CN102719728B - Technique for producing anti-acid pipeline steel by RH-LF-VD refining - Google Patents
Technique for producing anti-acid pipeline steel by RH-LF-VD refining Download PDFInfo
- Publication number
- CN102719728B CN102719728B CN201210200737.9A CN201210200737A CN102719728B CN 102719728 B CN102719728 B CN 102719728B CN 201210200737 A CN201210200737 A CN 201210200737A CN 102719728 B CN102719728 B CN 102719728B
- Authority
- CN
- China
- Prior art keywords
- steel
- vacuum
- desulfurization
- molten steel
- refining
- 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.)
- Expired - Fee Related
Links
Classifications
-
- 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
- Treatment Of Steel In Its Molten State (AREA)
Abstract
The invention relates to a technique for producing anti-acid pipeline steel by RH-LF-VD refining. According to the technique, convertor steel making and RH-LF-VD refining techniques are utilized to control the components of molten steel, thereby producing the low-carbon low-sulfur anti-acid (anti-HIC and anti-SCC) pipeline steel. The technique comprises the following steps: predesulfurizing molten iron, smelting in a convertor, carrying out RH vacuum decarburization, carrying out LF heating for desulfurization, carrying out VD vacuum decarburization, carrying out calcium treatment, carrying out soft blowing, continuously casting, and carrying out hot rolling. By using the secondary vacuum refining processes (RH vacuum refining and VD vacuum refining), the invention can reduce the decarburization load of the convertor, lower the oxidizability of the molten steel, eliminate the adverse effect of carburization in the LF furnace refining process, reduce the consumption of a strong deoxidizer, stabilize the production, ensure that the molten steel components are stably controlled within the production target, and satisfy the component control requirements of low carbon, low sulfur and high purity for anti-acid pipeline steel. The carbon content of the finished steel produced by the technical process provided by the invention can be controlled to 0.03%, and the sulfur content can be stably controlled to at most 0.0010%.
Description
Technical field
The invention belongs to the smelting production field of high-level antiacid pipe line steel, relate to the smelting technology that utilizes converter steelmaking and RH-LF-VD refining accurately to control composition in steel, this technique can alleviate converter decarburization burden greatly, reduce molten steel oxidation and tapping temperature, extend converter lining life, can give full play to again LF stove refining desulfuration effect, the disadvantageous effect of LF process carburetting is eliminated in RH and VD vacuum-treat, reduce strong reductor add-on, reduce deoxidation type inclusion in steel, improve purity, heat composition is even, stable processing technique, workable, meet antiacid (anti-HIC and SCC) pipe line steel to low-carbon (LC), the Composition Control requirement of low-sulfur and high cleanliness.
Background technology
It is long apart from transfer oil, most economical, the rational mode of transport of Sweet natural gas that pipeline is carried, and has the features such as efficient, economic, safety.Current transport pipe forward heavy caliber, high pressure future development.Pipe line steel is requiring high-intensity also require to have high low temperature arrest toughness and good welds simultaneously.And 20 since century 70, there is considerable change in the exploitation condition of various countries' oil, Sweet natural gas, although Sweet natural gas has carried out purifying treatment, H before conveying at present
2the existence of S and water causes that corrosive pipeline is still inevitable.Also have some particular oils, gas to carry regional pipe line steel also corrosion phenomenon can occur.Therefore pipe line steel is to resistance to corrosion in recent years, and particularly the requirement of anti-hydrogen induced cracking (HIC) and sulphide stress corrosion (SCC) is more and more higher.
Hydrogen induced cracking (Hydrogen Induced Crack-HIC) is that the hydrogen atom being generated by corrosion enters in steel, be gathered on the interface of MnS and mother metal, abnormal structure along carbon, manganese and phosphorous segregation expands or expands along banded structure phase boundary, when hydrogen atom is combined into hydrogen molecule, produce larger pressure, so form, be parallel to rolling surface, along the crackle of rolling direction.
