CN1302126C - Method for producing low-carbon high-sulfur (sulfur-phosphorous) easy-to-cut structural steel continuous casting billet - Google Patents
Method for producing low-carbon high-sulfur (sulfur-phosphorous) easy-to-cut structural steel continuous casting billet Download PDFInfo
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Abstract
The present invention relates to a production method for a continuous casting billet of low-carbon and high-sulphur free-cutting structural steel, which is characterized in that liquid steel is primarily refined, and a proper quantity of Al is added when the tapping oxygen activity is 700 ppm and the tapping amount is 20 %; refining slag is added when the tapping amount is 90 %; steel liquid is refined in a ladle furnace (LF), deoxidation is carried out on the slag surface, the materials are stirred by argon blown from the bottom, and the intensity is 0.5MPa; samples are analyzed after energization for 10 minutes, and components are adjusted; slag containing 58% of CaO, 11% of Al2O3, 9% of SiO2 and 8% of MgO is refined, and the oxygen activity is 60 ppm; when the temperature of the liquid steel reaches the liquid phase temperature of 90 DEG C above zero, the argon blown from the bottom is shut off, and sulfur core-spun yarn is rapidly added; continuous casting is carried out, the casting speed is reasonable, a continuous casting billet with the area of 140MM<2> is used as an example, and the casting speed is 2M/ min; the pressure value of each straightening roll at the tail end of a continuous casting machine is different from the conventional value of 10 Bar; a suitable continuous casting technical parameter is set. The produced continuous casting billets of steel with the brand numbers of 1213, 1215, etc., have the advantages of stable component, good continuous casting performance, low production cost, high quality of casting billets (in conformity with rolling requirements of subsequent heat processing), and obvious economic benefit.
Description
Technical field
The present invention relates to the smelting production method of metallurgy industry easy-to-cut structural steel, referring in particular to sulphur (or sulphur phosphorus is compound) is the smelting production method of easy-to-cut structural steel.
Background technology
Structure iron (mainly being structural low, structural carbon steel) is common iron and steel kind, and its production technique is: the killed steel smelting technology adds casting forming (high-temperature molten steel solidification forming).Generally, in the smelting process, for the purity (improving every performance index of steel) that improves steel, technique means is absolutely necessary in strong deoxidation measure (promptly adding strong deoxidant element in steel, as adding aluminium ingot bulk deoxidation, white slag diffusive deoxidation, vacuum carbon deoxidization etc.).The mode of high-temperature molten steel solidification forming has die casting and continuous casting dual mode (to implement the continuous casting mode as far as possible, improve recovery rate of iron, reduce production costs): die casting (high-temperature molten steel is watered into steel ingot, be processed into steel billet) recovery rate of iron lower (about about 84%) through blooming mill or forging press; Continuous casting (high-temperature molten steel is directly watered into steel billet) recovery rate of iron higher (about about 98%).
In recent years, along with machinery, industrial the developing rapidly of device fabrication, the easy cuttingization of structure steel material (reduction at double, the quality product of cutting cost increase substantially with production efficiency and significantly improve) becomes the pursuit that iron and steel uses the merchant (as in Japan, the machining time of part on automatic production line, every shortening 1 second can be saved 1 yen.), for satisfying machinery, the industrial easily cutting requirement of metallic substance of device fabrication, based on the also increase day by day of free-cutting steel (easy-to-cut structural steel) kind of structure iron.At present easy-to-cut structural steel mainly contains sulfur-bearing (sulphur phosphorus) easy-to-cut structural steel, leaded easy-to-cut structural steel two classes, because the factor of Lead contamination, Lead Treated Steel presents and gradually reduces and substituted trend; On the contrary, progress along with Materials science and Technology, cutting ability environment-friendly type, unleaded, sulfur-bearing (sulphur phosphorus) easy-to-cut structural steel progressively near or reach the level of Lead Treated Steel, therefore, sulphur (sulphur phosphorus) is the welcome that easy-to-cut structural steel has been subjected to steelmaker (Steel Plant), machinery, the industrial merchant of device fabrication (steel users unit), its usage quantity also constantly increases, and range of application constantly enlarges.
