CN107326258B - A kind of following minor diameter Ductile iron bar of diameter 25mm and preparation method thereof - Google Patents

A kind of following minor diameter Ductile iron bar of diameter 25mm and preparation method thereof Download PDF

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Publication number
CN107326258B
CN107326258B CN201710521415.7A CN201710521415A CN107326258B CN 107326258 B CN107326258 B CN 107326258B CN 201710521415 A CN201710521415 A CN 201710521415A CN 107326258 B CN107326258 B CN 107326258B
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iron
molten iron
diameter
casting
molten
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CN107326258A (en
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徐春杰
李翠芹
武迈
马萌
徐信锋
赵振
马东
李倩
淡江雷
张忠明
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Shaanxi Xili Huazhu New Material Technology Co., Ltd
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Xian University of Technology
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    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22C—ALLOYS
    • C22C37/00—Cast-iron alloys
    • C22C37/10—Cast-iron alloys containing aluminium or silicon
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B22—CASTING; POWDER METALLURGY
    • B22D—CASTING OF METALS; CASTING OF OTHER SUBSTANCES BY THE SAME PROCESSES OR DEVICES
    • B22D1/00—Treatment of fused masses in the ladle or the supply runners before casting
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B22—CASTING; POWDER METALLURGY
    • B22D—CASTING OF METALS; CASTING OF OTHER SUBSTANCES BY THE SAME PROCESSES OR DEVICES
    • B22D11/00—Continuous casting of metals, i.e. casting in indefinite lengths
    • B22D11/04—Continuous casting of metals, i.e. casting in indefinite lengths into open-ended moulds
    • B22D11/045—Continuous casting of metals, i.e. casting in indefinite lengths into open-ended moulds for horizontal casting
    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22C—ALLOYS
    • C22C33/00—Making ferrous alloys
    • C22C33/08—Making cast-iron alloys
    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22C—ALLOYS
    • C22C37/00—Cast-iron alloys
    • C22C37/04—Cast-iron alloys containing spheroidal graphite

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  • Chemical & Material Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Materials Engineering (AREA)
  • Metallurgy (AREA)
  • Organic Chemistry (AREA)
  • Refinement Of Pig-Iron, Manufacture Of Cast Iron, And Steel Manufacture Other Than In Revolving Furnaces (AREA)

Abstract

The invention discloses a kind of following minor diameter Ductile iron bars of diameter 25mm, by weight percentage consisting of: C:3.4~3.8%, Si:2.4~3.3%, Mn≤0.4%, P≤0.10%, S≤0.06%, remaining is Fe, and the sum of composition described above weight percent is 100%.The invention also discloses the preparation methods of above-mentioned Ductile iron bar.The following minor diameter Ductile iron bar of diameter 25mm of the present invention, dense structure, no shrinkage cavity shrinkage porosity etc. shrink class defect, hardness it is moderate (without radial carbide, free state carbide less than 10%), any surface finish, and there is high intensity.The intensity index of body sampling reaches the requirement of LZQT500-7, and machinability is good, and resistance to cutting is small, can be with High speed finish machining, and processed surface smoothness relative fluctuation is small.

Description

A kind of following minor diameter Ductile iron bar of diameter 25mm and preparation method thereof
Technical field
The invention belongs to cast iron materials casting technology fields, are related to a kind of following minor diameter Ductile iron bar of diameter 25mm, this Invention further relates to the preparation method of above-mentioned Ductile iron bar.
Background technique
Cast iron horizontal continuous-casting is the new technique of modern high-quality cast iron materials green production, is managed from Xi'an in 1986 Wang Yiqing professor, good rain after a long drought professor, Tsinghua University Wu Dehai professor, Xi'an Communications University professor Lu Wenhua of work university, which combine, to set about Since studying cast iron horizontal continuous caster technology, cast iron horizontal continuous caster technology develops nearly 30 years history in China.Cast iron level connects Tremendous development has been obtained in China in casting technology.The cast iron profile material product in China is mainly the circular section of Φ 30-250mm at present With a few rectangular section.However, cast iron profile material product circular section dimensions has reached Φ 11-665mm in the world.Side Rectangle profile size reaches the cast iron profile material of 470 × 470mm and 910 × 150mm and various profiled-cross-sections.Material not only includes ball There are also alloy cast iron profiles for swage material and gray iron profile.The cast iron profile material market demand is larger in the world, application field and to product Specification demands still expanding increasingly, dosage cumulative year after year.