Sulphide stress corrosion (Stress Corrosion Cracking-SCC) is at H
2s and CO
2under effect Deng various acid ions in corrosive medium, soil and groundwater, the hydrogen atom that corrosion generates enters steel inside through steel surface, and is progressively enriched in region of stress concentration, is ftractureed perpendicular to drawing force Directional Extension in steel embrittlement edge.
The pipe line steel Composition Design thought with high resistance HIC and SCC ability is low-carbon (LC), low-sulfur, low-phosphorous, suitable manganese content, microalloying, high cleanliness.In conjunction with hot controlled rolling and controlled cooling (TMCP) technique, reduce macrosegregation and banded structure simultaneously, obtain stable duplex structure, guarantee that pipe line steel has good mechanical property and acidresistant property.
Carbon is strengthening element traditional in steel, is also most economical element strengthening element.Yet carbon has disadvantageous effect to the toughness of steel, plasticity, weldability etc.And along with the increase of carbon content, HIC susceptibility increases.When carbon content pipe line steel lower than 0.11% time can have good weldability.When carbon content surpasses 0.05%, by causing the segregation aggravation of manganese and phosphorus, when carbon content is less than 0.04%, can effectively prevent the generation of HIC.Modern age, the evolution of pipe line steel was the process that constantly reduces carbon content, and general requirement is less than 0.10%, to the Ultra-low carbon content design that needs high tenacity or antiacid (anti-HIC and SCC) pipe line steel to adopt carbon to be less than 0.06%.The dark decarburization of molten steel is mainly to utilize vacuum refinement to process, and by the oxygen in molten steel, carries out decarburization, and by reducing, [C]+[O]={ the CO partial pressure of CO} reaction, promotes decarburizing reaction to carry out, and produces low-carbon (LC) or ultra low-carbon steel.The topmost equipment of molten steel vacuum decarburization is the refining of RH vacuum cycle and the refining of VD vacuum stirring.RH refining has the advantages that speed of response is fast, efficiency is high.RH can also carry out oxygen blast forces decarburization, and carbon content of molten steel is reduced to below 0.0010%.VD refining is a kind of widely used vacuum refinement mode, has equally good decarburization condition, and existing a lot of steel mills start to adopt VD to process to produce utmost point low-carbon (LC) or ultra low-carbon steel both at home and abroad, and have obtained good treatment effect.
Sulphur is the one of the chief elements of harm pipe line steel quality, antiacid (anti-HIC and SCC) performance of its severe exacerbation pipe line steel.Research shows: along with sulphur content in molten steel increases, crack sensitivity significantly increases; While only having in steel sulphur <0.0012%, HIC obviously reduces.In addition, sulphur also causes pipe line steel anisotropy, and on horizontal and thickness direction, toughness worsens.Pipe line steel is very harsh to the requirement of sulphur content, for X60 and the antiacid pipe line steel of above rank, obtains antiacid (anti-HIC and SCC) performance goodly after meeting tubulation, C<0.04% in steel, simultaneously S<0.0010% in steel.Ultra-deep desulfuration technology has mainly been applied the thought that system is controlled at present, from the sulphur content of controlling raw and auxiliary material, sets about, and starts to strengthen the desulfurization of each operation from molten iron pretreatment desulfurizing, and whole control, implements step by step, has obtained good sweetening effectiveness.Molten iron pre-desulfurization is a kind of less expensive, effective sulfur method, in industrial production, is adopted widely.The sweetening power of converter is quite limited.Special in the situation that the original sulphur content of molten iron is very low, due to the sulphur that enters the furnace charges such as slag material, steel scrap and refractory materials of stove and bring into, often occur that converter process returns sulphur phenomenon.Therefore, after converter tapping, must carry out secondary desulfurization to molten steel.Utilize LF stove heated by electrodes, steel ladle bottom argon blowing, make high basicity slag and carry out dark desulfurization, finished product sulphur content can be reduced to 0.0005%.
