CN101748243A - Method for preparing spring steel - Google Patents
Method for preparing spring steel Download PDFInfo
- Publication number
- CN101748243A CN101748243A CN200810179277A CN200810179277A CN101748243A CN 101748243 A CN101748243 A CN 101748243A CN 200810179277 A CN200810179277 A CN 200810179277A CN 200810179277 A CN200810179277 A CN 200810179277A CN 101748243 A CN101748243 A CN 101748243A
- Authority
- CN
- China
- Prior art keywords
- steel
- reductor
- slag
- molten steel
- weight
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
Links
Abstract
The invention discloses a method for preparing spring steel, comprising the following steps: blowing liquid iron; then tapping liquid steel and part of steel slag into a ladle for refining; degassing the refined liquid steel; and casting plastic molding the degassed liquid steel. The refining method comprises deoxidating and slag conditioning for the liquid steel and the steel slag in the ladle, wherein the deoxidating comprises adding a first deoxidizer before tapping finishing and adding a second deoxidizer in the liquid steel after tapping finishing. The first deoxidizer does not contain Al, and the dosage of the first deoxidizer causes the content of FeO + MnO in the steel slag not to be larger than 2.5 wt %. The second deoxidizer is Al, the dosage of the second deoxidizer causes the content of Als in the liquid steel to be 0.02-0.04wt %, and Als is Alsol. The method can greatly improve the inherent quality of the spring steel, and the fatigue life of prepared spring connections for rail damping can reach 5 million times.
Description
Technical field
The present invention relates to a kind of method for preparing spring steel.
Background technology
In the recent period, China is implementing the construction of railway Line for Passenger Transportation, and according to planning, China's Line for Passenger Transportation adopts the wheel-track type high-speed railway mostly, and the train speed per hour is for per hour more than 250 kilometers.The wheel-track type high-speed railway must adopt the spring fastenings (spring fastenings of rail and reinforcing bar pillow, be commonly referred to spring or spring fastener) vibration damping, and spring members is worked under the ten minutes harsh conditions usually, under present railway operation condition, require the spring steel web member, particularly must reach 5,000,000 times the fatigue lifetime of 60Si2MnA spring steel web member, and the remaining sex change amount after the fatigue test must could satisfy the railway operation needs less than 1 millimeter.Therefore, it is very necessary to research and develop high-quality spring steel.
A kind of high strength is provided among the CN 1386885A, high-plasticity, spring steel for vibration damping of high-speed train railway cheaply, the preparation method of this spring steel may further comprise the steps: be respectively according to each component content: C 0.48-0.54, Mn 1.15-14.5, Si 1.30-1.60, Cr 0.80-1.10, P≤0.020, S≤0.020, V 0.15-0.25, Mo≤0.010, surplus is Fe, by electric furnace+LF stove refining+VD vacuum-treat, carry out die casting then, the breaking down cogging, flaw detection, reconditioning, rolling, finishing, thermal treatment, the method of packing warehouse-in is carried out, wherein, the temperature of heating is 1000-1050 ℃, the temperature of open rolling is 980-1000 ℃, and the temperature of finish to gauge is 830-880 ℃.By having the mechanical property of σ b 〉=1900MPa, σ s 〉=1730MPa, δ 〉=17%, ψ 〉=38% after the thermal treatment, but any test data about the spring steel fatigue property is not disclosed, whether good with the fatigue property that this invention steel is described.Though this spring steel does not contain the Ni element in addition, but with silicomanganese be spring steel now than, still expensive V, Cr element have been added, and a spot of Mo element, even the V of interpolation 0.15% and 0.05% Mo element in the thick steel of estimation approximately, the cost of steel per ton is increased more than 700 yuan (Renminbi), and in fact economy is not very good.
Provide a kind of among the CN 1380434A and on the basis that existing silicomanganese is a spring steel, reduced C content, the method of adding the B element simultaneously reduces the decarburizing tendency of steel, improves the hardening capacity of steel, simultaneously by improving Heat Treatment Of Steel technology, obtain optimum mechanical properties and cooperate (combination of strength and toughness), can satisfy the requirement of China Express Railway spring steel for vibration damping more than 5,000,000 times the fatigue lifetime that makes the spring fastenings of making.The preparation method of this spring steel may further comprise the steps: to chemical ingredients (by percentage to the quality) be: C 0.26-0.42%, Si 1.-2.0%, Mn 0.6-1.0%, P, S≤0.030%, Cr, V, Ni≤0.35%, Cu≤0.25%, Bs 0.003-0.0008%, surplus is that the steel of Fe is heat-treated, and the medium that quenches in the described thermal treatment is the aqueous solution; The temperature of quenching is 800-1000 ℃, and the tempered temperature is 300-480 ℃.Adding expensive alloying element in the steel that this method makes, consider from the angle of economy, is to be better than the spring steel invented among the CN 1386885A.But China's railway spring fastenings adopts the manufacturing of 60Si2Mn (A) spring steel always, the technical process of each spring fastenings factory, equipment, and various production technologies are all based on 60Si2Mn (A) spring steel, use the spring steel in the CN 1380434A instead, pay investment and time is cost.In addition, improved hardening capacity in the B adding spring steel, be particularly suitable for heavy in section spring steel, but, then increased the hardening crack tendency of steel for the spring steel of small cross-section, make that thermal treatment process is difficult to formulate, even determined rational heat treatment technology, also can learn the difference of component owing to every stove tempering, it is improper to occur quenching, cause the spring steel hardening crack, increase the phenomenon of mill scrap.Because spring fastenings adopts the spring steel manufacturing of φ 14 and φ 20 poles mostly, belongs to the small cross-section spring steel, common silicomanganese is the requirement that spring steel can satisfy hardening capacity fully, therefore, selects that to contain the B spring steel be not too suitable for use.
Summary of the invention
The objective of the invention is to be used for the shortcoming of 60Si2Mn (A) spring steel for the preparation method of the spring steel that overcomes prior art, a kind of production method that can be used in preparation 60Si2Mn (A) spring steel is provided, can significantly improve the inner quality of spring steel, make the railway vibration damping made with reaching 5,000,000 times the fatigue lifetime of spring fastenings.
According to the method for preparing spring steel of the present invention, this method comprises molten iron is blown, then molten steel and part slag are tapped and carry out refining in the ladle, molten steel after the refining is outgased, and to the molten steel cast molding after the degassing, described purified method comprises carries out deoxidation and residue adjustment to molten steel in the ladle and slag, wherein, the method of described deoxidation be included in that tapping adds first reductor before finishing and tapping finishes after in molten steel adding second reductor, described first reductor is not for containing the reductor of Al, the consumption of described first reductor makes the amount of FeO+MnO in the described slag be not more than 2.5 weight %, described second reductor is an aluminium, it is 0.02-0.04 weight % that the consumption of described second reductor makes the content of Als in the molten steel, and described Als is sour molten aluminium.
Owing to take in the ladle with molten steel with having the part slag during molten steel is from the converter tapping to the ladle inevitably, therefore the purified process had both comprised that the deoxidation products of removing molten steel oxygen gesture and producing was mingled with other, also comprise slag is carried out deoxidation, thereby destroy the oxygen balance between molten steel and the slag, obtain hypoxic steel in slag thereby oxygen in the molten steel is transmitted.Though hope is few more good more with the slag that molten steel enters refining process in the steelmaking process usually, owing to can be entrained with slag inevitably during tapping at present, and owing to also part iron can be oxidized into slag in the converting process, therefore, by refining can also be from slag recovery part iron.Usually little so tapping back slag floats on the molten steel density of slag than molten steel, the present inventor finds, before having gone out steel, slag and molten steel are carried out deoxidation with first reductor that does not contain Al, after finishing, tapping in ladle, feeds Al line fast as second reductor, guarantee that with this Al line has entered molten steel before dissolving in slag, realize that the Al line only carries out deoxidation to molten steel, and in STEELMAKING PRODUCTION subsequently, no longer add Al, thereby avoided aluminium that the titanium in the slag is reverted in the molten steel, therefore the content of Ti is no more than 0.003% in the steel that guarantees to make, and improves effectively the fatigue lifetime of the spring steel that makes thus.Reach 5,000,000 the fatigue lifetime of the spring fastenings that the spring steel that uses method of the present invention to produce is made, and be not more than 1 millimeter at the remaining type variable of 5,000,000 fatigue test rear spring web members.
In addition, the spring steel that uses method of the present invention to produce, the technical parameter that equipment also need not be changed existing steel making working procedure need not be changed by each spring fastenings factory, just can produce and satisfy the high-quality spring fastenings product that the high-speed railway vibration damping is used.
Embodiment
According to the method for preparing spring steel of the present invention, this method comprises molten iron is blown, then molten steel is tapped and carry out refining in the ladle, molten steel after the refining is outgased, and to the molten steel casting after the degassing, described purified method comprises carries out deoxidation and residue adjustment to molten steel in the ladle and slag, wherein, the method of described deoxidation be included in that converter tapping adds first reductor before finishing and tapping finishes after in molten steel adding second reductor, described first reductor is not for containing the reductor of Al, the consumption of described first reductor makes the amount of FeO+MnO in the described slag be not more than 2.5 weight %, described second reductor is an aluminium, it is 0.02-0.04 weight % that the consumption of described second reductor makes the content of Als in the molten steel, and described Als is sour molten aluminium.
Can roughly steel be divided into aluminium-deoxidized aluminium killed steel and with two kinds of the Si killed steels of silicon deoxidation by the deoxidization technique type, aluminium killed steel has the oxygen balance concentration lower than Si killed steel, total oxygen demand in the aluminium killed steel (T[O]) also lower than Si killed steel, so most of producer adopts aluminium deoxidation technology to produce, to obtain the very steel of low oxygen content.When generally adopting aluminium deoxidation, the amount of the sour molten aluminium (Als) in the steel is higher usually, thereby obtains hypoxic steel.But in this case, be easy to take place the secondary oxidation of aluminium, produce a large amount of fragility Al that is unfavorable for fatigue property
2O
3Be mingled with, can cause also when serious that nozzle clogging causes the casting difficulty.Usually the way that solves is that the calcium that carries out molten steel is handled, and for example adopts under high basicity condition refining or is fed with calcium line by molten steel, thereby obtain low-melting calcium aluminate inclusion (Cl
2A
7, C
3A, CA, C represents CaO in the formula, and A represents Al
2O
3), bigger but these calcium aluminates are mingled with size, also be unfavorable for the fatigue property of spring steel.In addition, under the situation that adopts the silicon deoxidation, the total oxygen content in the steel (T[O]) is higher, this means in the steel to be mingled with total amount very high.In the case, also can not obtain the spring steel of high fatigue property.And the present inventor finds, by method of the present invention, the content of the molten aluminium of described acid (Als) is controlled to be 0.01-0.04 weight %, can avoids above-mentioned generation of defects preferably when being preferably 0.02-.04 weight %, help improving the anti-fatigue performance of steel.Aluminium in the steel is divided into two kinds, and a kind of is the deoxidation products Al that has little time to float in the slag
2O
3In aluminium because Al
2O
3Can not be dissolved in the acid,, all the other can be called sour molten aluminium by sour dissolved aluminium so will be called sour insoluble aluminium with oxygen bonded aluminium, sour molten aluminium " Als " commonly used expression, sour molten aluminium and sour insoluble aluminium sum are called full aluminium in the steel, " Al " or " Alt " commonly used expression.The alleged sour molten aluminium of the present invention refers to be present in as described above in the steel can be by sour dissolved aluminium (Als), the statement of related amount to the molten aluminium of acid also refer to above-mentioned can be by the amount of aluminium element in the molten aluminium of sour dissolved acid.
In addition, Ti is used for fixing the nitrogen element in the steel.Though under the condition of deoxidation fully, in titanium carbide (TiC), titanium nitride (TiN) and the titanium carbonitride (TiCN) of Ti formation more than 5 microns in the steel one or more, they can stop austenite grain boundary to be grown up, if but titanium content is crossed one or more the particle that can form at most among oarse-grained TiC, TiN and the TiCN, greatly worsen the toughness and the anti-fatigue performance of steel on the contrary.Therefore the Ti in the steel need be controlled in the alap scope.
The method for preparing spring steel provided by the invention is by once adding the Al of capacity or containing the reductor of Al in the refinement and deoxidation process of carrying out in ladle, and other smelting process for example blow and refining process in the reductor that no longer adds Al or contain Al, only by using the reductor that does not contain Al to come slag and molten steel are carried out deoxidation, avoided the Ti in the slag is reverted in the molten steel, the content that has guaranteed Ti in the gained spring steel is very low, usually be no more than 0.015 weight, preferably be no more than 0.006 weight %, more preferably no more than 0.003 weight %, and make spring steel obtained by this method have anti-fatigue performance preferably, guaranteed the fatigue lifetime of the spring fastenings that makes by this spring steel.
According to method provided by the invention, the described method that molten iron is blown can be the method for various blowing known in the field, for example hangs down and draws homlolgation or height to draw the method for re-blowing (or being called high catch carbon method).No matter described hanging down draws homlolgation to be meant the steel of which kind of carbon content scope of smelting, all control to lower level in the last scope of carrying out Converter Oxigen Blowing decarburization steel-making with carbon, (for example be generally 0.03-0.1 weight %, smelting carbon content is the steel of 0.54-0.64 weight %, when in converter, molten iron being blown, earlier molten iron is carried out oxygen decarburization, becomes the molten steel that carbon content is 0.03-0.1 weight %), add carburelant then and make carbon content reach the method for needed level.Described height draws the method for re-blowing to be meant steel at various carbon content area requirements, at last the scope of carbon is controlled to carbon content a little less than the target of Finished Steel what carry out Converter Oxigen Blowing decarburization steel-making, (or substantially not) adds the method for carburelant in molten steel slightly subsequently.Because the low homlolgation that draws is regardless of smelting which kind of steel, the operating procedure of its converter has only a kind of, only needing that promptly molten iron is carried out oxygen decarburization, to obtain carbon content be that the molten steel of 0.03-0.1 weight % just can be tapped, and the high method of re-blowing of drawing needs multiple corresponding converter smelting process at the steel of different kinds, therefore hanging down draws homlolgation to have extensive applicability more, in fact simplify the converter operation, met industrial demand, be beneficial to the automatization control of converter and the raising of output.But, because hanging down draws homlolgation need add the content that carburelant improves carbon in the steel, particularly when the smelting high carbon steel, need add a large amount of carburelants, so the harmful element sulphur in the carburelant has increased the purified difficulty of carrying out subsequently also in company with being added in the molten steel.And high draw the method for re-blowing just in time and lowly draw homlolgation opposite, because its needs do not add carburetting dosage slightly or substantially, greatly reduced the amount of the harmful element sulphur of introducing thus, make subsequently can more easily these harmful elements be controlled on the lower content in the refining process, help the control of quality.And spring steel belongs to the steel of the very high kind of specification of quality, and its good fatigue property is had strict requirement especially.Usually low high quality requirement of drawing homlolgation to be difficult to satisfy spring steel is thought by the steel mill that adopts bof process to produce spring steel, therefore generally adopts high mechanize of drawing the method for re-blowing to smelt to have limited STEELMAKING PRODUCTION.
The present inventor finds, adopting to hang down draws homlolgation to obtain the molten steel that carbon content is reduced to 0.3-0.1 weight %, adding carburelant subsequently, to make the carbon content in the molten steel be 0.59-0.64 weight %, simultaneously by the process before the tapping that begins to tap finishes, in molten steel and slag, add not aluminiferous reductor and carry out deoxygenation refining, and employing Al of disposable adding capacity in ladle carries out deoxidation to molten steel after tapping finishes, other smelting process for example blow and the refining process that carries out subsequently in the reductor that no longer adds Al or contain Al, and only by not aluminiferous reductor to the slag and/or the method for carrying out deoxidation, can reduce or avoid Al that the Ti in the slag is reverted in the molten steel on the one hand, on the other hand, can make the low sulphur that draws homlolgation to introduce of employing form MnS plasticity by this method and be mingled with, to the Al that forms
2O
3Fragility is mingled with certain package action, the anti-fatigue performance of prepared spring steel is improved, the content of sulphur need not controlled to such an extent that the low more anti-fatigue performance to spring steel is good more with also promptly needing dawn as known in the art, on the contrary, this method can be controlled at the content of sulphur suitable scope to improve the anti-fatigue performance of steel better.Therefore the present invention preferably uses to hang down and draws homlolgation that molten iron is blown, then molten steel and part slag are tapped and carry out the spring steel that the purified method is come the production better quality in the ladle, have suitability and more easy operability widely, the mechanize production that helps producing has wider promotional value.
More particularly, described molten iron is blown, then molten steel and part slag are tapped and carry out the purified method in the ladle and comprise in molten iron aerating oxygen and add slag former, obtain the molten steel that carbon content is 0.03-0.1 weight %, before tapping finishes, in molten steel, add carburelant.Described slag former can be the conventional various slag formers that use in this area, for example can be lime and/or rhombspar, and with respect to 1 ton of described molten iron, the amount that adds slag former is the 45-60 kilogram.Described carburelant can be the conventional various carburelants that use in this area, for example can be hard coal and/or pitch coke, and the carbon content after the consumption of carburelant finishes tapping in the molten steel is 0.59-0.64 weight %.
In tapping process; have the part slag inevitably and enter ladle with molten steel; though the oxide compound of the small amounts of iron that exists in the slag is reduced in the molten steel in refining process subsequently; usually the slag of still wishing to bring in the tapping process in the ladle is few as best one can; but present steel-smelting technology is difficult to accomplish this point; generally, the slag amount of taking in the ladle with respect to molten iron per ton is about the 4-12 kilogram.Thereby the purified deoxidation process mainly comprises residual sulphur, oxidation products, for example Al in the removal molten steel
2O
3, SiO
2Deng, and reduce the oxygen that the oxygen gesture of slag is beneficial in the molten steel and in slag, transmit, thereby reduce oxygen in the molten steel, make molten steel obtain refining, also comprise the oxide compound of the iron in the reduced steel slag simultaneously, to increase the utilization ratio of iron.Add first reductor in the process of method employing of the present invention in the molten steel that will be entrained with the part slag is tapped ladle, also promptly before finishing, tapping adds first reductor that does not contain Al from beginning to tap, first reductor that is added is along with flowing of molten steel in the tapping process can more fully contact with slag with molten steel, to remove the oxygen in molten steel and the slag as much as possible.Can this area conventional various reductors that do not contain Al that use of described first reductor for example can be silica flour, carbon dust and carbide of calcium (CaC
2) in one or more.Because silica flour can change the basicity of refining slag, its consumption is subjected to bigger restriction, and therefore first reductor is preferably carbide of calcium and carbon dust, more preferably silicon carbide.In the actual production, adopt calcium carbide (CaC usually
2Content is about 70-90 weight %) as the source of carbide of calcium.More preferably, described first reductor is a particle form, and particle diameter preferably is no more than the 1-3 millimeter.
Before the time of the adding of described first reductor can finish from the tapping that begins to tap whenever, for example can when tapping, add first reductor, add first reductor again after the part of also can tapping, as long as before tapping finishes, first reductor is added.Preferably, when being the 1/4-1/2 of total molten steel amount, tap begins to add described first reductor.The consumption of first reductor makes that the amount of FeO+MnO is not more than 2.5 weight % in the slag.Preferably, with respect to molten iron per ton, the consumption of described first reductor is the 1.5-2.5 kilogram.
Order to described carburelant and the adding of first reductor does not have special requirement, for example can add carburelant earlier and add first reductor again, can add first reductor earlier yet and add carburelant again, perhaps adds the carburelant and first reductor simultaneously.Preferably add the carburelant and first reductor simultaneously.More preferably, when adding the carburelant and first reductor, add ferro-silicon and/or ferro-silico-manganese.Can select various described ferro-silicon well known in the art and/or the kind of ferro-silico-manganese and the amount of adding according to concrete smelting situation.
Because the density of slag is littler than molten steel, the slag in the ladle of tapping normally floats on the molten steel with the form of liquid slag.In molten steel, add reductor this moment and will pass through slag earlier undoubtedly, contact with slag.In order to reduce even to avoid contacting of slag and the second reductor aluminium as far as possible, after preferably adopting tapping to finish, the present invention in ladle, adds Al fast, the Al of adding also is not able to do in time and floats over slag-metal reaction on the molten steel and just passed slag and arrive the method that molten steel removes the oxygen in the molten steel, also be, the Al of adding is only reacted with molten steel, reduce the oxygen in the molten steel further and avoided Al that the Ti in the slag is reverted in the molten steel.Preferably, the method for described adding second reductor is to feed the Al line by feeding wire machine in ladle.More preferably, the feeding speed of Al line is the 8-12 meter per second.The diameter of aluminum steel is preferably 5-12mm, more preferably 8-10mm.The consumption of described Al line makes oxygen activity (α in the molten steel after the deoxidation
[O]) being not more than 20ppm, the content of Als is about 0.02-0.04 weight % in the molten steel, is preferably 0.03-0.04 weight %.Specifically, with respect to molten iron per ton, the consumption of described second reductor is the 0.4-0.6 kilogram.After carrying out the deoxidation in this step, in the operation of subsequently steel-making, no longer add metal A l or contain the reductor of metal A l.
The method of described residue adjustment comprises and adds the 3rd reductor and slag supplying agent in slag after deoxidation and the molten steel, and described the 3rd reductor is not for containing the reductor of Al, and the consumption of the 3rd reductor makes that the content of FeO+MnO is not more than 1.5 weight % in the slag.Total principle is that the content of FeO+MnO in the slag that makes after the deoxidation is low as much as possible, that is to say, described 1.5 weight % represent is to add behind the 3rd reductor higher limit of the content of FeO+MnO in the slag, when if the consumption of first reductor makes the content of FeO+MnO in the slag be 1.5-2.5 weight %, the consumption of the 3rd reductor will make that at least the content of FeO+MnO is lower than 1.5 weight % in the slag, if the consumption of first reductor makes the content of FeO+MnO in the slag be lower than 1.5 weight %, preferably still add the 3rd reductor, further reduce the content of FeO+MnO in the slag.More particularly, the consumption with respect to described the 3rd reductor of molten iron per ton is the 1-2 kilogram.At this, the slag after the described deoxidation is meant the slag after the deoxidation of carrying out in the described refining.Described the 3rd reductor can for example can be silica flour, carbon dust and carbide of calcium (CaC for the conventional various reductors that do not contain Al that use in this area
2) in one or more.Because silica flour can change the basicity of refining slag, its consumption is subjected to bigger restriction, and therefore the 3rd reductor is preferably carbide of calcium and carbon dust, more preferably silicon carbide.In the actual production, adopt calcium carbide (CaC usually
2Content is about 70-90 weight %) as the source of carbide of calcium.。More preferably, described the 3rd reductor is a particle form, and particle diameter preferably is no more than the 1-3 millimeter.The consumption of described slag supplying agent makes CaO and SiO in the slag
2Weight ratio (CaO: SiO
2, weight: be 3-5 weight), be preferably 4-5.Described the 3rd reductor can be identical or different with first reductor.Described slag supplying agent can be the conventional various slag supplying agents that use in this area, and for example described is lime and/or fluorite.
Refining is preferably carried out in described refining in the LF stove, described purified temperature can be 1500-1565 ℃, and the purified time can be 5-20min.
In the purified process, the content of C in the molten steel, Si and Mn can change hardly, the content of P can increase, but can not surpass 0.03 weight %, the content of Ti can increase a little, but remains on the level that is not higher than 0.02 weight %, and the content of S can decrease but can not surpass 0.02 weight %, the content of Als can decrease, and reaches the level of 0.01-0.02 weight %.
After the refining, molten steel changed in the degassing equipment outgas.The method of the described degassing can be used the method for the various degassings well known in the art, for example vacuum refinement method (VD method), or molten steel vacuum circulation degassing method (RH method).Preferably, the condition of the described degassing comprises that vacuum tightness is below the 300Pa, and the time of the degassing is 10-20 minute, is preferably 12-15 minute.Described vacuum tightness refers to the interior absolute pressure of vacuum chamber of vacuum circulating degasification apparatus.The numerical value of vacuum tightness is more little, represents the air in this vacuum chamber few more.
Method to the molten steel casting after the degassing can be the known the whole bag of tricks of ability, for example ingot casting or continuous casting etc.Preferably by continuous cast method to the degassing after the molten steel casting.More preferably, the temperature of continuous casting is 1470-1500 ℃, and the time is 30-50min.
Further, method of the present invention can also according to the spring steel product of required processing to the steel ingot or the strand of casting be rolled, the step of finishing.Described step rolling, finishing is well known in the art, and there is no particular limitation.
The spring steel web member that the spring steel of prepared in accordance with the method for the present invention is made, wherein, with the gross weight that obtains spring steel is benchmark, contain the Ti of Mn, 0-0.015 weight % of Si, 0.6-0.9 weight % of C, 1.6-2 weight % of 0.59-0.64 weight % and the S of 0.0055-0.03 weight % in this spring steel, 0.01-0.02 the Als of weight %, surplus is an iron.
Set forth method and the spring steel web member for preparing spring steel according to of the present invention further below in conjunction with specific embodiment.
Embodiment 1
Present embodiment is in order to the preparation method of explanation spring steel according to the present invention.
(1) 135 tons of molten iron (wherein containing the C of 3.5 weight %, the S of 0.018 weight %) are added 120 tons of converters and blow, add 6.1 tons of lime slag making in the converting process, the content of carbon is 0.05 weight % in the control blow end point molten steel.Under 1690 ℃, tap in the ladle, the amount of the molten steel in the ladle of tapping is 125 tons, slag is about 1 ton, account for 15.2 weight % of the total quantity of slag that produces in the steelmaking process, the time begin to add and before tapping finishes, add the ferro-silico-manganese (silicone content 18%, manganese content 66%) of 820 kilograms hard coal, 2900 kilograms ferro-silicon (silicone content 75%) and 1600 kilograms and 270 kilograms calcium carbide (CaC wherein in tapping
2Content be 75%), the tapping carbon content of back in the molten steel that finish is 0.59 weight %, then with the Al line (diameter of Al line is 10 millimeters of φ) of 54 kilograms of the speed feedings of 8 meter per seconds.Record α in the molten steel subsequently
[O]Be 10ppm, the amount of Als is that the content of FeO in 0.035 weight %, the slag is that the content of 1.5 weight %, MnO is 0.2 weight % in the molten steel.
(2) then at LF stove refining liquid steel.The calcium carbide that adds earlier 135 kilograms in ladle, and the fluorite of 600 kilograms lime and 30 kilograms are 1525 ℃ of heating 12 minutes down.Analyze in the ladle that FeO content is that 0.12 weight %, CaO are 50.6 weight %, SiO less than 0.5 weight %, MnO content in the slag
2Be 16.5 weight %.The content of Ti is that the content of 0.002 weight %, Als is 0.02 weight %, α in the molten steel
[O]Be 1.5ppm.
(3) under vacuum tightness is the condition of 10Pa, carry out the RH method degassing 10 minutes then, cast 280 * 325mm strand at 6 machines, 6 stream caster machine top-pours then.It is 24 ℃/minute that casting machine is forced the cooling section speed of cooling, after being cooled to 1000 ℃, adopt natural air cooling mode cool to room temperature, subsequently behind 70 meters long walking beam furnace internal heating to 1200 ℃, and on the 950-800-800-850 open-train mill, be rolled into 150 * 150mm square steel, behind the square steel naturally cooling, after the process walking beam furnace was heated to 1150 ℃ again, tandem rolling became the pole of φ 14.
The pole of the φ 14 that rolls into is made 10 spring fastenings.Carry out 5,000,000 fatigue tests according to corresponding method among the TB/T2329-92, after 5,000,000 fatigue tests finish, spring fastenings all remains intact not fracture, and calculating the residual set value according to residual set=(∑ test back residual set)/10 is 0.19mm.
Comparative Examples 1
Method according to embodiment 1 is prepared, and different is to add 150kg aluminium cake before tapping finishes from beginning to tap in the step (1) molten steel and slag are carried out deoxidation.The pole of the φ 14 that rolls into is made 10 spring fastenings.Carry out 5,000,000 fatigue tests according to corresponding method among the TB/T2329-92, when fatigue test proceeds to 4,500,000 times, rupture.
Comparative Examples 2
Method according to embodiment 1 is prepared, and different is, adds 150kg aluminium cake before tapping finishes from beginning to tap in the step (1) molten steel and slag are carried out deoxidation, and add the 50kg aluminum shot in the step (2) carry out deoxidation in ladle.The pole of the φ 14 that rolls into is made 10 spring fastenings.Carry out 5,000,000 fatigue tests according to corresponding method among the TB/T2329-92, when fatigue test proceeds to 3,800,000 times, rupture.
Embodiment 2
Present embodiment is in order to the preparation method of explanation spring steel according to the present invention.
(1) 135 tons of molten iron (wherein containing the C of 3.8 weight %, the S of 0.02 weight %) are added 120 tons of converters and blow, add 8.1 tons of lime and rhombspar slag making in the converting process, the content of carbon is 0.03 weight % in the control blow end point molten steel.Under 1690 ℃, tap in the ladle, the amount of the molten steel in the ladle of tapping is 126 tons, slag is about 1 ton, account for the 13.1 weight % that bessemerize total quantity of slag of later stage, the time begin to add and before tapping finishes, add 900 kilograms hard coal in tapping, and be about that 32 ton hours begin to add and the calcium carbide of 450 kilograms of addings tapping finishes before (CaC wherein in tap
2Content be 75%), the tapping carbon content of back in the molten steel that finish is 0.64 weight %, then with the Al line (diameter of aluminum steel is 8 millimeters of φ) of 81 kilograms of the speed feedings of 10 meter per seconds.At this moment, α in the molten steel
[O]Be 15ppm, the amount of Als is that the content of FeO in 0.04 weight %, the slag is that the content of 1.2 weight %, MnO is 0.2 weight % in the molten steel.
(2) then at LF stove refining liquid steel.The calcium carbide that adds 270 kilograms earlier in ladle, and 700 kilograms quartz heated 5 minutes down at 1565 ℃.Analyze in the ladle that FeO is that 0.5 weight %, MnO content are that 0.1 weight %, CaO are 51.5 weight %, SiO in the slag
2Be 13 weight %.After the refining in the molten steel content of Ti be that the content of 0.0015 weight %, Als is 0.02 weight %, α
[O]Be 1.0ppm.
(3) under vacuum tightness is the condition of 300Pa, carry out the RH method degassing 20 minutes then, cast 280 * 325mm strand at 6 machines, 6 stream caster machine top-pours then.It is 24 ℃/minute that casting machine is forced the cooling section speed of cooling, after being cooled to 1000 ℃, adopt natural air cooling mode cool to room temperature, subsequently behind 70 meters long walking beam furnace internal heating to 1200 ℃, and on the 950-800-800-850 open-train mill, be rolled into 150 * 150mm square steel, behind the square steel naturally cooling, after the process walking beam furnace was heated to 1150 ℃ again, tandem rolling became the pole of φ 20.
The pole of the φ 20 that rolls into is made 10 spring fastenings.Carry out 5,000,000 fatigue tests according to corresponding method among the TB/T2329-92, after 5,000,000 fatigue tests finish, spring fastenings all remains intact not fracture, and calculating the residual set value according to residual set=(∑ test back residual set)/10 is 0.27mm.
Embodiment 3
Present embodiment is in order to the preparation method of explanation spring steel according to the present invention.
(1) 135 tons of molten iron (wherein containing the C of 4 weight %, the S of 0.015 weight %) are added 120 tons of converters and blow, add 7 tons of lime in the converting process, the content of carbon is 0.04 weight % in the control blow end point molten steel.Under 1685 ℃, tap in the ladle, the amount of the molten steel in the ladle of tapping is 124 tons, slag is 0.8 ton, account for the 11.0 weight % that bessemerize total quantity of slag of later stage, the time begin to add and before tapping finishes, add the ferro-silico-manganese (silicone content 18% of 850 kilograms hard coal, 2900 kilograms ferro-silicon (silicone content 75%) and 1600 kilograms in tapping, and be about 60 tons from tap and begin manganese content 66%), to the calcium carbide that adds 320 kilograms before tapping finishes (CaC wherein
2Content be 70%), the tapping carbon content of back in the molten steel that finish is 0.6 weight %, so with the Al line (diameter of aluminum steel is 9 millimeters of φ) of 65 kilograms of the speed feedings of 12 meter per seconds.At this moment, α in the molten steel
[O]Be 10ppm, the amount of Als is that the content of FeO in 0.03 weight %, the slag is that the content of 1.5 weight %, MnO is 1 weight % in the molten steel.
(2) ladle is changed over to carry out refining in the LF stove then.The calcium carbide that adds earlier 200 kilograms in ladle, and the fluorite of 650 kilograms lime and 50 kilograms are 1540 ℃ of heating 20 minutes down.Analyze in the ladle in the slag FeO for being that 0.1 weight %, CaO are 56.9 weight %, SiO less than 0.8 weight %, MnO content
2Be 12 weight %.After the refining in the molten steel content of Ti be that the content of 0.001 weight %, Als is 0.01 weight %, α
[O]Be 2.5ppm.
(3) under vacuum tightness is the condition of 200Pa, carry out the RH method degassing 15 minutes then, cast 280 * 325mm strand at 6 machines, 6 stream caster machine top-pours then.It is 24 ℃/minute that casting machine is forced the cooling section speed of cooling, after being cooled to 1000 ℃, adopt natural air cooling mode cool to room temperature, subsequently behind 70 meters long walking beam furnace internal heating to 1200 ℃, and on the 950-800-800-850 open-train mill, be rolled into 150 * 150mm square steel, behind the square steel naturally cooling, after the process walking beam furnace was heated to 1150 ℃ again, tandem rolling became the pole of φ 20.
The pole of the φ 20 that rolls into is made 10 spring fastenings.Carry out 5,000,000 fatigue tests according to corresponding method among the TB/T2329-92, after 5,000,000 times fatigue test finishes, spring fastenings all remains intact not fracture, and calculating the participation deformation values according to residual set=(∑ test back residual set)/10 is 0.57mm.
Embodiment 4
Present embodiment is in order to the preparation method of explanation spring steel according to the present invention.
Method according to embodiment 1 is prepared spring steel, different is, adopt height to draw the method for adding that molten iron is blown, be to add 7 tons of lime in the converting process of step (1), the content of carbon is 0.55 weight % in the control blow end point molten steel, in when beginning tapping and before tapping finishes, add 2900 kilograms ferro-silicon (silicone content 75%) and 1600 kilograms ferro-silico-manganese (silicone content 18%, manganese content 66%) and 700 kilograms calcium carbide, then with the Al line (diameter of aluminum steel is 5 millimeters of φ) of 70 kilograms of the speed feedings of 11 meter per seconds.At this moment, total content is 10ppm in the ladle, and the amount of Als is that the content of FeO in 0.03 weight %, the slag is that the content of 1.2 weight %, MnO is 0.2 weight % in the molten steel.
The pole of the φ 20 that rolls into is made 10 spring fastenings.Carry out 5,000,000 fatigue tests according to corresponding method among the TB/T2329-92, after 5,000,000 fatigue tests finish, spring fastenings all remains intact not fracture, and calculating the residual set value according to residual set=(∑ test back residual set)/10 is 0.27mm.
Table 1
| ??C | ??Si | ??Mn | ??P | ??S | ??Cr | ??Ni | ??Cu | ??Ti | ??Als | The trade mark | |
| Embodiment 1 | ??0.64 | ??1.82 | ??0.85 | ??0.013 | ??0.026 | ??0.25 | ??0.035 | ??0.04 | ??0.015 | ??0.013 | ??60Si2Mn(A) |
| Comparative Examples 1 | ??0.64 | ??1.86 | ??0.8 | ??0.015 | ??0.008 | ??0.20 | ??0.05 | ??0.05 | ??0.03 | ??0.05 | ??60Si2Mn(A) |
| Comparative Examples 2 | ??0.64 | ??1.79 | ??0.9 | ??0.01 | ??0.008 | ??0.15 | ??0.05 | ??0.05 | ??0.03 | ??0.07 | ??60Si2Mn(A) |
| ??C | ??Si | ??Mn | ??P | ??S | ??Cr | ??Ni | ??Cu | ??Ti | ??Als | The trade mark | |
| Embodiment 2 | ??0.63 | ??1.65 | ??0.74 | ??0.017 | ??0.0055 | ??0.12 | ??0.04 | ??0.04 | ??0.003 | ??0.01 | ??60Si2Mn(A) |
| Embodiment 3 | ??0.56 | ??1.6 | ??0.9 | ??0.03 | ??0.03 | ??0.15 | ??0.04 | ??0.04 | ??0.003 | ??0.01 | ??60Si2Mn(A) |
| Embodiment 4 | ??0.6 | ??2 | ??0.6 | ??0.007 | ??0.014 | ??0.05 | ??0.003 | ??0.05 | ??0.004 | ??0.012 | ??60Si2Mn(A) |
According to the result of embodiment 1-4 and Comparative Examples 1-2 as can be seen, the content of Ti is lower in the spring steel of the present invention, can be by 5,000,000 times fatigue test, and the spring steel of Comparative Examples 1 and Comparative Examples 2 does not then pass through.
Claims (8)
1. method for preparing spring steel, this method comprises molten iron is blown, then molten steel and part slag are tapped and carry out refining in the ladle, molten steel after the refining is outgased, and to the molten steel cast molding after the degassing, described purified method comprises carries out deoxidation and residue adjustment to molten steel in the ladle and slag, it is characterized in that, the method of described deoxidation be included in that tapping adds first reductor before finishing and tapping finishes after in molten steel adding second reductor, described first reductor is not for containing the reductor of Al, the consumption of described first reductor makes the amount of FeO+MnO in the described slag be not more than 2.5 weight %, described second reductor is an aluminium, it is 0.02-0.04 weight % that the consumption of described second reductor makes the content of Als in the molten steel, and described Als is sour molten aluminium.
2. method according to claim 1, wherein, with respect to molten iron per ton, the consumption of described first reductor is the 1.5-2.5 kilogram, the consumption of described second reductor is the 0.4-0.6 kilogram.
3. method according to claim 1 and 2, wherein, the adding method of described second reductor is to feed aluminum steel in ladle, the feeding speed of aluminum steel is the 8-12 meter per second.
4. method according to claim 1, wherein, described molten iron is blown, then molten steel and part slag are tapped and carry out the purified method in the ladle and comprise in molten iron aerating oxygen and add slag former, obtain the molten steel that carbon content is 0.03-0.1 weight %, added carburelant before tapping finishes in molten steel, the carbon content after the consumption of described carburelant finishes tapping in the molten steel is 0.59-0.64 weight %.
5. method according to claim 1, wherein, the method of described residue adjustment comprises and adds the 3rd reductor and slag supplying agent in slag after deoxidation and the molten steel, described the 3rd reductor is not for containing the reductor of Al, the consumption of the 3rd reductor makes that the content of FeO+MnO is not more than 1.5 weight % in the slag, and the consumption of described slag supplying agent makes CaO and SiO in the slag
2Weight ratio be 3-5.
6. method according to claim 5, wherein, with respect to molten iron per ton, the consumption of described the 3rd reductor is the 1-2 kilogram.
7. method according to claim 1 or 5, wherein, the described reductor that does not contain A1 is a carbide of calcium, described slag supplying agent is the mixture of lime or lime and fluorite.
8. method according to claim 1, wherein, the condition of the described degassing comprises that vacuum tightness is below the 300Pa, the time of the degassing is 10-20 minute.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN200810179277XA CN101748243B (en) | 2008-12-04 | 2008-12-04 | Method for preparing spring steel |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN200810179277XA CN101748243B (en) | 2008-12-04 | 2008-12-04 | Method for preparing spring steel |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN101748243A true CN101748243A (en) | 2010-06-23 |
| CN101748243B CN101748243B (en) | 2011-12-14 |
Family
ID=42475854
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN200810179277XA Active CN101748243B (en) | 2008-12-04 | 2008-12-04 | Method for preparing spring steel |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN101748243B (en) |
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103160636A (en) * | 2011-12-19 | 2013-06-19 | 攀钢集团西昌钢钒有限公司 | Method for converter steel tapping alloying molten steel component evening |
| CN103160634A (en) * | 2011-12-19 | 2013-06-19 | 攀钢集团攀枝花钢钒有限公司 | Steel-making method and application thereof and continuous casting method |
| CN106834937A (en) * | 2017-01-05 | 2017-06-13 | 河钢股份有限公司邯郸分公司 | A kind of 530MPa grades of Thin Specs galvanized steel and its production method |
| CN112342464A (en) * | 2020-10-19 | 2021-02-09 | 中天钢铁集团有限公司 | Production method of free-cutting steel hot-rolled wire rod for OA (office automation) shaft |
Family Cites Families (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN100411758C (en) * | 2006-06-06 | 2008-08-20 | 湖南华菱涟源钢铁有限公司 | A method for making semi-processed cold rolled silicon steel in thin slab continuous casting and continuous rolling process |
| CN100436603C (en) * | 2007-03-28 | 2008-11-26 | 北京科技大学 | Process of deoxygenating, desulfurizing and controlling non-metal inclusion content in steel |
-
2008
- 2008-12-04 CN CN200810179277XA patent/CN101748243B/en active Active
Cited By (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103160636A (en) * | 2011-12-19 | 2013-06-19 | 攀钢集团西昌钢钒有限公司 | Method for converter steel tapping alloying molten steel component evening |
| CN103160634A (en) * | 2011-12-19 | 2013-06-19 | 攀钢集团攀枝花钢钒有限公司 | Steel-making method and application thereof and continuous casting method |
| CN103160636B (en) * | 2011-12-19 | 2016-01-20 | 攀钢集团西昌钢钒有限公司 | The method of the even molten steel composition of a kind of converter tapping alloying |
| CN103160634B (en) * | 2011-12-19 | 2016-01-20 | 攀钢集团攀枝花钢钒有限公司 | A kind of method for making steel and application thereof and a kind of continuous cast method |
| CN106834937A (en) * | 2017-01-05 | 2017-06-13 | 河钢股份有限公司邯郸分公司 | A kind of 530MPa grades of Thin Specs galvanized steel and its production method |
| CN106834937B (en) * | 2017-01-05 | 2018-02-06 | 河钢股份有限公司邯郸分公司 | A kind of 530MPa levels Thin Specs galvanized steel and its production method |
| CN112342464A (en) * | 2020-10-19 | 2021-02-09 | 中天钢铁集团有限公司 | Production method of free-cutting steel hot-rolled wire rod for OA (office automation) shaft |
| CN112342464B (en) * | 2020-10-19 | 2021-07-27 | 中天钢铁集团有限公司 | Production method of free-cutting steel hot-rolled wire rod for OA (office automation) shaft |
Also Published As
| Publication number | Publication date |
|---|---|
| CN101748243B (en) | 2011-12-14 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN101671792B (en) | Spring steel and preparation method thereof | |
| CN102719759B (en) | Elastic bar steel for high-speed rail fastener and smelting production method thereof | |
| CN103556069B (en) | A kind of gas cylinder seamless large-diameter pipes and manufacture method thereof | |
| CN100462466C (en) | Method of producing low-temperature high-toughness steel and steel plate | |
| CN103276310A (en) | Rare-earth-containing H-shaped steel with low-temperature toughness and production method thereof | |
| CN111363976B (en) | Microalloyed steel with long service life, high strength and toughness for high-speed rail plate spring and production process thereof | |
| CN110747385B (en) | Production method of high-toughness and fatigue-resistant Q1100 ultrahigh-strength steel | |
| CN103266279A (en) | Rare earth containing H profile steel with high strength and high toughness and production method thereof | |
| CN103510020A (en) | Spring steel wire rod and its inclusion control method | |
| CN106591703A (en) | Steel plate for pressure vessel with yield strength being 345 MPa stage and production method | |
| CN104250703A (en) | 340MPa grade cold rolled low alloy high strength steel and manufacturing method thereof | |
| CN109182904A (en) | A kind of armored concrete fire resisting reinforcing bar and preparation method thereof | |
| CN101748243B (en) | Method for preparing spring steel | |
| CN106917043A (en) | A kind of resisting sulfide stress corrosion cracking sheet metal and its production method | |
| CN108690941B (en) | A kind of high-intensitive, long-life bainite railroad frog band steel and its production method | |
| CN114657313A (en) | Production method of high-chromium high-strength mining steel strand wire rod | |
| CN111004975A (en) | Screw-thread steel for building and production method thereof | |
| CN102337458B (en) | Steel with tensile strength not lower than 1100MPa for engineering machinery and production method thereof | |
| CN109161799A (en) | A kind of pillar of electrification rail contacting net is with hot rolled H-shaped and preparation method thereof | |
| CN111471936A (en) | Improved steel for agricultural machinery cutting tool and production method thereof | |
| CN101386958A (en) | Steel for high speed rail non-slag concrete slab sleeper steel wire and producing method thereof | |
| CN108149133B (en) | Boron-added high-carbon microalloyed high-strength carbon pure steel and preparation method thereof | |
| CN114293093B (en) | 600 MPa-grade vanadium-titanium micro-alloying hot-rolled steel bar and production method thereof | |
| CN113355595B (en) | Large-size high-strength prestressed steel, preparation process and application thereof | |
| CN103014521A (en) | High-hardness high-toughness wear-resistant steel and production method thereof |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C06 | Publication | ||
| PB01 | Publication | ||
| C10 | Entry into substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| C14 | Grant of patent or utility model | ||
| GR01 | Patent grant |