In response to the market demand, in recent years each producer exploitation different size horizontal continuous-casting cast iron profile material.But by In the production of Φ 25mm minor diameter Ductile iron bar horizontal continuous-casting there are larger difficulty, to hardware device and technique propose compared with High requirement, therefore domestic manufacturer's exploitation major diameter profile is relatively more, such as the Ductile iron bar of Φ 400mm.
Existing main problem is for Φ 25mm minor diameter Ductile iron bar material, during horizontal continuous-casting, ball Change treated molten iron cooled and solidified in water cooling graphite cannula, and with the production of " draw-stop-drawing " technique, when " draw-stop " is formed The step-length of each step, the step-length of usual Φ 30-60mm are about that (D is profile diameter to 1.5D-2D, i.e., general step-length is 45- 120mm), Φ 60mm or more is generally in order to guarantee productivity, and the step-length general control of profile is within 70-120mm.For Φ For 25mm or less minor diameter, firstly, since diameter is smaller, the Feeding channel of horizontal continuous-casting material internal it is easy to appear It is frozen to death, and intermittent center portion on the upper side therefore occurs there are shrinkage cavity or shrinkage porosites；Secondly as cooling velocity is very fast, tissue In it is easy to appear carbide, excessive high hardness, following process is difficult；Furthermore due to the presence for shrinking class defect and carbide, Φ The intensity of 25mm minor diameter Ductile iron bar material is not also high.
Existing main problem is for Φ 25mm minor diameter Ductile iron bar material horizontal continuously casting, due to cooling speed Degree is very fast, and technology controlling and process is slightly neglected when production, it is possible to occur freezing furnace phenomenon, i.e. profile solidifies completely in a crystallizer, Moreover, it is also possible to which solidification layer freezes crystallizer entrance, forces horizontal continuous-casting production disruption, causes to freeze furnace production Accident；Drawing is too fast, and step-length is excessive, it is also possible to which the scull that profile is formed in crystallizer is excessively thin, is not enough to bear pulling capacity And frictional force, it is thus possible to tensile phenomenon occur, runout phenomenon then occur.These phenomenons are likely to cause production disruption.
It can be seen that the following minor diameter Ductile iron bar material of Φ 25mm and production have larger difficulty, this is undoubtedly limited Application and development of this high-quality ductile iron material in China.
Summary of the invention
The object of the present invention is to provide a kind of following minor diameter Ductile iron bars of diameter 25mm, solve existing Φ 25mm or less Minor diameter Ductile iron bar is existing to shrink the not high problem of class defect, intensity.
It is a further object of the present invention to provide the preparation methods of the following minor diameter Ductile iron bar of above-mentioned diameter 25mm.
The technical scheme adopted by the invention is that a kind of following minor diameter Ductile iron bar of diameter 25mm, by weight percentage Consisting of: C:3.4~3.8%, Si:2.4~3.3%, Mn≤0.4%, P≤0.10%, S≤0.06%, remaining is Fe, with The sum of upper composition weight percent is 100%.
The features of the present invention also characterized in that
It is the Ductile iron bar for being less than Φ 25mm by the diameter that horizontal continuous-casting obtains.
Another technical solution of the present invention is a kind of preparation side of the following minor diameter Ductile iron bar of diameter 25mm Method is specifically implemented according to the following steps:
Step 1, cast iron melting:
Low manganese is cast into the magnesium iron pig iron, steel scrap, foundry returns, 75% ferrosilicon and SiC and is molten into molten iron in intermediate frequency furnace, Using stokehold fast analyzing constituent, the content of each element in base iron is adjusted: C:3.4~3.8%, Si:1.8~2.5%, Mn≤ 0.4%, P≤0.10%, S≤0.06%, remaining is Fe, and the sum of composition described above weight percent is 100%, tapping；
Step 2, the molten iron that step 1 obtains is subjected to spheroidising using dam-type molten ductile iron packet and bred；
Step 3, molten iron casting step 2 obtained enters holding furnace, and carry out horizontal continuous-casting to get to Φ 25mm with Lower minor diameter Ductile iron bar.
Feature of the present invention also resides in,
Fusion temperature is 1550~1580 DEG C in step 1, and tapping temperature is 1520~1550 DEG C.
