CN111286666A - Cleanliness control method for IF deep drawing steel - Google Patents
Cleanliness control method for IF deep drawing steel Download PDFInfo
- Publication number
- CN111286666A CN111286666A CN202010100971.9A CN202010100971A CN111286666A CN 111286666 A CN111286666 A CN 111286666A CN 202010100971 A CN202010100971 A CN 202010100971A CN 111286666 A CN111286666 A CN 111286666A
- Authority
- CN
- China
- Prior art keywords
- steel
- equal
- casting
- molten iron
- less
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
Links
Classifications
-
- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22C—ALLOYS
- C22C33/00—Making ferrous alloys
- C22C33/04—Making ferrous alloys by melting
- C22C33/06—Making ferrous alloys by melting using master alloys
-
- 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
- C21C1/00—Refining of pig-iron; Cast iron
- C21C1/02—Dephosphorising or 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
- 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
-
- 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
- C21C7/04—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
- C21C7/04—Removing impurities by adding a treating agent
- C21C7/068—Decarburising
-
- C—CHEMISTRY; METALLURGY
- C21—METALLURGY OF IRON
- C21C—PROCESSING OF PIG-IRON, e.g. REFINING, MANUFACTURE OF WROUGHT-IRON OR STEEL; TREATMENT IN MOLTEN STATE OF FERROUS ALLOYS
- C21C7/00—Treating molten ferrous alloys, e.g. steel, not covered by groups C21C1/00 - C21C5/00
- C21C7/04—Removing impurities by adding a treating agent
- C21C7/072—Treatment with gases
-
- C—CHEMISTRY; METALLURGY
- C21—METALLURGY OF IRON
- C21C—PROCESSING OF PIG-IRON, e.g. REFINING, MANUFACTURE OF WROUGHT-IRON OR STEEL; TREATMENT IN MOLTEN STATE OF FERROUS ALLOYS
- C21C7/00—Treating molten ferrous alloys, e.g. steel, not covered by groups C21C1/00 - C21C5/00
- C21C7/04—Removing impurities by adding a treating agent
- C21C7/076—Use of slags or fluxes as treating agents
-
- 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
-
- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22C—ALLOYS
- C22C38/00—Ferrous alloys, e.g. steel alloys
- C22C38/02—Ferrous alloys, e.g. steel alloys containing silicon
-
- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22C—ALLOYS
- C22C38/00—Ferrous alloys, e.g. steel alloys
- C22C38/04—Ferrous alloys, e.g. steel alloys containing manganese
-
- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22C—ALLOYS
- C22C38/00—Ferrous alloys, e.g. steel alloys
- C22C38/06—Ferrous alloys, e.g. steel alloys containing aluminium
-
- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22C—ALLOYS
- C22C38/00—Ferrous alloys, e.g. steel alloys
- C22C38/14—Ferrous alloys, e.g. steel alloys containing titanium or zirconium
-
- 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)
- Mechanical Engineering (AREA)
- Manufacturing & Machinery (AREA)
- Treatment Of Steel In Its Molten State (AREA)
Abstract
The invention discloses a method for controlling cleanliness of steel for IF deep drawing, and belongs to the technical field of steel-making processes of ferrous metallurgy. The method combines the production and removal of inclusions in the practical production processes of a converter process, an RH refining process, a casting machine process and the like for analysis, so that the production of the inclusions in the production process is reduced, the removal process of the inclusions is optimized, the secondary oxidation in the casting machine casting process is prevented, and the high-cleanliness stable control of the low inclusions in the IF steel is realized.
Description
Technical Field
The invention belongs to the technical field of steel metallurgy steelmaking technology, and particularly relates to a cleanliness control method of steel for IF deep drawing.
Background
IF steel is interstitial free steel, has extremely strong deep drawability, is widely applied to industries such as automobiles, household appliances and the like, and is particularly used for producing inner and outer plates of automobiles. For ultra-low carbon IF steel, the inclusion is the main cause of the surface quality defect of the product, and even can cause the scrapping treatment of the whole-roll cold-rolled sheet for high-grade automobile sheets; therefore, the key to solve the control of high-quality steel quality is to improve the cleanliness of molten steel and effectively control the inclusion. The cleanliness of molten steel generally refers to the content, composition, form and distribution of inclusions in the steel.
Ascron et al disclose the influence of the oxidability of ultra-low carbon steel top slag on the cleanliness of molten steel (Ascron et al, influence of the oxidability of ultra-low carbon steel top slag on the cleanliness of molten steel, proceedings of engineering science 2016, 12 months, vol.38, 12 th, hereinafter referred to as document 1), which improves the ability of top slag to adsorb inclusions by reducing the oxidability of ladle top slag, and reduces the iron oxide content in the ladle top slag to 4.68% by modifying the ladle top slag after the tapping of a converter. By reducing the oxidability of the steel ladle top slag, the oxygen transfer among steel slag is improved to a certain extent, and the absorption of oxide inclusions in molten steel by the slag is facilitated, so that the number of the inclusions in the molten steel is reduced, and the control level of the cleanliness of the molten steel is finally improved.
