CN101389772A - Method of producing steel for high carbon steel wire material excellent in wire-drawability and fatigue characteristic - Google Patents
Method of producing steel for high carbon steel wire material excellent in wire-drawability and fatigue characteristic Download PDFInfo
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- CN101389772A CN101389772A CNA2007800068074A CN200780006807A CN101389772A CN 101389772 A CN101389772 A CN 101389772A CN A2007800068074 A CNA2007800068074 A CN A2007800068074A CN 200780006807 A CN200780006807 A CN 200780006807A CN 101389772 A CN101389772 A CN 101389772A
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- C—CHEMISTRY; METALLURGY
- C21—METALLURGY OF IRON
- C21C—PROCESSING OF PIG-IRON, e.g. REFINING, MANUFACTURE OF WROUGHT-IRON OR STEEL; TREATMENT IN MOLTEN STATE OF FERROUS ALLOYS
- C21C7/00—Treating molten ferrous alloys, e.g. steel, not covered by groups C21C1/00 - C21C5/00
- C21C7/04—Removing impurities by adding a treating agent
- C21C7/064—Dephosphorising; Desulfurising
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B21—MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
- B21C—MANUFACTURE OF METAL SHEETS, WIRE, RODS, TUBES OR PROFILES, OTHERWISE THAN BY ROLLING; AUXILIARY OPERATIONS USED IN CONNECTION WITH METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL
- B21C37/00—Manufacture of metal sheets, bars, wire, tubes or like semi-manufactured products, not otherwise provided for; Manufacture of tubes of special shape
- B21C37/04—Manufacture of metal sheets, bars, wire, tubes or like semi-manufactured products, not otherwise provided for; Manufacture of tubes of special shape of bars or wire
-
- C—CHEMISTRY; METALLURGY
- C21—METALLURGY OF IRON
- C21C—PROCESSING OF PIG-IRON, e.g. REFINING, MANUFACTURE OF WROUGHT-IRON OR STEEL; TREATMENT IN MOLTEN STATE OF FERROUS ALLOYS
- C21C7/00—Treating molten ferrous alloys, e.g. steel, not covered by groups C21C1/00 - C21C5/00
- C21C7/0075—Treating in a ladle furnace, e.g. up-/reheating of molten steel within the ladle
-
- C—CHEMISTRY; METALLURGY
- C21—METALLURGY OF IRON
- C21C—PROCESSING OF PIG-IRON, e.g. REFINING, MANUFACTURE OF WROUGHT-IRON OR STEEL; TREATMENT IN MOLTEN STATE OF FERROUS ALLOYS
- C21C7/00—Treating molten ferrous alloys, e.g. steel, not covered by groups C21C1/00 - C21C5/00
- C21C7/04—Removing impurities by adding a treating agent
- C21C7/06—Deoxidising, e.g. killing
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- C—CHEMISTRY; METALLURGY
- C21—METALLURGY OF IRON
- C21C—PROCESSING OF PIG-IRON, e.g. REFINING, MANUFACTURE OF WROUGHT-IRON OR STEEL; TREATMENT IN MOLTEN STATE OF FERROUS ALLOYS
- C21C7/00—Treating molten ferrous alloys, e.g. steel, not covered by groups C21C1/00 - C21C5/00
- C21C7/04—Removing impurities by adding a treating agent
- C21C7/072—Treatment with gases
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- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22C—ALLOYS
- C22C38/00—Ferrous alloys, e.g. steel alloys
- C22C38/002—Ferrous alloys, e.g. steel alloys containing In, Mg, or other elements not provided for in one single group C22C38/001 - C22C38/60
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- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22C—ALLOYS
- C22C38/00—Ferrous alloys, e.g. steel alloys
- C22C38/005—Ferrous alloys, e.g. steel alloys containing rare earths, i.e. Sc, Y, Lanthanides
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- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22C—ALLOYS
- C22C38/00—Ferrous alloys, e.g. steel alloys
- C22C38/02—Ferrous alloys, e.g. steel alloys containing silicon
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- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22C—ALLOYS
- C22C38/00—Ferrous alloys, e.g. steel alloys
- C22C38/04—Ferrous alloys, e.g. steel alloys containing manganese
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- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22C—ALLOYS
- C22C38/00—Ferrous alloys, e.g. steel alloys
- C22C38/06—Ferrous alloys, e.g. steel alloys containing aluminium
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- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22C—ALLOYS
- C22C38/00—Ferrous alloys, e.g. steel alloys
- C22C38/18—Ferrous alloys, e.g. steel alloys containing chromium
- C22C38/40—Ferrous alloys, e.g. steel alloys containing chromium with nickel
- C22C38/42—Ferrous alloys, e.g. steel alloys containing chromium with nickel with copper
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- 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
Abstract
The invention provides a useful process in which a steel material for obtaining a steel wire material reduced in the content of hard non-rollable inclusions and having enhanced drawability and enhanced fatigue characteristics is produced by adequately controlling conditions in secondary refining and production conditions in a converter. Molten iron, cold pig iron, and scrap steel are used as major raw materials to be charged into a converter, the proportions of the molten iron, cold pig iron, and scrap steel being 96-100 mass%, 4 mass% or lower, and 2 mass% or lower, respectively, based on the whole major raw materials. Blowing in the converter is conducted while the average phosphorus concentration in the whole major raw materials is regulated to 0.02 mass% or lower. After completion of the blowing in the converter, secondary refining is conducted while regulating the flow rate of a molten-iron stirring gas to 0.0005-0.004 Nm<3>/min per ton of the molten iron. Subsequently, continuous casting is conducted while the flow rate of argon supplied for purging into a tundish is regulated to 0.04-0.10 Nm<3>/min per ton of the molten iron in the tundish.