Spheroidising pours method using tapping twice in step 2: first tapping 55~65% is carried out using rare earth magnesium nodularizer Spheroidising covers rapidly ladle lid after tapping, finishes to spheroidizing reacion, removes ladle lid, skims, then add it Remaining molten iron.
Nodulizer used by spheroidising is RE1.3Mg7Ca2Si40Fe alloy, dosage are molten iron total weight in ladle 1.2~1.3%, breed long-acting (70-72%) Si-Fe inovulant of the inovulant of use containing strontium and barium, inovulant total amount control System is the 0.6~0.7% of molten iron total weight.
It is bred in step 2 to breed twice, breeds carried out simultaneously with spheroidising for the first time, second pregnant using floating silicon It educates.
Inovulant is covered on above nodulizer when breeding for the first time, inovulant dosage is the 0.3% of molten iron total weight, grain Spend 3~8mm；It breeds and is completed in spheroidising for the second time, carried out after skimming, using floating silicon current-following inoculation, dosage is molten iron gross weight The 0.3~0.4% of amount, 1~3mm of granularity, inovulant is placed in the upper surface of molten iron in ladle, to pour into holding furnace with stream.
Casting interval time must not exceed 10min, and pouring temperature must not be lower than 1400 DEG C.
Horizontal continuous-casting is by the way of " draw-stop-drawing ", and traction electric machine revolving speed is during horizontal continuous-casting 600~900rpm, drawing time are 0.3~0.8s, and the residence time is 1~2s, and length of mould is 180~250mm, water inlet temperature Degree is room temperature, and leaving water temperature is 60~70 DEG C, and profile is 850~1000 DEG C in the temperature control that crystallizer exports.
The invention has the advantages that the following minor diameter Ductile iron bar of Φ 25mm of the present invention, dense structure, no shrinkage cavity shrinkage porosity Deng shrink class defect, hardness it is moderate (without radial carbide, free state carbide less than 10%), any surface finish, and there is height Intensity.The intensity index of body sampling reaches the requirement of LZQT500-7, and machinability is good, and resistance to cutting is small, can high speed Finishing, processed surface smoothness relative fluctuation are small.
Specific embodiment
The present invention is described in detail With reference to embodiment.
The present invention provides a kind of following minor diameter Ductile iron bars of diameter 25mm, by weight percentage consisting of: C:3.4 ~3.8%, Si:2.4~3.3%, Mn≤0.4%, P≤0.10%, S≤0.06%, remaining is Fe, composition described above weight percent Than the sum of be 100%.
The preparation method of the above-mentioned following minor diameter Ductile iron bar of diameter 25mm is specifically implemented according to the following steps:
Step 1, cast iron melting:
Molten iron is melted using 1.5 tons of intermediate frequency furnaces, according to the weight percent of each element needed for profile, deducts inovulant In the silicon amount brought into, weigh the low manganese casting magnesium iron pig iron, steel scrap, foundry returns, 75% ferrosilicon and SiC etc., be added in induction furnace, to All furnace charges are completely melt in furnace；Using stokehold fast analyzing constituent, C:3.4~3.8% in base iron is adjusted, Si:1.8~ 2.5%, Mn≤0.4%, P≤0.10%, S≤0.06%, fusion temperature be 1550~1580 DEG C, tapping temperature be 1520~ 1550℃。
Step 2, it spheroidising and breeds:
Nodularization uses dam-type ladle, and height and the diameter ratio of dam-type ladle are 1.7.Using low rare earth magnesium nodularization Agent RE1.3Mg7Ca2Si40Fe alloy, dosage are the 1.2~1.3% of weight of molten iron.(it is used below to be related to material amounts, relatively For the molten iron total weight that step 1 melting obtains)
It carries out scalding packet processing first before spheroidising, molten iron be poured into the ladle of pre- roasted mistake, then molten iron is toppled over In telegram in reply furnace, it is repeated three times.Then, nodulizer is added in dykes and dams, and be covered on inovulant used is once bred On nodulizer, dosage is 0.3%, 3~8mm of granularity of weight of molten iron, then is covered on nodulizer using low-sulfur iron filings, after tamping The thickness of iron filings coating is not less than 2cm.Spheroidising pours method using tapping twice: first tapping 55~65% carries out nodularization It handles, is covered with dedicated molten iron backpack cover rapidly after tapping, the absorptivity of Mg and RE are ensured with this, Mg is indirectly controlled with thisIt is residualFor 0.05~0.06%, REIt is residualIt is 0.016~0.018%.It is finished to spheroidizing reacion, removes dedicated molten iron backpack cover, then skim, Remaining iron liquid is added again, in case late inoculation and casting.