Xijianfu et al disclose a cleanliness control method for an IF steel-making process (Xijianfu et al, cleanliness control production practice for IF steel-making process, continuous casting, 2016 (2) month, vol.41, No. 1, hereinafter referred to as document 2), which is characterized in that a converter adopts a sliding plate to block slag to reduce the slag quantity and a modifier is added to reduce the viscosity of top slag so as to improve the adsorption and inclusion capacity of the top slag of a steel ladle; in the RH treatment process, the circulation flow in the vacuum process is mainly used, and the decarburization and degassing time of RH treatment is reduced, so that the smelting period is shortened; and the CCM mainly adopts argon to blow the tundish before casting, reduces secondary oxidation of molten steel, improves the cleanliness of the molten steel, improves the control level of impurities in a casting head billet, adopts automatic control for argon blowing of the stopper rod, and controls the flow rate of the argon blowing of the stopper rod in the whole casting process to be consistent.
Liu Peng and the like disclose a method for researching evolution of inclusions in IF steel and cleanliness of head and tail billets (LiuPeng and the like, research on evolution of inclusions in IF steel and cleanliness of head and tail billets, continuous casting, 12 months in 2017, and 6 th period in volume 42, hereinafter referred to as document 3).
The three documents all relate to control methods for improving the cleanliness of IF steel, and have the common point that the cleanliness of molten steel can be improved to a certain extent by controlling a certain point in a partial process, but the comprehensiveness of the cleanliness control of IF steel cannot be ensured.
Disclosure of Invention
In view of one or more of the problems in the prior art, the present invention provides a cleanliness control method for IF deep drawing steel, comprising the steps of:
1) designing components: the steel grade of the IF deep drawing steel comprises the following components in percentage by mass: less than or equal to 0.0030 percent, Si: less than or equal to 0.03%, Mn: 0.04-0.15%, P: less than or equal to 0.015%, S: less than or equal to 0.010 percent, Ti: 0.055-0.070%, Al: 0.020-0.060%, N: less than or equal to 0.0040 percent, O: less than or equal to 0.0030 percent, and the balance of Fe and inevitable impurities;
2) KR molten iron desulphurization: the in-position molten iron temperature requirement of the KR molten iron desulphurization process is greater than 1330 ℃, the silicon content in the molten iron is 0.40-0.60%, a deep desulphurization process is adopted in the KR molten iron desulphurization process, and the stirring time is more than or equal to 15 min; after stirring, standing, and then starting primary slagging-off, wherein the slagging-off rate is more than 95%, after primary slagging-off is finished, standing for more than or equal to 3min, then carrying out secondary slagging-off, wherein the slagging-off rate is more than 95%, sampling and measuring the temperature after slagging-off is finished, wherein the sulfur content in the molten iron of the KR separation station is less than 0.001%, obtaining deep desulfurized molten iron, and quickly hoisting the deep desulfurized molten iron to a converter area;
3) smelting in a converter: wherein the converter molten iron is the deep desulfurization molten iron and the scrap steel obtained in the step 2), and the content of sulfur element in the scrap steel is less than 0.003%; the adding amount of the scrap steel is 15-30 tons per furnace, and the total amount of the molten iron in the converter is 285-290 tons per furnace; during smelting, the converter is washed in advance, so that the sulfur increase of molten steel is avoided. In the smelting process of the converter, the addition amount of lime is 5-12 tons per furnace, the addition amount of dolomite is 5-10 tons per furnace, and the addition amount of iron-containing materials is 0-6 tons per furnace; the converter smelting process ensures good slagging, and avoids slag drying or splashing in the smelting process. Controlling the smelting end point temperature of the converter to be more than 1670 ℃ (the temperature is increased by 30 ℃ after the first furnace is poured once), controlling the oxygen content of molten steel at the end point to be 600-800 ppm, and hitting the target once at the end point as far as possible to avoid point blowing operation; before tapping, adopting front baffle operation to avoid slag discharge, and shaking the converter to the tapping position for sedation for more than or equal to 10 seconds; when the steel tapping amount reaches 1/5, top slag lime is added for 0.5-1.5 tons per furnace, lime agglomeration caused by rapid and concentrated addition is avoided when the top slag lime is added, and a certain heat preservation effect can be achieved by uniformly covering the top slag lime on the surface of molten steel; after tapping, adopting a rear baffle, discharging slag as little as possible, and forbidding argon stirring for a steel ladle in the whole tapping process; after tapping, adding 0.1-0.5 ton of modifier into the top slag by using a distributor, and uniformly covering the modifier on the surface of the top slag;