Sulphur (sulphur phosphorus) is that (in sulphur phosphorus easy-to-cut structural steel, people are referred to as sulphur phosphorus easy-to-cut structural steel to the easy-to-cut structural steel of S content 〉=0.04%, P content 〉=0.04% to easy-to-cut structural steel; The easy-to-cut structural steel of S content 〉=0.08%, P content 〉=0.04%, be referred to as high-sulfur phosphorus easy-to-cut structural steel; The easy-to-cut structural steel of S content 〉=0.08%, be referred to as the high-sulfur easy-to-cut structural steel; The easy-to-cut structural steel of C content≤0.20%, be referred to as the low-carbon (LC) easy-to-cut structural steel), be a kind of special structure iron kind (advantages such as work-ing life that in cutting process, have lower cutting force and cutting temperature, easily chip breaking, surface smoothness height and raising cutter, it is big to be widely used in the machining amount, in the machining industry such as production such as the equipment for office automation that the machining level of automation is high, household electrical appliances, instrument, IT and lathe).Be characterized in structure iron adding an amount of S, (in general, the S element in the steel makes it to produce sulfide inclusion to P content, reduces the plasticity and the lateral performance of steel; P element in the steel improves sosoloid intensity, thus the embrittlement ferrite; But, an amount of S, P content, uniform distribution by control oxide morphology, S, P, to the mechanical property of steel influence and little), purpose is to increase substantially the machining cutting ability (for machinery manufacturing industry provides material foundation towards the development of high speed, precise treatment and automation direction) of steel.
In the production process of low carbon high sulfur (sulphur phosphorus) easy-to-cut structural steel, on the one hand, need to adopt smelting and the method for deoxidation that is different from common process: add sulphur, phosphorus etc. in the steel and easily cut element (in order in steel, to obtain the suitable sulfide of uniform distribution, size and form, be used to improve cutting ability) time, oxygen level in the need control steel is (because sulphur and oxygen are in same gang in the periodic table of elements, both have similar physicochemical property, therefore, stablize the sulfide in the control steel, just requiring has suitable oxygen level in the molten steel.Oxygen level is low, is unfavorable for forming stable sulfide; Oxygen level height, molten steel are easy to generate boiling in process of setting, generate subsurface bubble.); In addition, (silicon, aluminium element have adverse influence to cutting ability to silicon, the aluminium content in the strict control of the need steel, and its content is low more good more.)。On the other hand, during the high-temperature molten steel solidification forming, because the Peritectic Reaction characteristic of soft steel, high-sulfur or high-sulfur phosphoric have a strong impact on the high-temp plastic of steel, the influence of factors such as the elevated oxygen level in the easy-to-cut structural steel, make the continuous casting production of low carbon high sulfur (sulphur phosphorus) easy-to-cut structural steel run into a series of technical barrier, properly settled (although the national standard of easy-to-cut structural steel has been founded by China since the sixties always, the continuous casting process The Application of Technology has also greatly obtained popularizing, but the continuous casting technology of easy-to-cut structural steel is not resolved always.This be because: when easy-to-cut structural steel adopted continuous casting to produce, watering property of existence was poor, problems such as serious sulphur phosphorous segregation and internal fissure appear in bleed-out, strand easily in the cast.Especially low carbon high sulfur easy-to-cut structural steel is in continuous cast mold, because the solidification shrinkage stress, the solidified shell discontinuity, cause strand corner crack and diagonal lines crackle easily, this defective can cause the blank head cracking in the operation of rolling, and causes rolling fault.)。Therefore, even to this day, domestic low carbon high sulfur (sulphur phosphorus) easy-to-cut structural steel generally adopts the die casting mode to organize production, makes the production cost high (the die casting billet yield is lower more than 14% than continuous casting) of easy-to-cut structural steel, can't carry out market competition with imported materials and items.At present, the annual import easy-to-cut structural steel of China (containing high-sulfur, sulphur phosphorus easy-to-cut structural steel) about 1,000,000 tons, domestic yearly capacity has only 2～30,000 tons.
Summary of the invention
The present invention develops the production method of a kind of low carbon high sulfur (sulphur phosphorus) easy-to-cut structural steel continuous casting billet, just refines by electric furnace or converter; Ladle furnace refining; The three-steps process of continuous caster cast, the continuous irrigatation castability of producing stable components (aluminium, silicone content are low, stable components such as sulphur, phosphorus, oxygen), molten steel is good, the qualified continuously cast bloom of slab quality stable (meeting the rolling performance requriements of subsequent thermal processing).
The production method of low carbon high sulfur provided by the invention, high-sulfur phosphorus easy-to-cut structural steel continuous casting billet is characterized in that adopting three-step approach smelting technology flow process: just refine at electric furnace more than 30 tons or converter; The ladle furnace refining of corresponding tonnage; Continuous casting; Produce 90 * 90mm
2～360 * 360mm
2The qualified continuously cast bloom of cross dimensions.