Step 3, late inoculation is handled:
Inoculation is using twice: carrying out with nodularization, is bred for the second time using floating silicon simultaneously for the first time.It breeds and adopts twice With long-acting (70-72%) the Si-Fe inovulant containing strontium and barium, inovulant total amount is the 0.6~0.7% of weight of molten iron.After skimming Late inoculation is carried out, secondary using floating silicon current-following inoculation, dosage is weight of molten iron 0.3~0.4%, 1~3mm of granularity.Inovulant It is placed in the upper surface of molten iron in ladle, to pour into holding furnace with stream.
Step 4, it is poured:
Use atomized diesel fuel nozzle by the baking of holding furnace internal protecting wall 30 minutes with up to shiny red before casting, in a crystallizer It is inserted into dummy bar head, dummy bar head is connected with dummy bar, and passes through traction machine travel drawing.By the molten iron warp after nodularization and inoculation The cast gate of holding furnace pours into holding furnace.Notice that first strand of molten iron for entering holding furnace will suitably stop to float on molten iron surface Post inoculant is directly entered crystallizer after avoiding post inoculant from pouring holding furnace.In order to ensure there can be no nodularizations and pregnant Educate decline, it is necessary to ensure that interval of each duration of pouring must not exceed 10min, and pouring temperature must not be lower than 1400 DEG C.
Step 5, horizontal continuous-casting:
Will treated stops 0.5~1 minute after molten iron pours into holding furnace, so that the molten iron for entering crystallizer is wrapped dummy ingot Head simultaneously starts dummy ingot traction after crystallization and freezing, carries out the production of horizontal continuous-casting mode using " draw-stop-drawing " technique.
Wherein traction electric machine revolving speed is 600~900rpm during horizontal continuous-casting, and the drawing time is 0.3~0.8s, Residence time is 1~2s, and length of mould is 180~250mm, and inflow temperature is room temperature, and leaving water temperature is 60~70 DEG C, profile Temperature control in crystallizer outlet is 850~1000 DEG C.Drawing speed and profile outlet temperature are controlled, runout is prevented and freezes furnace Accident.
The preparation method of the following minor diameter spheroidal graphite cast-iron profile material of Φ 25mm of the invention, is mainly characterized by: molten iron is molten Refining is using 1.5 tons of intermediate frequency furnace fusings.Simultaneously as the Ductile iron bar diameter of production is smaller, the amount of each molten iron discharging cannot Too much, too fast in heat preservation descent of temperature in order to avoid molten iron, occur to freeze furnace accident and nodularization and inoculation fade, tapping temperature Control requires the molten iron temperature for entering holding furnace that must not be lower than 1400 DEG C at 1520~1550 DEG C, and requires to ensure to pour every time Note time interval must not exceed 10min.In addition, nodularization pours method using tapping twice, to ensure using the iron compared with larger ratio of height to diameter Nodularization can be smoothly reacted after water packet, and combines and uses late inoculation method, it is ensured that nodularization and the effect bred.Horizontal continuity casting Use low traction electric machine revolving speed for 600~900rpm during making, the shorter drawing time is 0.3~0.8s, shorter stop Time is 1~2s, and use shorter length of mould for 180~250mm, which ensures that the small step-length of profile when producing, And then ungauged regions class defect inside profile, even tissue, hardness are uniform.
Embodiment 1
Φ 22mm spheroidal graphite cast-iron profile material and its preparation.
By weight percentage consisting of: C:3.6%, Si:2.4%, Mn:0.1%, P:0.04%, S:0.02%, remaining For Fe.
The preparation method of above-mentioned Φ 22mm minor diameter spheroidal graphite cast-iron profile, comprising the following steps:
(1) cast iron melting and composition adjustment
Molten iron is melted using 1.5 tons of intermediate frequency furnaces, furnace charge is that low manganese casts the magnesium iron pig iron, steel scrap, foundry returns, 75% silicon Iron and SiC etc. are completely melt to furnace charges all in furnace；Using stokehold fast analyzing constituent, the C:3.6% in base iron is adjusted, Si:1.8%, Mn:0.1%, P:0.04%, S:0.02%, fusion temperature are 1550 DEG C, and tapping temperature is 1520 DEG C.