4) RH vacuum treatment: during RH furnace treatment, the steel ladle arrives at the station to perform oxygen determination, carbon determination and temperature measurement operations, oxygen blowing amount is calculated according to the station entering molten steel condition, rapid oxygen blowing operation is performed, oxygen blowing is stopped at the treatment process and the decarburization end point, and molten steel cleanliness and the flocculation condition of a casting machine can be effectively improved. Wherein RH is in-place, oxygen is determined and temperature is measured, the in-place temperature is 1610 to 1630 ℃, and the oxygen blowing amount is 40 to 50m3Heating, adding 80-90 kg of heating aluminum particles per furnace, and measuring temperature after heating; after deep vacuum treatment is carried out for more than or equal to 15min, 150-250 kg/furnace of deoxidization and composition ferro-aluminum and 90-130 kg/furnace of alloy manganese are added, after ferro-aluminum is added, circulation is carried out for more than or equal to 3min, 250-280 kg/furnace of alloy ferrotitanium are added, decarburization and vacuum treatment time is more than or equal to 33min in total, and RH dislocation measurement temperature is 1590-1610 ℃; after the RH vacuum treatment is finished, the secondary modification treatment is carried out,uniformly adding 200-300 kg of modifier into the surface of the top slag per furnace, finally realizing that the content of iron oxide in the top slag is less than 5%, effectively improving oxygen transfer of a slag molten steel interface, avoiding secondary pollution of molten steel, and simultaneously improving the slag adsorption and inclusion capacity;
5) CCM process: argon is blown to the tundish before casting when a casting machine is used for casting, argon is continuously blown into the tundish during the casting process while a covering agent is added, the tundish is prevented from slagging by a slagging detection device after the pouring of the tundish is finished, the control range of superheat degree of the tundish during the casting process of the casting machine is 30-45 ℃, the flocculation condition of the casting machine is improved by adopting high superheat degree casting, simultaneously, meniscus at a blank shell of a casting blank is secondarily fused by high superheat degree control, the capturing of impurities at the meniscus is damaged, the impurities in molten steel float upwards and are adsorbed by protective slag, the quantity of the impurities under the casting blank is effectively reduced, and the surface quality of a finished product is improved; the production pulling speed is 1.3-1.4 m/min; the stopper rod blows argon control according to casting process stopper rod trend, and manual adjustment stopper rod blows argon flow, and the argon flow that blows is progressively increaseed when the wadding flows seriously, reduces when the stopper rod descends and blows argon flow control, has alleviated casting machine wadding flow phenomenon greatly, makes crystallizer liquid level fluctuation obtain obvious improvement, avoids the crystallizer to roll up the sediment phenomenon, promotes finished product and rolls up surface quality control, and the casting process stopper rod blows argon flow 4.0 ~ 10.0L/min.
The IF steel for deep drawing is DCO4 steel or DC03 steel.
The content of aluminum inclusion in the finished hot rolled coil of the IF deep drawing steel ranges from 2 ppm to 16ppm, and the total oxygen content is controlled to be less than 30 ppm; the inclusions in the hot rolled coil are controlled to be 0.5 grade except D-type fine series, and the inclusions in other types are controlled to be 0 grade.
The cleanliness control method for the IF deep drawing steel combines the production and removal of inclusions in practical production processes such as a converter process, an RH refining process, a casting machine process and the like for analysis, so that a process for reducing the production of the inclusions in the production process and optimizing the removal of the inclusions is formulated, secondary oxidation in the casting machine casting process is prevented, and high-cleanliness stable control of low-content inclusions in the IF steel is realized. The data show that the inclusion control of the IF steel finished product is very unstable before the method is not adopted, and the finished product coil often has the defects of surface warping, cracking, point-shaped linear shape and the like of the cold-rolled finished product coil due to the inclusion. Controlling the class B oxide to be 0.5-3.0 grade by detecting impurities in the hot rolled coil; the total oxygen content in steel is 40-60 ppm, and the cleanliness of molten steel is poor. The number of continuous casting furnaces of the casting machine is 4-6, and the capacity of the casting machine is severely limited. After the method is adopted, the annual inclusion control level is stable, the class A, class C and class DS 0 control is realized, the class B and class D control levels are less than 0.5 control level, the total oxygen content in steel is controlled to be less than 30ppm, the number of continuous casting furnaces is controlled to be stable for 15 furnaces, the inclusion control reaches the leading level of the industry, the quality defect of the surface of an evaluation coil is obviously low, and the high cleanliness stability control of IF steel is realized.