In order to meet the requirement of antiacid pipe line steel to molten steel composition, domestic each steel mill's main production process is a vacuum refinement (only through a vacuum refinement) technological process of hot metal pretreatment-top and bottom combined blown converter smelting-external refining (LF refining and RH or VD vacuum-treat combination)-continuous casting at present.LF sweetening power is more intense, and while smelting pipe line steel, desulfurization degree can reach 70% ~ 90%.But there is carburetting contradiction in LF desulfurization simultaneously.RH or VD vacuum refinement, possess decarburization, the effect such as degassed, but cause liquid steel temperature to reduce.Therefore in production process there is contradiction and restriction of production in molten steel decarburization and desulfurization and molten steel insulation.LF-RH technique for example, LF desulfurization heating process is before RH, and the prerequisite of desulfurization is that in steel, oxygen will be controlled at low-down level, therefore at converter tapping and LF processing, to add reductor molten steel to be carried out to the dark sweetening effectiveness of deep deoxidation guarantee LF early stage, when this causes follow-up RH vacuum refinement oxygen decarburization, oxygen content in steel is not enough to carbon to be removed to the level of steel grade requirement, can only force decarburization by oxygen blast in molten steel, in steel, add reductor to control oxygen level within the limits prescribed more afterwards.This has not only consumed too much reductor, and the inclusion in steel is increased, and removes difficulty and strengthens.Because RH operation is rear, while requiring LF stove terminal, liquid steel temperature is higher in addition, and to guarantee the temperature drop of RH refining process, and because LF refining process inevitably makes molten steel recarburization, while therefore also requiring converter tapping, carbon content will take off to lower level.And for RH-LF technique, because LF refining process makes molten steel recarburization, therefore require RH refining process carbon content in molten steel will be taken off to lower level, in guarantee finished product molten steel, carbon content control is in the scope requiring, RH treating processes difficulty strengthens, and molten steel temperature drop is also larger.Temperature is higher when reducing that the LF heating-up time, (LF heated by electrodes process is longer, and molten steel recarburization is more) just required converter tapping, and carbon content is lower.Also there is identical problem in LF-VD or VD-LF technique.Above technique is for once RH or VD vacuum refinement process all, increase converter smelting burden, reduce furnace life, Molten Steel Cleanliness is poor, simultaneously also harsher for the requirement of LF and RH or VD vacuum refinement process, all higher to the requirement of the raw material of whole each link of metallurgical technology flow process, equipment, operant level, in steel, to reach the stably manufactured difficulty of low or ultra low levels larger simultaneously for carbon and sulphur content.Carbon in Finished Steel, sulphur Composition Control are unstable, and antiacid (anti-HIC and SCC) performance can not stably reaching standard.
Summary of the invention
In order to address the above problem, object of the present invention provides the LF of the existing vacuum refinement of a kind of elimination (only through a vacuum refinement) to coordinate with RH or LF coordinates the deficiency of explained hereafter low-carbon and low-sulphur steel with VD, adopt the smelting technology of RH-LF-VD explained hereafter antiacid (anti-HIC and the SCC) pipe line steel of secondary vacuum refining (through secondary vacuum refining), stably manufactured, meets the Composition Control requirement of antiacid pipe line steel to low-carbon (LC), low-sulfur and high cleanliness better.