The first step, carry out the first refining of molten steel in the electric furnace of 30～100 tons (as be lower than 30 tons, be difficult for reaching high-efficiency and low-cost) or converter: tapping temperature is controlled at 1620～1660 ℃ (as tapping temperature greater than 1660 ℃, to be increased to smelt to consume also and makes terminal point oxygen too high; Tapping temperature is less than 1620 ℃, makes that to obtain furnaceman LF position molten steel temperature low excessively, and LF refining intensification task increases the weight of); Decide oxygen, and tapping oxygen activity (terminal point oxygen level) control 600～900ppm (too high as oxygen activity, can influence life-span of refining ladle; Suitable oxygen level helps the sulfide in the stable control steel);
In the process of electric furnace or converter tapping, tap 15～35% o'clock, the deoxidation of beginning killing, reductor is Al (add-on of Al is significantly less than the amount of being routinely added to), the add-on of Al=(0.02～0.035) tapping oxygen activity, the add-on unit K g of Al, the ppm of tapping oxygen activity unit, as tapping oxygen activity 700ppm, add-on 14～24Kg of Al; Technology adds carbon dust and silicon-manganese alloy routinely subsequently; Tap 80～95% o'clock adds refining slag: lime 7～9kg t, high Al brick fragment 0.8～1.0kg t, and lime contains Cao 〉=90%, and high Al brick fragment contains 30～34%SiO
2With 45～50%Al
2O
3
In second step, on the AC system ladle refining furnace (LF stove) that capacity and electric furnace or converter are complementary,, carry out the refining of molten steel by the control of slag system control, Control for Oxygen Content, interpolation sulphur:
(1) tapping is complete is controlled in the 15min to furnaceman LF position; Energising heats up, and adds 1～2kg t lime in two batches and (contains CaO 〉=90, adopt the SiFe powder of 0.25～0.35kg t and carbon dust or the phosphorus-containing alloy of 0.07～0.20kg t simultaneously, carry out top of the slag deoxidation; Be blown into argon gas from ladle bottom simultaneously, BOTTOM ARGON BLOWING intensity is controlled at 0.4～0.6Mpa respectively, and (BOTTOM ARGON BLOWING intensity is excessive, causes slag-metal reaction, molten steel to wash away seriously ladle lining, reduces ladle life; BOTTOM ARGON BLOWING intensity is too small, and molten steel temperature and composition and slag-metal reaction are all inhomogeneous and abundant, causes the aluminium deoxidation product of molten steel fully not float, and alloy element is skewness in steel); Switch on after 10 minutes, sampling analysis is successively adjusted except that S all elements to target value;
(2) refining top slag composition is controlled at: CaO content 50～60%, Al
2O
3Content 10～15%, SiO
2Content 8～12%, MgO content 6～10% (this top slag composition helps Al adsorption, silicon deoxidation products, and oxygen activity is between 30～80ppm in the control molten steel, and suitable oxygen level helps the sulfide in the stable control steel);
(3) when reaching liquidus temperature+80～95, molten steel temperature ℃ (that is to say, the alloying temperature drop of 70 ℃ of solid temperatures+10～25 ℃), and after all elements composition meets steel composition technological standard except that S, stir (avoiding steel stream to contact by turns) at the bottom of closing ladle with the top top of the slag, (add purpose fast to stable state molten steel feeding sulphur bundle component wire fast, be to reach the purpose that sulphur bundle component wire passes through the top slag blanket fast, avoid sulphur bundle component wire contact top slag and absorbed by the top slag, influence the recovery rate of sulphur), the recovery rate of the add-on of sulphur=(target content-residual volume)/sulphur, the recovery rate of sulphur=0.85～0.90;
(4) feed sulphuring treatment and finish, to the carbonization rice husk (insulation slows down the molten steel temperature drop) of ladle adding 0.9～1.1kg/t, bull ladle carries out continuous casting (avoid the recovery rate of sulphur to descend, and the sulphur content in the finished product molten steel that causes thus to be offscale) immediately.
