CN116497178A - LF (ladle furnace) rapid deep desulfurization method for Q345R steel - Google Patents
LF (ladle furnace) rapid deep desulfurization method for Q345R steel Download PDFInfo
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- CN116497178A CN116497178A CN202310535019.5A CN202310535019A CN116497178A CN 116497178 A CN116497178 A CN 116497178A CN 202310535019 A CN202310535019 A CN 202310535019A CN 116497178 A CN116497178 A CN 116497178A
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- 229910000831 Steel Inorganic materials 0.000 title claims abstract description 71
- 239000010959 steel Substances 0.000 title claims abstract description 71
- 238000000034 method Methods 0.000 title claims abstract description 56
- 238000006477 desulfuration reaction Methods 0.000 title claims abstract description 55
- 230000023556 desulfurization Effects 0.000 title claims abstract description 55
- 238000009847 ladle furnace Methods 0.000 title description 37
- XAGFODPZIPBFFR-UHFFFAOYSA-N aluminium Chemical compound [Al] XAGFODPZIPBFFR-UHFFFAOYSA-N 0.000 claims abstract description 109
- 229910052782 aluminium Inorganic materials 0.000 claims abstract description 109
- 239000002893 slag Substances 0.000 claims abstract description 109
- XKRFYHLGVUSROY-UHFFFAOYSA-N Argon Chemical compound [Ar] XKRFYHLGVUSROY-UHFFFAOYSA-N 0.000 claims abstract description 100
- 229910052786 argon Inorganic materials 0.000 claims abstract description 50
- 230000005540 biological transmission Effects 0.000 claims abstract description 35
- NINIDFKCEFEMDL-UHFFFAOYSA-N Sulfur Chemical compound [S] NINIDFKCEFEMDL-UHFFFAOYSA-N 0.000 claims abstract description 34
- 238000003756 stirring Methods 0.000 claims abstract description 34
- 229910052717 sulfur Inorganic materials 0.000 claims abstract description 34
- 239000011593 sulfur Substances 0.000 claims abstract description 34
- 235000008733 Citrus aurantifolia Nutrition 0.000 claims abstract description 32
- 235000011941 Tilia x europaea Nutrition 0.000 claims abstract description 32
- 239000004571 lime Substances 0.000 claims abstract description 32
- 230000008569 process Effects 0.000 claims abstract description 25
- 238000010079 rubber tapping Methods 0.000 claims abstract description 23
- 238000005070 sampling Methods 0.000 claims abstract description 17
- 229910000616 Ferromanganese Inorganic materials 0.000 claims abstract description 10
- DALUDRGQOYMVLD-UHFFFAOYSA-N iron manganese Chemical compound [Mn].[Fe] DALUDRGQOYMVLD-UHFFFAOYSA-N 0.000 claims abstract description 10
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 claims description 18
- VYPSYNLAJGMNEJ-UHFFFAOYSA-N Silicium dioxide Chemical compound O=[Si]=O VYPSYNLAJGMNEJ-UHFFFAOYSA-N 0.000 claims description 18
- 229910052799 carbon Inorganic materials 0.000 claims description 18
- 239000011572 manganese Substances 0.000 claims description 16
- PWHULOQIROXLJO-UHFFFAOYSA-N Manganese Chemical compound [Mn] PWHULOQIROXLJO-UHFFFAOYSA-N 0.000 claims description 10
- WUKWITHWXAAZEY-UHFFFAOYSA-L calcium difluoride Chemical compound [F-].[F-].[Ca+2] WUKWITHWXAAZEY-UHFFFAOYSA-L 0.000 claims description 10
- 239000010436 fluorite Substances 0.000 claims description 10
- AMWRITDGCCNYAT-UHFFFAOYSA-L hydroxy(oxo)manganese;manganese Chemical compound [Mn].O[Mn]=O.O[Mn]=O AMWRITDGCCNYAT-UHFFFAOYSA-L 0.000 claims description 10
- 229910052748 manganese Inorganic materials 0.000 claims description 10
- 239000000203 mixture Substances 0.000 claims description 9
- 239000000377 silicon dioxide Substances 0.000 claims description 9
- 235000012239 silicon dioxide Nutrition 0.000 claims description 9
- CYUOWZRAOZFACA-UHFFFAOYSA-N aluminum iron Chemical compound [Al].[Fe] CYUOWZRAOZFACA-UHFFFAOYSA-N 0.000 claims description 8
- 238000007670 refining Methods 0.000 claims description 8
- 239000002253 acid Substances 0.000 claims description 5
- BRPQOXSCLDDYGP-UHFFFAOYSA-N calcium oxide Chemical compound [O-2].[Ca+2] BRPQOXSCLDDYGP-UHFFFAOYSA-N 0.000 claims description 5
- 239000000292 calcium oxide Substances 0.000 claims description 5
- ODINCKMPIJJUCX-UHFFFAOYSA-N calcium oxide Inorganic materials [Ca]=O ODINCKMPIJJUCX-UHFFFAOYSA-N 0.000 claims description 5
- UQSXHKLRYXJYBZ-UHFFFAOYSA-N iron oxide Inorganic materials [Fe]=O UQSXHKLRYXJYBZ-UHFFFAOYSA-N 0.000 claims description 5
- NDLPOXTZKUMGOV-UHFFFAOYSA-N oxo(oxoferriooxy)iron hydrate Chemical compound O.O=[Fe]O[Fe]=O NDLPOXTZKUMGOV-UHFFFAOYSA-N 0.000 claims description 5
- 230000001105 regulatory effect Effects 0.000 claims description 4
- 239000002245 particle Substances 0.000 claims description 2
- 238000005272 metallurgy Methods 0.000 abstract description 2
- 230000000694 effects Effects 0.000 description 8
- 239000000523 sample Substances 0.000 description 8
- 230000003009 desulfurizing effect Effects 0.000 description 7
- OAICVXFJPJFONN-UHFFFAOYSA-N Phosphorus Chemical compound [P] OAICVXFJPJFONN-UHFFFAOYSA-N 0.000 description 6
- XUIMIQQOPSSXEZ-UHFFFAOYSA-N Silicon Chemical compound [Si] XUIMIQQOPSSXEZ-UHFFFAOYSA-N 0.000 description 6
- 229910001570 bauxite Inorganic materials 0.000 description 6
- 230000000052 comparative effect Effects 0.000 description 6
- 229910052698 phosphorus Inorganic materials 0.000 description 6
- 239000011574 phosphorus Substances 0.000 description 6