Detailed Description
The present inventors have specifically analyzed the characteristics of the processes of the aforementioned documents 1 to 3 in order to improve the level of inclusion control in steel, and have found that the above three documents have in common the fact that control is performed at a certain point in a partial process, and although the cleanliness control of molten steel can be improved to some extent, the completeness of cleanliness control of IF steel cannot be ensured. The invention combines the production and removal of inclusions in the practical production processes of converter process, RH refining process, casting machine process and the like for analysis, formulates the process for reducing the production of inclusions in the production process and optimizing the removal of inclusions, prevents secondary oxidation in the casting machine casting process, and realizes high-cleanliness stable control of low inclusions in IF steel.
Compared with the document 1, the invention discloses a method for improving the cleanliness of molten steel by controlling the whole process of steelmaking and continuous casting. The process means such as the accurate control of the converter end point oxygen content is adopted, and the converter end point molten steel oxygen content is less than 800 ppm; in the RH process, according to the in-place molten steel condition, one-time oxygen blowing and temperature raising operation is adopted in the in-place process, so that the operations of secondary and tertiary oxygen blowing and temperature raising or decarburization and the like in the treatment process are avoided, and for the in-place molten steel oxygen high-carbon low-heat, a small amount of carbon powder can be added for deoxidation in the RH vacuum treatment, so that the addition of aluminum and iron at the RH decarburization end is reduced, and oxide inclusions in the molten steel can be reduced; when the casting machine is well protected for casting, according to the flocculation condition in the tundish casting process, the argon blowing flow rate of the stopper rod is manually controlled to improve the liquid level fluctuation of the crystallizer, and the slag rolling phenomenon caused by the liquid level fluctuation is reduced, so that the control level of the cleanliness in steel is improved.
Compared with the document 2, the invention reduces the activity oxygen of the molten steel through the end point of the converter, and improves the end point carbon content, thereby reducing the content of deoxidation products in the molten steel; RH adopts chemical temperature raising and decarburization, and the steel ladle arrives at a station and adopts one-time oxygen blowing temperature raising or decarburization operation, so that the oxygen blowing operation in the RH treatment process is avoided, the inclusion in the molten steel can be effectively reduced and removed, and the cleanliness of the molten steel is improved; in addition to argon purging of the tundish before casting, the whole casting tundish continuously blows argon into the tundish through an argon pipeline arranged on the tundish cover while adding the covering agent; compared with the stopper rod argon blowing control in the document 2, the stopper rod argon blowing flow control method disclosed by the invention is used for improving the flocculation flow condition of the casting machine, the flocculation flow is improved by manually adjusting the stopper rod argon blowing flow control method by observing the stopper rod position in the casting process under the constant pulling speed control, the liquid level fluctuation of a crystallizer is effectively controlled, and the flow control is consistent instead of the whole casting time flow control.
Compared with the document 3, the invention is a control method for realizing the cleanness of molten steel by accurately controlling the steelmaking and continuous casting processes and innovating the process, not only improves the cleanliness control of head and tail billets, but also obviously improves the cleanliness control level of the molten steel in the whole casting process; in order to improve the defects caused by inclusions on the surface of a product coil, a casting machine is innovated for controlling the superheat degree of molten steel casting in the casting process, the control range of the superheat degree of IF steel casting in the prior art is 15-30 ℃, the control range of the superheat degree of IF steel casting is designed to be 30-45 ℃, and the superheat degree of the casting machine is increased, so that meniscus generated in the solidification process of a casting blank is secondarily fused, the inclusions are prevented from being captured by the meniscus, the floating of the inclusions in the molten steel in a crystallizer is promoted, the quantity of the inclusions under the IF steel casting blank is effectively reduced, and the quality control of the surface of the finished product coil is greatly improved.
The converter adopts a specific scheme that a computer simulation program is adopted, and simulation calculation is carried out on converter end point control according to sublance process data acquisition, so that point blowing operation is avoided, the oxygen content in end point molten steel is controlled within the range of 600-800 ppm, the tapping temperature is controlled to be more than 1670 ℃, the end point molten steel peroxidation control is avoided, and the purposes of low-oxygen, low-nitrogen and low-impurity stable control of the tapping molten steel are achieved; the steel tapping process adopts front and back slag stopping operation to avoid slag discharging operation, steel ladle top slag is subjected to primary modification treatment after steel tapping is finished, and the total iron content in the modified top slag is less than 5%. In the tapping process, in order to reduce the heat loss of molten steel, 4 turnovers are adopted in the ladle turnover, and the temperature drop in the tapping process is controlled to be less than 70 ℃. During RH furnace treatment, the steel ladle arrives at a station to perform oxygen determination, carbon determination and temperature measurement operations, oxygen blowing amount is calculated according to the condition of incoming molten steel, rapid oxygen blowing operation is performed, oxygen blowing in the middle and the final stages of vacuum treatment is avoided, vacuum decarburization end-point deoxidation and alloy aluminum iron are added for one time, the circulation is not less than 3min after the aluminum iron is added, the titanium-iron alloy is added, and secondary modification treatment is performed after the vacuum treatment is finished. Argon purging is carried out on the tundish before casting when the casting machine is used for casting, argon is continuously blown into the tundish while a covering agent is added in the tundish in the casting process, the tundish is prevented from slagging through slagging detection equipment after the ladle is used for casting, and the control range of the superheat degree of the tundish in the casting process of the casting machine is 30-45 ℃; the stopper rod blows the argon control according to casting process stopper rod trend, and manual adjustment stopper rod blows the argon flow, and argon flow is blown in the argon flow volume of progressively increaseing when the wadding flows seriously, reduces when the stopper rod descends and blows argon flow control.