The 3rd step, continuous casting (steel ladle pouring, tundish continuous casting)
(1) high-temperature molten steel in the ladle waters into T type tundish by protective casing, and the tundish superheating temperature is controlled at 10～35 ℃, and (superheating temperature is too high: steel billet easily cracks, and center segregation, shrinkage cavity defect are serious, and continuously cast bloom shell thickness differs, and easily causes bleedout; Superheating temperature is low excessively: cause that easily the mouth of a river freezes, force cast to be interrupted.); The melting steel amount of T type tundish is 6～25 tons, and (melting steel amount is too small, and molten steel is short in the tundish residence time, and to be mingled with floating interval of floating dock not enough for macrobead in the steel, easily produces the volume slag.); Before using in the T type tundish fully the cleaning, internal surface is as fire-resistant coating and the crack must not be arranged;
(2) molten steel in the tundish, waters and outpours 90 * 90mm with rational casting rate through continuous cast mold
2～360 * 360mm
2The qualified continuously cast bloom of cross dimensions; 140 * 140mm
2During cross dimensions, casting rate is 1.80～2.10m/min; 160 * 160mm
2During cross dimensions, casting rate is 1.60～1.9m/min; 180 * 180mm
2During cross dimensions, casting rate is 1.0～1.3m/min; 220 * 220mm
2During cross dimensions, casting rate is that (pulling rate is too fast: the liquid core of continuous casting billet cave increases by 0.7～0.9m/min, and the continuously cast bloom shell is too thin, easily produces the bleedout accident, is with liquid core aligning to be easy to generate stress crack simultaneously; Pulling rate is slow excessively: influence continuous caster throughput.)；
(3) the continuously cast bloom sedan-chair of continuous caster end is straight, adopt continuous sedan-chair straight, the pressure change of the straight roller of each continuous sedan-chair is conventional increase gradually, the force value of the straight roller of each sedan-chair is to differ from 9 conventional～12Bar (low carbon high sulfur easy-to-cut structural steel steel continuous casting billet carries out sedan-chair and directly is easy to generate the sedan-chair vertical crack during greater than 12Bar.), Bar is a flow pressure unit, 1Bar=1kg/sm3=1 Kilograms Per Second cubic meter; The straight front surface temperature of strand sedan-chair (is lower than this temperature and will falls into soft steel continuously cast bloom low temperature brittleness sensitive area, be easy to generate the sedan-chair vertical crack when sedan-chair is straight greater than 980 ℃.)。
(4) the continuous casting technology parameter is provided with: (A) continuous cast mold setting: select curved mold for use, length of mould is greater than 780mm, crystallizer bight abrasion loss is less than 1.2mm, mould reverse taper is moderate, steel-passing amount is controlled at that (steel-passing amount is less than 1500 tons between 1500～5000 tons, then mould reverse taper is excessive, and it is excessive that strand goes out the crystallizer resistance, causes the casting billet surface drawing crack easily; Steel-passing amount is excessive, and then mould reverse taper is too small, and it is too small that strand goes out the crystallizer resistance, causes bleed-out easily.); (B) crystallizer protecting residue is selected high-viscosity covering slag for use: basicity CaO/SiO2=0.85～1.00,1130～1150 ℃ of temperature are separated out in crystallization, (pool refers to viscosity unit to standard test viscosity 1.5～4.5 pools in the time of 1300 ℃, Poisson, Poise, 1P=0.1 * Pa.s), covering slag add-on 0.40～0.50kg/t; (C) the crystallizer cooling water flow is provided with, and is principle to guarantee that turnover crystallizer water temperature difference is not more than 9 ℃, cast 140 * 140mm
2Section discharge is 1580～1680l/min; Cast 160 * 160mm
2Section discharge is 1700～1800l/min; Cast 180 * 180mm
2Section discharge is 1900～2000l/min; Cast 220 * 220mm
2Section discharge is 2000～2100l/min; (discharge is low excessively, and then the crystallizer Inlet and outlet water temperature difference becomes big, illustrates that the molten steel in mold heat water that has little time to be cooled takes away, and solidified shell was grown thin, caused bleed-out easily; Discharge is too high, and air gap increases between crystallizer wall and the base shell, and crystallizer bight and border area hot-fluid are inhomogeneous, cause the strand bight to bear string stress, and the strand edge bear tension stress, so that crack in the strand bight.) (D) the secondary cooling intensity adopt 0.32～0.38l/kg the specific water (intensity of secondary cooling is excessive: heat exchange continuous casting blank temperature gradient is big, when aligning owing to easily crack between stress surface and the center; Intensity of secondary cooling is too small: easily cause continuous casting billet skin temperature too high, creep takes place and produces the bulge defective in solidified shell easily.); Two cold-zone each section specific waters are provided with ratio and are: sufficient roller section: move section: canned paragraph=(20～30): (45～55): (20～30); This ratio obtains cooling uniformly when helping guaranteeing with the strand of liquid core by two cold-zone each sections, guarantees the control of strand speed of cooling less than 200 ℃/m, and the strand temperature recovery is not more than 100 ℃/m; (E) the head end induction stirring is controlled at 330A/4～5.0Hz, and terminal induction stirring is controlled at 200A/9～11.0Hz, controls the rotation in positive and negative 5～10 seconds of terminal induction stirring simultaneously.