(2) nodularization
Nodularization uses dam-type ladle, and the height of dam-type ladle and the ratio of diameter are 1.7.Using low rare earth magnesium ball Agent RE1.3Mg7Ca2Si40Fe alloy, dosage are the 1.2% of weight of molten iron.It carries out scalding packet processing first before spheroidising, by iron Water pours into the ladle of pre- roasted mistake, then molten iron is toppled in telegram in reply furnace, is repeated three times.Then, nodulizer is added In dykes and dams, and it is covered on inovulant used is once bred on nodulizer, dosage is the 0.3% of weight of molten iron, granularity 3~ 8mm, then be covered on nodulizer using low-sulfur iron filings, the thickness of iron filings coating is not less than 2cm after tamping.Spheroidising uses Tapping pours method twice: first tapping 55%, carries out spheroidising, is covered with dedicated molten iron backpack cover rapidly after tapping, really with this The absorptivity for protecting Mg and RE, indirectly controls Mg with thisIt is residualFor 0.05%, REIt is residualIt is 0.016%.It finishes, removes dedicated to spheroidizing reacion Ladle lid, then skims, then adds remaining iron liquid, in case late inoculation and casting.
(3) it breeds
Inoculation is using twice: carrying out with nodularization, is bred for the second time using floating silicon simultaneously for the first time.Using containing strontium and barium Long-acting (70%) Si-Fe inovulant, inovulant overall control in weight of molten iron 0.6%.Carry out late inoculation after skimming, two Secondary to breed using floating silicon current-following inoculation, dosage is the 0.3% of weight of molten iron, granularity 1mm.Inovulant is placed in molten iron in ladle Upper surface, to be poured into holding furnace with stream.
(4) it is poured
Use atomized diesel fuel nozzle by the baking of holding furnace internal protecting wall 30 minutes with up to shiny red before casting, in a crystallizer It is inserted into dummy bar head, dummy bar head is connected with dummy bar, and passes through traction machine travel drawing.By the molten iron warp after nodularization and inoculation The cast gate of holding furnace pours into holding furnace.Notice that first strand of molten iron for entering holding furnace will suitably stop to float on molten iron surface Post inoculant is directly entered crystallizer after avoiding post inoculant from pouring holding furnace.In order to ensure there can be no nodularizations and pregnant Educate decline, it is necessary to ensure that 9min is divided between each duration of pouring, pouring temperature must not be lower than 1400 DEG C.
(5) continuously casting
Will treated stops 0.5min after molten iron pours into holding furnace, so that the molten iron into crystallizer is wrapped dummy bar head simultaneously Start dummy ingot traction after crystallization and freezing, the production of horizontal continuous-casting mode is carried out using " draw-stop-drawing " technique.
Wherein traction electric machine revolving speed is 600rpm during horizontal continuous-casting, and the drawing time is 0.4s, and the residence time is 1.4s, length of mould 200mm, inflow temperature are room temperature, and leaving water temperature is 60 DEG C, the temperature control that profile is exported in crystallizer It is made as 850 DEG C.Drawing speed and profile outlet temperature are controlled, runout is prevented and freezes furnace accident.
(6) it cuts, break, examining, finished product and packaging
According to regulation length cutting, notch depth is more than 1/3 diameter, is then broken.Appearance and fracture initial survey are carried out, then Carry out tissue and service check, warehousing finished products after qualification.
The step size controlling of Φ 22mm minor diameter spheroidal graphite cast-iron profile material of the present invention ungauged regions inside 20~30mm, profile Class defect, even tissue, hardness are uniformly HB210-245, tensile strength 520MPa, elongation 11.2%.
Embodiment 2
Φ 20mm spheroidal graphite cast-iron profile material and its preparation.
By weight percentage consisting of: C:3.4%, Si:2.8%, Mn:0.2%, P:0.06%, S:0.04%, remaining For Fe.