- 229910052710 silicon Inorganic materials 0.000 description 6
- 239000010703 silicon Substances 0.000 description 6
- 238000007664 blowing Methods 0.000 description 5
- WPBNNNQJVZRUHP-UHFFFAOYSA-L manganese(2+);methyl n-[[2-(methoxycarbonylcarbamothioylamino)phenyl]carbamothioyl]carbamate;n-[2-(sulfidocarbothioylamino)ethyl]carbamodithioate Chemical compound [Mn+2].[S-]C(=S)NCCNC([S-])=S.COC(=O)NC(=S)NC1=CC=CC=C1NC(=S)NC(=O)OC WPBNNNQJVZRUHP-UHFFFAOYSA-L 0.000 description 5
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 description 4
- 229910052760 oxygen Inorganic materials 0.000 description 4
- 239000001301 oxygen Substances 0.000 description 4
- 229910045601 alloy Inorganic materials 0.000 description 3
- 239000000956 alloy Substances 0.000 description 3
- 230000001276 controlling effect Effects 0.000 description 3
- 230000002349 favourable effect Effects 0.000 description 3
- 238000002360 preparation method Methods 0.000 description 3
- 239000000047 product Substances 0.000 description 3
- 239000013589 supplement Substances 0.000 description 3
- 229910000519 Ferrosilicon Inorganic materials 0.000 description 2
- XEEYBQQBJWHFJM-UHFFFAOYSA-N Iron Chemical compound [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 description 2
- 229910000720 Silicomanganese Inorganic materials 0.000 description 2
- 230000009286 beneficial effect Effects 0.000 description 2
- 238000009529 body temperature measurement Methods 0.000 description 2
- 238000009749 continuous casting Methods 0.000 description 2
- 230000003111 delayed effect Effects 0.000 description 2
- 238000007599 discharging Methods 0.000 description 2
- 238000005516 engineering process Methods 0.000 description 2
- 238000010438 heat treatment Methods 0.000 description 2
- PYLLWONICXJARP-UHFFFAOYSA-N manganese silicon Chemical compound [Si].[Mn] PYLLWONICXJARP-UHFFFAOYSA-N 0.000 description 2
- 238000004519 manufacturing process Methods 0.000 description 2
- 238000002844 melting Methods 0.000 description 2
- 230000008018 melting Effects 0.000 description 2
- 230000004048 modification Effects 0.000 description 2
- 238000012986 modification Methods 0.000 description 2
- 230000001502 supplementing effect Effects 0.000 description 2
- 230000002378 acidificating effect Effects 0.000 description 1
- 239000011230 binding agent Substances 0.000 description 1
- 230000008859 change Effects 0.000 description 1
- 238000006243 chemical reaction Methods 0.000 description 1
- 239000003153 chemical reaction reagent Substances 0.000 description 1
- 239000013068 control sample Substances 0.000 description 1
- 238000001816 cooling Methods 0.000 description 1
- 238000005520 cutting process Methods 0.000 description 1
- 230000007547 defect Effects 0.000 description 1
- 239000007789 gas Substances 0.000 description 1
- 239000011521 glass Substances 0.000 description 1
- 230000006872 improvement Effects 0.000 description 1
- 229910052742 iron Inorganic materials 0.000 description 1
- XWHPIFXRKKHEKR-UHFFFAOYSA-N iron silicon Chemical compound [Si].[Fe] XWHPIFXRKKHEKR-UHFFFAOYSA-N 0.000 description 1
- 239000000463 material Substances 0.000 description 1
- 238000002156 mixing Methods 0.000 description 1
- 230000009467 reduction Effects 0.000 description 1
- 229920006395 saturated elastomer Polymers 0.000 description 1
- 230000007306 turnover Effects 0.000 description 1
Classifications
-
- 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
-
- 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
-
- 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
-
- 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
-
- 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
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
- Y02P10/00—Technologies related to metal processing
- Y02P10/20—Recycling
Landscapes
- Chemical & Material Sciences (AREA)
- Engineering & Computer Science (AREA)
- Materials Engineering (AREA)
- Metallurgy (AREA)
- Organic Chemistry (AREA)
- Treatment Of Steel In Its Molten State (AREA)
Abstract
The invention discloses a method for LF rapid deep desulfurization of Q345R steel, belonging to the technical field of metallurgy. The method comprises the following steps: in the tapping process of the converter, lime, an aluminum-containing deoxidizer and ferromanganese are added, and sampling is carried out in an argon station after tapping is finished; molten steel is delivered to an LF furnace treatment position, the entering temperature is 1510-1530 ℃, argon with the temperature of 50-60 cubic meters per hour is adopted to blow off a slag shell, then small gear potential is used for power transmission and arcing, slag is added in batches for slag making, the electrode is changed to a gear potential after being stabilized, after the slag is added, aluminum wires are fed to mix acid-soluble aluminum to 0.060-0.065%, the temperature of the molten steel is raised to 1590-1600 ℃, and power is cut off; stirring with 100-120 cubic meters/hour argon, turning off argon sampling two, and completing desulfurization when the sulfur content of molten steel is below 0.002%. By adopting the method, the desulfurization time is 20-22 minutes, and the acid-soluble aluminum can be controlled in a proper range at the same time of desulfurization.