Compare with prior art, the present invention has following advantage:
1, production cost is low; Compare with die casting, the billet yield of steel improves more than 13%;
2, the silicon in the molten steel, sulphur, phosphorus content are stablized, Si≤0.05%, and Al≤0.003%, the recovery rate of phosphorus is greater than 98%, and the recovery rate of sulphur is greater than 85%;
3, equipment and technology highly versatile; Must not add specific equipment in addition; Its technology is suitable for the continuous casting production of all low carbon high sulfurs (sulphur phosphorus) easy-to-cut structural steel;
4, continuous casting billet quality is stable, and equiaxial crystal ratio is greater than 55% (the equiax crystal length * 100/ section length of side), and sulphur, phosphorus are evenly distributed on the casting blank section.
Specific embodiments
Certain steel-making subsidiary factory of Iron And Steel Company implements patent of the present invention, and the production cross dimensions is 90 * 90mm
2～360 * 360mm
2Low carbon high sulfur (sulphur phosphorus) easy-to-cut structural steel continuous casting billet (structure iron kind: 1108,1109,1110,1116,1117,1118,1119,1211,1212,1213,1215 of U.S.'s trade mark, SUM11, SUM12, SUM21, SUM22, SUM23, SUM25, SUM31, the SUM32 of Japan's trade mark, the Y12 of the Chinese trade mark, Y15, Y20; The Germany trade mark: 9S20,9SMn28,9SMn36,10S20 etc.; With cross dimensions 160 * 160mm
21213,1215 structure iron be example) thousands of tons of, its technical process is: 60 tons of (30～100 tons) electric furnaces just refine; The ladle furnace refining of 60 tons of (corresponding tonnage) BOTTOM ARGON BLOWING; 3 machines, 3 streams, 160 * 160mm
2The continuous caster cast.The first step in the 60T electric furnace, is carried out the first refining of molten steel: feed electric current and input oxygen, make the furnace charge fusing of packing into become the interior molten steel of 1640～1660 ℃ of temperature ranges; Decide oxygen, tapping oxygen activity (terminal point oxygen level) control 700ppm; The conventional tapping of EBT, during tap 10t (15～35%), beginning aluminum deoxidation agent deoxidation (add-on of Al is significantly less than the amount of being routinely added to), the add-on of Al=(0.02～0.035) * tapping oxygen activity=20kg; Technology adds required alloys such as carburelant (carbon dust) and silicon-manganese alloy routinely subsequently; Tap when (80～95%), adds refining slag more than 50t: lime 500kg (7～9kg/t), (0.8～1.0kg/t), lime contains Cao 〉=90% to high Al brick 50kg, and high Al brick fragment contains 32%SiO
2, 48%Al
2O
3In second step, on the AC system ladle refining furnace (LF stove) that capacity and electric furnace or converter are complementary, by the control of slag system control, Control for Oxygen Content, interpolation sulphur, carry out the refining of molten steel: (1) tapping is complete to be controlled at≤15min to furnaceman LF position; The energising of LF stove heats up, and adds the lime 100kg that contains Cao 〉=90% in two batches, adopts 20kg SiFe powder and 6kg carbon simultaneously, carries out top of the slag deoxidation, makes white slag; Be blown into argon gas from ladle bottom simultaneously, the BOTTOM ARGON BLOWING intensity control is at 0.4～0.6Mpa; Switch on after 10 minutes, sampling analysis is successively adjusted element, adjusts except that S all elements to target value; Refining top slag composition is controlled at: CaO content 58%, Al
2O
3Content 11%, SiO
2Content 9%, MgO content 8%, oxygen activity is at 43ppm; (3) reach liquidus temperature+80～95 ℃=1615 ℃ (1213,1215 liquidus temperature is respectively 1515 ℃, 1517 ℃) when molten steel temperature, stir at the bottom of closing ladle, adopt sulphur bundle component wire to add sulphur to the stable state molten steel fast, sulphur recovery rate estimation with 0.85, the add-on 0.28% of sulphur finally realizes target 0.27%; (4) feed sulphuring treatment and finish, to the carbonization rice husk of ladle adding 1kg/t, bull ladle carries out continuous casting immediately.In the 3rd step, continuous casting: the high-temperature molten steel in the ladle is by protective casing, and (tundish is cleared up before using fully, internal surface is as fire-resistant coating and the crack must not be arranged to water the T type tundish of 12 tons of melting steel amounts into; The tundish superheating temperature is controlled at 15～35 ℃); 3 machines, 3 stream casters, make the molten steel in the tundish divide 3 flow points not enter 3 crystallizer (continuous cast mold settings: select curved mold for use by the dummy head in the crystallizer, length of mould is greater than 780mm, crystallizer bight abrasion loss is less than 1.2mm, mould reverse taper is moderate, and steel-passing amount is controlled between 1500～5000 tons; Crystallizer protecting residue is selected high-viscosity covering slag for use: basicity CaO/SiO
