium
Processing, Calcium treatment terminate after into LF stoves with the flow Argon 8min of 60NL/min, molten steel is outbound.
RH is refined：After the completion of the refining of LF stoves, molten steel is transferred to RH stove ladles and is vacuum-treated, control vacuum degree is
70Pa, refining temperature are 1545 DEG C, and molten steel, which enters after RH ladle furnaces are vacuum-treated 8min, to be initially added into 2kg/t molten steel nitrogen contents and be
The ferromanganese that 2kg/t molten steel nitrogen contents are 0.001% is added in 0.002% ferrosilicon.After being vacuum-treated 18min, it is added into ladle
The iron calcium line of 4m/t molten steel carries out Calcium treatment, and with the flow blowing argon gas 8min of 70NL/min after Calcium treatment, molten steel is outbound.
Continuous casting：Molten steel is sent to continuous casting working procedure, is opened and is carried out Argon 8min to tundish before pouring；Long nozzle is close using seal washer
Envelope is produced into the generous continuous casting billet product that cross section is 280mm × 380mm.
By obtained continuous casting billet milling at 60kg rail, the rail P+S+O+N+H=0.0166% that is produced, wherein P
0.0080%, S 0.0030%, O 0.0010%, N 0.0045%, H 0.0001%.All kinds of gradings of field trash：0.5 grade of A classes,
B classes, C classes, D classes are 0 grade.
By Examples 1 to 3 and comparative example 1 it is found that the method for the present invention makes P+ by the control to P, S, O, N and H in molten steel
S+O+N+H≤160ppm, all kinds of grading≤1.0 grade of field trash, significantly improves heavy rail steel cleanness, and there is significant society to imitate
Benefit is worthy of popularization.
Claims (10)
1. improving the smelting process of heavy rail steel cleanness, it is characterised in that include the following steps：
A, molten iron pre-processes：Using active lime and deactivating magnesium powder as desulfurizing agent to desulfurizing iron, S content≤0.003% is obtained,
The desulfurized molten iron that P content is 0.080%~0.120%；
B, converter smelting：Step a desulfurized molten irons are added into converter, using active lime, quartz sand and dolomitic lime as slag making
The dosage of material double slag dephosphorization, first time slag making materials active lime is 5~20kg/t molten iron；The dosage of quartz sand be 5~
10kg/t molten iron；The dosage of dolomitic lime is 5~10kg/t molten iron；The dosage of second of slag making materials active lime be 5~
10kg/t molten iron；The dosage of quartz sand is 5~10kg/t molten iron；The dosage of dolomitic lime is 5~10kg/t molten iron, while with oxygen
Rifle oxygen supply is blown, and the molten steel of P content≤0.003% is obtained after finishing blowing, low nitrogen alloy is added in molten steel tapping process；
C, LF refining：Molten steel obtained by step b is sent to LF ladle furnaces, is heated after calcium carbide and high alkalinity refining slag is added, is refined
After 20~30min, it is added quartz sand into molten steel, after refining 5~10min, molten steel Calcium treatment, molten steel is outbound after Argon；
D, RH is refined：After the completion of LF refining, molten steel is transferred to RH ladle furnaces and is vacuum-treated, be added low nitrogen alloy, at vacuum
After the completion of reason, Calcium treatment is carried out to molten steel, molten steel is outbound after Argon processing；
E, continuous casting：Continuous casting is carried out to molten steel obtained by step d.
2. the smelting process according to claim 1 for improving heavy rail steel cleanness, it is characterised in that：In step b, it is added the
Second of slag making materials, which is added, after slag making materials blowing 8~10min deslagging continues 5~8min of blowing, deslagging tapping.
3. the smelting process according to claim 1 or 2 for improving heavy rail steel cleanness, it is characterised in that：In step a, institute
The dosage for stating active lime is 4~6kg/t molten iron；The dosage of deactivating magnesium powder is 1~3kg/t molten iron.
4. improving the smelting process of heavy rail steel cleanness according to claims 1 to 3 any one of them, it is characterised in that：Step b
In the molten steel tapping process, when low nitrogen alloy is added for 1/2 or more in tap.
5. improving the smelting process of heavy rail steel cleanness according to Claims 1 to 4 any one of them, it is characterised in that：Step b
In the converting process, the blowing rifle position of oxygen rifle is controlled in 1.5~2.5m.
6. improving the smelting process of heavy rail steel cleanness according to Claims 1 to 5 any one of them, it is characterised in that：Step c
In, the dosage of the calcium carbide is 0.2~0.8kg/t molten steel；The dosage of the high alkalinity refining slag is 1~5kg/t molten steel；Institute
The dosage for stating quartz sand is 0.2~0.8kg/t molten steel.
7. improving the smelting process of heavy rail steel cleanness according to claim 1~6 any one of them, it is characterised in that：Step c
In d, the flow of the LF and RH refining Argon processing is 50~80NL/min, and the duration is 5~10min.
8. improving the smelting process of heavy rail steel cleanness according to claim 1~7 any one of them, it is characterised in that：Step d
In, the RH refining controllings vacuum degree≤100Pa is vacuum-treated 15~20min.
9. the method for improving heavy rail steel cleanness according to claim 1~8 any one of them, it is characterised in that：Step b and d
In, nitrogen content≤0.01% of the low nitrogen alloy of the converter smelting and RH refining additions.
10. the method for improving heavy rail steel cleanness according to claim 1~9 any one of them, it is characterised in that：In step e,
The casting process uses bloom continuous casting, is produced into the generous continuous casting billet product that cross section is 250mm × 250mm or more.
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Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
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| CN110904303A (en) * | 2019-10-31 | 2020-03-24 | 邯郸钢铁集团有限责任公司 | Smelting method of rail steel |
| CN112481545A (en) * | 2020-11-04 | 2021-03-12 | 邯郸钢铁集团有限责任公司 | Production method of high-cleanliness low-cost high-speed rail steel |
| CN115505818A (en) * | 2022-08-25 | 2022-12-23 | 包头钢铁（集团）有限责任公司 | Smelting method of high-carbon steel rail containing RE element |
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| CN1824816A (en) * | 2005-02-25 | 2006-08-30 | 宝钢集团上海梅山有限公司 | Steel for extended automobile crossbeam and mfg, method thereof |
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| CN115505818A (en) * | 2022-08-25 | 2022-12-23 | 包头钢铁（集团）有限责任公司 | Smelting method of high-carbon steel rail containing RE element |
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Application publication date: 20181113 |