Description
Technical Field
The invention relates to the technical field of metallurgy, in particular to a method for rapidly and deeply desulfurizing LF of Q345R steel.
Background
The boiler container steel such as Q345R requires molten steel sulfur less than or equal to 0.002%, acid-soluble aluminum 0.015% -0.030%, LF+RH technology, in the case of the shapesteel target technology, LF furnace deep desulfurization treatment is required, converter endpoint sulfur is 0.040% or less, except 500 kg lime, 300 kg bauxite, 140 kg aluminum iron, other silicon manganese, high manganese, low manganese, silicon iron and the like are added during converter tapping, 800-1100 kg lime, 180-220 kg fluorite and 200 kg aluminum slag are also added in LF, and the process needs 30-35 minutes to remove sulfur.
The basic operation is that molten steel is fed into an LF furnace treatment position, slag is firstly added for 2 minutes, stirring is continued for 3 minutes, 100 cubic meters/hour of argon is used for transmitting power for 15 minutes after stirring, then 100 cubic meters/hour of argon is used for stirring for 2 minutes, sampling is carried out for about 6 minutes, the process of waiting for samples is continued to transmit 60 cubic meters/hour of argon, lime, aluminum slag and fluorite are continuously supplemented after the samples are discharged, 100 cubic meters/hour of argon is used for desulfurization, stirring is carried out for 4 minutes, sampling of the second argon is closed, and the results of the samples are obtained. The total time is 32 minutes, and if the components are qualified, the outlet temperature is controlled.
The continuous casting and drawing period is 35 minutes, molten steel passes through LF and then reaches RH, and continuous casting is carried out after treatment, and a crown block is required to turn over for many times, so that it is critical that the LF furnace can not remove sulfur rapidly, otherwise, the sulfur is found to be not removed when the second sample is found to be out, and the production is seriously influenced. The ideal result is that sulfur is removed to the extent at the time of sampling, as the pressure at LF is much easier.
In view of the foregoing, it is desirable to provide a method for LF fast deep desulfurization of Q345R steel.
Disclosure of Invention
The invention aims to overcome the defects of the prior art and provide a method for rapidly and deeply desulfurizing LF of Q345R steel.
The invention solves the technical problems by adopting the following technical scheme.
The embodiment of the invention provides a method for LF fast deep desulfurization of Q345R steel, which comprises the following steps:
in the tapping process of the converter, lime, an aluminum-containing deoxidizer and ferromanganese are added, and sampling is carried out in an argon station after tapping is finished; molten steel is delivered to an LF furnace treatment position, the entering temperature is 1510-1530 ℃, argon with the temperature of 50-60 cubic meters per hour is adopted to blow off a slag shell, then small gear potential is used for power transmission and arcing, slag is added in batches for slag making, the electrode is changed to a gear potential after being stabilized, after the slag is added, aluminum wires are fed to mix acid-soluble aluminum to 0.060-0.065%, the temperature of the molten steel is raised to 1590-1600 ℃, and power is cut off; stirring with 100-120 cubic meters/hour argon, turning off argon sampling two, and completing desulfurization when the sulfur content of molten steel is below 0.002%.
The invention has the following beneficial effects:
the invention provides a method for LF fast deep desulfurization of Q345R steel, which comprises the following steps: lime, aluminum-containing deoxidizer and ferromanganese are added in the tapping process of the converter, the alkalinity and carbon content of molten steel are improved while deoxidizing, and the tapping is carried out and then sampling is carried out in an argon station; turning on an LF furnace, turning on bottom argon blowing, feeding power while adding slag in batches to produce slag with good fluidity, feeding aluminum wires to control the content of acid-soluble aluminum in molten steel, on one hand, increasing the fluidity of slag, improving the desulfurization reaction coefficient, and on the other hand, creating conditions for RH treatment, so that RH does not need to be matched with aluminum in the circulation process, controlling the content of acid-soluble aluminum in a finished product to be 0.015% -0.030%, heating and argon blowing stirring after aluminum matching until sulfur is removed to be less than 0.002%, and desulfurizing is completed.