2=0.9,1130～1150 ℃ of temperature are separated out in crystallization, standard test viscosity 1.5～4.5 pools in the time of 1300 ℃, covering slag add-on 0.45kg/t; The crystallizer cooling water flow is provided with: 1700～1800l/min, to guarantee that turnover crystallizer water temperature difference is not more than 9 ℃ is principle) in, well-regulated vibration by each crystallizer simultaneously makes molten steel in the process that progressively moves down, under the stirring of the magnetic stirrer of the cooling of the water coolant of the stirring of crystallizer magnetic stirrer, secondary cooling zone, secondary cooling zone end, be frozen into 160 * 160mm gradually
2Qualified continuously cast bloom.Pulling rate (casting rate) 1.70～1.80m/min.The secondary cooling intensity adopts the specific water of 0.36l/kg; Two cold-zone each section specific waters are provided with ratio and are: sufficient roller section: move section: canned paragraph=(20～30): (45～55): (20～30)=25: 50: 25.The head end induction stirring is controlled at 330A/5.0Hz, and terminal induction stirring is controlled at 200A/11.0Hz, controls the rotation in positive and negative 5～10 seconds of terminal induction stirring simultaneously.The continuously cast bloom sedan-chair of continuous caster end is straight, adopts continuous sedan-chair straight, and the pressure change of the straight roller of each continuous sedan-chair is conventional increase gradually, and the force value of the straight roller of each sedan-chair is to differ from 9 conventional～12Bar.
Implement that patent of the present invention produces 1110,1117,1213,1215, low carbon high sulfur (sulphur phosphorus) easy-to-cut structural steel continuous casting billet of the trades mark such as Y12, Y15, silicon in the molten steel, sulphur, phosphorus content stable components, Si≤0.05%, Al≤0.003%, the recovery rate of phosphorus is greater than 98%, and the recovery rate of sulphur is greater than 85%; And continuous casting billet quality is stable, and the casting blank section equiaxial crystal ratio is greater than 55%, and sulphur, phosphorus are evenly distributed on the section; And low production cost (compare with the die casting process of routine, the billet yield of steel improves more than 13%); Low carbon high sulfur (sulphur phosphorus) easy-to-cut structural steel continuous casting billet with patent production of the present invention, the industrial accident that head opening, initiation tandem rolling heap steel or curling round the roll does not take place in follow-up hot-work is rolling and skid, stopped heat when rolling (head opening and curling round the roll, skid and the cause) phenomenon of stopping work, the production efficiency height, and the steel billet lumber recovery is greater than 94%; Wire rod and the bar product of the Φ that hot-work rolls out more than 5.5, steady quality, conformance with standard requires to use through the user, and cutting ability and mechanical property are good, have satisfied machinofacture merchant's requirement.
Claims (2)
1, the production method of low carbon high sulfur, high-sulfur phosphorus easy-to-cut structural steel continuous casting billet is characterized in that adopting three-step approach smelting technology flow process: just refine at electric furnace more than 30 tons or converter; The ladle furnace refining of corresponding tonnage;
Continuous casting; Produce 90 * 90mm
2～360 * 360mm
2The qualified continuously cast bloom of cross dimensions;
The first step, in 30～100 tons electric furnaces or converter, carry out the first refining of molten steel:
Tapping temperature is controlled at 1620～1660 ℃; Decide oxygen, tapping oxygen activity control 600～900ppm, tapping oxygen activity is exactly the terminal point oxygen level;
In the process of electric furnace or converter tapping, tap 15～35% o'clock, the deoxidation of beginning killing, reductor is Al, and the add-on of Al is significantly less than the amount of being routinely added to, the add-on of Al=(0.02～0.035) * tapping oxygen activity, the add-on unit K g of Al, the ppm of tapping oxygen activity unit; Technology adds carbon dust and silicon-manganese alloy routinely subsequently; Tap 80～95% o'clock adds refining slag: lime 7～9kg/t, high Al brick fragment 0.8～1.0kg/t;