Description
Technical field
The present invention relates to be used to make the method for the steel of the carbon steel wire rod with high that is used to obtain stringiness and material of excellent fatigue characteristics, particularly relate to being used to make and reduce hard and the minimum non-metal kind inclusion of ductility and improve the useful method of the steel wire rod of stringiness and fatigue characteristic with steel.
Background technology
Tyre cord with steel and spring steel in, if there is an aluminum oxide (Al
2O
3) and spinel (Al
2O
3And so on hard and minimum non-metal kind inclusion (the particularly oxide-based inclusion of ductility such as MgO), sometimes be called for short " inclusion " below), then to the operation of finest wire, become the reason of damaging stringiness sometimes, become the starting point of fatigure failure sometimes in the goods stage in wire drawing.Therefore, in the manufacturing processed of steel wire rod, reduce above-mentioned inclusion or undertaken innoxious particularly important by softening raising ductility.
From reducing the viewpoint of the inclusion that exists the steel wire rod as far as possible, various technology have been proposed so far.For example the method for patent documentation 1,2 publicities is, as reductor use Si, the Mn of molten steel, restriction Al concentration reduces inclusion thus.In addition, the technology that patent documentation 3,4 proposes is, accommodates the Al in the fire-resistant body container of molten steel by restriction
2O
3Concentration is to seek to reduce inclusion.A kind of technology that also has motion to propose is, by using Al
2O
3CaO-SiO that concentration is low
2Be that fusing assistant comes refined molten steel, to reduce the inclusion (for example patent documentation 5,6) in the steel.
But, the technology that is proposed so far, be usually directed to the technology the secondary refining of being implemented from the effusive molten steel of converter, even only the condition of this secondary refining is suitably controlled, not only inclusion can be fully reduced, and the operation of front and the condition of secondary refining must be suitably controlled than secondary refining.
Patent documentation 1; (Japan) spy opens the scope of clear 50-No. 081907 communique patent application etc.
Patent documentation 2:(Japan) spy opens the scope of clear 50-No. 11618 communique patent applications etc.
Patent documentation 3:(Japan) spy opens the scope of 2003-No. 245758 communique patent applications etc.
Patent documentation 4:(Japan) spy opens the scope of 2004-No. 211148 communique patent applications etc.
Patent documentation 6:(Japan) spy opens the scope of flat 9-No. 059744 communique patent application etc.
Summary of the invention
The present invention sets up in light of this situation, its purpose is, provide a kind of by suitable control secondary refining condition and the steel useful method of the high steel wire rod of the non-rolling inclusion of making the hard that has been used to be reduced and stringiness and fatigue characteristic of creating conditions of converter.
Can realize the manufacture method of the present invention of above-mentioned purpose, it is characterized in that, the main raw material of converter of packing into is molten iron, cold pig iron and steel scrap, and, with ratiometer with respect to these main raw material total qualities, molten iron is 96～100%, cold pig iron is below 4%, steel scrap is below 2%, and, all the mean P concentration in the main raw materials is below 0.02%, so to bessemerize, and following the operation: the molten steel in the time of will bessemerizing the secondary refining after the end stirs gas flow and is decided to be in per 1 ton of molten steel at 0.0005Nm
3/ minute more than 0.004Nm
3/ minute below, the Ar flow that carries out fine purifiation in then will the tundish in continuous casting is decided to be in the per 1 ton of molten steel in the tundish at 0.04Nm
3/ minute more than 0.10Nm
3/ minute below.
In the methods of the invention as the steel wire rod steel of object, for example preferred steel wire rod with the chemical ingredients composition of steel in quality % contain C:0.4～1.3%, Si:0.1～2.5%, Mn:0.2～1.0%, below the Al:0.003%, surplus is Fe and unavoidable impurities.
In addition, in the methods of the invention as the steel wire rod steel of object, also contain more than one that (a) select as required from Ni:0.05～1%, Cu:0.05～1% and Cr:0.05～1.5%, (b) more than one that select from Li:0.02～20ppm, Mg:0.02～20ppm, Ce:3～100ppm and La:3～100ppm can further improve the characteristic of steel wire rod according to the kind of the composition that is contained.
In the present invention, by suitably controlling the material rate and the mean P concentration of the main raw material of the converter of packing into, suitably control simultaneously and in tundish, carry out purified Ar flow when molten steel in the secondary refining stirs gas flow and continuous casting, can obtain the steel wire rod steel, its non-extension inclusion that has reduced the hard in the steel wire rod is brought into play good stringiness when wire drawing, possess good fatigue characteristic simultaneously, more effectively provide a kind of high-intensity fine steel wire that is called tyre cord to reach the steel wire rod steel of the best when the manufacturings such as spring of demanding fatigue characteristic.
Description of drawings
Fig. 1 is the molten iron ratio of expression in the main raw material and the graphic representation of the relation of the broken string number of times of every 10t steel;
Fig. 2 is the cold pig iron ratio of expression in the main raw material and the graphic representation of the relation of the broken string number of times of every 10t steel;
Fig. 3 is the steel scrap ratio of expression in the main raw material and the graphic representation of the relation of the broken string number of times of every 10t steel;
Fig. 4 is the refining Ar flow of expression in the tundish and the graphic representation of the relation of the broken string number of times of every 10t steel.
