79 results about "Liquid steel" patented technology

The application provides a crystallizer protection slag for casting high-hydrogen-content medium-carbon steel liquid steel and application thereof, wherein the chemical composition of the crystallizer protection slag has the following mass percentages: SiO2: 25-32%, CaO: 29-36%, Al2O3: 1-4%, MgO: 3-6%, Na2O: 7-12%, F: 6-10%, C 总 : 3-6%, MnO: 2-4%, Li2O: 0.5-1%, and the rest is other inevitable impurities. The crystallizer protection slag can significantly reduce the occurrence rate of crystallizer sticking alarm emergency speed reduction and the occurrence rate of leakage during continuous casting when used for casting high-hydrogen-content medium-carbon steel liquid steel. Thus, the high-hydrogen-content medium-carbon steel liquid steel can be directly subjected to continuous casting without additional dehydrogenation treatment, the production efficiency is improved, and the production cost is solved.

Method for producing liquid steel in an electric arc furnace with final decarburization The invention relates to a method for producing liquid steel in an electric arc furnace (2) comprising successively: - melting a metal load in the electric arc furnace (2) for generating a steel bath (10); - denitrogenating the steel bath (10) to reach a nitrogen content %N below a targeted nitrogen content %Ntarg, wherein the carbon content %C remains greater than a targeted carbon content %Ntarg; - applying a final decarburization treatment to reach a carbon content %C ≤ %%Ntarg, to reach an oxygen content %Op greater than 200 ppm, wherein oxygen is injected at a flow rate above 0.3 Nm3 / min / ton, the ambient air being at a pressure of above 90% of the atmospheric pressure; - tapping the steel bath (10), the oxygen content %Op reached by the final decarburization treatment being maintained up to the tapping.

The invention relates to a method for producing liquid steel in an electric arc furnace (2) comprising successively: - defining a targeted nitrogen content wt. %Ntarg of the produced liquid steel, - introducing a metal load in the electric arc furnace (2) and - melting it for generating a steel bath (10) and a slag (12); - carburizing the steel bath (10) by adding a carbon amount equal to or greater than a minimum denitrogenation carbon amount CdeN said amount CdeN being defined as a function of the nitrogen content in excess to wt. %Ntarg at the beginning of the step (E4), - injecting a flow of oxygen to reach a nitrogen content wt. %N such that wt. %N ≤ wt. %Ntarg, - tapping the steel bath (10) to obtain the produced liquid steel.

This invention discloses a method for controlling surface weld scar defects in large square billets of high-carbon chromium bearing steel, belonging to the field of metallurgical technology. For GCr15 steel, the method for controlling surface weld scar defects includes the following steps: molten steel enters the crystallizer, forming a solidified billet shell, and leaves the crystallizer under the action of a straightening machine. In the secondary cooling chamber, the molten steel is cooled by water spray, gradually solidifying into a large square billet. The protective slag addition rate is controlled at 58-60 g / min, the large billet drawing speed is 0.9-1.1 m / min, and the crystallizer cooling water flow rate is 142-144 m³ / min. 3 The above controls various parameters during the continuous casting process of high-carbon chromium bearing steel GCr15, ultimately reducing the surface weld scar defect rate of large billets to less than 1%. Compared with existing control methods, this significantly reduces the weld scar defect on the surface of GCr15 steel.

The utility model belongs to the technical field of steel slag treatment, and particularly relates to a device for recovering metal from steel slag through reduction. The device for recovering metal through steel slag reduction comprises a reaction tank and a vibration generating device, liquid steel slag to be subjected to reduction reaction is contained in the reaction tank, the reaction tank is arranged on the vibration generating device, and the vibration generating device drives the reaction tank to vibrate. According to the utility model, the reaction tank is arranged on the vibration generation device, so that fine iron powder obtained by a reduction reaction can be gathered into iron particles by adopting vibration treatment after the reduction reaction of liquid steel slag, and the larger the particles are, the lower the oxidation degree is, so that the reduction effect is guaranteed; the problem that the recovery rate is reduced due to the fact that metal iron is oxidized again in the follow-up treatment process is solved.

The application discloses a preparation method of a medium-high carbon steel hot-rolled coil and the medium-high carbon steel. The preparation method of the medium-high carbon steel hot-rolled coil comprises the following steps: slab continuous casting: medium-high carbon steel liquid steel is cast and drawn to obtain a slab, and a pre-descaling treatment is performed on the slab to reduce oxides on the surface of the slab, thereby obtaining a pretreated slab; slab heating: the pretreated slab is subjected to a heating treatment, and after the heating treatment, a high-pressure water descaling treatment is performed, thereby obtaining a to-be-processed slab; rolling: the to-be-processed slab is rolled to obtain a strip steel. According to the embodiment of the application, the slab after the slab continuous casting is subjected to the pre-descaling treatment before the slab is heated in a furnace, and after the heating treatment, the high-pressure water descaling treatment is performed before rolling, thereby removing the initial thick iron oxide scale on the surface of the slab and ensuring that the uniformity of the iron oxide scale formed on the surface of the slab during hot rolling is good.

This invention relates to a method for producing support roll steel, belonging to the field of metallurgical industry, and solves the problems of high cost and severe shrinkage porosity in existing support roll steel. The method for producing support roll steel includes: smelting, deoxidizing, desulfurizing, and refining the support roll steel ingot raw material, adjusting the alloy composition to obtain a first portion of support roll steel molten steel, tapping the steel, vacuum casting, and solidifying to obtain a solidified billet shell and liquid steel inside the billet shell; smelting, deoxidizing, desulfurizing, and refining the support roll steel ingot raw material, adjusting the alloy composition to obtain a second portion of support roll steel molten steel, tapping the steel, mixing the second portion of support roll steel molten steel with the liquid steel inside the billet shell within the solidified billet shell of the first portion of support roll steel, vacuum casting, solidifying to obtain a complete support roll steel ingot, demolding, removing the sprue, forging, removing the riser, heat treating, and machining to obtain the support roll steel; the composition of the first portion of support roll steel and the second portion of support roll steel molten steel differs.

The invention relates to a method for RH magnesium treatment of molten steel, which comprises the following steps: smelting initial molten steel through RH to obtain intermediate molten steel; magnesium alloy is added into the intermediate molten steel under the RH vacuum condition for magnesium treatment, and magnesium-treated molten steel is obtained; continuously casting the magnesium-treated molten steel to obtain a steel billet; feO + MnO in the steel ladle top slag above the initial molten steel is less than or equal to 4% by mass; the content of acid-soluble aluminum Als in the intermediate molten steel is 0.02%-Alb1, and the Alb1 is the upper limit value of the aluminum content of the intermediate molten steel before magnesium treatment. The adding position of the magnesium alloy is limited in the upper area of the RH descending pipe, so that the magnesium alloy enters the deep position of a steel ladle along with descending initial molten steel flow, and the acting time of the alloy and intermediate molten steel is prolonged. Magnesium steam is inhibited and an alloy structure is protected by utilizing a vacuum environment, and nodulizing and dispersion of inclusions can be realized only by adding a small amount of the alloy. According to the method, secondary oxidation of the magnesium treatment molten steel is effectively inhibited, the cleanliness is improved, the continuous casting nozzle nodulation risk is eliminated, and stable continuous casting operation is guaranteed.

The utility model discloses a device for synchronously controlling a withdrawal and straightening machine and a dummy bar of a continuous casting machine. The device comprises a potentiometer, a PLC (Programmable Logic Controller) control system, a signal isolation module, a withdrawal and straightening machine frequency converter, a dummy bar frequency converter and a digital display instrument. The potentiometer is connected to an analog quantity input port of the PLC control system through the one-input one-output optoelectronic isolator and is used for inputting an initial control signal; the output end of the PLC control system is connected with the withdrawal and straightening machine frequency converter and the dummy bar frequency converter to drive the two frequency converters to operate. A feedback signal of the withdrawal and straightening machine frequency converter is divided into two paths to be transmitted to the PLC control system and the withdrawal and straightening machine digital display instrument through the one-input two-output isolator, and a feedback signal of the dummy bar frequency converter is directly accessed to the dummy bar digital display instrument. The device eliminates electromagnetic interference through a photoelectric isolation module, integrates a water distribution model and a molten steel temperature data interface, adopts a standardized interface design for hardware, is adaptive to different continuous casting machine models, has the characteristics of strong anti-interference capability, stable signal transmission and visual real-time monitoring, and effectively improves the operation reliability of equipment.

The invention relates to a metal mold extrusion imbedding method, which is specially used for an imbedding casting which cannot be used for imbedding a large-proportion insert in gravity casting, and comprises the following steps of: fixing all inserts on an insert assembly which is made of a thin steel plate, can be put into a metal mold, has a casting appearance, is provided with an opening at the upper end and is used for isolating molten steel from directly contacting with the metal mold; the method comprises the following steps: putting an insert assembly into a furnace, heating to 600-1000 DEG C, putting into a metal mold, closing and locking the mold, quantitatively pouring molten steel at an upper end opening, starting a press, carrying out closed extrusion on the molten steel by an upper mold, enabling the molten steel to enter a small space between inserts, and wetting the surfaces of the inserts at a certain temperature under pressure to form metallurgical bonding.

The application provides a chemical vapor deposition polycrystalline diamond steel liquid erosion polishing method and relates to the technical field of diamond material processing. The chemical vapor deposition polycrystalline diamond steel liquid erosion polishing method places steel material with a carbon content of 0-0.77% and a weight of 0.1-5 kg in a ceramic crucible, uses inductive coupling to heat the steel material to 1400-1800 DEG C and controls the liquid surface to be stable, uses a motion controller with a moving control precision of not more than 0.02 mm to immerse the sample in the steel liquid for 0.1 s-10 min and then take out the sample, and carbon atoms constituting the sample are dissolved and diffused into the steel liquid under the action of the steel liquid erosion, so that the sample surface is rapidly flattened. The method has the advantages that a new way is provided for realizing high-speed, high-yield and high-throughput polishing processing of chemical vapor deposition polycrystalline diamond.

The invention relates to a method for producing liquid steel in an electric arc furnace (2) comprising successively: - defining a targeted nitrogen content wt. %Ntarg of the produced liquid steel, - introducing a metal load in the electric arc furnace (2) and - melting it for generating a steel bath (10) and a slag (12); - carburizing the steel bath (10) by adding a carbon amount equal to or greater than a minimum denitrogenation carbon amount CdeN, said amount CdeN being defined as a function of the nitrogen content in excess to wt. %Ntarg at the beginning of the step (E4), - injecting a flow of oxygen to reach a nitrogen content wt. %N such that wt. %N ≤ wt. %Ntarg, - tapping the steel bath (10) to obtain the produced liquid steel.

Method of producing steel using an Electrical Arc Furnace (EAF), the method comprising: (a) melting a metal load (L) in the EAF and generating liquid steel (LS); (c) tapping the liquid steel (LS) from the EAF; and (d) performing secondary metallurgy on the liquid steel (LS) in at least one secondary metallurgy reactor to adjust the chemical composition of the liquid steel (LS), wherein the method comprises adding a first slag compound (SC1) with nitrogen affinity in the liquid steel (LS) during tapping of the liquid steel (LS) from the EAF and creating a ladle slag (S2).

The utility model relates to the technical field of tundish flow control, in particular to a magnesium flow stabilizer for a tundish, which comprises a hollow magnesium body, the top of the magnesium body is provided with an opening, the inner bottom of the magnesium body is provided with a corundum drainage body coaxial with the magnesium body, and the corundum drainage body is provided with a circular top surface; wherein the inner bottom surface of the magnesian body is an arc-shaped surface which is in smooth transition with the inner wall surface of the magnesian body and the outer wall surface of the corundum drainage body; by means of the smooth arc transition design of the inner bottom face of the magnesium body and the outer wall face of the corundum drainage body, turbulence and local scouring during flowing of molten steel are effectively reduced, the high hardness characteristic of the corundum drainage body is combined, erosion to the magnesium body is remarkably reduced, and the service life is prolonged. The inner wall face of the magnesium body is designed to be a conical face, the flow speed of molten steel is guided to be evenly distributed, and local scouring aggravation caused by sudden change of the flow speed is avoided.

Method for producing liquid steel in an electric arc furnace with final decarburization The invention relates to a method for producing liquid steel in an electric arc furnace (2) comprising successively: - melting a metal load in the electric arc furnace (2) for generating a steel bath (10); - denitrogenating the steel bath (10) to reach a nitrogen content %N below a targeted nitrogen content %Ntarg, wherein the carbon content %C remains greater than a targeted carbon content %Ctarg; - applying a final decarburization treatment to reach a carbon content %C ≤ %Ctarg, to reach an oxygen content %Op greater than 200 ppm, wherein oxygen is injected at a flow rate above 0.3 Nm3 / min / ton, the ambient air being at a pressure of above 90% of the atmospheric pressure; - tapping the steel bath (10), the oxygen content %Op reached by the final decarburization treatment being maintained up to the tapping.

The application discloses a kind of continuous casting tundish residual steel height on-line detection and automatic control method, comprising the following steps: setting liquidus temperature measuring point in tundish;Casting operation starts, liquid steel enters tundish;Temperature measured by temperature measuring instrument continues to rise and is higher than 1450 DEG C, start into continuous casting state;Temperature measured by temperature measuring instrument is maintained at 1500-1550 DEG C, continuous casting state continues to carry out;Temperature measured by temperature measuring instrument drops and is lower than 1500 DEG C, start to detect temperature drop rate;Temperature drop rate measured by temperature measuring instrument reaches per minute cooling more than 12.5 DEG C, judge tundish residual steel as low liquid level state;Record current tundish tonnage data;Close tundish outlet, end casting operation.The application solves the security risk when manual operation, prevents abnormal accident from happening due to manual judgment, effectively controls production logistics stability and safety, solves production safety and the effect of controlling continuous casting production quality problem.

The application discloses a method for producing low-oxygen-content molten steel by adopting an EF+LFV process, wherein 20-30% of weight of slagging materials of smelting raw materials is added with carbon-increasing materials, so that the carbon content of the smelting raw materials reaches 1.20-1.50% of the weight of the smelting raw materials, the oxidation end point temperature is controlled to be greater than or equal to 1630 DEG C, and the carbon content at the oxidation end point is not less than the lower limit of the carbon content required by the smelted steel minus 0.05%; Si-Mn alloy, Si-Fe alloy and carbon-increasing agent are sequentially added into a refining ladle when tapping; and the molten steel is slagged and wire-feeding deoxidized during the refining period; and the molten steel produced by adopting the method has an oxygen content of less than or equal to 20 ppm, so that the purity of the molten steel is ensured to be high, and the production requirements are met.

The invention discloses a flow control valve suitable for ultrahigh-temperature molten steel, which belongs to the field of ultrahigh-temperature valves and comprises a main valve body, a graphite lining, a lining fixing cover plate, an upper plate cover, a lower plate cover and a fireproof valve plate. The graphite lining layer, the ceramic heat insulation layer and the hollow convection layer are designed in the whole valve to achieve gradient heat regulation and control, heat dissipation of the valve body and electrical elements is effectively achieved (the valve body is made of 310S stainless steel, and the heat resistance limit is 1200 DEG C), the internal temperature is kept constant (the temperature of the inner wall of the graphite lining is larger than 1600 DEG C), and molten steel condensation is avoided. The inclined fire-resistant valve plate is adopted as a core adjusting element and is matched with the graphite lining, so that adhesion of molten steel on the plate surface can be reduced in the process of adjusting the flow of the molten steel, and the service life is prolonged.

This invention discloses a method and system for online reconstruction of mineral phases in high-temperature steel slag, belonging to the field of steel slag resource utilization technology. The method involves crushing coal gangue and room-temperature steel slag to a particle size of 0.5 to 3 mm, mixing them at a mass ratio of 1:0.5 to 1.5 to prepare a reconstruction adjuster, and then adding the reconstruction adjuster and high-temperature liquid steel slag (temperature above 1350℃) to a mixing furnace at a mass ratio of 0.1 to 0.5:1. After settling, the mineral phase reconstruction is completed, converting free calcium oxide into dicalcium silicate and tricalcium silicate, magnesium oxide, ferrous oxide, and manganese oxide into the RO phase, and ferric oxide into ferrous oxide and elemental iron. The mixture after the reaction is cooled to below 500℃, then crushed, magnetically separated, and ground to a specific surface area of ​​400 square meters per kilogram to obtain a cementitious material. This invention utilizes the sensible heat of the high-temperature steel slag itself, eliminating the need for additional heating, achieving high-value utilization of solid waste. The prepared cementitious material exhibits high hydration activity and good volume stability. The process is simple and easy to implement, contributing to the metallurgical industry's achievement of dual-carbon goals.

The invention relates to an integrated iron-making and steelmaking site with a reduced carbon footprint and improved circularity of the natural resources and to a process for producing iron and steel with a reduced carbon footprint and improved circularity of the natural resources.

The present application belongs to the technical field of continuous casting hollow steel and non-ferrous pipe blank, and particularly relates to a direct production of hollow pipe blank near-end type continuous casting system, method and application. The continuous casting system comprises a ladle, a long nozzle, a tundish, a separation ring, a crystallizer, a fan-shaped section, a fan-shaped section driving device, a secondary cooling water nozzle, a casting blank cutting device and a blank discharging equipment. The liquid steel in the tundish passes through a crystallizer with an angle θ with the horizontal plane and forms a certain thickness of primary solidification shell on the surface, and is then pulled out by the fan-shaped section clamping roller obliquely upward. Since the liquid steel of the tundish, the crystallizer and the fan-shaped section are in communication with each other, the liquid steel level does not rise with the rising of the pipe blank. When the height of the pipe blank pulled out obliquely upward is higher than the liquid steel level, only the hollow blank shell with a certain thickness, i.e. the hollow pipe blank, is left in the pipe blank. The hollow pipe blank produced by the present application can be directly applied to actual needs, and can also be used as a raw material for seamless steel pipe rolling production.

An immersion nozzle (1) through which liquid steel can be poured from a tundish into a mould, the nozzle comprising: a substantially tubular tubular body (2) extending from a first end (3) to a second end (4); a channel (5) extending through the tubular body (2) along a longitudinal axis (A) from the first end (3) towards the second end (4); at least one inlet port (6) opening into the channel (5) at the first end (3); a plurality of outlet ports (8) opening into the channel (5) in a region (7) adjacent the second end (4); and at least one rotatable insert (10); wherein the immersion nozzle (1) has at least one rotatable insert (10) and is configured such that a flow of molten metal entering the immersion nozzle (1) at the at least one inlet port (6) flows through the channel (5) and around the rotatable insert (10), and exits the immersion into nozzle (1) via the plurality of outlet ports (8), such that rotation of the rotatable insert (10) is driven by the flow of molten metal.

The application belongs to the technical field of continuous casting of steel, and particularly relates to a continuous casting method for improving center segregation of high-carbon steel small billets. The continuous casting method for improving center segregation of high-carbon steel small billets with a size of 160mm*160mm comprises the following steps: after refining, high-carbon steel liquid steel enters a tundish, the superheat degree is controlled to be 17-25 DEG C, and a crystallizer electromagnetic stirring is adopted; the two-cool water control adopts a strategy of separate control of inner and outer arc surfaces and two side surfaces, and the inner and outer arc surface ratio water quantity / two side surface ratio water quantity control range is 2.5-3.5; a dynamic soft reduction process is adopted at the solidification end of the cast billet, the reduction is carried out within a solid phase rate range of 0.2-0.6, and the reduction amount is 10-15mm; and the high-carbon steel is produced according to the continuous casting method, and the cast billet center segregation index is reduced from 1.18 to 1.05 and below.