In second step, on the AC system LF ladle refining furnace that capacity and electric furnace or converter are complementary,, carry out the refining of molten steel by the control of slag system control, Control for Oxygen Content, interpolation sulphur:
(1) tapping is complete is controlled in the 15min to furnaceman LF position; Energising heats up, and adds in two batches and contains the lime 1～2kg/t of CaO 〉=90%, and adopt the SiFe powder of 0.25～0.35kg/t and carbon dust or the phosphorus-containing alloy of 0.07～0.20kg/t, carries out top of the slag deoxidation; Be blown into argon gas from ladle bottom simultaneously, BOTTOM ARGON BLOWING intensity is controlled at 0.4～0.6Mpa respectively; Switch on after 10 minutes, sampling analysis is successively adjusted except that S all elements to target value;
(2) refining top slag composition is controlled at: CaO content 50～60%, Al
2O
3Content 10～15%, SiO
2Content 8～12%, MgO content 6～10%; Oxygen activity is between 30～80ppm in the control molten steel;
(3) reach liquidus temperature+80～95 ℃ when molten steel temperature, and after all elements composition meets steel composition technological standard except that S, stir at the bottom of closing ladle, fast to stable state molten steel feeding sulphur bundle component wire, the recovery rate of the add-on of sulphur=(target content-residual volume)/sulphur, the recovery rate of sulphur is calculated with 0.85～0.90;
(4) feed sulphuring treatment and finish, to the carbonization rice husk of ladle adding 0.9～1.1kg/t, bull ladle carries out continuous casting immediately;
The 3rd step, continuous casting:
(1) high-temperature molten steel in the ladle waters into T type tundish by protective casing, and the tundish superheating temperature is controlled at 10～35 ℃; The melting steel amount of T type tundish is 6～25 tons; Before using in the T type tundish fully the cleaning, internal surface is as fire-resistant coating and the crack must not be arranged;
(2) molten steel in the tundish, waters and outpours 90 * 90mm with rational casting rate through continuous cast mold
2～360 * 360mm
2The qualified continuously cast bloom of cross dimensions; 140 * 140mm
2During cross dimensions, casting rate is 1.80～2.10m/min; 160 * 160mm
2During cross dimensions, casting rate is 1.60～1.9m/min; 180 * 180mm
2During cross dimensions, casting rate is 1.0～1.3m/min; 220 * 220mm
2During cross dimensions, casting rate is 0.7～0.9m/min;
(3) the continuously cast bloom sedan-chair of continuous caster end is straight, adopts continuous sedan-chair straight, and the pressure change of the straight roller of each continuous sedan-chair is conventional increase gradually, and the force value of the straight roller of each sedan-chair is to differ from 9 conventional～12Bar, and Bar is a flow pressure unit, 1Bar=1kg/sm
3=1 Kilograms Per Second cubic meter; The straight front surface temperature of strand sedan-chair is greater than 980 ℃;
(4) the continuous casting technology parameter is provided with: (A) continuous cast mold setting: select curved mold for use, length of mould is greater than 780mm, and crystallizer bight abrasion loss is less than 1.2mm, and mould reverse taper is moderate, and steel-passing amount is controlled between 1500～5000 tons; (B) crystallizer protecting residue is selected high-viscosity covering slag for use: 1130～1150 ℃ of temperature are separated out in basicity CaO/SiO2=0.85～1.00, crystallization, standard test viscosity 1.5～4.5 pools in the time of 1300 ℃, and pool refers to viscosity unit, covering slag add-on 0.40～0.50kg/t; (C) the crystallizer cooling water flow is provided with, and is principle to guarantee that turnover crystallizer water temperature difference is not more than 9 ℃, cast 140 * 140mm
2Section discharge is 1580～1680l/min; Cast 160 * 160mm
2Section discharge is 1700～1800l/min; Cast 180 * 180mm
2Section discharge is 1900～2000l/min; Cast 220 * 220mm
2Section discharge is 2000～2100l/min; (D) the secondary cooling intensity adopts the specific water of 0.32～0.38l/kg; Two cold-zone each section specific waters are provided with ratio and are: sufficient roller section: move section: canned paragraph=(20～30): (45～55): (20～30); Guarantee the control of strand speed of cooling less than 200 ℃/m, the strand temperature recovery is not more than 100 ℃/m; (E) the head end induction stirring is controlled at 330A/4～5.0Hz, and terminal induction stirring is controlled at 200A/9～11.0Hz, controls the rotation in positive and negative 5～10 seconds of terminal induction stirring simultaneously.