Technical scheme of the present invention is: the technique of antiacid pipe line steel is produced in a kind of RH-LF-VD refining, technical process is molten iron pre-desulfurization-converter smelting-RH vacuum decarburization-LF intensification desulfurization-VD vacuum decarburization-calcium processing-soft blow-continuous casting and hot rolling again, specifically comprises the following steps:
Molten iron pre-desulfurization: blast-meltedly first carry out desulfurization through hot metal pretreatment, according to the existing molten iron pre-desulfurization processing unit of each production unit, select paddling process or hot metal ladle Desulfurization by injecting method, after molten iron pre-desulfurization EO, in desulfurization slag, be rich in sulphur, for avoiding molten iron to return sulphur, slag removed totally, desulfurizing iron rate reaches 90%, enters stove Sulfur Content in Hot Iron content and is less than 0.003%;
Converter smelting: the molten iron that step 1 was processed adopts top and bottom combined blown converter to smelt, to add in molten iron account for molten iron total amount 10 ~ 15% low-phosphorous, low-sulfur steel scrap, whole smelting process is carried out whole process bottom blowing argon gas, molten steel is fully stirred, so that composition and the temperature of even molten steel, endpoint molten steel carbon content is controlled at 0.08% ~ 0.12%, oxygen level is 0.06% ~ 0.08%, phosphorus content≤0.008%, tapping temperature is controlled at 1630 ~ 1660 ℃, during tapping, adopt pushing off the slag operation, in case non-return phosphorus, wherein, slag material comprises: lime 50 ~ 65kg/t, light dolomite 15 ~ 25kg/t, basicity of slag is controlled at 3.5 ~ 4.0,
RH vacuum refinement decarburization deoxidation: utilize in step 2 after converter tapping oxygen level more than needed in molten steel, by vacuumizing reduction [C]+[O]={ CO partial pressure of CO} reaction, at vacuum pressure, be less than 100Pa, adopt large recycle stream flow 1200 ~ 1400L/min to carry out vacuum cycle, treatment time 15min, while reaching terminal, carbon content of molten steel is controlled at 0.01% ~ 0.03%;
LF slag adopts CaO-Al
2o
3-SiO
2the desulfurization of ternary basic slag system, basicity is controlled at 4.0-6.0, FeO in slag and MnO content are less than 0.8%, adopt the heating of electrode submerged arc, molten steel adds after LF stove, improves ladle bottom argon blowing rate to 400 ~ 600NL/ min, treatment time is 35 ~ 45min, during the tapping of LF stove refining terminal, molten steel sulphur content is ≤0.0008%, and carbon content is 0.03% ~ 0.05%, and liquid steel temperature is 1620 ~ 1630 ℃;
VD vacuum refinement decarburization is degassed: the molten steel of above-mentioned steps is carried out to VD vacuum refinement, at vacuum pressure, be less than 100Pa, adopt large recycle stream flow 1200 ~ 1400L/min to carry out vacuum cycle, treatment time 20 ~ 25min, carry out vacuum decarburization, degassed, obtaining carbon content is 0.03% ~ 0.04%, sulphur content is≤0.0010% molten steel, through RH, process qualified molten steel and carry out calcium processing and soft blow, the soft blow time is more than 12min, must reach the antiacid pipe line steel that the composition of pipe line steel Antacid effectiveness requires.
According to target composition requirement, utilize this technical process to produce, in Finished Steel, carbon content can be stablized and is controlled at 0.03%, simultaneously sulphur content can stablize be controlled at≤0.0010%, meet the Composition Control requirement of antiacid (anti-HIC and SCC) pipe line steel to low-carbon (LC), low-sulfur and high cleanliness.
After smelting molten steel end of processing, producer can require pouring molten steel to become strand (slab, thin slab or circle base) with user according to self continuous casting installation for casting, through controlled rolling and controlled cooling (TMCP), antiacid (anti-HIC and SCC) pipeline steel billet that organization of production and performance meet the demands.
Special feature of the present invention is: molten steel, through the secondary vacuum refining process of RH-LF-VD, is introduced into RH through converter smelting molten steel and carries out vacuum cycle refining decarburization, deoxidation; Carry out afterwards LF stove refining desulfuration; Enter subsequently VD and carry out vacuum cycle refining, because RH vacuum refinement has removed the carbon of the overwhelming majority in steel, so VD vacuum refinement main purpose is the increment that removes LF refining process carbon, and degassed, removal of inclusions, finally casts simultaneously.
The invention has the advantages that: utilize the secondary vacuum refinery practice of RH-LF-VD to control composition in steel, greatly alleviate converter decarburization burden, reduce molten steel oxidation and tapping temperature, improve furnace life; The disadvantageous effect of eliminating the carburetting of LF stove refining process, has alleviated LF stove production burden; Reduce the use of strong reductor, reduce nonmetallic inclusionsin steel content; Stablize whole process production process, guarantee that molten steel composition is controlled in productive target, meet the Composition Control requirement of antiacid (anti-HIC and SCC) pipe line steel to low-carbon (LC), low-sulfur and high cleanliness.
