Fusing agent additive for manufacturing ultra-low phosphoretic steel with outside-stove refining dephosphorization and its manufacturing method

The invention relates to a method for controlling phosphorus in the production of ultra-low phosphorous steel by microalloy steel, high carbon steel and special steel, in particular to a flux additive for producing the ultra-low phosphorous steel by external refining dephosphorization and a preparation method thereof. The flux additive is prepared by mixing raw materials according to a formula and respectively taking dephosphorizing flux, calcium fluoride, calcium carbonate or magnesium carbonate or a mixture of the calcium carbonate and the magnesium carbonate, calcium oxide or magnesium oxide or a mixture of the calcium oxide and the magnesium oxide, and adhesive through material mixing and drying. The method has scientific formula and simple and reasonable process, can realize the quick refining dephosphorization of molten steel until the content of the phosphorus is lower than 0.0030 percent proven by application, is high in efficiency, steady and short in time, remedies the defect ...

Method for slag melting and cooling by using pellet ore for converter smelting

The invention discloses a method for melting slag and cooling through pellets in converter smelting. The method is characterized in that after blowing is carried out for 3 to 4 minutes in an earlier stage of converter blowing, ironmaking pellets are added; the amount of the ironmaking pellets is 4 to 16 kilograms per ton of steel; and the particle size of the ironmaking pellets is between 10 and 15 millimeters. A process adopting the pellets for melting slag can effectively reduce the temperature of a molten pool, is favorable for removing the earlier-stage phosphorus of liquid iron, uniformly raising the temperature of the molten pool and melting slag in a converter smelting process, and can reduce oxygen blowing time. The ironmaking pellets contains about 93 percent of Fe2O3. In addition, the ironmaking pellets are extensive in source and low in price, and are good materials for melting slag and cooling.

Technique for controlling accurate addition of micro-element in steel

The invention relates to an external refining technology for steel making, in particular to a process method for controlling the accurate adding of trace elements in steel, which comprises the following steps of: a. initial deoxidation: molten steel is subjected to primary smelting in a converter, a deoxidizing agent is added into a ladle for the initial deoxidation during the tapping process, the adding amount of the deoxidizing agent is between 1.5 and 3.5kg/t; b. deep deoxidation: aluminum is added to perform the deep deoxidation to the molten steel after the initial desoxydation is finished, and acid-soluble aluminum in the molten steel is controlled to between 0.02 and 0.04 percent; c. refining: the ladle is transported to an LF, RH, CAS-OB or VD station for refining; d. the adding of compound spheres: the ladle is transported to the RH station, and the compound spheres are added into a blanking tube at the opposite side of a RH descending tube; and e. continuous casting: the continuous ...

Technological process for molten steel secondary refining dephosphorization to produce ultra-low phosphorus steel

The invention relates to a process for controlling phosphor in producing an ultra-low phosphorus steel by a microalloy steel, a high carbon steel and a special steel, in particular to a process methodfor producing the ultra-low phosphorus steel by refining and dephosphorization outside a molten steel furnace. The method comprises: (1) a step of tapping in a converter, during which, a tapping temperature is between 1550 and 1660 DEG C; a phosphor content is lower than 0.02 percent in tapping; and steel is tapped by adopting the treatment of non-deoxidization and slag stopping; (2) a step of primary dephosphorization, during which, a dephosphorization fusing agent is added into a steel ladle along the steel flow when the steel is tapped in the converter; and an adding amount of the dephosphorization fusing agent is between 5 and 20 kg/t; (3) a step of deep dephosphorization, during which, cored wire is fed to a steel liquid by adopting a wire feeding process; (4) a step of slag skimming: ...

Method for preparing pure iron with extremely low gas content

The invention discloses a method for preparing pure iron with extremely low gas content. The method comprises the following steps of: (1) pre-desulfurizing molten iron and controlling sulfur content to be 0.003 to 0.015 percent; (2) smelting in a converter: bottom-blowing mixed gas of nitrogen gas and argon gas at the early stage of desulfurization by using a double-slag smelting process, and bottom-blowing argon gas at the late stage of the desulfurization, wherein carbon (C) content is less than 0.03 percent and phosphor (P) content is less than 0.008 percent at the blow end point; and discharging steel by stopping slag and deoxidizing aluminum particles, wherein the temperature of a hanging tank after steel discharging is greater than 1,635 DEG C; (3) removing slag; (4) performing RH deep decarbonization, wherein the inlet temperature is more than 1,615 DE C, the outlet temperature is more than 1,645 DEG C, and C content is less than 0.002 percent and Als content ranges from 0.020 to ...