The following examples of the DC04 steel grade are used for the purpose of specifically illustrating the present disclosure, and are for the purpose of describing the present disclosure only for the convenience of understanding, and are not intended to limit the present disclosure.
Example 1
KR deep desulfurization treatment is adopted, the sulfur content of KR arrival molten iron is 0.0037%, the heating amount of a desulfurizing agent in the treatment process is 2.2 tons, the stirring time is 18min, the slag skimming frequency is more than 2 times, and the slag skimming rate is more than 95%. The molten iron fed into the converter is deep-cast iron, the scrap steel is self-produced scrap steel (low sulfur, the content of sulfur element is less than 0.003 percent), the adding amount is 25 tons, the total loading amount of the molten iron and the scrap steel is controlled to be 285-290 tons, the temperature of the molten iron fed into the converter is 1325 ℃, and the silicon content in the molten iron is 0.56 percent. 8.9 tons of lime and 9.1 tons of dolomite are added into slag materials in the smelting process of the converter, and the adding amount of iron sheet balls is 1.3 tons. The converter had a final oxygen content of 760ppm, a carbon content of 0.04% and a final temperature of 1674 ℃.1 ton of top slag lime is added in the tapping process, and 300kg of modifier is added after tapping. RH in-place oxygen determination and temperature measurement are carried out, the in-place temperature is 1610 ℃, and the oxygen blowing amount is 50m3ForHeating, adding 90kg of heating aluminum particles, heating after adding aluminum, measuring the temperature to 1620 ℃, carrying out deep vacuum treatment for 15min, adding 200kg of deoxidation and composition ferro-aluminium (the vacuum degree of the deep vacuum treatment is less than 2.5Mbar), 90kg of alloy manganese, circulating for 3min after adding ferro-aluminium, adding 270kg of alloy ferrotitanium, wherein the total decarburization and vacuum treatment time is 33min, and the RH dislocation measurement temperature is 1598 ℃. The superheat degree of the casting machine in the casting process is 35 ℃, the production drawing speed is 1.4m/min, the argon blowing flow of the stopper rod in the casting process is 4.6L/min (the maximum flow is less than 10L/min), the flow control stopper rod in the casting process is stable, and the flocculation phenomenon does not exist, so the argon blowing flow of the stopper rod of the furnace is not adjusted.
Example 2
KR deep desulfurization treatment is adopted, the sulfur content of KR arrival molten iron is 0.0052%, the heating amount of a desulfurizing agent in the treatment process is 3.3 tons, the stirring time is 20min, the slag removing frequency is more than 2 times, and the slag removing rate is more than 95%. Deep-cast iron is selected as molten iron fed into the converter, self-produced scrap steel (low sulfur and sulfur content less than 0.003%) is selected as scrap steel, the adding amount is 23 tons, the total loading amount of the molten iron and the scrap steel is controlled to be 285-290 tons, the temperature of the molten iron fed into the converter is 1305 ℃, and the silicon content in the molten iron is 0.34%. 5.7 tons of lime and 6.7 tons of dolomite are added into slag materials in the smelting process of the converter. The converter end point oxygen content was 620ppm, the carbon content was 0.05%, and the end point temperature was 1672 ℃.1 ton of top slag lime is added in the tapping process, and 200kg of modifier is added after tapping. RH in-place oxygen determination and temperature measurement are carried out, the in-place temperature is 1625 ℃, and the oxygen blowing amount is 40m3Heating, adding 80kg of heating aluminum particles, heating with aluminum, measuring the temperature of 1634 ℃, carrying out deep vacuum treatment for 15min, adding 200kg of deoxidation and composition ferro-aluminum (the vacuum degree of the deep vacuum treatment is less than 2.5Mbar), 130kg of alloy manganese, adding ferro-titanium alloy after circulation for 3min, adding 270kg of ferrotitanium alloy, wherein the total decarburization and vacuum treatment time is 34min, and the RH dislocation measurement temperature is 1606 ℃. The superheat degree of the casting machine in the casting process is 45 ℃, the production drawing speed is 1.3m/min, the argon blowing flow of the stopper rod in the casting process is 5.0L/min (the maximum flow is less than 10L/min), the flow control stopper rod in the casting process rises by 3mm, and the flocculation phenomenon exists, so that the argon blowing flow of the stopper rod of the furnace is increased by 0.5L/min.