The high-level antiacid pipe line steel market requirement is huge, and only Middle East in 2012 plans that antiacid X60 ~ X65 pipe line steel is 300,000 tons.High-level antiacid pipe line steel production difficulty is large, market value is high, antiacid pipe line steel than the common pipe line steel market value of same level high 2000 yuan per ton, RH-LF-VD technique guarantees under the prerequisite of the quality of production in the high-level antiacid pipe line steel technique of stably manufactured, multiple operation comprehensive matching, through production practice, RH-LF-VD explained hereafter cost is increasing under 120 yuan of prerequisites, steel grade is produced lumber recovery and is brought up to more than 90% by 70% of single vacuum technology, according to 6500 yuan of calculating of antiacid pipe line steel ton steel production cost, ton steel obtains direct economic benefit (6500/70%-6500/90%)-120=1943 unit.Process application of the present invention will realize the bumper harvests of economic benefit and social resources saving.
Technical process of the present invention is applicable to producing other simultaneously and requires low-carbon (LC) (Ultra-low carbon) steel grade of low-sulfur (super low sulfur) simultaneously.
The processing parameter of explained hereafter line pipe of the present invention and the contrast of single vacuum refining process are as following table.
Table 1
Table 1
Embodiment
Below in conjunction with specific embodiment, technical scheme of the present invention is described further.
The technique that antiacid pipe line steel is produced in a kind of RH-LF-VD refining of the present invention, technical process is molten iron pre-desulfurization-converter smelting-RH vacuum decarburization-LF intensification desulfurization-VD vacuum decarburization-calcium processing-soft blow-continuous casting and hot rolling again, specifically comprises the following steps:
Molten iron pre-desulfurization: blast-melted first through hot metal ladle Desulfurization by injecting method, sweetening agent is granule magnesium desulfurizer.Granular magnesium winding-up intensity is 8 ~ 12kg/min, and the carrier gas flux of carrying as pulvis is 120 ~ 150rn
3/ h, according to the initial sulphur content height of molten iron, MAGNESIUM METAL consumption is 0.4 ~ 0.8kg/t, the quantity of slag is generally at 7 ~ 17kg/t.Treatment cycle is less than 22min, and hot metal temperature drop is 13 ~ 20 ℃, after molten iron pre-desulfurization EO, is rich in sulphur in desulfurization slag, for avoiding molten iron to return sulphur, slag must be removed totally, makes desulfurizing iron rate reach 90% left and right, enters stove molten steel sulfur content and is less than 0.003%.
Converter smelting: adopt top and bottom combined blown converter to smelt, whole smelting process is carried out whole process bottom blowing argon gas, molten steel is fully stirred, so that composition and the temperature of even molten steel, endpoint carbon content of converter is controlled at 0.08% ~ 0.12%, oxygen level is 0.06% ~ 0.08%, phosphorus content≤0.008%.Consider the electrode submerged arc heating molten steel heating effect of LF refining furnace, Tapping Temperature of Bof can reduce relatively, and converter terminal tapping temperature is controlled at 1630 ~ 1660 ℃, improves converter lining life, prevents Molten Steel over-oxidation.During tapping, adopt pushing off the slag operation, the quantity of slag under strict control, in case non-return phosphorus.During tapping, according to the needs of RH decarburization, adopt weak deoxidation operation, make oxygen level and carbon content meet RH vacuum nature decarbonization process demand.
RH vacuum refinement decarburization deoxidation: in RH decarburization deoxidization technique, vacuumize under not oxygen blown condition and carry out the decarburization of nature oxygen; By reducing, [C]+[O]={ the CO partial pressure of CO} reaction, promotes decarburization while deoxygenation to carry out, and while reaching terminal, carbon content control is in 0.01% left and right.