Detailed Description
In order to make the objects, technical solutions and advantages of the embodiments of the present invention more clear, the technical solutions of the embodiments of the present invention will be clearly and completely described below. The specific conditions are not noted in the examples and are carried out according to conventional conditions or conditions recommended by the manufacturer. The reagents or apparatus used were conventional products commercially available without the manufacturer's attention.
The method for LF fast deep desulfurization of Q345R steel provided by the embodiment of the invention is specifically described below.
The embodiment of the invention provides a method for LF fast deep desulfurization of Q345R steel, which comprises the following steps:
in the tapping process of the converter, lime, an aluminum-containing deoxidizer and ferromanganese are added, and sampling is carried out in an argon station after tapping is finished; molten steel is delivered to an LF furnace treatment position, the entering temperature is 1510-1530 ℃, argon with the temperature of 50-60 cubic meters per hour is adopted to blow off a slag shell, then small gear potential is used for power transmission and arcing, slag is added in batches for slag making, the electrode is changed to a gear potential after being stabilized, after the slag is added, aluminum wires are fed to mix acid-soluble aluminum to 0.060-0.065%, the temperature of the molten steel is raised to 1590-1600 ℃, and power is cut off; stirring with 100-120 cubic meters/hour argon, turning off argon sampling two, and completing desulfurization when the sulfur content of molten steel is below 0.002%.
In an alternative embodiment, the end point carbon of the converter is 0.06-0.11%, the manganese is 0.09-0.15%, and 400-700 kg of lime, 120-160 kg of aluminum-containing deoxidizer and 1400-2000 kg of ferromanganese are added in the tapping process, calculated by 120 tons of molten steel;
preferably, lime, aluminum-containing deoxidizer and ferromanganese are added in the tapping process of the converter, the carbon content of molten steel is regulated to the middle lower limit, and the alkalinity is regulated to 10-15;
preferably, the aluminum-containing deoxidizer includes at least one of aluminum slag, aluminum particles, and aluminum iron.
In an alternative embodiment, the slag charge is started after the small gear potential is adopted to transmit power for 50-60 seconds;
preferably, the slag comprises lime, fluorite, synthetic slag and aluminum slag; the slag charge dosage is as follows: 500-550 kg of lime, 380-430 kg of synthetic slag, 100-110 kg of fluorite and 170-190 kg of aluminum slag;
preferably, the feeding mode is as follows: adding fluorite, synthetic slag and lime, and then adding 3 batches of aluminum slag, wherein the total time of feeding is controlled to be 4-5.5 minutes;
more preferably, the feed rate is 230-270 kg of slag per minute.
In an alternative embodiment, slag is added in the small-gear potential power transmission process, and after submerged arc rotation, the temperature can be quickly increased by using a large gear, and the original gear can be kept to continue power transmission;
preferably, after the submerged arc is well rotated, the original gear is kept to continuously transmit power, after slag is added, the electrode is lifted up after power failure, and then large-gear potential power transmission is performed, and the aluminum wire is fed.
In an alternative embodiment, the small-gear power transmission gear is 8 gears, 7 gears, 6 gears and 5 gears, the corresponding active power is 8500KW, 9000KW, 10000KW and 11000KW, the large-gear power transmission gear is 4 gears, 3 gears and 2 gears, and the corresponding active power is 12500KW, 13500KW and 15000KW;
preferably, the power transmission time is 15-17.5 minutes.
In an alternative embodiment, the amount of aluminum wire fed is: according to argon station one, 0.001% acid-soluble aluminum is added every 5 m, and aluminum wire is added according to calculated amount.
In an alternative embodiment, the LF outbound acid soluble aluminum is controlled to be between 0.038% and 0.042% so that RH is no longer aluminum in the circulating process and the finished acid soluble aluminum content is controlled to be between 0.015% and 0.030%.
In an alternative embodiment, 100-120 cubic meters/hour of argon is used for stirring for 4-5 minutes after power down.
In an alternative embodiment, the composition of the control sample di-refining slag is as follows: 52-57 parts of calcium oxide, 2.9-4.2 parts of silicon dioxide, 0.16-0.57 part of manganese oxide, 0.75-1.88 parts of ferric oxide and 12-18 parts of alkalinity.
In an alternative embodiment, the desulfurization time is 19-22 minutes.
The method for LF fast deep desulfurization of the Q345R steel comprises the following steps:
step 1: lime, aluminum iron and ferromanganese are added in the tapping process of the converter, and silicomanganese and ferrosilicon are not added. The purpose is not to generate silicon dioxide, because the silicon dioxide is an acidic oxide, the alkalinity of slag is reduced, and under the conditions of good slag fluidity and good deoxidization, the higher the alkalinity is, the faster the desulfurization is.
Step 2: after molten steel reaches an LF furnace, argon with the speed of 50-60 cubic meters per hour is adopted, power transmission gear with the speed of 8-5 gears is used for power transmission arcing, the electrode is stably rotated to 4-2 gears, slag is added in batches during power transmission, aluminum wires are fed after the slag is added, acid-soluble aluminum is directly mixed to 0.060% -0.065%, and the aluminum feeding amount is calculated according to the first argon station sample and 0.001% increase of each 5 meters. The aluminum is prepared in such a way, firstly, the acid-soluble aluminum of the LF outlet is controlled to be 0.038% -0.042%, and conditions are created for RH treatment, so that the RH does not need to be prepared in the circulation process, and the acid-soluble aluminum of the finished product can be 0.015% -0.030%; secondly, for quick desulfurization, the higher the acid-soluble aluminum in molten steel is, the more favorable is for desulfurization, the acid-soluble aluminum loss is about 0.001% per minute when the LF refining process is powered on, and about 0.003% per minute is lost when stirring, so that the acid-soluble aluminum loss is about 0.030% when stirring for 15 minutes and the power on and 5 minutes, thus, the deoxidization influence of the tapping process can be deviated, the acid-soluble aluminum range is 0.030% -0.040% when sampling II, and the more or less can be adjusted according to the tested components because the distance is not far from the target components, thereby being beneficial to accurately controlling the acid-soluble aluminum of the outlet and controlling the desulfurization amount of molten steel at the highest limit.
Step 3: during slag adding and melting (0-6 minutes of power transmission), the submerged arc loss is reduced by using 8-7 gears, the temperature is raised by 3 ℃ per minute, after slag is melted, the power transmission gear can be quickly raised by using a large gear, for example, 2 gears, the temperature is raised by 8 ℃ per minute, the temperature of molten steel is raised to 1590-1600 ℃, the temperature of molten steel reaches a station 1520 ℃, the temperature of slag adding and cooling is 25 ℃, the temperature is raised to 1597 ℃, 1520-25+6x3+10.5x8=1597, and the time is 16.5 minutes. In theory, the higher the temperature is, the more favorable the desulfurization is, but the higher the temperature is, the stronger the molten steel is sucked, namely the faster the acid-soluble aluminum in the molten steel burns out, and the desulfurizing capability of the molten steel is correspondingly weakened along with the reduction of the acid-soluble aluminum in the molten steel, so in practice, the desulfurizing effect is better by taking the temperature range. Through practice, the sulfur is stirred after the power is transmitted and the temperature is increased to 1560 ℃, but the sulfur is stirred after the temperature is increased to 1630 ℃, the desulfurization effect is similar to that of the stirring when the power is increased to 1590-1600 ℃, and the time is relatively delayed.
Step 4: stirring with 100 cubic meters/hour of argon for 4-5 minutes, and sampling with argon was turned off. The stirring time is less than 3 minutes, and the desulfurization time is often insufficient, so in order to ensure that one desulfurization is successful, we can stir for a little time, but the stirring is more than 6 minutes, the desulfurization is not obvious, namely if the stirring is carried out for 5 minutes, the desulfurization can be removed from 0.028% to 0.002%, the stirring is carried out for 6 minutes and 7 minutes, and the sulfur can be reduced to 0.0019%, so that the desulfurization is not obvious.
Through the steps, the slag comprises the following components: 52-57 of calcium oxide, 2.9-4.2 of silicon dioxide, 0.16-0.57 of manganese oxide, 12-18 of alkalinity and 0.75-1.88 of ferric oxide, sulfur can be stably removed below 0.002% basically in 20-22 minutes during desulfurization, and the subsequent refining operation is conventional alloy preparation and outlet temperature control.
The features and capabilities of the present invention are described in further detail below in connection with the examples.
Example 1
The method for rapidly deeply desulfurizing the LF of the Q345R steel comprises the following steps of:
step 1: the end point of the converter is 0.066 percent of carbon and 0.126 percent of manganese, 600 kg of lime and 150 kg of aluminum iron are added in the tapping process, 0.01 percent of high manganese is added for every 250 kg of carburetion, 0.14 to 0.15 percent of carbon is added, 2000 kg of carbon is added, and the steel is sampled to an argon station after the steel is discharged. The components are as follows:
| composition of the components | Carbon (C) | Silicon (Si) | Manganese (Mn) | Phosphorus (P) | Sulfur (S) | Acid-soluble aluminum |
| Content% | 0.146 | 0.008 | 1.243 | 0.015 | 0.027 | 0.009 |
Step 2: after molten steel reaches an LF furnace, measuring the temperature to 1518 ℃, blowing off a slag shell by adopting 50 cubic meters per hour of argon, then feeding power to an arc starting power transmission gear of 8 grades, adding 110 kg fluorite, 400 kg synthetic slag, 500 kg lime and 180 kg aluminum slag in batches while feeding power, starting to add slag in the total amount of 1190 kg at 50 seconds of power transmission, adding 250 kg per minute in batches, adding slag in the 6 minutes of power transmission, then powering off and lifting an electrode, calculating the aluminum feeding amount by 0.001 percent per 5 meters according to an argon station sample, feeding an aluminum wire 270 meters, adding acid-soluble aluminum 270/5 to 0.001 percent=0.054 percent, and directly adding the acid-soluble aluminum to 0.009 percent+0.0054 percent=0.063 percent.
Step 3: after 4 minutes of power transmission, the submerged arc is well turned, the temperature can be quickly raised by using a large gear, and the original gear can be kept for continuous power transmission, because the power is cut off and the electrode is lifted when the aluminum wire is fed, the gear shifting is better for the electric appliance under the power cut-off condition, then the gear shifting is carried out when the aluminum wire is fed, the gear shifting is carried out, the temperature is raised by 8 ℃ per minute, the power transmission is carried out for 11 minutes, and the temperature of molten steel is raised to 1518-25+6x3+1x8=1599 ℃. Power transmission time was 17 minutes.