The chemical component content of DC04 obtained in examples 1-2 was measured, and the results are shown in Table 1, and the results of the inclusion test of the hot rolled coil are shown in Table 2.
TABLE 1 DC04 chemical composition
| Examples of the invention | C | Si | Mn | P | S | Ti | Alt | Als | N | O |
| 1 | 0.002 | 0.005 | 0.11 | 0.012 | 0.008 | 0.060 | 0.0476 | 0.046 | 0.002 | 0.0025 |
| 2 | 0.002 | 0.005 | 0.15 | 0.015 | 0.003 | 0.061 | 0.0458 | 0.046 | 0.002 | 0.0024 |
TABLE 2 inspection of inclusions in hot rolled coils
According to the tables 1 and 2, the steel making and continuous casting processes adopt the method, the chemical components of the finished product and the detection and control of the impurities included in the hot rolled coil all reach the target requirements, the nitrogen content and the oxygen content are controlled to be lower, the content range of the aluminum inclusion is 2-16 ppm, the total oxygen content is controlled to be less than 30ppm, and the molten steel achieves the purpose of high-cleanliness control. The hot rolled coil is used for detecting the inclusions of steel coils with different thicknesses, the D-type fine system is controlled to be 0.5 grade, and the inclusions of other types are controlled to be 0 grade. Thus, by the method of the invention, a high level of cleanliness control of the deep drawing DC04 steel grade is achieved.
The method is applied to actual production of steel making and continuous casting processes of IF steel DC04 and DC03 steel, effectively solves the problem of flocculation in a continuous casting machine in the production process of DC04 and DC03 steel, greatly reduces the scrap rate of finished inclusion, solves the problem of the influence of the number of continuous casting furnaces of a casting machine on the improvement of productivity, improves the number of continuous casting furnaces of the casting machine in a single casting time from 4-6 furnaces to 15 furnaces, and greatly improves the average daily yield of the casting machine. The rejection rate of the finished coil due to the inclusion is reduced by about 1 percent, and the benefit is generated by about 347.7 ten thousand yuan all the year.
Finally, it should be noted that: although the present invention has been described in detail with reference to the foregoing embodiments, it will be apparent to those skilled in the art that changes may be made in the embodiments and/or equivalents thereof without departing from the spirit and scope of the invention. Any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.
Claims (3)
1. A cleanliness control method for IF deep drawing steel is characterized by comprising the following steps:
1) designing components: the IF deep drawing steel comprises the following components in percentage by mass: less than or equal to 0.0030 percent, Si: less than or equal to 0.03%, Mn: 0.04-0.15%, P: less than or equal to 0.015%, S: less than or equal to 0.010 percent, Ti: 0.055-0.070%, Al: 0.020-0.060%, N: less than or equal to 0.0040 percent, O: less than or equal to 0.0030 percent, and the balance of Fe and inevitable impurities;
2) KR molten iron desulphurization: the in-position molten iron temperature requirement of the KR molten iron desulphurization process is greater than 1330 ℃, the silicon content in the molten iron is 0.40-0.60%, a deep desulphurization process is adopted in the KR molten iron desulphurization process, and the stirring time is more than or equal to 15 min; after stirring, standing, and then starting primary slagging-off, wherein the slagging-off rate is more than 95%, after primary slagging-off is finished, standing for more than or equal to 3min, then carrying out secondary slagging-off, wherein the slagging-off rate is more than 95%, sampling and measuring the temperature after slagging-off is finished, and the sulfur content in the KR molten iron at an off-station is less than 0.001%, so as to obtain deep desulfurized molten iron;
3) smelting in a converter: wherein the converter molten iron is the deep desulfurization molten iron and the scrap steel obtained in the step 2), and the content of sulfur element in the scrap steel is less than 0.003%; the adding amount of the scrap steel is 15-30 tons per furnace, and the total amount of the molten iron in the converter is 285-290 tons per furnace; in the smelting process of the converter, the addition amount of lime is 5-12 tons per furnace, the addition amount of dolomite is 5-10 tons per furnace, and the addition amount of iron-containing materials is 0-6 tons per furnace; controlling the smelting end point temperature of the converter to be more than 1670 ℃, and controlling the oxygen content of the molten steel at the end point to be 600-800 ppm; before tapping, adopting front baffle operation to avoid slag discharge, and shaking the converter to the tapping position for sedation for more than or equal to 10 seconds; when the steel tapping amount reaches 1/5, adding top slag lime into the steel slag for 0.5 to 1.5 tons per furnace; after tapping, adopting a rear baffle, and forbidding argon stirring in a ladle in the whole tapping process; after tapping, adding 0.1-0.5 ton of modifier into the top slag by using a distributor, and uniformly covering the modifier on the surface of the top slag;