The preparation method of above-mentioned Φ 20mm minor diameter spheroidal graphite cast-iron profile, comprising the following steps:
(1) cast iron melting and composition adjustment
Molten iron is melted using 1.5 tons of intermediate frequency furnaces, furnace charge is that low manganese casts the magnesium iron pig iron, steel scrap, foundry returns, 75% silicon Iron and SiC etc. are completely melt to furnace charges all in furnace；Using stokehold fast analyzing constituent, the C:3.4% in base iron is adjusted, Si:2.0%, Mn:0.2%, P:0.06%, S:0.04%, fusion temperature are 1565 DEG C, and tapping temperature is 1535 DEG C.
(2) nodularization
Nodularization uses dam-type ladle, and the height of dam-type ladle and the ratio of diameter are 1.7.Using low rare earth magnesium ball Agent RE1.3Mg7Ca2Si40Fe alloy, dosage are the 1.25% of weight of molten iron.It carries out scalding packet processing first before spheroidising, it will Molten iron pours into the ladle of pre- roasted mistake, then molten iron is toppled in telegram in reply furnace, is repeated three times.Then, by nodulizer plus Entering in dykes and dams, and be covered on inovulant used is once bred on nodulizer, dosage is the 0.3% of weight of molten iron, granularity 3~ 8mm, then be covered on nodulizer using low-sulfur iron filings, the thickness of iron filings coating is not less than 2cm after tamping.Spheroidising uses Tapping pours method twice: first tapping 60%, carries out spheroidising, is covered with dedicated molten iron backpack cover rapidly after tapping, really with this The absorptivity for protecting Mg and RE, indirectly controls Mg with thisIt is residualFor 0.055%, REIt is residualIt is 0.017%.It finishes, removes special to spheroidizing reacion It with ladle lid, then skims, then adds remaining molten iron, in case late inoculation and casting.
(3) it breeds
Inoculation is using twice: carrying out with nodularization, is bred for the second time using floating silicon simultaneously for the first time.Using containing strontium and barium Long-acting (71%) Si-Fe inovulant, inovulant overall control in weight of molten iron 0.65%.Late inoculation is carried out after skimming, For late inoculation using floating silicon current-following inoculation, dosage is the 0.35% of weight of molten iron, granularity 2mm.Inovulant is placed in iron in ladle The upper surface of water, to be poured into holding furnace with stream.
(4) it is poured
Use atomized diesel fuel nozzle by the baking of holding furnace internal protecting wall 30 minutes with up to shiny red before casting, in a crystallizer It is inserted into dummy bar head, dummy bar head is connected with dummy bar, and passes through traction machine travel drawing.By the molten iron warp after nodularization and inoculation The cast gate of holding furnace pours into holding furnace.Notice that first strand of molten iron for entering holding furnace will suitably stop to float on molten iron surface Post inoculant is directly entered crystallizer after avoiding post inoculant from pouring holding furnace.In order to ensure there can be no nodularizations and pregnant Educate decline, it is necessary to ensure that 9min is divided between each duration of pouring, pouring temperature must not be lower than 1400 DEG C.
(5) continuously casting
Will treated that molten iron pours into holding furnace stops 0.8min, so that the molten iron into crystallizer is wrapped dummy bar head simultaneously Start dummy ingot traction after crystallization and freezing, the production of horizontal continuous-casting mode is carried out using " draw-stop-drawing " technique.
Wherein traction electric machine revolving speed is 750rpm during horizontal continuous-casting, and the drawing time is 0.45s, and the residence time is 1.55s, length of mould 220mm, inflow temperature are room temperature, and leaving water temperature is 65 DEG C, the temperature that profile is exported in crystallizer Control is 900 DEG C.Drawing speed and profile outlet temperature are controlled, runout is prevented and freezes furnace accident.
(6) it cuts, break, examining, finished product and packaging
According to regulation length cutting, notch depth is more than 1/3 diameter, is then broken.Appearance and fracture initial survey are carried out, then Carry out tissue and service check, warehousing finished products after qualification.
The step size controlling of Φ 20mm minor diameter spheroidal graphite cast-iron profile material of the present invention ungauged regions inside 20~25mm, profile Class defect, even tissue, hardness are uniformly HB210-245, tensile strength 524MPa, elongation 12.2%.
Embodiment 3
Φ 18mm spheroidal graphite cast-iron profile material and its preparation.
By weight percentage consisting of: C:3.8%, Si:3.3%, Mn:0.3%, P:0.08%, S:0.04%, remaining For Fe.
The preparation method of above-mentioned Φ 18mm minor diameter spheroidal graphite cast-iron profile, comprising the following steps:
(1) cast iron melting and composition adjustment
Molten iron is melted using 1.5 tons of intermediate frequency furnaces, furnace charge is that low manganese casts the magnesium iron pig iron, steel scrap, foundry returns, 75% silicon Iron and SiC etc. are completely melt to furnace charges all in furnace；Using stokehold fast analyzing constituent, the C:3.8% in base iron is adjusted, Si:2.4%, Mn:0.3%, P:0.08%, S:0.04%, fusion temperature are 1580 DEG C, and tapping temperature is 1550 DEG C.
(2) nodularization
Nodularization uses dam-type ladle, and the height of dam-type ladle and the ratio of diameter are 1.7.Using low rare earth magnesium ball Agent RE1.3Mg7Ca2Si40Fe alloy, dosage are the 1.3% of weight of molten iron.It carries out scalding packet processing first before spheroidising, by iron Water pours into the ladle of pre- roasted mistake, then molten iron is toppled in telegram in reply furnace, is repeated three times.Then, nodulizer is added In dykes and dams, and it is covered on inovulant used is once bred on nodulizer, dosage is 0.3%, granularity 8mm of weight of molten iron, It is covered on nodulizer using low-sulfur iron filings again, the thickness of iron filings coating is not less than 2cm after tamping.Spheroidising is using twice Tapping pours method: first tapping 65%, carries out spheroidising, is covered with dedicated molten iron backpack cover rapidly after tapping, ensure Mg with this With the absorptivity of RE, Mg is indirectly controlled with thisIt is residualFor 0.06%, REIt is residualIt is 0.018%.It is finished to spheroidizing reacion, removes dedicated molten iron Backpack cover, then skims, then add remaining iron liquid, in case late inoculation and casting.
(3) it breeds
Inoculation is using twice: carrying out with nodularization, is bred for the second time using floating silicon simultaneously for the first time.Using containing strontium and barium Long-acting (72%) Si-Fe inovulant, inovulant overall control in weight of molten iron 0.7%.Carry out late inoculation after skimming, two Secondary to breed using floating silicon current-following inoculation, dosage is the 0.4% of weight of molten iron, granularity 3mm.Inovulant is placed in molten iron in ladle Upper surface, to be poured into holding furnace with stream.
(4) it is poured
Use atomized diesel fuel nozzle by the baking of holding furnace internal protecting wall 30 minutes with up to shiny red before casting, in a crystallizer It is inserted into dummy bar head, dummy bar head is connected with dummy bar, and passes through traction machine travel drawing.By the molten iron warp after nodularization and inoculation The cast gate of holding furnace pours into holding furnace.Notice that first strand of molten iron for entering holding furnace will suitably stop to float on molten iron surface Post inoculant is directly entered crystallizer after avoiding post inoculant from pouring holding furnace.In order to ensure there can be no nodularizations and pregnant Educate decline, it is necessary to ensure that casting interval time must not exceed 10min every time, and pouring temperature must not be lower than 1400 DEG C.
(5) continuously casting
Will treated stops 1min after molten iron pours into holding furnace, make the molten iron into crystallizer wrap dummy bar head and Start dummy ingot traction after crystallization and freezing, the production of horizontal continuous-casting mode is carried out using " draw-stop-drawing " technique.
Wherein traction electric machine revolving speed is 900rpm during horizontal continuous-casting, and the drawing time is 0.4s, and the residence time is 2s, length of mould 250mm, inflow temperature are room temperature, and leaving water temperature is 70 DEG C, the temperature control that profile is exported in crystallizer It is 1000 DEG C.Drawing speed and profile outlet temperature are controlled, runout is prevented and freezes furnace accident.
(6) it cuts, break, examining, finished product and packaging
According to regulation length cutting, notch depth is more than 1/3 diameter, is then broken.Appearance and fracture initial survey are carried out, then Carry out tissue and service check, warehousing finished products after qualification.
The step size controlling of Φ 18mm minor diameter spheroidal graphite cast-iron profile material of the present invention ungauged regions inside 20~25mm, profile Class defect, even tissue, hardness are uniformly HB220-255, tensile strength 534MPa, elongation 9.6%.