Embodiment
Usually, in the converter operation,, also pack into from cold pig iron behind steel scrap inside and outside the Steel Plant (steel scrap) and the molten steel solidification etc. except the molten iron of blast furnace manufacturing, oxidation is on one side removed C and is improved molten iron temperature on one side, can make the molten steel of C concentration about 0.03～1%.The molten iron temperature of converter is about 1200～1400 ℃ though pack into this moment, and the high more amount that will improve the steel scrap and the cold pig iron of the converter of can packing into more of this temperature just can be made more molten steel from the least possible molten iron.
But, when making tyre cord, owing to being difficult to not reduce the P that production efficiency is removed converter, thereby must reduce P concentration in the main raw materials such as molten iron, cold pig iron and steel scrap of the converter of packing into as far as possible with the high carbon steel of steel and spring steel and so on.In addition; raw material as the converter of packing into; material except above-mentioned molten iron, cold pig iron and steel scrap; also comprise the iron ore that is used for the scorification adjustment, the rhombspar that is used for the converter refractory protection; and in the present invention, will be called main raw material except that the raw material these materials (molten iron, cold pig iron and steel scrap).
In the middle of the main raw material, because normally molten iron was carrying out dephosphorization treatment in advance before the packing into of converter, thereby the temperature of the molten iron of the converter of packing into is low, and the needed heat residue of the steel scrap of packing into is few.Though heat is remaining on a small quantity can be by replenishing the C excessive oxidation in the molten iron, the tyre cord of the hard inclusions thing of disliking aluminium and so on steel and spring steel in, need avoid the excessive oxidation of C as possible.Promptly, melting the oxygen concn of depositing in the feasible molten steel of bessemerizing when finishing of the excessive oxidation of C rises, cause the usage quantity of employed FeSi alloy in the deoxidation of molten steel to increase, and comprise a small amount of Al inevitably in its FeSi alloy, consequently cause the increase of the aluminium family inclusion in the molten steel.
Therefore, in order to reduce the aluminium family inclusion in the molten steel, just must improve the hot redundancy of the main raw material of the converter of packing into as far as possible.Based on this viewpoint, present inventors discover, suitably regulate the ratio of molten iron, cold pig iron and steel scrap in the main raw material, are being effective aspect the hot redundancy that improves main raw material.
The relation of the broken string number of times when at first, present inventors have studied molten iron ratio, cold pig iron ratio and the steel scrap ratio (establishing the ratio that adds up to each raw material of 100% o'clock of molten iron, cold pig iron and steel scrap) in the main raw material of the converter of packing into and steel wire rod 10t (ton) carried out wire drawing.The relation of molten iron ratio in the main raw material and broken string number of times as shown in Figure 1, and is as shown in table 2 with the relation of a kind of cold pig iron and broken string number of times, with the relation of a kind of steel scrap and broken string number of times (implication of broken string number of times is with reference to following embodiment) as shown in table 3.
Show as this result, if molten iron ratio less than 96%, cold pig iron ratio surpass 4% or the steel scrap ratio surpass 2%, the number of times that then breaks increases.Show that thus the main raw material of the converter of packing into uses molten iron ratio 96% or more, the ratio of cold pig iron ratio 4% following steel scrap ratio below 2%, breaking aspect the number of times in reduction is being effectively.And preferred molten iron ratio is more than 98%, more preferably 100%.The scope of preferred cold pig iron ratio is below 2% in addition.
In the present invention, the mean P concentration that must will pack in the main raw material of converter is made as below 0.02%.Though taking off P and taking off C and carry out simultaneously when bessemerizing owing to must suppressing taking off C in the high carbon steel of steel and spring steel and so at tyre cord, thereby can not expect to take off C in bessemerizing.In addition, even the P concentration in the steel wire rod then also will be caused the increase of broken string frequency, the reduction of fatigue strength because of the influence of P segregation if surpass 0.02%.Therefore, need before blowing, the P concentration in the whole main raw material be suppressed to below 0.02%, preferably be suppressed to below 0.015%.
Among the present invention, in the secondary refining after bessemerizing end (for example casting ladle refining), also need the stirring gas flow (below be sometimes referred to as " gas flow ") when suitably slag and molten steel are stirred in control.Though the molten steel that converter is forged after the end carries out deoxidation by Si and Mn, generate Al because of the trace of Al that is contained in the alloys (reductor) such as FeSi, FeMn, SiMn this moment
2O
3, cause in the product residual as deleterious inclusion.Therefore, need when secondary refining, remove Al
2O
3
Based on such viewpoint, need make gas flow reach every 1t (ton) molten steel 0.0005Nm
3/ minute more than and strengthen contact between slag-molten steel.The preferred 0.0006Nm of this gas flow
3/ minute more than, more preferably 0.0007Nm
3/ minute more than.But, if make this gas flow surplus, then will make the melting loss of the fire-resistant body of casting ladle remarkable, not only operation is gone up undesirablely, but also refractory body is sneaked in the molten steel and product is brought disadvantageous effect.Therefore, gas flow need be made as 0.004Nm
3/ minute below, preferred 0.0035Nm
3/ minute below, more preferably 0.003Nm
3/ minute below.
In addition, the kind that is used for the gas of above-mentioned stirring does not have special restriction, but comparatively unsuitable with the molten steel generation chemical reaction and the argon that can obtain more at an easy rate.In addition, the blowing method of gas is also unrestricted, can adopt the method that is blown into by refractory body system nozzle from molten steel top to reach the method that is blown into from the bottom and the side of casting ladle.
Finished the molten steel of secondary refining,, can temporarily be contained in the container that is called as tundish from casting ladle when casting continuously though available continuous casting machine is cast.If the space in this tundish is residual air is arranged, then, when making steel wire rod, increase the broken string number of times by generating inclusion because of airborne oxygen makes molten steel oxidation.Therefore, in casting, need in the tundish to carry out fine purifiation with Ar gas.