4) RH vacuum treatment: RH is in-place, oxygen is determined, temperature is measured, in-place temperature is 1610-1630 ℃, and oxygen blowing amount is 40-50 m3Heating, adding 80-90 kg of heating aluminum particles per furnace, and measuring temperature after heating; after deep vacuum treatment is carried out for more than or equal to 15min, 150-250 kg/furnace of deoxidization and composition ferro-aluminum and 90-130 kg/furnace of alloy manganese are added, after ferro-aluminum is added, circulation is carried out for more than or equal to 3min, 250-280 kg/furnace of alloy ferrotitanium are added, decarburization and vacuum treatment time is more than or equal to 33min in total, and RH dislocation measurement temperature is 1590-1610 ℃; after the RH vacuum treatment is finished, carrying out secondary modification treatment, and uniformly adding 200-300 kg of modifier into the surface of the top slag per furnace;
5) CCM process: argon purging is carried out on the tundish before casting when the casting machine is used for casting, argon is continuously blown into the tundish while a covering agent is added in the tundish in the casting process, the tundish is prevented from slagging through slagging detection equipment after the pouring of the tundish is finished, the control range of the superheat degree of the tundish in the casting process of the casting machine is 30-45 ℃, the production drawing speed is 1.3-1.4 m/min, and the argon blowing flow of the stopper rod in the casting process is 4.0-10.0L/min.
2. The cleanliness control method for IF deep drawing steel according to claim 1, wherein the IF deep drawing steel is of the DCO4 or DC03 steel grade.
3. The cleanliness control method for the IF deep drawing steel according to claim 1 or 2, wherein the content of the aluminum inclusion in the finished hot rolled coil of the IF deep drawing steel is in the range of 2-16 ppm, and the total oxygen content is controlled to be less than 30 ppm; the inclusions in the hot rolled coil are controlled to be 0.5 grade except D-type fine series, and the inclusions in other types are controlled to be 0 grade.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202010100971.9A CN111286666B (en) | 2020-02-19 | 2020-02-19 | Cleanliness control method for IF deep drawing steel |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202010100971.9A CN111286666B (en) | 2020-02-19 | 2020-02-19 | Cleanliness control method for IF deep drawing steel |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN111286666A true CN111286666A (en) | 2020-06-16 |
| CN111286666B CN111286666B (en) | 2021-06-22 |
Family
ID=71024520
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202010100971.9A Active CN111286666B (en) | 2020-02-19 | 2020-02-19 | Cleanliness control method for IF deep drawing steel |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN111286666B (en) |
Cited By (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN112921149A (en) * | 2021-01-25 | 2021-06-08 | 包头钢铁（集团）有限责任公司 | Steel-making production control method of ultra-low sulfur steel |
| CN113430335A (en) * | 2021-06-10 | 2021-09-24 | 包头钢铁（集团）有限责任公司 | Method for efficiently decarbonizing RH refining furnace |
| CN113584259A (en) * | 2021-08-03 | 2021-11-02 | 攀钢集团西昌钢钒有限公司 | Method for washing RH furnace |
| CN114959419A (en) * | 2022-05-27 | 2022-08-30 | 包头钢铁（集团）有限责任公司 | Production method of low-yield-ratio cold-rolled deep-drawing thick steel strip DC03 |
| CN115323115A (en) * | 2022-09-15 | 2022-11-11 | 湖南华菱涟源钢铁有限公司 | Method for improving cleanliness of filter steel |
| CN115652029A (en) * | 2022-10-25 | 2023-01-31 | 山东钢铁集团日照有限公司 | Control method for sulfur content of deep drawing steel |
Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2012167329A (en) * | 2011-02-15 | 2012-09-06 | Jfe Steel Corp | Steel pipe for line pipe with excellent collapse resisting performance |
| JP2012184500A (en) * | 2011-02-15 | 2012-09-27 | Jfe Steel Corp | High tensile strength steel sheet having excellent low temperature toughness in weld heat-affected zone, and method for producing the same |
| CN102719593A (en) * | 2011-03-29 | 2012-10-10 | 鞍钢股份有限公司 | Method for smelting ultra-low carbon steel |
| CN109706284A (en) * | 2019-01-31 | 2019-05-03 | 邯郸钢铁集团有限责任公司 | A method of ultra low carbon IF steel is produced based on CSP thin-slab caster |