Claims (3)

1. a kind of preparation method of the following minor diameter Ductile iron bar of diameter 25mm, which is characterized in that specifically implement according to the following steps:
Step 1, cast iron melting:
Low manganese is cast into the magnesium iron pig iron, steel scrap, foundry returns, 75% ferrosilicon and SiC and is molten into molten iron in intermediate frequency furnace, is used Stokehold fast analyzing constituent, adjust base iron in each element content: C:3.4~3.8%, Si:1.8~2.5%, Mn≤ 0.4%, P≤0.10%, S≤0.06%, remaining is Fe, and the sum of composition described above weight percent is 100%, tapping；
Step 2, the molten iron that step 1 obtains is subjected to spheroidising using dam-type molten ductile iron packet and bred, at the nodularization Reason pours method using tapping twice: first tapping 55~65%, carries out spheroidising using rare earth magnesium nodularizer, covers rapidly after tapping Upper ladle lid, finishes to spheroidizing reacion, removes ladle lid, skims, then add remaining molten iron；
Nodulizer used by the spheroidising is RE1.3Mg7Ca2Si40Fe alloy, dosage are molten iron total weight in ladle 1.2~1.3%, it breeds using the long-acting Si-Fe inovulant containing strontium and barium 70-72%, inovulant overall control is in molten iron gross weight The 0.6~0.7% of amount；
It is described to breed to breed twice, it breeds carried out simultaneously with spheroidising for the first time, bred for the second time using floating silicon；Described Inovulant is covered on above nodulizer when once breeding, inovulant dosage is the 0.3% of molten iron total weight, 3~8mm of granularity； Breed and completed in spheroidising for the second time, carried out after skimming, using floating silicon current-following inoculation, dosage be molten iron total weight 0.3~ 0.4%, 1~3mm of granularity, inovulant is placed in the upper surface of molten iron in ladle, to pour into holding furnace with stream；
Step 3, molten iron casting step 2 obtained enters holding furnace, and carries out horizontal continuous-casting to get small to Φ 25mm or less Diameter Ductile iron bar；
The horizontal continuous-casting is by the way of " draw-stop-drawing ", and traction electric machine revolving speed is during horizontal continuous-casting 600~900rpm, drawing time are 0.3~0.8s, and the residence time is 1~2s, and length of mould is 180~250mm, water inlet temperature Degree is room temperature, and leaving water temperature is 60~70 DEG C, and profile is 850~1000 DEG C in the temperature control that crystallizer exports.
2. a kind of preparation method of the following minor diameter Ductile iron bar of diameter 25mm according to claim 1, which is characterized in that Fusion temperature is 1550~1580 DEG C in the step 1, and tapping temperature is 1520~1550 DEG C.
3. a kind of preparation method of the following minor diameter Ductile iron bar of diameter 25mm according to claim 1, which is characterized in that The casting interval time must not exceed 10min, and pouring temperature must not be lower than 1400 DEG C.
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Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN1900340A (en) * 2006-07-21 2007-01-24 中国重型汽车集团有限公司 Cast state high strength high extensibility nodular cast iron material
CN103882282A (en) * 2014-03-28 2014-06-25 日月重工股份有限公司 Molten iron of hundred-tonnage ferritic nodular cast iron casting and preparation method of molten iron
CN104404360A (en) * 2014-10-23 2015-03-11 陕西华安铸铁型材有限公司 Large diameter grey cast iron section bar material and preparation method thereof

Family Cites Families (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS55164055A (en) * 1979-06-08 1980-12-20 Toyota Motor Corp Spherical graphite cast iron for surface quenching
JP2010156003A (en) * 2008-12-26 2010-07-15 Nippon Piston Ring Co Ltd Cast-iron member with cast-in spray deposit film, method for manufacturing the same, cylinder liner with cast-in spray deposit film, and wear-resistant ring with cast-in spray deposit film

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN1900340A (en) * 2006-07-21 2007-01-24 中国重型汽车集团有限公司 Cast state high strength high extensibility nodular cast iron material
CN103882282A (en) * 2014-03-28 2014-06-25 日月重工股份有限公司 Molten iron of hundred-tonnage ferritic nodular cast iron casting and preparation method of molten iron
CN104404360A (en) * 2014-10-23 2015-03-11 陕西华安铸铁型材有限公司 Large diameter grey cast iron section bar material and preparation method thereof

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