Fig. 4 is the graphic representation of the relation of the fine purifiation Ar airshed (flow of the every 1t molten steel in the tundish) in the expression tundish and the number of times (every 1t steel) that breaks.This result shows, at the not enough 0.04Nm of fine purifiation Ar airshed
3/ minute situation under, the oxidation of the molten steel that causes because of airborne oxygen becomes obviously, causes the broken string number of times to increase.Therefore, need make fine purifiation Ar airshed reach 0.04Nm
3/ minute more than.But, if the fine purifiation Ar airshed of every 1t molten steel surpasses 0.04Nm
3/ minute, then have the saturated trend of above-mentioned effect.
In the moiety just the Al amount be subjected to restriction as follows, and other composition is not particularly limited, and comprises Wire Drawing such as ordinary steel cord thread as follows simultaneously with steel and spring steel as the steel (high carbon steel) of object in the present invention.Particularly, be exactly include C:0.4～1.3%, Si:0.1～2.5%, Mn:0.2～1.0% respectively, more than the Al:0.003%.The scope of these preferred compositions is set and be the reasons are as follows.
(C：0.4～1.3％)
C is to improving the useful element of intensity, in order to bring into play this effect, preferably containing more than 0.4%, more preferably more than 0.5%.But, if C content surplus,, thereby preferably be controlled at (more preferably below 1.2%) below 1.3% then owing to make steel embrittlement infringement stringiness.
(Si：0.1～2.5％)
Si is the element with desoxydatoin, in order to bring into play this effect, preferably contains more than 0.1%, more preferably contains more than 0.2%.But, if Si content surplus, then owing to generate a large amount of SiO as the deoxidation resultant
2And the infringement stringiness, thereby preferably be controlled at (more preferably below 2.3%) below 2.5%.
(Mn：0.2～1.0％)
Mn is the same with Si to have desoxydatoin, still has the element of Control and Inclusion Removal effect simultaneously.In order to bring into play these effects effectively, preferably containing Mn is (more preferably more than 0.3%) more than 0.2%.On the other hand, if the Mn surplus is then owing to make steel embrittlement infringement stringiness, thereby preferably be controlled at (more preferably below 0.9%) below 1.0%.
(more than the Al:0.003%)
If Al content height is the Al in the inclusion then
2O
3Concentration uprises, and might generate the coarse-grain Al of the reason that causes broken string
2O
3, thereby preferably control as far as possible, based on this viewpoint, preferably be suppressed to (more preferably below 0.002%) below 0.003%.
In the present invention, as the basal component in the steel of object as above, rest part is iron and unavoidable impurities, as this unavoidable impurities, can allow sneaking into of the element brought into according to situations such as raw material, goods and materials, producing apparatuss.In addition, obviously contain following element and also help further to improve characteristic.
(be selected from group that Ni:0.05～1%, Cu:0.05～1% and Cr:0.05～1.5% constitute more than one)
Though Ni not too helps the intensity of steel wire to improve, and but is the flexible element that performance improves the wire drawing material.In order to bring into play this effect, preferably contain more than 0.01%, more preferably more than 0.02%.Even but also just make above-mentioned effect saturated, thereby preferred (more preferably below 0.9%) below 1% owing to excessively contain Ni.
Cu is the element that helps the high strength of steel wire by the precipitation-hardening effect.Preferably contain more than 0.01% in order to bring into play this effect, more preferably more than 0.02%.But, if to contain Cu excessive, then because segregation takes place in the grain boundary, at the hot-rolled process of steel crackle and scar take place easily, therefore preferably be controlled at (more preferably below 0.9%) below 1%.
Cr has the effect of the work hardening rate when improving Wire Drawing, even lower working modulus also can be guaranteed high strength easily.And Cr also has the effect of the erosion resistance that improves steel, for example under the situation of the stiffening web (superfine steel) that is applied to tire etc., also can play a role effectively aspect the corrosion that suppresses this superfine steel.In order to bring into play these effects, preferably containing Cr is more than 0.05%, more preferably more than 0.1%.But if it is superfluous to contain the Cr amount, then relative with perlite hardening capacity uprises, and causes the difficulty of steel wire patent.In addition, make the obvious densification that becomes of the secondary scales of skin that peel off cause mechanical descaling's property and pickling deterioration.Therefore preferably the Cr amount is made as below 1.5%, more preferably is made as below 1.4%.
(be selected from group that Li:0.02～20ppm, Mg:0.02～20ppm, Ce:3～100ppm and La:3～100ppm constitute more than one)
These elements have the effect of the further softening of non-metallic inclusion that makes in the steel.In order to bring into play this effect, preferably containing Li is that 0.02ppm above (more preferably more than the 0.03ppm), Mg are that 0.02ppm above (more preferably more than the 0.03ppm), Ce are that 3ppm above (more preferably more than the 5ppm), La are 3ppm above (more preferably more than the 5ppm).But,, therefore preferably Li, Mg are controlled at respectively (more preferably 10ppm is following) below the 20ppm even also just make effect saturated owing to excessively take in above-mentioned element.In addition, preferably Ce, La are controlled at (more preferably 80ppm is following) below the 100ppm respectively.
The steel that in manufacture method of the present invention, obtain, via hot-rolled process be made into steel wire rod thereafter, its diameter of section is 3～10mm, and this steel wire rod is of great use at wire-drawing process as the material of superfine high-tensile steel wires such as the tyre cord of demanding stringiness, piano wire for example.In addition, the starting material as the spring of demanding fatigue characteristic, wireline etc. are of great use.
Below, enumerate embodiment and be described more specifically the present invention, but the present invention is not limited by following embodiment certainly, to implement but on adapting to, address can suitably be changed in the scope of following aim, these are included in technical scope of the present invention.
Embodiment
(manufacturings of steel)
At hot metal pre process procedures, P is reduced to 0.007～0.020% with making, S is reduced to 0.002～0.01% molten iron, converter in all proportions perhaps mixes this molten iron and cold pig iron and/or steel scrap and packs into, take off the concentration of C blowing to regulation, then, to the casting ladle tapping, utilize casting ladle heating hard-cover to put and implement composition adjustment (moiety is with reference to following table 2,5) and slag refining (secondary refining).And the slag during the casting ladle refining is CaO/SiO
2=0.7～1.7, Al
2O
3CaO-SiO of=4～25%
2-Al
2O
3System.In addition, the molten steel during the casting ladle refining stirs gas and uses Ar, makes its flow at every 1t molten steel 0.0002～0.0080Nm
3/ minute/range of t.The gas stirring time all was made as more than 15 minutes.
Above-mentioned casting ladle refining is continuously cast continuously, and having obtained the cross section is the casting sheet of 600mm * 380mm.The molten steel amount is made as 20t in the tundish during with casting, at this every 1t molten steel 0.02～0.13Nm
3/ minute/scope of t makes refining Ar fluctuations in discharge.To cast sheet then and be heated to 1260 ℃, carry out that piecemeal is rolling to form the limit of 155mm until the cross section, afterwards, implement the steel wire rod that hot rolling obtains Φ 5.5 or Φ 8.0mm again.
Cut out 1000g from the steel wire rod that obtains, for the compositional analysis of sour dissolved inclusion extraction and inclusion.The method of the inclusion extraction of this moment and the compositional analysis (quantitatively) of inclusion is as follows.
(method that inclusion extracts)
60%) and sulfuric acid (concentration: 96%) be mixed into the beaker of the acid solution of 5:25:1 by volume respectively, steel wire rod is packed into wherein at first, gets ready in advance and packed into pure water, nitric acid (concentration:.To this beaker heating, make solution temperature remain on 90～95 ℃, steel wire rod is dissolved fully.After the dissolving, filter with the filtering net of 10 μ m.Thereafter, in residuing in the inclusion of filtering net, having carried out major diameter is the composition and the number instrumentation thereof of the above inclusion of 20 μ m.
(inclusion quantitatively)
When inclusion quantitative, use EPMA[Electron Probe MicrdAnalyzer, Jeol Ltd. makes (JXA-8000 series)], be that 20kV, specimen current are under the condition of 0.01 μ A at acceleration voltage, carried out quantitative analysis with characteristic X-ray energy dispersed light spectrometer.Quantitative object elements is made as Al, Mn, Si, Mg, Ca, Ti, Zr, O.Quantivative approach is, measuring above-mentioned concentration of element is the X ray intensity of known substances, the relation of X ray intensity and concentration of element is made typical curve and making in advance, use this typical curve and according to the observation the X ray intensity ball of object inclusion gone out the concentration that exists of each element.Then, suppose that each element is with Al
2O
3, MnO, SiO
2, MgO, CaO, TiO
2, ZrO
2Form exist, based on by above-mentioned each concentration of element of quantitatively obtaining, calculate the Al in the inclusion
2O
3, MnO, SiO
2, MgO, CaO, TiO
2, ZrO
2Have concentration, will contain Al
2O
3Inclusion more than 80% is an inclusion as aluminium, and has measured its major diameter and number.
＜embodiment 1: the evaluation of stringiness 〉
Stringiness when the steel wire rod of having estimated the Φ 5.5mm that will obtain with above-mentioned form by following main points is applied to tyre cord.
(evaluation method)
Broken string number of times during Φ 5.5mm → Φ 0.2mm wire drawing
(drawing process)
Remove with hydrochloric acid after the oxide scale film of steel wire rod of above-mentioned Φ 5.5mm, (clear and mechanical Co., Ltd. makes: model C D-610-7+BD610) has carried out being stretched to the dry wire drawing of Φ 1.2mm with continuous drawing machine.The diameter of the wortle that uses at this wire-drawing process is 4.8,4.2,3.7,3.26,2.26,2.85,2.5,2.2,1.93,1.69,1.48,1.3 (unit all is mm).In addition, the drawing speed at Φ 1.2mm is 400m/ minute.Carry out the epithelium of zinc phosphate during wire drawing on the surface of wire rod in advance and handle, lubricant uses with the material of calcium stearate as main body.
Wire drawing to the wire rod of Φ 1.2mm is heated to after the 1230K, in the lead bath of 830K, implements the steel wire patent.After having made the fine pearlite tissue, carried out the copper facing (thickness: about 1.5 μ m) of Cu:Zn=7:3 (mass ratio).And (KOCH Co., Ltd. makes: model KPZIII/25-SPZ250), carry out Wire Drawing until forming Φ 0.2mm in the end to use wet wire drawer.Impregnation bath in the wire drawing has used moisture 75 quality %, natural acid, amine complex salt, interfacial agent has been carried out blended solution.Diameter at the employed wortle of this wire-drawing process is 1.176,0.959,0.880,0.806,0.741,0.680,0.625,0.574,0.527,0.484,0.444,0.408,0.374,0.343,0.313,0.287,0.260,0.237,0.216 (unit all is mm).Drawing speed at Φ 0.2mm is 500m/ minute.
The condition of converter main raw material is shown in following table 1, and the chemical composition of steel is as shown in table 2, and the condition of the result of stringiness and secondary refining is simultaneously as shown in table 3.
Table 1
Table 2
Table 3
| Test No. | Molten steel in the secondary refining stirs gas flow (Nm 3/ minute/t) | At the fine purifiation Ar of tundish gas flow (Nm 3/ minute/t) | The Al that |
The broken string number of times of per 10 tons of steel wire rods (inferior/10 ton) |
| 1 | 0.0010 | 0.08 | 2 | 1.9 |
| ? 2 | 0.0025 | 0.07 | 3 3 | 2.8 |
| 3 | 0.0037 | 0.10 | 5 | 3.9 |
| 4 | 0.0030 | 0.09 | 6 | 5.6 |
| 5 | 0.0005 | 0.04 | 9 | 7.8 |
| 6 | 0.0038 | 0.07 | 8 | 7.0 |
| 7 | 0.0009 | 0.05 | 5 | 6.1 |
| 8 | 0.0013 | 0.06 | 7 | 7.8 |
| 9 | 0.0009 | 0.10 | 6 | 13.5 |
| 10 | 0.0011 | 0.08 | 14 | 16.1 |
| 11 | 0.0003 | 0.08 | 15 | 15.4 |
| 12 | 0.0045 | 0.08 | 13 | 14.2 |
| 13 | 0.0002 | 0.08 | 17 | 16.8 |
| 14 | 0.0075 | 0.08 | 19 | 17.7 |
| 15 | 0.0011 | 0.12 | 6 | 5.0 |
| 16 | 0.0023 | 0.03 | 20 | 24.1 |
| 17 | 0.0025 | 0.02 | 25 | 28.0 |
| 18 | 0.0010 | 0.07 | 15 | 17.3 |
| 19 | 0.0025 | 0.07 | 15 | 13.6 |
| 20 | 0.0013 | 0.09 | 16 | 12.0 |
| 21 | 0.0030 | 0.08 | 13 | 12.7 |
| 22 | 0.0005 | 0.12 | 17 | 16.1 |
| 23 | 0.0010 | 0.08 | 13 | 12.2 |
| 24 | 0.0038 | 0.11 | 18 | 14.3 |
| 25 | 0.0009 | 0.08 | 18 | 18.0 |
| 26 | 0.0003 | 0.08 | 21 | 19.6 |
| 27 | 0.0070 | 0.08 | 25 | 20.0 |
Can do following investigation (and following No. represents the experiment No. in table 1～3) based on these results.
Experiment in No.1～8 shows, owing to satisfy condition given to this invention, thereby Al
2O
3The inclusion number is few, and the few stringiness of the broken string number of times during Wire Drawing is good.Relative therewith, the experiment in No.9～27, because less than foot condition given to this invention, thereby the result of stringiness difference often of the broken string when causing Wire Drawing.
Particularly, be exactly that the P concentration in the converter main raw material has surpassed 0.02%, thereby can not guarantee good stringiness owing to No.9,10.No.11～14, though the proportioning of main raw material, P concentration and the refining Ar flow in tundish all in scope given to this invention because the molten steel of secondary refining stirring gas flow is outside scope given to this invention, thereby stringiness is poor.No.15～17, though the proportioning of main raw material, P concentration and the refining Ar flow in tundish all in scope given to this invention because the molten steel of secondary refining stirring gas flow is outside scope given to this invention, thereby stringiness is poor.No.18～25, though the P concentration of main raw material, the molten steel of secondary refining stir gas flow and the refining Ar flow in tundish reaches all in scope given to this invention, but because the proportioning of main raw material is outside scope given to this invention, thereby stringiness is poor.No.26,27, though the refining Ar flow in tundish in scope given to this invention because the molten steel of the proportioning of main raw material and secondary refining stirs gas flow outside scope given to this invention, thereby stringiness is poor.
Embodiment 2: the evaluation of fatigue characteristic
Fatigue characteristic when the steel wire rod of having estimated the Φ 8.0mm that will obtain with above-mentioned form by following main points is applied to spring.
Evaluation method
The middle village formula rotary bending fatigue test of Φ 8.0mm steel wire rod
The modulator approach of test portion and test method
Φ 8.0mm steel wire rod has been implemented oil tempering → distortion annealing → shot peening handle → once more after the distortion annealing, formula rotating bending fatigue machine in village's has carried out fatigue test under the following conditions in the use, obtains damage rate and has carried out the evaluation of fatigue characteristic.
The fatigue test condition
Test film length: 650mm
Test strip number: 30
Test load: 95.8kgf/mm
2(940MPa)
Speed of rotation: 4500rpm
Number of times is ended in test: 2 * 10
7Inferior
Damage rate calculation formula: damage rate=lose bar number/(all supplying test film) * 100 (%)
The condition of converter main raw material is shown in following table 4, and the chemical composition of steel is as shown in table 5, and the condition of the result of stringiness and secondary refining is simultaneously as shown in table 6.
Table 4
Table 5
Table 6
| Test No. | Molten steel in the secondary refining stirs gas flow (Nm 3/ minute/t) | At the fine purifiation Ar of tundish gas flow (Nm 3/ minute/t) | The Al that |
The broken string number of times of every 10t steel wire rod (inferior/10t) |
| 28 | 0.0010 | 0.08 | 3 | 17 |
| 29 | 0.0025 | 0.07 | 2 | 17 |
| 30 | 0.0037 | 0.10 | 4 | 27 |
| 31 | 0.0030 | 0.09 | 5 | 33 |
| 32 | 0.0005 | 0.04 | 9 | 37 |
| 33 | 0.0038 | 0.10 | 5 | 23 |
| 34 | 0.0009 | 0.05 | 4 | 27 |
| 35 | 0.0013 | 0.06 | 8 | 37 |
| 36 | 0.0012 | 0.10 | 8 | 43 |
| 37 | 0.0009 | 0.09 | 7 | 53 |
| 38 | 0.0007 | 0.10 | 16 | 63 |
| 39 | 0.0003 | 0.08 | 16 | 57 |
| 40 | 0.0045 | 0.08 | 12 | 53 |
| 41 | 0.0055 | 0.08 | 19 | 60 |
| 42 | 0.0010 | 0.12 | 4 | 27 |
| 43 | 0.0013 | 0.02 | 19 | 60 |
| 44 | 0.0018 | 0.01 | 25 | 70 |
| 45 | 0.0013 | 0.12 | 17 | 63 |
| 46 | 0.0013 | 0.13 | 17 | 63 |
| 47 | 0.0030 | 0.10 | 17 | 77 |
| 48 | 0.0010 | 0.09 | 20 | 80 |
| 49 | 0.0025 | 0.09 | 17 | 67 |
| 50 | 0.0013 | 0.09 | 17 | 63 |
| 51 | 0.0030 | 0.10 | 17 | 77 |
| 52 | 0.0005 | 0.09 | 22 | 77 |
| 53 | 0.0002 | 0.09 | 24 | 83 |
| 54 | 0.0080 | 0.09 | 25 | 83 |
Can do following thinking (and following No. represents the experiment No. in table 4～6) based on these results.
Because No.28～36 satisfy regulation of the present invention, thereby the damage rate during fatigue test shows material of excellent fatigue characteristics for a short time.Relative therewith, because No.9～27 are less than the regulation of unabridged version invention, thereby losing during fatigue test is many, and fatigue characteristic are poor.
Particularly, exactly owing to the P concentration in No.9, the 10 converter main raw materials has surpassed 0.02%, thereby can not guarantee good fatigue characteristic.No.39～41, though the proportioning of main raw material, P concentration and the refining Ar flow in tundish all in scope given to this invention because the molten steel of secondary refining stirring gas flow is outside scope given to this invention, thereby fatigue characteristic are poor.No.42～44, though the molten steel of the proportioning of main raw material, P concentration and secondary refining stirs gas flow all in scope given to this invention, owing to the refining Ar flow in tundish outside scope given to this invention, thereby fatigue characteristic are poor.No.45～52, though the P concentration of main raw material, the molten steel of secondary refining stirring gas flow and the refining Ar flow in tundish are all in scope given to this invention, but because the proportioning of main raw material is outside scope given to this invention, thereby fatigue characteristic are poor.No.53,54, though the refining Ar flow in tundish in scope given to this invention because the molten steel of the proportioning of main raw material and secondary refining stirs gas flow outside scope given to this invention, thereby fatigue characteristic are poor.
Claims (4)
1, the carbon steel wire rod with high of a kind of stringiness and the excellent in fatigue characteristics manufacture method of steel, it is characterized in that, the main raw material of converter of packing into is molten iron, cold pig iron and steel scrap, and, total amount with respect to these main raw materials, in quality ratio, molten iron is 96～100%, cold pig iron is below 4%, steel scrap is below 2%, and all the mean P concentration in the main raw material is below 0.02%, so bessemerize, and following the operation: the molten steel in the time of will bessemerizing the secondary refining after the end stirs gas flow and is decided to be in per 1 ton of molten steel at 0.0005Nm
3/ minute more than 0.004Nm
3/ minute below, the Ar flow that carries out fine purifiation in then will the tundish in continuous casting is decided to be in the per 1 ton of molten steel in the tundish at 0.04Nm
3/ minute more than 0.10Nm
3/ minute below.
2, manufacture method as claimed in claim 1, it is characterized in that, steel wire rod with the chemical ingredients of steel form in quality % contain C:0.4～1.3%, Si:0.1～2.5%, Mn:0.2～1.0%, below the Al:0.003%, surplus is Fe and unavoidable impurities.
3, manufacture method as claimed in claim 1 is characterized in that, steel wire rod also contains more than one that select with steel in quality % from Ni:0.05～1%, Cu:0.05～1% and Cr:0.05～1.5%.
4, manufacture method as claimed in claim 1 is characterized in that, steel wire rod also contains more than one that select with steel from Li:0.02～20ppm, Mg:0.02～20ppm, Ce:3～100ppm and La:3～100ppm.