Step 4: after power failure, 110 cubic meters/hour of argon is used for stirring for 4.5 minutes, and then argon is turned down to take a slag sample. The slag comprises the following components: 55.6 parts of calcium oxide, 3.9 parts of silicon dioxide, 0.26 part of manganese oxide, 14.2 parts of alkalinity and 0.99 part of ferric oxide, wherein the total desulfurization time is 17 minutes and 4.5 minutes = 21.5 minutes, the temperature measurement is 1576 ℃, and the components of a molten steel sample are as follows:
| composition of the components | Carbon (C) | Silicon (Si) | Manganese (Mn) | Phosphorus (P) | Sulfur (S) | Acid-soluble aluminum |
| Content% | 0.152 | 0.033 | 1.299 | 0.016 | 0.002 | 0.041 |
Through the steps, sulfur can be basically and stably removed to less than 0.002%, and the subsequent refining operation is conventional alloy preparation and outlet temperature control. Continuously transmitting power for 400 seconds by 4 grades, supplementing 30 meters of aluminum wires, 270 kilograms of ferrosilicon, 200 kilograms of high manganese, measuring the temperature to 1610 ℃, and taking out the station, wherein the sampling components are as follows:
| composition of the components | Carbon (C) | Silicon (Si) | Manganese (Mn) | Phosphorus (P) | Sulfur (S) | Acid-soluble aluminum |
| Content% | 0.163 | 0.202 | 1.399 | 0.016 | 0.002 | 0.040 |
Example 2
The method for rapidly deeply desulfurizing the LF of the Q345R steel comprises the following steps of:
step 1: the end point of the converter is 0.088 percent of carbon and 0.107 percent of manganese, 500 kg of lime and 125 kg of aluminum iron are added in the tapping process, 0.01 percent of high manganese is added for every 250 kg of carburetion, 0.14 to 0.15 percent of carbon is added, 1500 kg of carbon is added, and the steel is sampled to an argon station after the steel is discharged. The components are as follows:
| composition of the components | Carbon (C) | Silicon (Si) | Manganese (Mn) | Phosphorus (P) | Sulfur (S) | Acid-soluble aluminum |
| Content% | 0.148 | 0.008 | 93.6 | 0.016 | 0.032 | 0.012 |
Step 2: after molten steel is fed into an LF furnace, measuring the temperature to 1512 ℃, blowing off a slag shell by adopting 60 cubic meters per hour of argon, then feeding power to an 8-gear power transmission gear for arcing, feeding power to begin feeding slag at 50 seconds, feeding 110 kg fluorite, 400 kg synthetic slag, 500 kg lime and 180 kg aluminum slag in batches while feeding power, feeding the total amount of 1190 kg in batches by adding 240 kg per minute, feeding slag in batches when feeding power for 6 minutes, then cutting off power, lifting an electrode, calculating the aluminum feeding amount by adding 0.001 percent per 5 meters according to an argon station sample, feeding an aluminum wire of 260 meters, adding the acid-soluble aluminum amount of 260.001 percent to 0.052 percent of the molten steel by adding 260/5, and directly distributing the acid-soluble aluminum to 0.012 percent+0.0052 percent=0.064 percent.
Step 3: after 4 minutes of power transmission, submerged arc is well converted, 2-gear power transmission is used, the electrode is lifted to feed aluminum wires after the slag is added, and then the power is cut off, the aluminum wires are fed, the power transmission is continued for 12 minutes, and the temperature of molten steel is raised to 1512-25+4x3+12x8=1595 ℃. Power transmission takes 16 minutes.
Step 4: after power failure, 115 cubic meters/hour of argon is used for stirring for 5 minutes, and then the argon is turned down to take a slag sample. The slag comprises the following components: 54.5 of calcium oxide, 3.3 of silicon dioxide, 0.16 of manganese oxide, 16.5 of alkalinity and 0.88 of ferric oxide, the total desulfurization time is 16 minutes+5 minutes=21 minutes, the temperature measurement is 1572 ℃, and the components of the molten steel sample are as follows:
| composition of the components | Carbon (C) | Silicon (Si) | Manganese (Mn) | Phosphorus (P) | Sulfur (S) | Acid-soluble aluminum |
| Content% | 0.156 | 0.033 | 0.957 | 0.016 | 0.002 | 0.038 |
Through the steps, sulfur can be basically and stably removed to less than 0.002%, and the subsequent refining operation is conventional alloy preparation and outlet temperature control. Continuously transmitting power for 500 seconds by 4 grades, supplementing 40 meters of aluminum wires, 790 kilograms of silicomanganese, measuring the temperature to 1611 ℃, and taking out, wherein the sampling components are as follows:
| composition of the components | Carbon (C) | Silicon (Si) | Manganese (Mn) | Phosphorus (P) | Sulfur (S) | Acid-soluble aluminum |
| Content% | 0.165 | 0.202 | 1.405 | 0.016 | 0.002 | 0.040 |
Comparative example 1
Similar to the procedure of example 1, the only difference is that: the slag material does not contain synthetic slag, and the result is that: the sulfur content was 0.003%.