2, the production method of low carbon high sulfur according to claim 1, high-sulfur phosphorus easy-to-cut structural steel continuous casting billet is characterized in that: in the refining slag of electric furnace or the adding of converter tapping process, lime contains CaO 〉=90%, and high Al brick fragment contains 30～34%SiO
2With 45～50%Al
2O
3
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| CN101444885B (en) * | 2008-12-29 | 2012-09-26 | 杭州钢铁集团公司 | Continuous casting process for HG20 martensitic steel |
| CN101580912B (en) * | 2009-06-19 | 2011-04-20 | 武汉钢铁(集团)公司 | Low carbon high sulfur free-cutting steel production process |
| CN101773930B (en) * | 2010-01-21 | 2011-07-20 | 广州珠江钢铁有限责任公司 | Method for producing 65Mn hot rolled steel plate |
| CN101824510B (en) * | 2010-05-14 | 2012-06-13 | 东北大学 | Argon blowing method at bottom of steel ladle for continuously casting steel |
| CN102465239B (en) * | 2010-11-13 | 2013-06-12 | 山西太钢不锈钢股份有限公司 | Method for increasing sulfur yield of high sulfur stainless steel |
| CN102211160B (en) * | 2011-05-13 | 2013-02-27 | 攀钢集团有限公司 | Continuous casting method of sulfur-containing easy-cutting pinion steel |
| CN102825236B (en) * | 2012-08-31 | 2015-02-04 | 首钢京唐钢铁联合有限责任公司 | Method for eliminating transverse crack defect of boron-containing steel continuous casting billet corner |
| CN104087708B (en) * | 2014-05-22 | 2016-04-27 | 武汉钢铁(集团)公司 | Fractured connecting rod high-sulfur phosphorus high-strength steel continuously cast bloom production method |
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| CN104907513A (en) * | 2015-06-09 | 2015-09-16 | 石家庄钢铁有限责任公司 | Method for continuous casting of large rectangular billet of low-carbon hadifield steel |
| CN107186192B (en) * | 2017-04-26 | 2019-05-28 | 江苏省沙钢钢铁研究院有限公司 | Continuous casting method for improving segregation of billet cord steel |
| CN109252086A (en) * | 2017-07-13 | 2019-01-22 | 鞍钢股份有限公司 | Production method of high-sulfur steel |
| CN107790664B (en) * | 2017-10-24 | 2019-07-30 | 南京钢铁股份有限公司 | A kind of billet continuous casting method of high sulfur content automatic steel |
| CN107866538B (en) * | 2017-11-24 | 2020-06-19 | 南京钢铁股份有限公司 | Continuous casting production method for square billet of vanadium-containing and nitrogen-containing microalloyed peritectic steel |
| CN110722119B (en) * | 2019-10-25 | 2021-12-07 | 广东韶钢松山股份有限公司 | Continuous casting production process for preparing low-carbon high-sulfur high-oxygen free-cutting steel at high drawing speed |
| CN111321276B (en) * | 2020-04-10 | 2021-12-03 | 北京首钢股份有限公司 | Method for improving yield of magnesium element in molten steel |
| CN111455138A (en) * | 2020-05-19 | 2020-07-28 | 首钢贵阳特殊钢有限责任公司 | Smelting method of medium-high carbon sulfur-lead composite free-cutting structural steel |
| CN112080700B (en) * | 2020-09-14 | 2022-02-01 | 新余钢铁股份有限公司 | High-sulfur low-aluminum free-cutting steel continuous casting slab and production method thereof |
| CN114058927B (en) * | 2021-10-22 | 2022-06-07 | 江苏沙钢集团淮钢特钢股份有限公司 | Production method of high-phosphorus peritectic steel |
Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4671499A (en) * | 1985-02-22 | 1987-06-09 | Nippon Steel Corporation | Tundish for continuous casting of free cutting steel |
| JPS62207548A (en) * | 1986-03-07 | 1987-09-11 | Nippon Steel Corp | Production of free-cutting sulfur steel by continuous casting method |
| JPH0273914A (en) * | 1988-09-09 | 1990-03-13 | Nippon Steel Corp | Production of free cutting steel with continuous casting method and composite alloy wire using to production thereof |
| JPH10511A (en) * | 1996-06-12 | 1998-01-06 | Okuma Mach Works Ltd | Machining chip precipitation preventing device |
-
2005
- 2005-03-04 CN CNB2005100242054A patent/CN1302126C/en not_active Expired - Fee Related
Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4671499A (en) * | 1985-02-22 | 1987-06-09 | Nippon Steel Corporation | Tundish for continuous casting of free cutting steel |
| JPS62207548A (en) * | 1986-03-07 | 1987-09-11 | Nippon Steel Corp | Production of free-cutting sulfur steel by continuous casting method |
| JPH0273914A (en) * | 1988-09-09 | 1990-03-13 | Nippon Steel Corp | Production of free cutting steel with continuous casting method and composite alloy wire using to production thereof |
| JPH10511A (en) * | 1996-06-12 | 1998-01-06 | Okuma Mach Works Ltd | Machining chip precipitation preventing device |
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