The dark desulfurization of LF stove refining: LF slag adopts CaO-Al
2o
3-SiO
2the desulfurization of ternary basic slag system, in slag, (FeO+MnO) is less than 0.8%.Molten steel, after LF stove, improves ladle bottom argon blowing rate to 400 ~ 600NL/ min, the heating of LF stove electrode submerged arc, and desulfurization improves Molten Steel Cleanliness, alloy fine setting, temperature adjustment.LF stove refining endpoint molten steel sulphur content is ≤0.0008%.Due at LF stove refining process molten steel recarburization, LF stove refining endpoint carbon content is controlled at 0.03% ~ 0.05%.The liquid steel temperature that simultaneously requires control to enter VD refining station is 1620 ~ 1630 ℃, and while guaranteeing casting, molten steel overheat is 15 ± 5 ℃.
VD vacuum refinement decarburization is degassed: due to LF stove refining carburetting, recycling VD pumping high vacuum carries out vacuum decarburization, degassed.VD vacuum refinement terminal is controlled at <0.03% by carbon content of molten steel, simultaneously sulphur content be controlled at≤0.0008%, reach the composition requirement of pipe line steel Antacid effectiveness.Through VD, process qualified molten steel and can carry out as required calcium processing and soft blow, more than the soft blow time is controlled at 12min.
Continuous casting: casting process requires whole process protection casting.
Hot rolling: strand through controlled rolling, control cold, the antiacid pipeline steel billet that organization of production and performance meet the demands.
Antiacid pipe line steel through molten iron pre-desulfurization-converter smelting-RH vacuum refinement-LF refining-VD vacuum refinement-continuous casting and hot rolling explained hereafter, according to target composition requirement, carbon content can be stablized and is controlled at 0.03%, simultaneously sulphur content can stablize be controlled at≤0.0010%, meet the specification of quality of antiacid (anti-HIC and SCC) pipe line steel to low-carbon (LC), low-sulfur and high cleanliness.
Embodiment: antiacid (anti-HIC and SCC) X65 pipe line steel is smelted in south China steel mill application technical process of the present invention, idiographic flow: the antiacid X65 pipe line steel of 28.6mm thickness that molten iron pre-desulfurization-converter smelting-RH refining (decarburization deoxidation)-LF refining (intensification desulfurization)-VD refining (decarburization is degassed)-sheet billet continuous casting-hot rolling is produced, Finished Steel carbon content control is below 0.03%, sulphur content is less than 0.0006%, and steel plate reaches antiacid survey requirement completely after rolling tubulation.After single vacuum (LF-RH) technique and two vacuum (RH-LF-VD) process pipeline steel pipes, sampling quality contrast sees the following form.
Table 1
Table 1
The present invention can also have other concrete parameter of implementing, and the technical scheme that the equal replacement of all employings or equivalent transformation form, within all dropping on the scope of protection of present invention.