The synthetic slag is mixed slag of lime and bauxite accounting for approximately 50% of the total weight of the synthetic slag and other binders, and is easier to melt compared with lime, if the synthetic slag is changed into the synthetic slag with the weight of 200 kg of lime and 200 kg of bauxite, when slag is added in refining, if the synthetic slag and the bauxite are added together, the synthetic slag is easy to fill out of a belt, and in the production operation standard, the synthetic slag and the bauxite are only added in the same way and cannot be mixed. If a little lime is added, the lime is stopped, then a little bauxite is added, the lime is stopped, and the operation is repeated for N times to achieve the effect of mixing and adding, so that the operation is troublesome, and the metallurgical effect is good without synthetic slag.
That is why the total amount of slag and slag composition are considered, and the larger the total amount of slag is, the higher the cost is, so that the smaller the amount of slag is on the basis of meeting the quality requirement, so that the amount of synthetic slag is as small as possible, and if the lime is selected to be reduced, the alkalinity of the slag is insufficient; the alkalinity of the slag is considered, the proportion of the synthetic slag is higher, the alkalinity in the slag is reduced, the converter slag discharging and the furnace number of slag discharging are also considered, the silicon dioxide in the slag is higher, the alkalinity of the slag is lower, so that 380-430 kg of synthetic slag is taken, even if a little slag is discharged, the final slag alkalinity is proper, and the range can be reached.
Comparative example 2
Similar to the procedure of example 1, the only difference is that: after the aluminum wire is added, the temperature is raised to 1570 ℃, and the result is that: the sulfur content was 0.004%.
In the attack work of the shortest time quick desulfurization, we try desulfurization at different temperatures, find that the desulfurization effect is good and stable when the temperature is 1590 ℃ or above, but the influence change on the desulfurization is not obvious along with the temperature rise, so that the stirring of argon can be used for breaking the power when the temperature of molten steel rises to 1590 ℃ or above. When the temperature of the molten steel reaches 1590 ℃ or above, power transmission is continued, and the desulfurization time is naturally delayed, and the range of 19-22 minutes is exceeded.
However, when the temperature of molten steel is 1570 ℃ or below, the electrode is lifted by stirring with large argon gas when power is off, the desulfurization effect is much worse, the effect is worse when the temperature is lower, and the stirring is further performed when the temperature is required to be 1590 ℃ or above, so that the operation result is stable.
Comparative example 3
Similar to the procedure of example 1, the only difference is that: the alkalinity of molten steel is 4, and the result is: the sulfur content was 0.009%.
In the prior art, 2000-2400 kg of silicon-manganese components are used in the tapping process of the converter, so that the slag contains high silicon dioxide, generally about 10, and the alkalinity in the slag is reduced to 3-6, so that the prior LF furnace is only required to be supplemented with 700-1000 kg of lime, otherwise the slag can become glass slag, and the desulfurization capability is greatly reduced.
If the alkalinity is increased to more than 20, the lime addition amount, the aluminum wire feeding amount, the heating power consumption and the argon stirring are definitely more than those in the embodiment 1, the cost is high, and the desulfurization effect is not obvious. Because the desulfurization condition still needs high temperature, low oxygen, high alkalinity and large argon stirring, the desulfurization is much worse in absence of one condition, but meets or exceeds one condition, the desulfurization is not good, and the sulfur in the molten steel is low.
Comparative example 4
Similar to the procedure of example 1, the only difference is that: the amount of the fed aluminum wire is 400 meters, and the result is that: the sulfur content was 0.002%.
The higher the acid-soluble aluminum in the molten steel, the more favorable and more stable the desulfurization, but the unfavorable the LF outbound component control, the same operation, LF outbound acid-soluble aluminum is 0.050%, which exceeds the upper limit of the range. If argon is used for stirring or slag is added for adsorbing part of acid-soluble aluminum, the cost is wasted, and the quality of molten steel is also not necessarily good.
If only 100 meters of aluminum wire is fed and the acid soluble aluminum is blended to 0.029%, then desulfurization is much worse, resulting in 0.008%.
In the test process, the influence of acid-soluble aluminum in molten steel on desulfurization is researched, and the result is that the higher the acid-soluble aluminum is, the faster and the more stable the desulfurization is, wherein when the acid-soluble aluminum in the molten steel reaches 0.050% or more, the desulfurization is very stable, and the aluminum is less added in the later stage of refining, so that the burning loss range of the acid-soluble aluminum is collected when large argon is mixed, finally, after slag melting is stabilized, the acid-soluble aluminum is added to 0.060-0.065%, basically until sampling is completed, sulfur can be stably removed to the range, and the acid-soluble aluminum in the molten steel is close to the outlet range of an LF furnace, so that the later-stage aluminum supplement or aluminum supplement is not needed, and the aim of aluminum supplement is fulfilled after the molten steel reaches an RH furnace is fulfilled.
Comparative example 5
Similar to the procedure of example 1, the only difference is that: the argon blowing stirring time was increased by 2 minutes, resulting in: the sulfur content was 0.0017%.
When we studied that the molten steel temperature was above 1590 ℃, the effect of stirring time on desulfurization was such that the first 5 minutes increased with time and significantly increased, but after exceeding 5 minutes, increased with time and did not significantly increase, and since the desulfurization ability of slag was saturated under stirring with large argon, desulfurization was not apparent after 5 minutes of stirring. In the practical process, the stirring is carried out for 4 minutes, and the sulfur can be basically removed to 0.002%, so that the sulfur can be removed to 0.002% or below after the sulfur is added for 0.5-1 minute, and the cost is wasted by continuously stirring.