Technique for manufacturing ultra-low phosphoretic steel with outside-stove refining dephosphorization

The invention relates to a method for controlling phosphorus in the production of ultra-low phosphorous steel by microalloy steel, high carbon steel and special steel, in particular to a process method for producing the ultra-low phosphorous steel by external refining dephosphorization, which comprises the following steps of: 1) converter tapping: the temperature is between 1,550 and 1,660 DEG C, the content of the phosphorus is less than 0.02 percent, and the nondeoxidation and the slag-stopping treatment are adopted for tapping; 2) initial dephosphorization: dephosphorizing flux is added into a ladle with steel stream during the converter tapping, and the adding amount is between 5 and 20kg/t; 3) deep dephosphorization: a powder spraying process is adopted to spray combined flux into molten steel; 4) slag skimming: the vacuum breaking and the slag skimming are performed , and then ladle covering flux is added; 5) heating and stirring: the heating and stirring are performed in a refining ...

Method for producing high-purity pure iron

The invention provides a method for producing high-purity pure iron, which comprises the following steps of: (1) preliminary desulphurization of molten iron: controlling the sulphur content of molten iron charged into a revolving furnace at 0.002%-0.015%; (2) smelting of the revolving furnace: dephosphorizing by using the double slag process, tapping slag after dephosphorization, changing slag, controlling C to be less than 0.03% and P to be less than 0.008% at blowing end, carrying out slag-blocked tapping and aluminium deoxidation, and hanging pots at temperature of above 1635 DEG C; (3) slagging off: removing more than 95% of oxidizing slag; (4) RH deep decarburization: controlling RH charging temperature to be above 1615 DEG C, controlling C to be less than 0.002% and Als to be from 0.020% to 0.035% at smelting end, and controlling the discharging temperature to be above 1645 DEG C; (5) LF (Low Frequency) deep decarburization: adding a deep dephosphorizing agent before entering anLF ...

Technique for desulfurization in refining process

The invention relates to an external refining process for various microalloy steel and special steel, in particular to a process method for desulphurization during the refining process, which is the preferred process method for the desulphurization during the refining processes of various microalloy steel or special steel. The process comprises the following steps of: a. deoxidation: molten steel is subjected to deoxidation treatment first to realize that alpha[O] is less than or equal to 0.0003 percent; b. the spraying of combined powder: the molten steel is refined at an LF, RH, VD or CAS-OB station, and a powder spraying process is adopted to spray the combined powder into the molten steel at the LF, RH, VD or CAS-OB station; and c. continuous casting: the continuous casting adopts the whole-process protection casting. Proven by application, the process has strong desulphurization ability with a desulphurization rate between 60 and 90 percent, can realize the refining desulphurization ...

Composite sphere for manufacturing ultra-low phosphoretic steel with outside-stove refining dephosphorization and its manufacturing method

The invention relates to a method for controlling phosphorus in the production of ultra-low phosphorous steel by microalloy steel and special steel, in particular to a compound sphere for producing the ultra-low phosphorous steel by external refining dephosphorization and a preparation method thereof. The compound sphere consists of a spherical core and a shell, wherein, the spherical core mainly comprises dephosphorizing flux, calcium carbonate, magnesium carbonate or a mixture of the calcium carbonate and the magnesium carbonate, and the shell mainly comprises one of calcium oxide or magnesium oxide or a mixture of the calcium oxide and the magnesium oxide; and the compound sphere is prepared by material mixing, drying, and compound sphere preparation on sphere preparation equipment. The method has scientific formula and simple and reasonable process, can realize the quick refining dephosphorization of molten steel until the content of the phosphorus is lower than 0.0030 percent proven ...

Technique for manufacturing ultra-low phosphoretic steel with outside-stove refining dephosphorization of liquid steel

The invention relates to a method for controlling phosphorus in the production of ultra-low phosphorous steel by microalloy steel, high carbon steel and special steel, in particular to a process method for producing the ultra-low phosphorous steel by external refining dephosphorization of molten steel, which comprises the following steps of: 1) converter tapping: the temperature is between 1,550 and 1,660 DEG C, the content of the phosphorus is less than 0.02 percent, and the nondeoxidation and the slag-stopping treatment are adopted for tapping; 2) initial dephosphorization: dephosphorizing flux is added into a ladle with steel stream during the converter tapping, and the adding amount is between 5 and 20kg/t; 3) deep dephosphorization: the positions of a blanking tube and a descending tube are adjusted to ensure that the descending tube is positioned at the opposite side of the blanking tube, a ladle is transported to a RH station and is pumped into vacuum, compound spheres are added ...

Method for producing fine oxide dispersion steel

The invention relates to an external refining technology for steel making, in particular to a preparation method for fine oxide dispersion steel, which comprises the following steps that: i) a deoxidation product is removed, wherein, power, cored wires, compound pellets or compound spheres are fed into molten steel at an LF, RH, VD or CAS-OB station through a method of power spraying, wire feeding, pellet shooting, or direct feeding of the spheres after the molten steel is deoxidated; and ii) a dispersed oxide is generated, wherein, when the content of oxygen in the molten steel is between 0.0001 and 0.008 percent, a deoxidizing element among Ti, Zr, RE, Y, Al, Ca, Mg and Ba is added into the molten steel. The method is more effective and safer to the control of oxide inclusions in the molten steel, and can steadily and quickly perform the mass production of the fine oxide dispersion steel the oxide particle diameters of which are less than 1mu m, thereby extremely improving the quality ...

Technological process for removing fine occluded foreignsubstance in molten steel

The invention relates to an external refining technology of various micro-alloy steels and special steels, in particular to a technology for removing slag inclusions in molten steel. The technology of the invention comprises the steps as follows: a. the adjustment of an RH work position: the positions of a down pipe and a feed pipe of the RH are adjusted to ensure that the down pipe is positioned at the opposite side of the feed pipe; b. refining: after being transported to the RH work position, ladles are done with temperature measurement, sampling, vacuumizing, ingredient adjustment and clean circulation; c. input of compound spheres: after the refining, the compound spheres are put into the molten steel at the work position; d. continuous casting: after the compound spheres are put into the molten steel, the molten steel is then directly cast on a machine and the continuous casting adopts a whole-process protection casting. The technology of the invention can control the size and the ...

Powder preparation additive for outside-stove refining dephosphorization, removing fine foreign matter and its manufacturing method

The invention relates to an external refining method for microalloy steel and special steel, in particular to a powder additive for external refining desulphurization and fine inclusion removal and a preparation method thereof. The powder additive is the preferred powder additive for refining desulphurization and fine inclusion removal of various microalloy steel or special steel. The powder additive is prepared by mixing raw materials of low melting point premelting slag powder, calcium fluoride, calcium carbonate or magnesium carbonate or a mixture of the calcium carbonate and the magnesium carbonate, calcium oxide or magnesium oxide or a mixture of the calcium oxide and the magnesium oxide, and adhesive according to a formula. The method has scientific formula and simple and reasonable process, can effectively remove inclusions in molten steel, can realize the quick refining desulphurization of the molten steel until the content of sulfur is lower than 0.0030 percent proven by application ...

Long nozzle for pouring basket metallurgy and application thereof

The invention provides a long nozzle for pouring basket metallurgy and the application thereof; the long nozzle comprises a nozzle body, a through hole is arranged on the wall of an upper part of thenozzle and is connected with an external conveying pipe by a joint, and the axial direction of the through hole and the axial direction of the upper part of the nozzle form 10-90 degrees. The long nozzle can effectively control non-metallic inclusion in molten steel, accurately control and regulate the content of trace elements in molten steel and produce fine oxides to disperse steel; the long nozzle has simple structure and rational design, and has high efficiency on removing fine oxides and can slow down the blocking phenomenon of a pouring basket submersed nozzle; the long nozzle can control extra particle quantity , has high hit rate to trace alloy elements and uniform ingredients; by adopting the long nozzle, various beneficial additives are added in the steel, and the application isstrong ...

Manganese-based fluxing agent for converter steelmaking and preparation method thereof

The invention provides a manganese-based fluxing agent for converter steelmaking. The manganese-based fluxing agent comprises the following components of 60-75 percent of manganese oxide, 10-20 percent of calcium oxide, 5-10 percent of silicon dioxide, 3-5 percent of ferrous oxide and 3-5 percent of aluminum oxide, wherein the total manganese content accounts for 40-55 percent of the manganese oxide. The preparation method of the fluxing agent comprises the following steps: the manganese ore fines, the lime powder and the reducing agent are prepared according to the composition of the fluxing agent, the prepared materials are evenly mixed and then burnt with a continuous strand sinter machine, the thickness of the fabric is 300-500 mm in the burning process, the temperature is controlled between 1300 DEG C and 1500 DEG C, and then the materials are cooled, crushed and processed after burning. The manganese-based fluxing agent is favorable for environmental protection, has good continuous ...

Technological process for removing small inclusions in secondary refining

The invention relates to an external refining technology of various micro-alloy steels and special steels, in particular to a technology for removing slag inclusions in molten steel by the external refining technology. The technology of the invention comprises the steps as follows: a. molten steel is refined at LF, RH, VD or CAS-OB work position; b. a wire feeding technology is adopted to feed cored wires into the molten steel at the work positions; c. the molten steel is then directly cast on a machine after the wire feeding and the continuous casting adopts a whole-process protection casting. As the added cored wires have a scientific and reasonable prescription, when micro-air bubbles occur in the molten steel, the bubbles have high collision probability with the slag inclusions and fine slag drops have the function of wash heat and can also effectively remove the slag inclusions in the molten steel. The technology of the invention can control the size and the quantity of the non-metallic ...

Method for producing fine oxide dispersion steel

Technological process for removing fine occluded foreignsubstance in molten steel

The invention relates to an external refining technology of various micro-alloy steels and special steels, in particular to a technology for removing slag inclusions in molten steel. The technology of the invention comprises the steps: a. molten steel is refined at LF, RH, VD or CAS-OB work position; b. a powder spraying technology is adopted to spray powder into the molten steel at the work positions; c. the molten steel is then directly cast on a machine after the powder spraying and the continuous casting adopts a whole-process protection casting. As the added powder has a scientific and reasonable prescription, when micro-air bubbles occur in the molten steel, the bubbles have high collision probability with the slag inclusions and fine slag drops have the function of wash heat and can also effectively remove the slag inclusions in the molten steel. The technology of the invention can control the size and the quantity of the non-metallic inclusions in steel and the total oxygen amount ...

Additive for preparing fine oxide dispersion steel, preparation and use thereof

The invention relates to an external furnace refining technology for steelmaking, in particular to an additive for preparing fine oxide dispersion steel, a method for making the same and an application of the additive. The invention belongs to the metallurgical technology field. The additive is a composite sphere consisting of a sphere core and a shell; and the shell of the composite sphere mainly consists of one or two compounds of calcium oxide or magnesia, wherein, the sphere core consists of one material mainly comprising beneficial oxide and swelling agent or another material mainly comprising low-melting point pre-smelting slag powder and swelling agent. Through adopting wire feeding, powder spraying and pill shooting, or even a direct throwing mode, the additive is fed in LF, RH, VD or CAS-OB in order that the oxide class impurity is fine, dispersed and distributed in steel; the addition type is beneficial for application and can stably and rapidly produce fine oxide dispersion steel ...

Technological process for removing fine occluded foreignsubstance in molten steel

The invention relates to an external refining technology of various micro-alloy steels and special steels, in particular to a technology for removing slag inclusions in molten steel. The technology ofthe invention comprises the steps: a. molten steel is refined at LF, RH, VD or CAS-OB work position; b. a powder spraying technology is adopted to spray powder into the molten steel at the work positions; c. the molten steel is then directly cast on a machine after the powder spraying and the continuous casting adopts a whole-process protection casting. As the added powder has a scientific and reasonable prescription, when micro-air bubbles occur in the molten steel, the bubbles have high collision probability with the slag inclusions and fine slag drops have the function of wash heat and canalso effectively remove the slag inclusions in the molten steel. The technology of the invention can control the size and the quantity of the non-metallic inclusions in steel and the total oxygen amount ...

Technological process for removing small inclusions in secondary refining

The invention relates to an external refining technology of various micro-alloy steels and special steels, in particular to a technology for removing slag inclusions in molten steel by the external refining technology. The technology of the invention comprises the steps as follows: a. molten steel is refined at LF, RH, VD or CAS-OB work position; b. a wire feeding technology is adopted to feed cored wires into the molten steel at the work positions; c. the molten steel is then directly cast on a machine after the wire feeding and the continuous casting adopts a whole-process protection casting. As the added cored wires have a scientific and reasonable prescription, when micro-air bubbles occur in the molten steel, the bubbles have high collision probability with the slag inclusions and fine slag drops have the function of wash heat and can also effectively remove the slag inclusions in the molten steel. The technology of the invention can control the size and the quantity of the non-metallic ...

Technique for preparing fine oxide dispersion steel

The invention relates to an external refining technology for steel making, in particular to a process method for preparing fine oxide dispersion steel, which comprises the following steps that: i) a deoxidation product is removed, wherein, power, cored wires, compound pellets or compound spheres are fed into molten steel at an LF, RH, VD or CAS-OB station through a method of power spraying, wire feeding, pellet shooting, or direct feeding of the spheres after the molten steel is deoxidated; and ii) a dispersed oxide is generated, wherein, when the content of oxygen in the molten steel is between 0.0001 and 0.008 percent, the compound spheres, spherical cores of which are mainly beneficial oxides and expanding agents, are added into the molten steel during the refining process. The method is more effective and safer to the control of oxide inclusions in the molten steel, and can steadily and quickly perform the mass production of the fine oxide dispersion steel the oxide particle diameters ...

Composite deoxidant for smelting steel and its preparation

The composite deoxidant has the chemical composition of: Si 20-60 wt%, Al 2-15 wt%, Ba 5-25 wt%, Sr 4-15 wt%, Ca 3-10 wt% and Fe the rest. It is prepared through once reduction smelting process in ore-smelting furnce by using the raw materials including silica, barite, celestite,bauxite, limestone, iron filings and coke in a certain proportion. It has the advantages of low aluminum content, high desulfurizing effect and low melting point of deoxidized product.

Core cabling wire for outside-stove refining dephosphorization, removing fine foreign matter and its manufacturing method

The invention relates to an external refining method for various microalloy steel and special steel, in particular to a cored wire for external refining desulphurization and fine inclusion removal of molten steel and a preparation method thereof. A wire core of the cored wire is prepared by mixing raw materials of low melting point premelting slag powder, calcium fluoride, calcium carbonate or magnesium carbonate or a mixture of the calcium carbonate and the magnesium carbonate, calcium oxide or magnesium oxide or a mixture of the calcium oxide and the magnesium oxide, and adhesive according to a formula; a powder material of the wire core takes low carbon steel strip with 2 to 5mm as a sheath; and a monolayer steel lapping mode is adopted to prepare the cored wire on a wire making machine. The method has scientific formula and simple and reasonable process, can effectively remove inclusions in the molten steel, can realize the quick refining desulphurization of the molten steel until the ...

Continuous casting method for increasing equal thickness continuous casting plate billet equal axial crystal rate in non-oriented silicon steel

The present invention provides a continuous casting method capable of increasing non-oriented silicon steel medium-thickness continuous cast slab equiaxial crystal rate. It is characterized by that it adopts a medium-thickness slab continuous casting machine, in the continuous casting second cooling zone it adopts a roller electromagnetic stirring equipment. The casting billet size of continuous casting machine is 100-150mmX850-1550mm, pouring speed is 1.5-3.5m/min, the cooling pattern: the narrow edge of crystallizer is 14-25m3/h, the wide edge of crystallizer is 250-290m3/h and second cooling intensity is 1.3-1.8L/kg. The described electromagnetic stirring equipment includes 2-4 pairs of introroller built-in traveling wave magnetic field type electromagnetic stirring devices which are assembled into two groups and mounted.

Technique for manufacturing ultra-low phosphate steel by molten steel refining and dephosphorizing outside furnace

Long nozzle for pouring basket metallurgy and application thereof

The invention provides a long nozzle for pouring basket metallurgy and the application thereof; the long nozzle comprises a nozzle body, a through hole is arranged on the wall of an upper part of the nozzle and is connected with an external conveying pipe by a joint, and the axial direction of the through hole and the axial direction of the upper part of the nozzle form 10-90 degrees. The long nozzle can effectively control non-metallic inclusion in molten steel, accurately control and regulate the content of trace elements in molten steel and produce fine oxides to disperse steel; the long nozzle has simple structure and rational design, and has high efficiency on removing fine oxides and can slow down the blocking phenomenon of a pouring basket submersed nozzle; the long nozzle can control extra particle quantity , has high hit rate to trace alloy elements and uniform ingredients; by adopting the long nozzle, various beneficial additives are added in the steel, and the application is ...

Technique for desulfurization in refining process

The invention relates to an external refining process for various microalloy steel and special steel, in particular to a process method for desulphurization during the refining process, which is the preferred process method for the desulphurization during the refining processes of various microalloy steel or special steel. The process comprises the following steps of: a. deoxidation: molten steelis subjected to deoxidation treatment first to realize that alpha[O] is less than or equal to 0.0003 percent; b. the spraying of combined powder: the molten steel is refined at an LF, RH, VD or CAS-OB station, and a powder spraying process is adopted to spray the combined powder into the molten steel at the LF, RH, VD or CAS-OB station; and c. continuous casting: the continuous casting adopts thewhole-process protection casting. Proven by application, the process has strong desulphurization ability with a desulphurization rate between 60 and 90 percent, can realize the refining desulphurization ...

Production method of fine oxide dispersion steel

The invention provides a method for producing fine oxide dispersion steel, which is characterized in that: a through hole of which the axial direction and the axial direction of the upper part of a water gap have an angle of between 10 and 90 DEG is formed on the wall of the upper part of a long water gap for tundish metallurgy; the through hole is connected with a gas source through a joint connected with an external delivery pipe; and powder feed equipment blows beneficial oxide fine powder into molten steel through the external delivery pipe and the long water gap during continuous casting of steel, wherein the powder granularity is between 1nm and 500 mu m. Used carriers are inert gases Ar or N2, the gas flow is between 3 and 500 l/min, and the air pressure is between 1.0 and 12atm. By the technique, oxide inclusions in the molten steel can be effectively and completely controlled, and a great amount of fine oxide dispersion steel of which the oxide grain diameter is less than 2 mu ...

Core cabling wire for secondary refining dephosphorization to produce ultra-low phosphorus steel and preparation thereof

The invention relates to a process for controlling phosphor in producing an ultra-low phosphorus steel by a microalloy steel, a high carbon steel and a special steel, in particular to a cored wire for producing the ultra-low phosphorus steel by refining and dephosphorization outside a furnace and a preparation method thereof. A core part of the cored wire is prepared by adopting the raw materials of a dephosphorization fusing agent, calcium fluoride, calcium carbonate or magnesium carbonate or a mixture of the calcium carbonate and the magnesium carbonate, calcium oxide or magnesia or a mixture of the calcium oxide and the magnesia and a caking agent according to a formula at a mixture ratio; and a powdery material of the core part uses a low-carbon steel strip with a thickness of between 2 and 5 mm as a husk and adopts a monolayer steel related joint mode to prepare the cored wire on a wire manufacturing machine. The cored wire has a scientific formula and a simple and reasonable process ...

Continuous casting method for increasing equal thickness continuous casting plate billet equal axial crystal rate in non-oriented silicon steel

The present invention provides a continuous casting method capable of increasing non-oriented silicon steel medium-thickness continuous cast slab equiaxial crystal rate. It is characterized by that it adopts a medium-thickness slab continuous casting machine, in the continuous casting second cooling zone it adopts a roller electromagnetic stirring equipment. The casting billet size of continuous casting machine is 100-150mmX850-1550mm, pouring speed is 1.5-3.5m/min, the cooling pattern: the narrow edge of crystallizer is 14-25m3/h, the wide edge of crystallizer is 250-290m3/h and second cooling intensity is 1.3-1.8L/kg. The described electromagnetic stirring equipment includes 2-4 pairs of introroller built-in traveling wave magnetic field type electromagnetic stirring devices which are assembled into two groups and mounted.

Composite sphere for manufacturing ultra-low phosphoretic steel with outside-stove refining dephosphorization and its manufacturing method

The invention relates to a method for controlling phosphorus in the production of ultra-low phosphorous steel by microalloy steel and special steel, in particular to a compound sphere for producing the ultra-low phosphorous steel by external refining dephosphorization and a preparation method thereof. The compound sphere consists of a spherical core and a shell, wherein, the spherical core mainlycomprises dephosphorizing flux, calcium carbonate, magnesium carbonate or a mixture of the calcium carbonate and the magnesium carbonate, and the shell mainly comprises one of calcium oxide or magnesium oxide or a mixture of the calcium oxide and the magnesium oxide; and the compound sphere is prepared by material mixing, drying, and compound sphere preparation on sphere preparation equipment. The method has scientific formula and simple and reasonable process, can realize the quick refining dephosphorization of molten steel until the content of the phosphorus is lower than 0.0030 percent proven ...

Technological process for molten steel secondary refining dephosphorization to produce ultra-low phosphorus steel

The invention relates to a process for controlling phosphor in producing an ultra-low phosphorus steel by a microalloy steel, a high carbon steel and a special steel, in particular to a process method for producing the ultra-low phosphorus steel by refining and dephosphorization outside a molten steel furnace. The method comprises: (1) a step of tapping in a converter, during which, a tapping temperature is between 1550 and 1660 DEG C; a phosphor content is lower than 0.02 percent in tapping; and steel is tapped by adopting the treatment of non-deoxidization and slag stopping; (2) a step of primary dephosphorization, during which, a dephosphorization fusing agent is added into a steel ladle along the steel flow when the steel is tapped in the converter; and an adding amount of the dephosphorization fusing agent is between 5 and 20 kg/t; (3) a step of deep dephosphorization, during which, cored wire is fed to a steel liquid by adopting a wire feeding process; (4) a step of slag skimming: ...

Technique for outside-stove refining dephosphorization

The invention relates to an external refining process for various microalloy steel and special steel, in particular to a process method for external refining desulphurization, which is the preferred process method for desulphurization during the refining processes of various microalloy steel or special steel. The process comprises the following steps of: a. deoxidation: molten steel is firstly subjected to deoxidation treatment to realize that alpha[O] is less than or equal to 0.0003 percent; b. the adjustment of a RH station: the positions of a RH descending tube and a blanking tube are adjusted to ensure that the RH descending tube is positioned at the opposite side of the blanking tube; c. the adding of compound spheres: after a ladle is transported to the RH station, the compound spheres are added into the molten steel at the RH station after temperature measurement sampling, vacuum pumping, clean recycle and refining are finished; and d. continuous casting: the continuous casting adopts ...

Technological process for secondary refining desulphurization

The invention relates to an external refining technique used for various micro-alloyed steel and special steel, in particular to a technical method used for the external refining desulfurization, which is preferred in the refining desulfurization process of various micro-alloyed steel or the special steel. The technique comprises the following: a. a step of deoxidizing, in which the molten steel is deoxidized to realize that alpha [O] is less than or equal to 0.0003 percent; b. a step of feeding a core-spun yarn, in which the molten steel is refined at the position of LF, RH, VD or CAS-OB, the yarn feeding technique is adopted to feed the core-spun yarn into the molten steel at the positions; and c. a step of continuous casting, in which the continuous casting process is cast protectivelyin the whole process. The a technique shows that the technique has strong decarbolizing ability and the desulfurization degree between 60 and 90 percent by application, realizes that the molten steelis ...

Method of removing impurity from molten steel

The invention provides a method of removing impurity from molten steel and is characterized by: on the wall of tundish metallurgical long outlet upper potion, forming a through hole whose axial direction forms an angle of 10 to 90 DEG with the axial direction of outlet upper portion, connecting the through hole with gas source through a joint connected with an external conveyer pipe, during continuous casting, through the external conveyer pipe blowing into the long outlet with inert gas with a gas flow of 3 to 300 l/min and an air pressure of 1.0 to 10 atm; or through the external conveyer pipe and long outlet, using powder-sending equipment to blow into molten steel with carbonate powder or various synthesis slag powder with a granularity of 0.1 to 3 mm, the carriers being inert gas Ar or N2 with a gas flow of 3 to 400 l/min and an air pressure of 1.0 to 15 atm. The invention is advantageous by easy operation, low costs and high impurity removing efficiency; it is in favor of alleviating ...

Control method for accurately adding trace elements to steels

The invention provides a control method for accurately adding trace elements to steels. The control method is characterized in that the wall of the upper part of a long nozzle for pouring basket metallurgy is provided with a through hole with an axial direction at an angle of 10-90 degrees with the axial direction of the upper part of the long nozzle; the through hole is connected with a gas source through a connector connected with an external delivery pipe; powder delivery equipment jets various alloy powder materials, rare earth powder and various beneficial additives contained in the steels to liquid steel through the external delivery pipe and the long nozzle during continuous steel casting; powder granularity is 0.05-3mm; a used carrier is an inert gas Ar or N2; gas flow rate is 3-500L/minute; and gas pressure is 1.0-12atm. The invention can be used for outstandingly enhancing the stable and effective recovery rate of the trace elements in the steels; trace alloying elements have ...

Technique for preparing fine oxide dispersion steel

Lf furnace steel slag ball

Composite sphere for outside-stove refining dephosphorization, removing fine foreign matter and its manufacturing method

The invention relates to an external refining method for microalloy steel and special steel, in particular to a compound sphere for external refining desulphurization and fine inclusion removal and a preparation method thereof. The compound sphere is the preferred compound sphere for refining desulphurization and fine inclusion removal of various microalloy steel or special steel. The compound sphere consists of a spherical core and a shell, wherein, the spherical core mainly comprises low melting point premelting slag powder, calcium carbonate, magnesium carbonate or a mixture of the calcium carbonate and the magnesium carbonate; and the shell mainly comprises one of calcium oxide or magnesium oxide or a mixture of the calcium oxide and the magnesium oxide. The method has scientific formula and simple and reasonable process, can effectively remove inclusions in molten steel, can realize the quick refining desulphurization of the molten steel until the content of sulfur is lower than 0.0030 ...

Surface modified superfine powder and production method of surface modified superfine powder

The invention relates to surface modified superfine powder and a production method of the surface modified superfine powder. The surface modified superfine powder consists of one of ceramic, pre-melted slag and alloy material or mixture of two or three of the ceramic, the pre-melted slag and the alloy material, a surface modifier and a superfine powder surface modifier; and the superfine powder with the size of less than 5 microns is prepared by primary crushing of a crusher, airflow micro powder grinding, stirring of a high-speed stirring reaction kettle and surface modification. The selection of components is reasonable, and the raw materials have many categories, are easily obtained and have low price; and the proportion is scientific, the preparation method is reliable and feasible, and the finished powder has good surface physical and chemical properties and conveying property and good flowability and totally can meet the use requirements of tundish powder spraying metallurgy. The ...

Composite sphere for outside-stove refining desulfurization, removing fine foreign matter and its manufacturing method

Technological process for secondary refining desulphurization

The invention relates to an external refining technique used for various micro-alloyed steel and special steel, in particular to a technical method used for the external refining desulfurization, which is preferred in the refining desulfurization process of various micro-alloyed steel or the special steel. The technique comprises the following: a. a step of deoxidizing, in which the molten steel is deoxidized to realize that alpha [O] is less than or equal to 0.0003 percent; b. a step of feeding a core-spun yarn, in which the molten steel is refined at the position of LF, RH, VD or CAS-OB, the yarn feeding technique is adopted to feed the core-spun yarn into the molten steel at the positions; and c. a step of continuous casting, in which the continuous casting process is cast protectively in the whole process. The a technique shows that the technique has strong decarbolizing ability and the desulfurization degree between 60 and 90 percent by application, realizes that the molten steel is ...

Composite deoxidant for smelting steel and its prepn.

Technique for outside-stove refining dephosphorization

The invention relates to an external refining process for various microalloy steel and special steel, in particular to a process method for external refining desulphurization, which is the preferred process method for desulphurization during the refining processes of various microalloy steel or special steel. The process comprises the following steps of: a. deoxidation: molten steel is firstly subjected to deoxidation treatment to realize that alpha[O] is less than or equal to 0.0003 percent; b. the adjustment of a RH station: the positions of a RH descending tube and a blanking tube are adjusted to ensure that the RH descending tube is positioned at the opposite side of the blanking tube; c. the adding of compound spheres: after a ladle is transported to the RH station, the compound spheres are added into the molten steel at the RH station after temperature measurement sampling, vacuum pumping, clean recycle and refining are finished; and d. continuous casting: the continuous castingadopts ...

Technological process for removing fine occluded foreign substance in molten steel

Technique for controlling accurate addition of micro-element in steel

Additive for preparing fine oxide dispersion steel, preparation and use thereof

The invention relates to an external furnace refining technology for steelmaking, in particular to an additive for preparing fine oxide dispersion steel, a method for making the same and an application of the additive. The invention belongs to the metallurgical technology field. The additive consists of raw materials proportioned according to a formula; low-melting point pre-smelting slag powder, calcium fluoride, calcium carbonate, magnesium carbonate or a mixture of calcium carbonate and magnesium carbonate, calcium oxide, magnesia or a mixture of calcium oxide and magnesia and caking agent are respectively adopted and prepared to additives with various additive types of core-spun yarn, powder, a composite pellet and a composite sphere; through adopting wire feeding, powder spraying and pill shooting, or even a direct throwing mode, the additive is fed in LF, RH, VD or CAS-OB in order that the oxide class impurity is fine, dispersed and distributed in steel; and the addition type is beneficial ...