Claims (1)
1. a technique for antiacid pipe line steel is produced in RH-LF-VD refining, and technical process is molten iron pre-desulfurization-converter smelting-RH vacuum decarburization-LF intensification desulfurization-VD vacuum decarburization-calcium processing-soft blow-continuous casting and hot rolling again, it is characterized in that, specifically comprises the following steps:
Step 1: molten iron pre-desulfurization: blast-meltedly first carry out desulfurization through hot metal pretreatment, according to the existing molten iron pre-desulfurization processing unit of each production unit, select paddling process or hot metal ladle Desulfurization by injecting method, after molten iron pre-desulfurization EO, in desulfurization slag, be rich in sulphur, for avoiding molten iron to return sulphur, slag removed totally, desulfurizing iron rate reaches 90%, enters stove Sulfur Content in Hot Iron content and is less than 0.003%;
Step 2: converter smelting: the molten iron that step 1 was processed adopts top and bottom combined blown converter to smelt, to add in molten iron account for molten iron total amount 10 ~ 15% low-phosphorous, low-sulfur steel scrap, whole smelting process is carried out whole process bottom blowing argon gas, molten steel is fully stirred, so that composition and the temperature of even molten steel, endpoint molten steel carbon content is controlled at 0.08% ~ 0.12%, oxygen level is 0.06% ~ 0.08%, phosphorus content≤0.008%, tapping temperature is controlled at 1630 ~ 1660 ℃, during tapping, adopt pushing off the slag operation, in case non-return phosphorus, wherein, slag material comprises: lime 50 ~ 65kg/t, light dolomite 15 ~ 25kg/t, basicity of slag is controlled at 3.5 ~ 4.0,
Step 3:RH vacuum refinement decarburization deoxidation: utilize in step 2 after converter tapping oxygen level more than needed in molten steel, by vacuumizing reduction [C]+[O]={ CO partial pressure of CO} reaction, at vacuum pressure, be less than 100Pa, adopt large recycle stream flow 1200 ~ 1400L/min to carry out vacuum cycle, treatment time 15min, while reaching terminal, carbon content of molten steel is controlled at 0.01% ~ 0.03%;
Step 4:LF slag adopts CaO-Al
2o
3-SiO
2the desulfurization of ternary basic slag system, basicity is controlled at 4.0-6.0, FeO in slag and MnO content are less than 0.8%, adopt the heating of electrode submerged arc, molten steel adds after LF stove, improves ladle bottom argon blowing rate to 400 ~ 600NL/ min, treatment time is 35 ~ 45min, during the tapping of LF stove refining terminal, molten steel sulphur content is ≤0.0008%, and carbon content is 0.03% ~ 0.05%, and liquid steel temperature is 1620 ~ 1630 ℃;
Step 5:VD vacuum refinement decarburization is degassed: the molten steel that step 4 is obtained carries out VD vacuum refinement, at vacuum pressure, be less than 100Pa, adopt large recycle stream flow 1200 ~ 1400L/min to carry out vacuum cycle, treatment time 20 ~ 25min, carry out vacuum decarburization, degassed, obtaining carbon content is 0.03% ~ 0.04%, sulphur content is≤0.0010% molten steel, through VD, process qualified molten steel and carry out calcium processing and soft blow, the soft blow time is more than 12min, must reach the antiacid pipe line steel that the composition of pipe line steel Antacid effectiveness requires.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201210200737.9A CN102719728B (en) | 2012-06-18 | 2012-06-18 | Technique for producing anti-acid pipeline steel by RH-LF-VD refining |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201210200737.9A CN102719728B (en) | 2012-06-18 | 2012-06-18 | Technique for producing anti-acid pipeline steel by RH-LF-VD refining |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN102719728A CN102719728A (en) | 2012-10-10 |
| CN102719728B true CN102719728B (en) | 2014-04-02 |
Family
ID=46945591
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201210200737.9A Expired - Fee Related CN102719728B (en) | 2012-06-18 | 2012-06-18 | Technique for producing anti-acid pipeline steel by RH-LF-VD refining |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN102719728B (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP4215627A4 (en) * | 2021-05-20 | 2024-03-06 | Laiwu Steel Yinshan Section Co., Ltd. | Low-cost smelting method for polar-use steel using ultra-high phosphorus molten iron |
Families Citing this family (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| TWI560276B (en) * | 2014-06-04 | 2016-12-01 | China Steel Corp | Steel making method |