| CN110016610A (en) * | 2019-03-20 | 2019-07-16 | 包头钢铁（集团）有限责任公司 | Low nitrogen ultra low-carbon steel of a kind of Ti system and preparation method thereof |
-
2020
- 2020-02-19 CN CN202010100971.9A patent/CN111286666B/en active Active
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2012167329A (en) * | 2011-02-15 | 2012-09-06 | Jfe Steel Corp | Steel pipe for line pipe with excellent collapse resisting performance |
| JP2012184500A (en) * | 2011-02-15 | 2012-09-27 | Jfe Steel Corp | High tensile strength steel sheet having excellent low temperature toughness in weld heat-affected zone, and method for producing the same |
| CN102719593A (en) * | 2011-03-29 | 2012-10-10 | 鞍钢股份有限公司 | Method for smelting ultra-low carbon steel |
| CN109706284A (en) * | 2019-01-31 | 2019-05-03 | 邯郸钢铁集团有限责任公司 | A method of ultra low carbon IF steel is produced based on CSP thin-slab caster |
| CN110016610A (en) * | 2019-03-20 | 2019-07-16 | 包头钢铁（集团）有限责任公司 | Low nitrogen ultra low-carbon steel of a kind of Ti system and preparation method thereof |
Cited By (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN112921149A (en) * | 2021-01-25 | 2021-06-08 | 包头钢铁（集团）有限责任公司 | Steel-making production control method of ultra-low sulfur steel |
| CN113430335A (en) * | 2021-06-10 | 2021-09-24 | 包头钢铁（集团）有限责任公司 | Method for efficiently decarbonizing RH refining furnace |
| CN113584259A (en) * | 2021-08-03 | 2021-11-02 | 攀钢集团西昌钢钒有限公司 | Method for washing RH furnace |
| CN114959419A (en) * | 2022-05-27 | 2022-08-30 | 包头钢铁（集团）有限责任公司 | Production method of low-yield-ratio cold-rolled deep-drawing thick steel strip DC03 |
| CN115323115A (en) * | 2022-09-15 | 2022-11-11 | 湖南华菱涟源钢铁有限公司 | Method for improving cleanliness of filter steel |
| CN115323115B (en) * | 2022-09-15 | 2024-01-30 | 湖南华菱涟源钢铁有限公司 | Method for improving cleanliness of filter steel |
| CN115652029A (en) * | 2022-10-25 | 2023-01-31 | 山东钢铁集团日照有限公司 | Control method for sulfur content of deep drawing steel |
| CN115652029B (en) * | 2022-10-25 | 2024-01-23 | 山东钢铁集团日照有限公司 | Control method for sulfur content of deep drawing steel |
Also Published As
| Publication number | Publication date |
|---|---|
| CN111286666B (en) | 2021-06-22 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN111286666B (en) | Cleanliness control method for IF deep drawing steel | |
| CN106148821B (en) | Phosphorate the production technology of high-strength IF steel | |
| CN109082496A (en) | A kind of method of whole process hypoxemia position smelting suprelow carbon steel | |
| CN109252010B (en) | Smelting method for controlling oxidability of IF steel top slag | |
| CN112522601A (en) | Process method for producing Nb-containing low-cost small-medium-specification hot-rolled H-shaped steel | |
| CN112517634A (en) | Process for producing low-cost 355MPa hot-rolled H-shaped steel | |
| CN111471920A (en) | Non-quenched and tempered steel for U-shaped bolt and production method thereof | |
| KR101365525B1 (en) | Two-phase stanless steel and argon oxygen decarburization refining method of the two-phase stainless steel | |
| CN113025781B (en) | Method for producing low-carbon low-silicon ultralow-sulfur steel by adopting LF (ladle furnace) single-link process | |
| CN112795834B (en) | Production method of medium-carbon, medium-silicon and high-aluminum dual-phase steel continuous casting billet | |
| CN114293101A (en) | Economical high-grade welding wire steel H04E and preparation method thereof | |
| CN111621621B (en) | Control method of Mn in molten steel in RH vacuum treatment process | |
| CN112080690A (en) | DC06 automobile plate hot-rolled strip steel and control method for edge warping defect thereof | |
| CN103225009A (en) | Method for producing high-cleanness steel | |
| KR101258785B1 (en) | Manufacturing method of duplex stainless steel | |
| CN110016533B (en) | Production process of steel substrate for high-quality filter | |
| CN114000047A (en) | Low-carbon high-chromium steel plate blank and continuous efficient production method thereof | |
| CN113604724A (en) | 904L super austenitic stainless steel and preparation method thereof | |
| JPH06207212A (en) | Production of high creanliness extra-low carbon steel of extremely low s | |
| CN110846470A (en) | Method for accurately controlling carbon content in RH refined low-carbon steel | |
| CN113913580A (en) | Production method of ultralow-carbon low-aluminum structural molten steel | |
| KR101786931B1 (en) | Method for refining of molten stainless steel | |
| CN115612776B (en) | Production method of plain carbon steel without refining | |
| KR20190076314A (en) | Method for Refining Low Carbon Steel | |
| KR101354947B1 (en) | Method for refining austenitic stainless steel for strip casting |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |