WO2021106484A1 - 溶鋼の鋳造方法、連続鋳造鋳片の製造方法及び軸受用鋼材の製造方法 - Google Patents
溶鋼の鋳造方法、連続鋳造鋳片の製造方法及び軸受用鋼材の製造方法 Download PDFInfo
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- WO2021106484A1 WO2021106484A1 PCT/JP2020/040513 JP2020040513W WO2021106484A1 WO 2021106484 A1 WO2021106484 A1 WO 2021106484A1 JP 2020040513 W JP2020040513 W JP 2020040513W WO 2021106484 A1 WO2021106484 A1 WO 2021106484A1
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- gas
- tundish
- molten steel
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- replacement
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B22—CASTING; POWDER METALLURGY
- B22D—CASTING OF METALS; CASTING OF OTHER SUBSTANCES BY THE SAME PROCESSES OR DEVICES
- B22D41/00—Casting melt-holding vessels, e.g. ladles, tundishes, cups or the like
- B22D41/50—Pouring-nozzles
- B22D41/58—Pouring-nozzles with gas injecting means
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B22—CASTING; POWDER METALLURGY
- B22D—CASTING OF METALS; CASTING OF OTHER SUBSTANCES BY THE SAME PROCESSES OR DEVICES
- B22D11/00—Continuous casting of metals, i.e. casting in indefinite lengths
- B22D11/10—Supplying or treating molten metal
- B22D11/11—Treating the molten metal
- B22D11/116—Refining the metal
- B22D11/117—Refining the metal by treating with gases
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B22—CASTING; POWDER METALLURGY
- B22D—CASTING OF METALS; CASTING OF OTHER SUBSTANCES BY THE SAME PROCESSES OR DEVICES
- B22D11/00—Continuous casting of metals, i.e. casting in indefinite lengths
- B22D11/10—Supplying or treating molten metal
- B22D11/103—Distributing the molten metal, e.g. using runners, floats, distributors
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B22—CASTING; POWDER METALLURGY
- B22D—CASTING OF METALS; CASTING OF OTHER SUBSTANCES BY THE SAME PROCESSES OR DEVICES
- B22D11/00—Continuous casting of metals, i.e. casting in indefinite lengths
- B22D11/10—Supplying or treating molten metal
- B22D11/106—Shielding the molten jet
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B22—CASTING; POWDER METALLURGY
- B22D—CASTING OF METALS; CASTING OF OTHER SUBSTANCES BY THE SAME PROCESSES OR DEVICES
- B22D41/00—Casting melt-holding vessels, e.g. ladles, tundishes, cups or the like
- B22D41/005—Casting melt-holding vessels, e.g. ladles, tundishes, cups or the like with heating or cooling means
- B22D41/01—Heating means
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B22—CASTING; POWDER METALLURGY
- B22D—CASTING OF METALS; CASTING OF OTHER SUBSTANCES BY THE SAME PROCESSES OR DEVICES
- B22D7/00—Casting ingots, e.g. from ferrous metals
- B22D7/06—Ingot moulds or their manufacture
- B22D7/062—Stools for ingot moulds
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B22—CASTING; POWDER METALLURGY
- B22D—CASTING OF METALS; CASTING OF OTHER SUBSTANCES BY THE SAME PROCESSES OR DEVICES
- B22D7/00—Casting ingots, e.g. from ferrous metals
- B22D7/06—Ingot moulds or their manufacture
- B22D7/10—Hot tops therefor
- B22D7/108—Devices for making or fixing hot tops
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B22—CASTING; POWDER METALLURGY
- B22D—CASTING OF METALS; CASTING OF OTHER SUBSTANCES BY THE SAME PROCESSES OR DEVICES
- B22D7/00—Casting ingots, e.g. from ferrous metals
- B22D7/12—Appurtenances, e.g. for sintering, for preventing splashing
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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
Definitions
- the present invention relates to a method for casting molten steel, a method for manufacturing continuously cast slabs, and a method for manufacturing steel materials for bearings.
- Patent Document 1 and Patent Document 2 disclose a method for preheating a tundish that is repeatedly used hot. According to these techniques, the burner used for preheating is burned with an amount of air (oxygen amount) smaller than the theoretical amount of air (the amount of oxygen required to completely burn the fuel) of the fuel supplied to the burner. It is stated that this will promote the dissolution and removal of the bare metal remaining in the tundish and prevent oxidation.
- oxygen amount an amount of air (oxygen amount) smaller than the theoretical amount of air (the amount of oxygen required to completely burn the fuel) of the fuel supplied to the burner. It is stated that this will promote the dissolution and removal of the bare metal remaining in the tundish and prevent oxidation.
- Patent Document 3 describes in the tundish by purging the inside of the tundish with argon, which is an inert gas. A method for reducing the gas-liquid reaction between molten steel and the atmosphere is disclosed. Further, in Patent Document 4, when only an oxide is considered as a non-metal inclusion of concern in terms of quality, the inside of the tundish is purged with nitrogen, which is a cheaper inert gas, so that the inside of the tundish can be purged. A method for reducing the gas-liquid reaction between the molten steel and the atmosphere is disclosed.
- Patent Document 5 before injecting molten steel into the tundish, the inside of the tundish is enriched with oxygen in the combustion air and the fuel gas is burned at an air ratio of 0.75 to 0.98. Disclosed are techniques for heating and sustaining the heating of the tundish even after the molten steel is injected into the tundish.
- the tundish is generally provided with a gas passage for preheating a refractory, an opening for temperature measurement and sampling of molten steel, and the like. Furthermore, since deformation of the iron container in a high temperature environment such as molten steel is unavoidable, it is difficult to industrially suppress the occurrence of a slight gap in the tundish.
- the present invention has been made by paying attention to the above-mentioned problems.
- it prevents an increase in the oxygen concentration in the tundish at the time of injecting molten steel, which tends to cause inflow of the atmosphere, and the atmosphere of the molten steel and the oxygen in the atmosphere.
- -It is an object of the present invention to provide a method for casting molten steel, a method for producing continuously cast slabs, and a method for producing steel materials for bearings, which can suppress a liquid reaction.
- the present invention which is a method for casting molten steel using a continuous casting facility, incomplete combustion of a substitution gas containing at least a flammable gas inside a tundish which is an intermediate container of the continuous casting facility. After the replacement step of replacing the gas inside the tundish by blowing under the conditions and the replacement step, the blowing of the replacement gas is stopped, and the tundish is used in the continuous casting facility.
- a method for casting molten steel which comprises a casting step of performing continuous casting without blowing the replacement gas into the steel.
- it is a method of casting molten steel using a ingot making facility, in which a substitution gas containing at least a flammable gas is blown into the mold of the ingot making facility under incomplete combustion conditions. After the replacement step of replacing the gas inside the tundish and the replacement step, the blowing of the replacement gas is stopped, and the replacement gas is blown into the tundish by the incubator using the mold.
- a method for casting molten steel is provided, including a casting process in which casting is performed without casting.
- the molten steel discharged from the converter or electric furnace is smelted in the secondary smelting facility, and the molten steel smelted in the secondary smelting facility is cast in the continuous casting facility and continuously cast.
- This is a method for producing slabs, in which a substitution gas containing at least a flammable gas is blown into the inside of the tundish, which is an intermediate container of the continuous casting facility, under incomplete combustion conditions, and the gas inside the tundish is blown.
- the blowing of the replacement gas is stopped, and the continuous casting is performed using the tundish without blowing the replacement gas into the tundish in the continuous casting facility.
- the casting step including the step, continuous casting is started using the tundish containing a flammable gas component in an incompletely burned state inside, and the volume of molten steel injected into the tundish is the same as that of the tundish.
- a method for producing a continuously cast slab in which the oxygen concentration in the gas phase of the tundish is 2.0% or less until it reaches 60% of the volume.
- a material obtained by refining molten steel discharged from a converter or electric furnace in a secondary refining facility and casting the molten steel refined in the above secondary refining facility in a continuous casting facility is used.
- This is a method of manufacturing steel materials for bearings, in which a substitution gas containing at least a flammable gas is blown into the inside of the tundish, which is an intermediate container of the continuous casting facility, under incomplete combustion conditions, and the inside of the tundish. After the replacement step of replacing the gas and the replacement step, the blowing of the replacement gas is stopped, and the continuous casting facility is used for continuous casting without blowing the replacement gas into the tundish.
- the casting step continuous casting is started using the tundish containing a flammable gas component in an incompletely burned state, and the volume of molten steel injected into the tundish is the above.
- a method for producing a steel material for a bearing wherein the oxygen concentration in the gas phase of the tundish is 2.0% or less until it reaches 60% of the volume of the tundish.
- the tundish it is possible to heat the tundish, prevent an increase in the oxygen concentration in the tundish particularly at the time of injecting molten steel, and suppress the gas-liquid reaction between the molten steel and oxygen in the atmosphere.
- a method for casting molten steel, a method for producing continuously cast slabs, and a method for producing steel materials for bearings are provided.
- the refined molten steel is continuously cast using a continuous casting facility.
- the continuous casting equipment is not particularly limited as long as it is generally used in casting molten steel.
- molten steel contained in a ladle (not shown) is injected into the tundish 1 shown in FIG. 1, and then molten steel is injected from the tundish 1 into a mold (not shown).
- a mold (not shown).
- slabs, blooms, billets and other slabs having a desired shape are cast. As shown in FIG.
- the tundish 1 has an injection hole 10 formed in the upper lid and four stopper holes 11a to 11d.
- the injection hole 10 is an opening formed in the center of the upper lid of the tundish 1 through which a long nozzle (not shown) connected to the ladle is inserted.
- the four stopper holes 11a to 11d are holes formed so as to line up in the longitudinal direction of the tundish 1, and are openings through which the four stoppers (not shown) are inserted.
- the injection hole 10 is formed between the central stopper holes 11b and 11c.
- the tundish 1 shown in FIG. 1 is provided in a continuous casting facility for casting slabs such as bloom with 4 strands.
- the positions of the four stopper holes 11a to 11d are provided corresponding to the positions of the strands on which the mold is installed.
- the steel type of the molten steel cast in the present embodiment is a bearing steel in which oxides need to be reduced as non-metal inclusions.
- a heating step of heating the tundish 1 is performed.
- gas supply pipes 2 are provided in the two stopper holes 11b and 11c on the central side, respectively.
- the gas supply pipe 2 is a pipe for supplying (blowing) oxygen-containing gas and flammable gas, and the tips at which the gas is injected are provided from the two stopper holes 11b and 11c toward the inside of the tundish 1. ..
- the oxygen-containing gas and the flammable gas are supplied from the gas supply device to the gas supply pipe 2, and the respective supply amounts (flow rates) can be adjusted individually.
- the flammable gas is, for example, C gas, which is a flammable gas generated and recovered in a coke oven.
- the C gas contains CO gas and various hydrocarbon gases, which are flammable gas components, and has, for example, a composition as shown in Table 1.
- the oxygen-containing gas is, for example, air.
- the inside of the tundish 1 is heated by blowing the oxygen-containing gas and the flammable gas into the inside of the tundish 1 through the two stopper holes 11b and 11c and burning the combustible gas.
- the flow rate of the amount of oxygen-containing gas blown to burn the flammable gas is adjusted so that the amount of oxygen contained in the oxygen-containing gas is equal to or more than the amount for completely burning the flammable gas.
- the oxygen-containing gas is blown together with the flammable gas under the condition that the air ratio is 1.4 or more.
- the air ratio is the amount of oxygen in the oxygen-containing gas actually flowing with respect to the amount of oxygen in the oxygen-containing gas theoretically required to completely burn the blown combustible gas (flow rate, so-called theoretical oxygen amount). It is the ratio of (flow rate, so-called amount of oxygen used).
- the oxygen-containing gas is air
- the amount of air actually flowing flow rate, so-called air amount used
- the minimum amount of air theoretically required to completely burn the combustible gas blown in flow rate, so-called theoretical air amount).
- the flammable gas is completely burned at an air ratio of 1, but in reality it is difficult to completely burn the flammable gas with only the theoretical amount of air, so the air ratio is generally supplied as a value larger than 1. By doing so, complete combustion is achieved. That is, in reality, when the air ratio is 1.4 or more, the flammable gas is completely burned, and when the air ratio is less than 1.4, some combustible gas components remain unburned (incomplete combustion).
- the temperature inside the tundish 1 is lower than the ignition point of the flammable gas, ignition does not occur naturally, so that the gas blown in using the ignition point is ignited.
- the heating step is performed until the process shifts to the replacement step described later. While the heating step is being performed, the two stopper holes 11a and 11d and the injection holes 10 in which the gas supply pipe 2 is not installed may be provided with a fire-resistant lid.
- a replacement step of replacing the gas inside the tundish 1 is performed by blowing a replacement gas containing at least a flammable gas into the tundish 1 under incomplete combustion conditions.
- the replacement gas is a gas that is blown into the tundish 1 from the two gas supply pipes 2 in the replacement step, and is preferably a mixture of a flammable gas and an oxygen-containing gas.
- the amount of the oxygen-containing gas contained in the replacement gas is made smaller than the amount required for complete combustion of the combustible gas contained in the replacement gas.
- the incomplete combustion condition is a blowing condition in which the amount of oxygen in the replacement gas is less than the amount required for complete combustion of the combustible gas, and the replacement gas is not completely burned.
- the air ratio of the replacement gas is preferably 1.3 or less, more preferably 1.0 or less.
- the flammable gas is preferably a flammable gas having a higher specific density than air, and for example, propane gas is more preferable.
- propane gas is more preferable.
- the gas component of the flammable gas in the incomplete combustion state tends to stay below the tundish 1.
- the gas component of the flammable gas in the incomplete combustion state is less likely to be replaced and mixed with the air that has entered the tundish 1, and the molten steel is less likely to be oxidized for a longer period of time.
- Propane gas has a higher specific density than air and is widely distributed as a fuel gas, and is relatively inexpensive and easily available.
- the CO concentration contained in the flammable gas is preferably in a range in which Fe oxidation does not occur based on the equilibrium relationship between the CO gas contained in the flammable gas and Fe at the temperature inside the tundish. If Fe content such as adhered bullion is present in the tundish, depending on the composition of the flammable gas, this Fe content may be oxidized even when only the flammable gas, which is the most difficult condition to oxidize, is blown. There is. If the Fe component is oxidized and the casting step described later is carried out in the state where the Fe oxide is present in the tundish, the Fe oxide reacts with Al in the molten steel in the casting step, and the Al oxide is present. There is a risk of reoxidation.
- the oxidation reaction of Fe in a CO-CO 2 atmosphere can be considered from the equations (3) obtained from the equations (1) and (2).
- the equilibrium relationship of the equation (3) is given as a function of the ratio of the CO partial pressure to the CO 2 partial pressure and the temperature as shown in the equation (4).
- ⁇ G 1 , ⁇ G 2 and ⁇ G 3 are the standard free energy changes (J) of the reactions of Eqs.
- T is the temperature (K)
- a Fe is Fe. activity
- a FeO is activity of FeO
- p CO is the partial pressure of CO
- p CO2 is CO 2 partial pressure
- (s) and (g) indicate solid and gas, respectively.
- the value on the right side of Eq. (4) at 1000 ° C is 1.3. That is, if the ratio of the CO partial pressure to the CO 2 partial pressure is 1.3 or more, the equilibrium of Eq. (3) proceeds to the left, that is, the condition is that Fe oxidation does not occur thermodynamically.
- the volume concentration (vol%) in the standard state of the flammable gas component may be used, respectively. For example, in bearing steels that require high cleanliness, the CO gas concentration in the flammable gas is ensured so that the CO partial pressure with respect to the CO 2 partial pressure is 1.3 or more, so that it is refined during the replacement process.
- the reoxidation of Al in the molten steel due to the oxide of Fe is suppressed, and high cleanliness is ensured. Further, when C gas having the components shown in Table 1 is used as the flammable gas, the ratio of the CO partial pressure to the CO 2 partial pressure is 1.3 or more, so that it can be used without adjusting the C gas component. ..
- the replacement step is performed until the gas component in the incompletely burned state of the flammable gas remains in the tundish 1.
- the gas component in the incompletely burned state of the combustible gas is the case where the combustible gas is contained as an unburned (unreacted) gas component as it is infused, or the composition of the gas generated by complete combustion. Also includes the case where it is contained as a gas component having a composition of a gas having a low degree of oxidation. Similar to the heating step, the two stopper holes 11a and 11d and the injection holes 10 in which the gas supply pipe 2 is not installed are provided with fire-resistant lids while the replacement step is being performed. May be good.
- the atmosphere is entrained from the injection hole 10 as the molten steel is injected into the tundish 1, so that the atmosphere flows into the tundish 1.
- the inflow of air is generated from the gaps formed in the four stopper holes 11a to 11d and the tundish 1.
- the inside of the tundish 1 is positively pressured, so that the inflow of the atmosphere from the gap is suppressed. Inflow is likely to occur.
- the gas component in the incomplete combustion state of the flammable gas is present inside the tundish 1 due to the incomplete combustion of the replacement gas.
- the oxygen gas in the atmosphere that has flowed into the inside of the tundish 1 at the initial stage of casting reacts with CO contained in the flammable gas by the reaction of the following formula (6), and the reaction with Al in the molten steel is suppressed. It will be. Further, when the flammable gas contains a hydrocarbon-based gas, the reaction of the formula (7) also occurs, so that the gas-liquid reaction between the molten steel and oxygen in the atmosphere can be suppressed.
- the molten steel In the casting process, when a predetermined amount of molten steel is injected into the tundish 1, a covering material such as tundish flux is put into the tundish 1.
- the charged covering material melts and covers the bath surface of the molten steel. Therefore, after the coating material is added, the molten steel is blocked from the atmospheric gas in the tundish 1, and the molten steel is less likely to be reoxidized. That is, as in the present embodiment, the reoxidation of the molten steel is suppressed over the entire period of the casting process by setting the gas component in the tundish 1 in the incomplete combustion state of the combustible gas at the initial stage of casting. You will be able to do it.
- the equipment used for injecting the replacement gas in the replacement step need only change the air ratio of the equipment used in the heating step. Therefore, unlike Patent Documents 1 and 2, it is not necessary to introduce new equipment, and reoxidation of molten steel can be prevented easily and inexpensively.
- an inert gas such as Ar gas may be blown into the tundish within a range that does not involve the inflow of air.
- the blowing of an inert gas such as Ar gas is preferably performed at a low flow velocity so as not to attract the atmosphere, and further, a replacement gas or a flammable gas in an incompletely burned state after a certain period of time has passed since the start of casting.
- the casting step it is preferable to start continuous casting with a flammable gas component in an incomplete combustion state inside the tundish.
- a flammable gas component in an incomplete combustion state inside the tundish.
- the atmosphere is entrained from the injection hole 10, so that the atmosphere flows into the tundish 1.
- the tundish 1 contains a combustible gas component in an incompletely burned state
- the oxygen gas in the inflowing atmosphere is a combustible gas component in an incompletely burned state due to the reaction of the above equation (6). It reacts with CO and suppresses the reaction with Al in molten steel.
- the volume of the molten steel injected into the tundish 1 is the tundish 1.
- the oxygen concentration in the gas phase of the tundish 1 is 2.0% or less until it reaches 60% of the volume.
- the gas component in the incompletely burned state of the flammable gas remains in the tundish 1 until the volume of the molten steel injected into the tundish 1 reaches 60% of the volume of the tundish 1 from the start of casting.
- the oxygen concentration in the tundish gas phase is maintained at a low value of 2.0% or less, the reoxidation of the molten steel in the casting process can be more reliably suppressed.
- the molten steel contains more combustible gas components in an incompletely burned state in the tundish 1. Infusion can be done. That is, since the reoxidation of molten steel in the casting process can be more reliably suppressed, it is more preferable that the period from the completion of the replacement process to the start of the casting process is within 10 minutes.
- the period from the completion of the replacement process to the start of the casting process is longer than 10 minutes, the combustible gas component in the incompletely burned state remaining in the tundish 1 is dissipated to the outside of the tundish 1. Therefore, the antioxidant effect of the molten steel may be reduced.
- the time when the replacement step is completed is the time when the supply of the replacement gas is stopped.
- the time when the casting process starts is the time when the injection of molten steel from the ladle into the tundish is started.
- the C gas generated in the coke oven of a steel mill is used as a flammable gas, the operating cost is excellent.
- propane gas is used as the flammable gas as described above, it is easy to maintain the state in which the molten steel is difficult to oxidize for a longer period of time.
- the molten steel is continuously cast to produce a continuously cast slab having a predetermined shape.
- a steel material for bearings may be manufactured using this continuously cast slab as a material. In this case, a known technique can be used for rolling the continuously cast slab and finishing the steel material obtained by rolling.
- the equipment for casting is a continuous casting equipment, but the present invention is not limited to such an example.
- the equipment for casting may be the ingot making equipment 3 as shown in FIG.
- the ingot making equipment 3 is an equipment for casting an ingot by pouring and ingot refined molten steel.
- the ingot-forming equipment 3 is an equipment generally used in the bottom-pouring ingot-forming method, and has an injection pipe 30, a surface plate 31, two molds 32, and two lids 33.
- the injection pipe 30 and the two molds 32 are provided on the surface plate 31 so as to reach the two molds 32 through the surface plate 31 from the injection path 34 through which the molten steel 4 passes.
- a lid 33 is provided on each of the two molds 32 for air-cutting.
- a replacement step is performed in which the inert gas flows into the inside of the two molds 32 and the injection path 34.
- the molten steel 4 is poured from the injection pipe 30 and a casting step is performed in which the molten steel 4 is poured into the two molds 32 through the injection path 34.
- the replacement gas is blown into the two molds 32 and the injection path 34 in the same manner as in the above embodiment, so that the air flowing into the mold 32 through the gap with the lid 33 can be used.
- Oxygen gas contained in the atmosphere entrained at the time of injection into the injection pipe 30 can be reduced.
- the replacement gas may be blown only from the upper part of the two molds 32.
- the ingot making facility 3 shown in FIG. 2 is an example, and the shape, the number of molds, and the like can be appropriately changed.
- C gas generated in a coke oven is used as the flammable gas, but the present invention is not limited to such an example.
- the flammable gas may be any other gas as long as it reacts with oxygen gas and burns.
- the flammable gas may be a hydrocarbon gas or a CO gas.
- propane gas when a gas having a specific density heavier than air, such as propane gas, is used as the flammable gas among the hydrocarbon gases, the state in which the molten steel is hardly oxidized is likely to be maintained for a longer time. Therefore, when the cleanliness of the product is more important, propane gas should be used.
- propane gas should be used.
- the hydrocarbon gas contains hydrogen, the hydrogen concentration in the molten steel may increase. Therefore, in the case of a steel type having a strict hydrogen concentration, it is preferable to appropriately adjust the type and concentration of the hydrocarbon used from the allowable upper limit of the hydrogen concentration and the hydrogen concentration in the molten steel.
- the continuous casting facility has the tundish 1 having the shape shown in FIG. 1, but the present invention is not limited to such an example.
- the continuous casting equipment is not particularly limited as long as it is a general one. Therefore, the shape and the number of strands of the tundish 1 may be other than those shown in FIG.
- the steel type of the molten steel is a bearing steel, but the present invention is not limited to such an example.
- the steel grade of the molten steel may be another steel grade as long as there is concern about reoxidation of active elements such as Si, Mn, Al, and Ti in the molten steel by oxygen gas.
- the heating step is performed, but the present invention is not limited to such an example.
- the treatment after the replacement step may be performed without performing the heating step.
- the replacement gas is blown through the two stopper holes 11b and 11c, but the present invention is not limited to such an example.
- the replacement gas may be supplied through holes other than the two stopper holes 11b and 11c, for example, the injection hole 10 and the stopper holes 11a and 11d, and other holes provided for temperature measurement or sampling.
- the method for casting molten steel according to one aspect of the present invention is a method for casting molten steel using a continuous casting facility, in which at least flammable gas is placed inside the tundish 1 which is an intermediate container of the continuous casting facility.
- a replacement step of replacing the gas inside the tundish 1 by blowing the containing replacement gas under incomplete combustion conditions, and after the replacement step, the blowing of the replacement gas is stopped, and the continuous casting facility is used using the tundish 1.
- a tundish 1 containing a flammable gas component in an incompletely burned state is used in the casting step.
- continuous casting is started using the tundish 1 containing a flammable gas component in an incompletely burned state, and the volume of molten steel injected into the tundish 1 is increased.
- the oxygen concentration in the gas phase of the tundish 1 is 2.0% or less. According to the configuration of (3) above, the reoxidation of molten steel can be suppressed more reliably.
- the period from the end of the replacement step to the start of the casting step is within 10 minutes. According to the configuration of (4) above, it is possible to suppress the emission of the combustible gas component in the incomplete combustion state remaining in the tundish 1 to the outside of the tundish 1, and the reoxidation of the molten steel is more reliably performed. It will be possible to suppress it.
- a gas containing at least a flammable gas and an oxygen-containing gas is used as the replacement gas. According to the configuration of (5) above, since a part of the replacement gas is burned in the replacement step, the temperature drop of the tundish 1 can be suppressed or prevented.
- the oxygen in the oxygen-containing gas in the replacement gas actually blown with respect to the flow rate of oxygen theoretically required to completely burn the flammable gas in the replacement gas.
- the air ratio which is the ratio of the flow rate, is 1.3 or less.
- the air ratio is set to 1.0 or less in the replacement step. According to the configurations (6) and (7) above, since a part of the replacement gas is burned in the replacement step, the temperature drop of the tundish 1 can be more effectively suppressed or prevented.
- the oxygen-containing gas is air. According to the configuration of (8) above, the equipment configuration can be simplified and the cost of the oxygen-containing gas can be reduced.
- the flammable gas used in the replacement step is a flammable gas having a higher specific density than air.
- the gas component of the combustible gas in the incomplete combustion state is less likely to be replaced and mixed with the air that has entered the tundish 1, and the state in which the molten steel is less likely to be oxidized is maintained for a longer period of time. It will be easier.
- the flammable gas is propane gas.
- the CO concentration contained in the flammable gas is adjusted to the equilibrium relationship between the CO gas contained in the flammable gas and Fe at the temperature inside the tundish. Based on this, the range is set so that Fe oxidation does not occur. According to the configuration of (11) above, since the oxidation of Fe by CO 2 can be suppressed, the reoxidation of Al in the molten steel in the casting process can be further reduced. (12) In any one of the above configurations (1) to (11), the replacement gas has a ratio of the CO partial pressure to the CO 2 partial pressure of 1.3 or more. According to the configuration (12) above, oxidation of Fe by CO 2 can be suppressed, for example, in high-quality bearing steel.
- the method for casting molten steel according to one aspect of the present invention is a method for casting molten steel 4 using the ingot making equipment 3, and is a substitution method containing at least a flammable gas inside the mold 32 of the ingot making equipment 3. After the replacement step of blowing gas under incomplete combustion conditions to replace the gas inside the mold 32 and the replacement step, the blowing of the replacement gas is stopped and the mold 32 is used to replace the mold with a mold in a lumping facility. Includes a casting process in which casting is performed without blowing gas. According to the configuration of the above (13), even in the ingot building equipment 3 as shown in FIG. 2, the reoxidation of the molten steel 4 can be suppressed for the same reason as the configuration of the above (1).
- molten steel discharged from a converter or an electric furnace is smelted in a secondary smelting facility, and the molten steel smelted in the secondary smelting facility is continuously cast.
- This is a method of producing continuously cast slabs by casting with equipment.
- a replacement gas containing at least a flammable gas is blown into the tundish 1 which is an intermediate container of the continuous casting equipment under incomplete combustion conditions.
- the blowing of the replacement gas is stopped, and continuous casting is performed using the tundish 1 in a continuous casting facility without blowing the replacement gas into the tundish.
- the casting step including the casting step to be performed, continuous casting is started using the tundish containing a flammable gas component in an incompletely burned state inside, and the volume of molten steel injected into the tundish 1 is the tundish 1.
- the oxygen concentration in the gas phase of the tundish 1 is 2.0% or less until it reaches 60% of the volume of the steel.
- the continuously cast slab is a continuously cast slab that is a material for bearing steel.
- a continuously cast slab which is a material of a bearing steel having high cleanliness can be manufactured.
- molten steel discharged from a converter or an electric furnace is smelted in a secondary smelting facility, and the molten steel smelted in the secondary smelting facility is continuously cast.
- This is a method of manufacturing steel materials for bearings using the material cast in the above method, in which a substitution gas containing at least a flammable gas is blown into the inside of the tundish 1 which is an intermediate container of a continuous casting facility under incomplete combustion conditions.
- the blowing of the replacement gas is stopped, and the tundish 1 is used continuously without blowing the replacement gas into the tundish in a continuous casting facility.
- the casting process which includes a casting process in which casting is performed, continuous casting is started using the tundish 1 containing a flammable gas component in an incompletely burned state inside, and the volume of molten steel injected into the tundish 1 is tan.
- the oxygen concentration in the gas phase of the tundish 1 is 2.0% or less until it reaches 60% of the volume of the dish 1. According to the configuration of the above (16), a steel material for bearings having high cleanliness can be manufactured for the same reason as the configuration of the above (1).
- air flow rate supplied was 42Nm 3 / min. That is, the air ratio was set to 1.4, that is, 1.4 times the amount of air theoretically required for complete combustion of C gas.
- the molten steel was previously subjected to hot metal pretreatment (dephosphorization / desulfurization), converter (decarburization / dephosphorization), LF (slag in the ladle), and RH degassing (floating inclusions).
- a replacement step of blowing the replacement gas into the tundish 1 was performed.
- the replacement step that is, 5 minutes after the injection of the replacement gas was stopped
- molten steel was injected into the tundish 1 and continuous casting was performed to perform the casting step.
- the oxygen concentration in the gas phase in the tundish 1 was measured during the period from the start of injection of the molten steel to the injection of the molten steel by the volume of the tundish 1 (20 tons).
- the oxygen concentration in the tundish 1 was 0.3% at the start of injection and 0.2% at the time of injecting molten steel (18t) having 90% of the tundish capacity.
- the molten steel was sampled at the stage where the molten steel corresponding to the volume of the tundish 1 (20 tons) was injected, and the total amount of oxygen and the total amount of nitrogen in the molten steel were analyzed.
- the molten steel was sampled even at the end of the RH degassing treatment, which is the stage where the refining treatment was completed, and the total amount of oxygen and the total amount of nitrogen in the molten steel at the end of the RH degassing treatment were analyzed. Then, from each analysis result, the total amount of oxygen and total nitrogen picked up from the end of the RH degassing treatment to the injection of 20 tons of molten steel was investigated.
- the total oxygen and total nitrogen pickup amounts are the amounts of change in each analytical value from the end of the RH degassing treatment to the injection of 20 tons of molten steel.
- the example as a comparative example, a conventional casting method in which the casting step is performed after the heating step without performing the replacement step is also carried out, and the total amount of oxygen and total nitrogen picked up is investigated.
- the conditions of the heating step and the casting step in the comparative example were the same as those in the example.
- the oxygen concentration in the tundish 1 was 3.4% at the start of injection and 4% at the time of injecting molten steel (18t) having 90% of the tundish capacity.
- FIG. 3 shows the survey results of the total oxygen and total nitrogen pickup amounts in Examples and Comparative Examples.
- the total nitrogen pickup amount is about the same in the examples and the comparative examples, whereas the total oxygen pickup amount is 10 ppm in the comparative example but 0 ppm in the example. It was confirmed that it was significantly reduced. This suggests that the oxygen in the atmosphere mixed in the tundish 1 was consumed by causing a combustion reaction with the flammable gas.
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Abstract
Description
ところで、タンディッシュには、一般的に、耐火物を予熱するためのガスの通り道や、溶鋼の温度測定・サンプル採取を目的とした開口部等が予め加工されて設けられている。さらに、溶鋼のような高温下の環境での鉄容器の変形は不可避であるため、タンディッシュにおけるわずかな隙間の発生を工業的に抑止することは困難である。
このため、特に、軸受鋼といった鋼中の酸化物に対して厳格な鋼種において、設備のトラブル等を伴わず、溶鋼と大気中の酸素との気-液反応をより低減する方法が求められている。
図1を参照して、本発明の一実施形態に係る溶鋼の鋳造方法について説明する。本実施形態では、精錬処理された溶鋼を、連続鋳造設備を用いて連続鋳造する。連続鋳造設備は、溶鋼の鋳造において一般的に用いられるものであればよく、特に限定されない。連続鋳造設備を用いた連続鋳造では、取鍋(不図示)に収容された溶鋼を、図1に示すタンディッシュ1に注入し、その後、タンディッシュ1から鋳型(不図示)に溶鋼を注入することで所望の形状のスラブやブルーム、ビレット等の鋳片が鋳造される。タンディッシュ1は、図1に示すように、上蓋に形成される注入孔10と、4個のストッパー孔11a~11dを有する。注入孔10は、タンディッシュ1の上蓋の中央に形成され、取鍋に接続されるロングノズル(不図示)が挿通される開口部である。4個のストッパー孔11a~11dは、タンディッシュ1の長手方向に並ぶようにして形成される孔であり、4本のストッパー(不図示)がそれぞれ挿通される開口部である。なお、注入孔10は、中央のストッパー孔11b,11cの間に形成される。なお、図1に示すタンディッシュ1は、4ストランドでブルーム等の鋳片を鋳造する連続鋳造設備に設けられるものである。そして、4個のストッパー孔11a~11dの位置は、鋳型が設置される各ストランドの位置に対応して設けられる。また、本実施形態において鋳造される溶鋼の鋼種は、非金属介在物として酸化物を低減する必要がある、軸受鋼である。
本実施形態では、まず、タンディッシュ1を加熱する加熱工程を行う。加熱工程では、図1に示すように、中央側の2個のストッパー孔11b,11cに、ガス供給管2がそれぞれ設けられる。ガス供給管2は、酸素含有ガスと可燃性ガスとを供給する(吹き込む)管であり、ガスが噴射される先端が2個のストッパー孔11b,11cからタンディッシュ1の内部に向かって設けられる。酸素含有ガス及び可燃性ガスは、ガス供給装置からガス供給管2に供給され、それぞれの供給量(流量)が個別に調整可能に構成される。可燃性ガスは、例えば、コークス炉にて発生し、回収された可燃性のガスであるCガスである。Cガスは、可燃性のガス成分である、COガス及び各種の炭化水素ガスを含み、例えば、表1に示すような組成からなる。また、酸素含有ガスは、例えば空気である。
加熱工程は、後述する置換工程に移行するまで行われる。なお、加熱工程が行われている間、ガス供給管2が設置されていない、2個のストッパー孔11a,11d及び注入孔10には、耐火性の蓋が設けられてもよい。
加熱工程の後、タンディッシュ1の内部に少なくとも可燃性ガスを含む置換ガスを不完全燃焼条件で吹き込んで、タンディッシュ1の内部のガスを置換する置換工程を行う。
置換ガスは、置換工程において、2個のガス供給管2からタンディッシュ1の内部に吹き込まれるガスであり、可燃性ガスと酸素含有ガスとを混合させたものであることが好ましい。この場合、置換ガスに含まれる上記酸素含有ガスの量を、置換ガスに含まれる上記可燃性ガスの完全燃焼に必要な量より少なくする。つまり、不完全燃焼条件とは、置換ガス中の酸素の量を可燃性ガスの完全燃焼に必要な量よりも少なくし、置換ガスを完全燃焼させない吹込み条件である。なお、置換ガスの空気比を1.3以下とすることが好ましく、1.0以下とすることがより好ましい。このようにすることで、可燃性ガスの一部が燃焼するため、置換工程におけるタンディッシュ1の内部の温度低下を抑制または防止することができる。また、置換ガスを、可燃性ガスのみとしてもよい。しかし、可燃性ガスのみを置換ガスとして吹き込んだ場合、可燃性ガスの燃焼が起こりにくいため、タンディッシュ1の内部の温度が低下する可能性がある。このため、可燃性ガスのみを置換ガスとして吹き込むことは、置換工程におけるガスの吹き込み時間が短い場合やタンディッシュ1の内部の温度が充分に高い場合等、温度低下が問題とならない場合のみに行うことが好ましい。
置換工程の後、置換ガスの吹き込みを停止し、タンディッシュ1を用いて、タンディッシュ1に置換ガスを吹き込まずに溶鋼の連続鋳造を行う鋳造工程が行われる。
鋳造工程では、注入孔10に挿通されたロングノズル(不図示)を通じて、取鍋からタンディッシュ1へと溶鋼が注入される。そして、タンディッシュ1の下面の各ストランドの位置に設けられた、浸漬ノズルを通じて鋳型へと溶鋼が注入されることで、鋳造が行われる。
CO+1/2O2→CO2 ・・・(6)
CmHn+(m/2+n/4)O2→mCO2+n/2H2O ・・・(7)
なお、置換工程が終了する時点は、置換ガスの送給を止めた時点である。また、鋳造工程が開始する時点は、取鍋からタンディッシュに溶鋼の注入を開始した時点である。
以上で、特定の実施形態を参照して本発明を説明したが、これら説明によって発明を限定することを意図するものではない。本発明の説明を参照することにより、当業者には、開示された実施形態とともに種々の変形例を含む本発明の別の実施形態も明らかである。従って、特許請求の範囲に記載された発明の実施形態には、本明細書に記載したこれらの変形例を単独または組み合わせて含む実施形態も網羅すると解すべきである。
さらに、上記実施形態では、溶鋼の鋼種が軸受鋼であるとしたが、本発明はかかる例に限定されない。溶鋼の鋼種は、溶鋼中のSi,Mn,Al,Ti等の活性元素の酸素ガスによる再酸化が懸念されるものであれば、他の鋼種であってもよい。
さらに、上記実施形態では、置換ガスを2個のストッパー孔11b,11cから吹き込むとしたが、本発明はかかる例に限定されない。置換ガスは、2個のストッパー孔11b,11c以外の孔、例えば、注入孔10やストッパー孔11a,11d、測温またはサンプリングのために設けられる他の孔を通じて供給されてもよい。
(1)本発明の一態様に係る溶鋼の鋳造方法は、連続鋳造設備を用いた溶鋼の鋳造方法であって、連続鋳造設備の中間容器であるタンディッシュ1の内部に、少なくとも可燃性ガスを含む置換ガスを不完全燃焼条件で吹き込んで、タンディッシュ1の内部のガスを置換する置換工程と、置換工程の後、置換ガスの吹込みを停止し、タンディッシュ1を用いて、連続鋳造設備でタンディッシュ1に置換ガスを吹き込まずに連続鋳造を行う鋳造工程と、を含む。
上記(1)の構成によれば、タンディッシュ1へ溶鋼を注入する際に、タンディッシュ1内に可燃性ガスの不完全燃焼状態のガス成分が存在している。このため、注入孔や隙間等から流入した大気中の酸素ガスが可燃性ガスの不完全燃焼状態のガス成分と反応し、溶鋼と大気中の酸素との気-液反応が抑制されるため、溶鋼の再酸化が抑制される。
(3)上記(2)の構成において、鋳造工程では、内部に不完全燃焼状態の可燃性ガス成分を含むタンディッシュ1を用いて連続鋳造を開始し、タンディッシュ1に注入された溶鋼体積がタンディッシュ1の容積の60%に達するまでの期間、タンディッシュ1の気相中の酸素濃度が2.0%以下である。
上記(3)の構成によれば、溶鋼の再酸化をより確実に抑制することができるようになる。
上記(4)の構成によれば、タンディッシュ1内に残っている不完全燃焼状態の可燃性ガス成分のタンディッシュ1外への放散を抑制することができ、溶鋼の再酸化をより確実に抑制することができるようになる。
(5)上記(1)~(4)のいずれか1つ構成において、置換工程では、置換ガスとして可燃性ガス及び酸素含有ガスを少なくとも含むガスを用いる。
上記(5)の構成によれば、置換工程において、置換ガスの一部が燃焼するため、タンディッシュ1の温度低下を抑制または防止することができる。
(7)上記(6)の構成において、置換工程では、空気比を1.0以下とする。
上記(6),(7)の構成によれば、置換工程において、置換ガスの一部が燃焼するため、タンディッシュ1の温度低下をより効果的に抑制または防止することができる。
(8)上記(5)~(7)のいずれか1つの構成において、酸素含有ガスが空気である。
上記(8)の構成によれば、設備構成を簡易なものとすることができ、酸素含有ガスに掛かるコストを低減することができる。
上記(9)の構成によれば、不完全燃焼状態の可燃性ガスのガス成分が、タンディッシュ1内に侵入した空気で置換・混合されにくくなり、溶鋼が酸化されにくい状態がより長く維持されやすくなる。
(10)上記(9)の構成において、可燃性ガスが、プロパンガスである。
上記(11)の構成によれば、CO2によるFeの酸化を抑えることができるため、鋳造工程における溶鋼中のAlの再酸化をより低減することができる。
(12)上記(1)~(11)のいずれか1つの構成において、置換ガスは、CO2分圧に対するCO分圧の比が1.3以上である。
上記(12)の構成によれば、例えば高品質な軸受鋼等において、CO2によるFeの酸化を抑えることができる。
上記(13)の構成によれば、図2に示すような造塊設備3においても、上記(1)の構成と同様な理由から、溶鋼4の再酸化を抑制することができる。
上記(14)の構成によれば、上記(1)の構成と同様な理由から、清浄性の高い連続鋳造鋳片を製造することができる。
(15)上記(14)の構成において、連続鋳造鋳片が軸受鋼の素材となる連続鋳造鋳片である。
上記(15)の構成によれば、上記(1)の構成と同様な理由から、清浄性の高い軸受鋼の素材となる連続鋳造鋳片を製造することができる。
上記(16)の構成によれば、上記(1)の構成と同様な理由から、清浄性の高い軸受用鋼材を製造することができる。
実施例では、まず、加熱工程として、容量20t(容積:3.6m3)のタンディッシュ1の内部をCガスと空気とを混合燃焼させ、180分間予熱を行なった。この際、Cガス流量は10Nm3/minとした。このCガス流量に対する理論空気量は30Nm3/minであるが、Cガスを完全燃焼させるため、供給する空気流量は42Nm3/minとした。すなわち、空気比を1.4、つまりCガスを完全燃焼させるために理論的に必要な空気量の1.4倍とした。また、溶鋼には、予め、溶銑予備処理(脱リン・脱硫)、転炉(脱炭・脱リン)、LF(取鍋内造滓)、RH脱ガス(介在物浮上)処理を施した。
10 注入孔
11a~11d ストッパー孔
2 ガス供給管
3 造塊設備
30 注入管
31 定盤
32 鋳型
33 蓋
34 注入経路
4 溶鋼
5 取鍋
Claims (16)
- 連続鋳造設備を用いた溶鋼の鋳造方法であって、
前記連続鋳造設備の中間容器であるタンディッシュの内部に、少なくとも可燃性ガスを含む置換ガスを不完全燃焼条件で吹き込んで、前記タンディッシュの内部のガスを置換する置換工程と、
前記置換工程の後、前記置換ガスの吹込みを停止し、前記タンディッシュを用いて、前記連続鋳造設備で前記タンディッシュに前記置換ガスを吹き込まずに連続鋳造を行う鋳造工程と、
を含む、溶鋼の鋳造方法。 - 前記鋳造工程では、内部に不完全燃焼状態の可燃性ガス成分を含む前記タンディッシュを用いる、請求項1に記載の溶鋼の鋳造方法。
- 前記鋳造工程では、内部に不完全燃焼状態の可燃性ガス成分を含む前記タンディッシュを用いて連続鋳造を開始し、前記タンディッシュに注入された溶鋼体積が前記タンディッシュの容積の60%に達するまでの期間、前記タンディッシュの気相中の酸素濃度が2.0%以下である、請求項2に記載の溶鋼の鋳造方法。
- 前記置換工程が終了してから前記鋳造工程が開始するまでの期間が、10分以内である、請求項2または請求項3に記載の溶鋼の鋳造方法。
- 前記置換工程では、前記置換ガスとして前記可燃性ガス及び酸素含有ガスを少なくとも含むガスを用いる、請求項1~4のいずれか1項に記載の溶鋼の鋳造方法。
- 前記置換工程では、前記置換ガス中の前記可燃性ガスを完全燃焼させるのに理論上必要な酸素の流量に対する前記置換ガス中の前記酸素含有ガス中の酸素の流量の比である空気比を1.3以下とする、請求項5に記載の溶鋼の鋳造方法。
- 前記置換工程では、前記空気比を1.0以下とする、請求項6に記載の溶鋼の鋳造方法。
- 前記酸素含有ガスが空気である、請求項5~7のいずれか1項に記載の溶鋼の鋳造方法。
- 前記可燃性ガスが、空気より比重の大きい可燃性のガスである、請求項1~8のいずれか1項に記載の溶鋼の鋳造方法。
- 前記可燃性ガスが、プロパンガスである、請求項9に記載の溶鋼の鋳造方法。
- 前記可燃性ガスに含まれるCO濃度を、前記可燃性ガスに含まれるCOガスとFeとのタンディッシュ内部の温度における平衡関係に基づいて、前記Feの酸化が起こらない範囲とする、請求項1~10のいずれか1項に記載の溶鋼の鋳造方法。
- 前記置換ガスは、CO2分圧に対するCO分圧の比が1.3以上である、請求項1~11のいずれか1項に記載の溶鋼の鋳造方法。
- 造塊設備を用いた溶鋼の鋳造方法であって、
前記造塊設備の鋳型の内部に、少なくとも可燃性ガスを含む置換ガスを不完全燃焼条件で吹き込んで、前記鋳型の内部のガスを置換する置換工程と、
前記置換工程の後、前記置換ガスの吹込みを停止し、前記鋳型を用いて、前記造塊設備で前記鋳型に前記置換ガスを吹き込まずに鋳造を行う鋳造工程と、
を含む、溶鋼の鋳造方法。 - 転炉または電気炉から出鋼された溶鋼を二次精錬設備で精錬し、前記二次精錬設備で精錬した溶鋼を連続鋳造設備で鋳造し、連続鋳造鋳片を製造する方法であって、
前記連続鋳造設備の中間容器であるタンディッシュの内部に、少なくとも可燃性ガスを含む置換ガスを不完全燃焼条件で吹き込んで、前記タンディッシュの内部のガスを置換する置換工程と、
前記置換工程の後、前記置換ガスの吹込みを停止し、前記タンディッシュを用いて、前記連続鋳造設備で前記タンディッシュに前記置換ガスを吹き込まずに連続鋳造を行う鋳造工程と、
を含み、
前記鋳造工程では、内部に不完全燃焼状態の可燃性ガス成分を含む前記タンディッシュを用いて連続鋳造を開始し、前記タンディッシュに注入された溶鋼体積が前記タンディッシュの容積の60%に達するまでの期間、前記タンディッシュの気相中の酸素濃度が2.0%以下である、連続鋳造鋳片の製造方法。 - 前記連続鋳造鋳片が、軸受用鋼材の素材となる連続鋳造鋳片である、請求項14に記載の連続鋳造鋳片の製造方法。
- 転炉または電気炉から出鋼された溶鋼を二次精錬設備で精錬し、前記二次精錬設備で精錬した溶鋼を連続鋳造設備で鋳造した素材を使用して軸受用鋼材を製造する方法であって、
前記連続鋳造設備の中間容器であるタンディッシュの内部に、少なくとも可燃性ガスを含む置換ガスを不完全燃焼条件で吹き込んで、前記タンディッシュの内部のガスを置換する置換工程と、
前記置換工程の後、前記置換ガスの吹込みを停止し、前記タンディッシュを用いて、前記連続鋳造設備で前記タンディッシュに前記置換ガスを吹き込まずに連続鋳造を行う鋳造工程と、
を含み、
前記鋳造工程では、内部に不完全燃焼状態の可燃性ガス成分を含む前記タンディッシュを用いて連続鋳造を開始し、前記タンディッシュに注入された溶鋼体積が前記タンディッシュの容積の60%に達するまでの期間、前記タンディッシュの気相中の酸素濃度が2.0%以下である、軸受用鋼材の製造方法。
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CN114774619A (zh) * | 2022-04-29 | 2022-07-22 | 中国铁建重工集团股份有限公司 | 一种低氮高碳铬轴承钢及其生产方法 |
Citations (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPH07308741A (ja) * | 1994-05-17 | 1995-11-28 | Sumitomo Metal Ind Ltd | 注入溶鋼流のシール方法 |
JPH08159664A (ja) * | 1994-12-02 | 1996-06-21 | Kawasaki Steel Corp | 炉内の無酸化加熱方法 |
JP2000158101A (ja) * | 1998-11-27 | 2000-06-13 | Sumitomo Metal Ind Ltd | タンディッシュの予熱方法 |
JP2003266157A (ja) * | 2002-03-14 | 2003-09-24 | Furukawa Electric Co Ltd:The | ベルト&ホイール式連続鋳造圧延法による低酸素銅線材の製造方法 |
JP2020032442A (ja) * | 2018-08-29 | 2020-03-05 | Jfeスチール株式会社 | 溶鋼の鋳造方法 |
Family Cites Families (18)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPH0422567A (ja) * | 1990-05-17 | 1992-01-27 | Sumitomo Metal Ind Ltd | 再使用タンディッシュの加熱方法 |
JPH04143047A (ja) | 1990-10-03 | 1992-05-18 | Sumitomo Metal Ind Ltd | 溶融金属容器の加熱方法 |
JPH04238656A (ja) | 1991-01-09 | 1992-08-26 | Sumitomo Metal Ind Ltd | 連続鋳造用タンディッシュの再使用方法 |
JPH07299548A (ja) | 1994-05-09 | 1995-11-14 | Kawasaki Steel Corp | タンディッシュの予熱方法 |
EP0750170B1 (en) * | 1994-12-02 | 2003-01-22 | Kawasaki Steel Corporation | Non-oxidizing heating method and apparatus therefor |
JPH0947850A (ja) * | 1995-07-31 | 1997-02-18 | Kawasaki Steel Corp | タンディッシュの無酸化加熱方法 |
JP3498436B2 (ja) * | 1995-07-31 | 2004-02-16 | Jfeスチール株式会社 | タンディッシュの無酸化保熱装置およびその制御方法 |
JP3902319B2 (ja) * | 1998-03-04 | 2007-04-04 | 新日本製鐵株式会社 | ビレットの連続鋳造方法 |
AT412349B (de) * | 2003-06-25 | 2005-01-25 | Voest Alpine Ind Anlagen | Verfahren zur herstellung einer legierten metallschmelze und erzeugungsanlage hierzu |
JP4510911B2 (ja) | 2008-07-24 | 2010-07-28 | 新日本製鐵株式会社 | 高周波用無方向性電磁鋼鋳片の製造方法 |
JP5195609B2 (ja) | 2009-04-21 | 2013-05-08 | 新日鐵住金株式会社 | タンディッシュの熱間再使用方法 |
KR20120044426A (ko) * | 2010-10-28 | 2012-05-08 | 현대제철 주식회사 | 턴디쉬 예열 방법 |
JP5556675B2 (ja) * | 2011-01-12 | 2014-07-23 | Jfeスチール株式会社 | 2次精錬設備のインターロック装置 |
KR101553150B1 (ko) * | 2014-03-27 | 2015-09-15 | 현대제철 주식회사 | 턴디쉬의 공연비 제어 방법 및 그 장치 |
RU2718442C1 (ru) * | 2016-09-16 | 2020-04-06 | Ниппон Стил Стэйнлесс Стил Корпорейшн | Способ непрерывной разливки |
JP6278168B1 (ja) * | 2017-04-25 | 2018-02-14 | Jfeスチール株式会社 | 鋼の連続鋳造方法 |
JP6493635B1 (ja) * | 2017-08-30 | 2019-04-03 | Jfeスチール株式会社 | 鋼の連続鋳造方法および薄鋼板の製造方法 |
CN108359898A (zh) * | 2018-03-21 | 2018-08-03 | 温州市赢创新材料技术有限公司 | 一种低氧低夹杂轴承钢的制备方法 |
-
2020
- 2020-10-28 KR KR1020227017982A patent/KR20220088928A/ko not_active Application Discontinuation
- 2020-10-28 CN CN202080081735.5A patent/CN114746195A/zh active Pending
- 2020-10-28 WO PCT/JP2020/040513 patent/WO2021106484A1/ja unknown
- 2020-10-28 JP JP2021523319A patent/JP6969707B2/ja active Active
- 2020-10-28 EP EP20894667.3A patent/EP4066961A4/en active Pending
- 2020-11-13 TW TW109139717A patent/TWI755930B/zh active
Patent Citations (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPH07308741A (ja) * | 1994-05-17 | 1995-11-28 | Sumitomo Metal Ind Ltd | 注入溶鋼流のシール方法 |
JPH08159664A (ja) * | 1994-12-02 | 1996-06-21 | Kawasaki Steel Corp | 炉内の無酸化加熱方法 |
JP2000158101A (ja) * | 1998-11-27 | 2000-06-13 | Sumitomo Metal Ind Ltd | タンディッシュの予熱方法 |
JP2003266157A (ja) * | 2002-03-14 | 2003-09-24 | Furukawa Electric Co Ltd:The | ベルト&ホイール式連続鋳造圧延法による低酸素銅線材の製造方法 |
JP2020032442A (ja) * | 2018-08-29 | 2020-03-05 | Jfeスチール株式会社 | 溶鋼の鋳造方法 |
Non-Patent Citations (2)
Title |
---|
See also references of EP4066961A4 |
STEEL REFINING, 2000 |
Cited By (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
CN114774619A (zh) * | 2022-04-29 | 2022-07-22 | 中国铁建重工集团股份有限公司 | 一种低氮高碳铬轴承钢及其生产方法 |
CN114774619B (zh) * | 2022-04-29 | 2023-10-24 | 中国铁建重工集团股份有限公司 | 一种低氮高碳铬轴承钢及其生产方法 |
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