Applications Claiming Priority (3)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2006095555 | 2006-03-30 | ||
| JP095555/2006 | 2006-03-30 | ||
| PCT/JP2007/056199 WO2007114100A1 (en) | 2006-03-30 | 2007-03-26 | Process for producing steel for high-carbon steel wire material with excellent drawability and fatigue characteristics |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN101389772A true CN101389772A (en) | 2009-03-18 |
| CN101389772B CN101389772B (en) | 2012-03-21 |
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| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN2007800068074A Expired - Fee Related CN101389772B (en) | 2006-03-30 | 2007-03-26 | Method of producing steel for high carbon steel wire material excellent in wire-drawability and fatigue characteristic |
Country Status (4)
| Country | Link |
|---|---|
| US (1) | US20090038439A1 (en) |
| KR (1) | KR101022068B1 (en) |
| CN (1) | CN101389772B (en) |
| WO (1) | WO2007114100A1 (en) |
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| CN103649354A (en) * | 2011-07-15 | 2014-03-19 | Posco公司 | Wire rod having superior hydrogen delayed fracture resistance, method for manufacturing same, high strength bolt using same and method for manufacturing bolt |
| CN106947920A (en) * | 2015-09-22 | 2017-07-14 | Posco公司 | The spring steel and its manufacture method of excellent in fatigue characteristics |
| CN107794446A (en) * | 2017-10-27 | 2018-03-13 | 宁波市鄞州永佳电机工具有限公司 | A kind of inner hexagon spanner |
| CN116334498A (en) * | 2023-05-29 | 2023-06-27 | 张家港荣盛特钢有限公司 | Wire rod for steel strand and preparation method thereof |
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| EP2060649B1 (en) * | 2007-11-19 | 2013-12-04 | Kabushiki Kaisha Kobe Seiko Sho (Kobe Steel, Ltd.) | Spring steel and spring superior in fatigue properties |
| KR101053328B1 (en) * | 2008-12-04 | 2011-08-01 | 주식회사 포스코 | Method for manufacturing cast steel of high carbon steel wire for drawing with excellent internal quality and cast steel manufactured by the method |
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| US3619174A (en) * | 1965-11-27 | 1971-11-09 | Sumitomo Metal Ind | Method for controlling the carbon content in and/or the temperature of the steel |
| US3960547A (en) * | 1972-12-18 | 1976-06-01 | Youngstown Sheet And Tube Company | Steelmaking process |
| JPS62158810A (en) * | 1985-12-28 | 1987-07-14 | Kobe Steel Ltd | Method for determining main material charging quantity in converter operation |
| JPS648216A (en) * | 1987-06-29 | 1989-01-12 | Nippon Steel Corp | Production of high ti steel |
| JP2501617Y2 (en) * | 1990-11-27 | 1996-06-19 | 住友金属工業株式会社 | Sealing machine for molten steel in tundish for continuous casting |
| JP3282865B2 (en) * | 1993-01-12 | 2002-05-20 | 川崎製鉄株式会社 | Manufacturing method of high carbon steel for high strength ultra fine wire |
| JP3348988B2 (en) * | 1994-08-05 | 2002-11-20 | 新日本製鐵株式会社 | Cleaning method for molten steel in tundish |
| JP3536461B2 (en) * | 1995-08-24 | 2004-06-07 | Ｊｆｅスチール株式会社 | High carbon steel wire with excellent drawability and aging resistance |
| JP3297998B2 (en) | 1998-02-26 | 2002-07-02 | 住友金属工業株式会社 | Melting method of high clean ultra low carbon steel |
| US6264716B1 (en) * | 1999-03-19 | 2001-07-24 | Nupro Corporation | Process for controlling the stirring energy delivered by a gas flowing through a liquid |
| BR0006819B1 (en) * | 1999-06-16 | 2011-05-17 | High carbon steel wire excellent in workability and fatigue resistance after wire working. | |
| WO2002022891A1 (en) * | 2000-09-14 | 2002-03-21 | Nkk Corporation | Refining agent and refining method |
| JP2002105527A (en) * | 2000-09-26 | 2002-04-10 | Kawasaki Steel Corp | Method for producing high cleanliness steel |
| JP4515025B2 (en) | 2002-12-27 | 2010-07-28 | 株式会社神戸製鋼所 | High strength steel wire rod with excellent cold drawability |
| JP4417792B2 (en) | 2004-06-30 | 2010-02-17 | 株式会社神戸製鋼所 | High cleanliness steel with excellent fatigue strength or cold workability |
| JP4718359B2 (en) * | 2005-09-05 | 2011-07-06 | 株式会社神戸製鋼所 | Steel wire rod excellent in drawability and fatigue characteristics and manufacturing method thereof |
-
2007
- 2007-03-26 US US12/162,550 patent/US20090038439A1/en not_active Abandoned
- 2007-03-26 KR KR20087023845A patent/KR101022068B1/en active IP Right Grant
- 2007-03-26 WO PCT/JP2007/056199 patent/WO2007114100A1/en active Application Filing
- 2007-03-26 CN CN2007800068074A patent/CN101389772B/en not_active Expired - Fee Related
Cited By (6)
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|---|---|---|---|---|
| CN103649354A (en) * | 2011-07-15 | 2014-03-19 | Posco公司 | Wire rod having superior hydrogen delayed fracture resistance, method for manufacturing same, high strength bolt using same and method for manufacturing bolt |
| CN103649354B (en) * | 2011-07-15 | 2016-07-06 | Posco公司 | The wire rod with excellent resistance to Delayed hydride cracking, the method manufacturing described wire rod, the high-strength bolt using described wire rod and the method manufacturing bolt |
| CN106947920A (en) * | 2015-09-22 | 2017-07-14 | Posco公司 | The spring steel and its manufacture method of excellent in fatigue characteristics |
| CN107794446A (en) * | 2017-10-27 | 2018-03-13 | 宁波市鄞州永佳电机工具有限公司 | A kind of inner hexagon spanner |
| CN116334498A (en) * | 2023-05-29 | 2023-06-27 | 张家港荣盛特钢有限公司 | Wire rod for steel strand and preparation method thereof |
| CN116334498B (en) * | 2023-05-29 | 2024-01-19 | 张家港荣盛特钢有限公司 | Wire rod for steel strand and preparation method thereof |
Also Published As
| Publication number | Publication date |
|---|---|
| US20090038439A1 (en) | 2009-02-12 |
| WO2007114100A1 (en) | 2007-10-11 |
| KR101022068B1 (en) | 2011-03-17 |
| KR20080106562A (en) | 2008-12-08 |
| CN101389772B (en) | 2012-03-21 |
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