| CN109161630B (en) * | 2018-09-25 | 2020-07-24 | 湖南华菱湘潭钢铁有限公司 | Smelting method of HIC-resistant pipeline steel |
| CN109881095B (en) * | 2019-03-14 | 2020-12-18 | 南京钢铁股份有限公司 | grade-B acid-resistant pipeline steel plate and smelting process |
| CN111926147A (en) * | 2020-08-04 | 2020-11-13 | 承德建龙特殊钢有限公司 | Method for producing low-sulfur and low-phosphorus steel by using semisteel water |
Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101240397A (en) * | 2008-02-29 | 2008-08-13 | 南京钢铁股份有限公司 | Converter-RH-LF-continuous casting technique for producing pipe line steel |
| CN102061351A (en) * | 2010-12-21 | 2011-05-18 | 南阳汉冶特钢有限公司 | Method for producing low-carbon steel and ultra-low-carbon steel by VD, LF and VD processes |
-
2012
- 2012-06-18 CN CN201210200737.9A patent/CN102719728B/en not_active Expired - Fee Related
Patent Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101240397A (en) * | 2008-02-29 | 2008-08-13 | 南京钢铁股份有限公司 | Converter-RH-LF-continuous casting technique for producing pipe line steel |
| CN102061351A (en) * | 2010-12-21 | 2011-05-18 | 南阳汉冶特钢有限公司 | Method for producing low-carbon steel and ultra-low-carbon steel by VD, LF and VD processes |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP4215627A4 (en) * | 2021-05-20 | 2024-03-06 | Laiwu Steel Yinshan Section Co., Ltd. | Low-cost smelting method for polar-use steel using ultra-high phosphorus molten iron |
Also Published As
| Publication number | Publication date |
|---|---|
| CN102719728A (en) | 2012-10-10 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN105039648B (en) | Method for smelting low-carbon and high-manganese-content molten steel through argon oxygen decarburizing furnace | |
| CN110453032B (en) | Method for smelting ultralow manganese steel by using high-manganese molten iron | |
| CN102676744A (en) | Technique for refined production of antiacid pipeline steel through VD-LF-VD | |
| CN102719600A (en) | Production method of ultra low carbon steel | |
| CN105018855B (en) | Method for producing circular sulfur-resistant pipeline steel billet for oil and gas collection and transmission | |
| CN102719728B (en) | Technique for producing anti-acid pipeline steel by RH-LF-VD refining | |
| CN102719614B (en) | Process for producing anti-acid pipeline steel by Ruhrstahl Heraecus (RH)-ladle furnace (LF)-RH refining | |
| CN102864378B (en) | Process for smelting low-cost X70 pipeline steel moderate-thickness plate blanks | |
| CN104032095B (en) | A kind of method of liquid steel dephosphorization agent and liquid steel dephosphorization | |
| CN107201422A (en) | A kind of production method of mild steel | |
| CN104195290A (en) | Molten steel dephosphorization agent and molten steel dephosphorization refining method | |
| CN107385139A (en) | A kind of smelting process of high-carbon steel | |
| CN109234489A (en) | The control method of catch carbon stage nitrogen increased amount is reduced when a kind of converter smelting mild steel | |
| CN103571999A (en) | Method for smelting nitrogen-controlling martensite stainless steel through total molten iron | |
| CN104531953B (en) | A kind of refine argon jetting method being applied to SPHC steel grade | |
| CN102876845A (en) | Method for producing ultra-low phosphorus steel through applying pre-melting calcium ferrite to refine outside LF (Ladle Furnace) molten steel furnace | |
| CN105463149A (en) | Process for deoxidation smelting of aluminum-bearing steel by means of silicon carbide | |
| CN102534095A (en) | Smelting process for super clean pipeline steel | |
| CN105256094A (en) | Method for smelting weathering resistant steel | |
| CN101413044B (en) | Alloy addition method for improving yield of ferromolybdenum | |
| CN108977612A (en) | The smelting process of high-strength weather-resistant bolt steel | |
| CN103352168B (en) | A kind of low-carbon high-chromium steel and converter smelting process thereof | |
| CN107955858A (en) | A kind of production method of ultra-low-carbon steel SAE1006 | |
| CN104046923B (en) | The X80 pipe line steel smelted under half steel condition and production technique thereof | |
| CN103484599A (en) | Smelting method of high-manganese wear-resistant steel |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C06 | Publication | ||
| PB01 | Publication | ||
| C10 | Entry into substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| C14 | Grant of patent or utility model | ||
| GR01 | Patent grant | ||
| CF01 | Termination of patent right due to non-payment of annual fee | ||
| CF01 | Termination of patent right due to non-payment of annual fee |
Granted publication date: 20140402 Termination date: 20180618 |