Comparative example 6
Similar to the procedure of example 1, the only difference is that: 50 kg of aluminum iron is added in converter tapping, and the result is that: the sulfur content was 0.015%.
Because the aluminum iron added in the tapping is insufficient in deoxidization, the acid-soluble aluminum is 0, and the molten steel also has higher oxygen, the LF process is insufficient in acid-soluble aluminum, the slag is poor in deoxidization, and the desulfurization is seriously affected.
When tapping from the converter, carbon and oxygen are determined by an instrument, and the addition amount of aluminum and iron for deoxidization is calculated according to the oxygen content, so that the molten steel is ensured to have more acid-soluble aluminum after the steel is discharged. However, if 300 kg is added, deoxidation is certainly good, but the cost is high because the yield of the addition of the LF furnace is higher compared with that of the addition of the LF furnace.
The above is only a preferred embodiment of the present invention, and is not intended to limit the present invention, but various modifications and variations can be made to the present invention by those skilled in the art. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.
Claims (10)
1. A method for LF rapid deep desulfurization of Q345R steel, comprising the steps of:
in the tapping process of the converter, lime, an aluminum-containing deoxidizer and ferromanganese are added, and sampling is carried out in an argon station after tapping is finished; molten steel is delivered to an LF furnace treatment position, the entering temperature is 1510-1530 ℃, argon with the temperature of 50-60 cubic meters per hour is adopted to blow off a slag shell, then small gear potential is used for power transmission and arcing, slag is added in batches for slag making, the electrode is changed to a gear potential after being stabilized, after the slag is added, aluminum wires are fed to mix acid-soluble aluminum to 0.060-0.065%, the temperature of the molten steel is raised to 1590-1600 ℃, and power is cut off; stirring with 100-120 cubic meters/hour argon, turning off argon sampling two, and completing desulfurization when the sulfur content of molten steel is below 0.002%.
2. The method according to claim 1, wherein the converter endpoint carbon is 0.06-0.11%, the manganese is 0.09-0.15%, and 400-700 kg of lime, 120-160 kg of aluminum-containing deoxidizer and 1400-2000 kg of ferromanganese are added in the tapping process, based on 120 tons of molten steel;
preferably, lime, aluminum-containing deoxidizer and ferromanganese are added in the tapping process of the converter, the carbon content of molten steel is regulated to the middle lower limit, and the alkalinity is regulated to 10-15;
preferably, the aluminum-containing deoxidizer includes at least one of aluminum slag, aluminum particles, and aluminum iron.
3. The method of claim 1, wherein the slag charging is restarted after 50-60 seconds of power transmission by using a small gear potential;
preferably, the slag comprises lime, fluorite, synthetic slag and aluminum slag; the slag charge dosage is as follows: 500-550 kg of lime, 380-430 kg of synthetic slag, 100-110 kg of fluorite and 170-190 kg of aluminum slag;
preferably, the feeding mode is as follows: adding fluorite, synthetic slag and lime, and then adding 3 batches of aluminum slag, wherein the total time of feeding is controlled to be 4-5.5 minutes;
more preferably, the feed rate is 230-270 kg of slag per minute.
4. The method of claim 1, wherein slag is added in the process of power transmission by adopting a small gear potential, and after submerged arc rotation, the temperature can be quickly increased by using a large gear, and the power transmission can be continued by maintaining the original gear;
preferably, after the submerged arc is well rotated, the original gear is kept to continuously transmit power, after slag is added, the electrode is lifted up after power failure, and then large-gear potential power transmission is performed, and the aluminum wire is fed.
5. The method according to claim 4, wherein the small-gear power transmission gear is 8, 7, 6, 5, corresponding to the active power being 8500KW, 9000KW, 10000KW, 11000KW, the large-gear power transmission gear is 4, 3, 2, corresponding to the active power being 12500KW, 13500KW, 15000KW;
preferably, the power transmission time is 15-17.5 minutes.
6. The method of claim 1, wherein the amount of aluminum wire fed is: according to argon station one, 0.001% acid-soluble aluminum is added every 5 m, and aluminum wire is added according to calculated amount.
7. The method of claim 6, wherein the LF outbound acid soluble aluminum is controlled to be between 0.038% and 0.042% so that RH is no longer aluminum in the circulating process and the finished acid soluble aluminum content is controlled to be between 0.015% and 0.030%.
8. The method of claim 1, wherein 100-120 cubic meters/hour of argon is used for stirring for 4-5 minutes after power down.
9. The method of claim 7, wherein the composition of the sample di-refining slag is controlled as follows: 52-57 parts of calcium oxide, 2.9-4.2 parts of silicon dioxide, 0.16-0.57 part of manganese oxide, 0.75-1.88 parts of ferric oxide and 12-18 parts of alkalinity.
10. The method of claim 1, wherein the total desulfurization time is 19 to 22 minutes.
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| CN101654722A (en) * | 2009-09-23 | 2010-02-24 | 秦皇岛首秦金属材料有限公司 | External refining ternary synthetic slag for pipe line steel and using method |
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