The present application relates to a kind of GH4093 high-temperature alloy forgings and its manufacturing method, belong to metal processing technical field.The manufacturing method includes the following steps: vacuum induction smelting, using Ni-B alloy optimization refining process, improve the purity of liquid steel and composition uniformity;Vacuum consumable melting, further purify metal, improve crystalline structure, reduce segregation;Forging breakdown, after upsetting, drawing and multiple back furnace heating, prepare high-quality blank;Forging into material, adopt optimized process and forge out the size head structure forging blank;Heat treatment, by solid solution and aging treatment, significantly improve grain structure and mechanical properties.The chemical composition of the obtained forging includes: C:0.05%-0.08%, Cr:18.0%-21.0%, Co:15.0%-21.0%, Al:1.0%-2.0%, Ti:2.0%-3.0%, B:≤0.02%, the balance is Ni and impurities.The manufacturing method of the present application is advanced, and the quality of product is stable, significantly improves the comprehensive performance and size precision of the prepared forging, meets the demand of high-end field such as aviation, nuclear energy and other complex structure high-temperature alloy forgings.

The utility model discloses a high-temperature molten steel sampler, which belongs to the technical field of molten steel sampling, and is characterized in that gas can be smoothly discharged through an air hole plug, and molten steel cannot pass through the air hole plug due to higher viscosity, so that the forming quality of a sample is ensured, and air holes or defects in the sample are avoided. The high-temperature molten steel sampler comprises a refractory mortar sampler body, a first sampling cavity is formed in the refractory mortar sampler body, a second sampling cavity is formed in one end of the first sampling cavity, an air hole is horizontally formed in the refractory mortar sampler body, and an exhaust hole is formed in the end, away from the second sampling cavity, of the air hole and extends out of the refractory mortar sampler body. A second molten steel inlet chamber is formed in the end, away from the second sampling cavity, of the refractory mortar sampler, a sealing steel sheet is embedded in the second molten steel inlet chamber, a bottom steel sheet is installed at the end, away from the second sampling cavity, of the refractory mortar sampler, and a first molten steel inlet chamber is arranged between the bottom steel sheet and the sealing steel sheet.

The application relates to a continuous casting process for improving the quality of ultra-high-carbon-steel casting billets and belongs to the technical field of metallurgy. The continuous casting process is as follows: liquid ultra-high-carbon-steel liquid steel is poured from a ladle into a tundish through a long nozzle, then poured into a crystallizer through a submerged nozzle, the liquid steel is cooled and solidified in the crystallizer to form a billet shell with uniform thickness and a liquid core, the billet shell is completely solidified in a secondary cooling chamber and is bent and straightened, the continuous casting is carried out, the casting machine is finally pulled out, and a flame cutting machine is used to cut the casting billets into required sizes, and the casting billets are loaded into a hot-rolling heating furnace after cooling control. The obtained casting billets are free of surface cracks, the center segregation is less than or equal to C1.0, and the center porosity is less than or equal to 1.0.

The application relates to a liquid steel slag interface sampling device and belongs to the technical field of molten steel detection. The device comprises a sampler main body in a tubular structure with open ends and used for collecting a molten steel sample, a balloon and a ball in the balloon, the balloon is connected with the side surface of the sampler main body, and the ball is fixed in the balloon through fusible material to realize entering the sampler main body and plugging the opening under a high-temperature environment. When the device is used for sampling, the fusible material in the balloon fails due to the high temperature of the molten steel, the ball quickly enters the inside of the sampler to plug the opening, the molten steel and the steel slag are simultaneously taken out under the molten state, and the taken-out sample can be further treated and analyzed. The device is simple in structure, can be mass-produced, is convenient to use, can quickly and simultaneously obtain the molten steel and the molten steel slag, and is convenient for subsequent analysis.

The invention belongs to the technical field of double-roller cast rolling, and relates to a method for improving the surface quality of a rolled strip. By means of the method, when the surface quality of the rolled belt goes wrong, online working roller replacement can be achieved. According to the method disclosed by the invention, the replacement of the working roll comprises the steps of synchronously lifting the tundish and the transition ladle, and conveying the drainage groove to the lower part of the distributed liquid outlet hole of the transition ladle through the slide rail or the guide rail so as to carry out molten steel drainage. And at the moment, under the condition that the ladle big ladle sliding plate and the tundish sliding plate are not closed and the transition ladle is not cut off, replacement of the working roller with the surface quality problem can be completed, and the surface quality of the rolled strip is improved. And after replacement, the tundish and transition ladle system is recovered to the casting working position for continuous casting, and normal rolling production is recovered in a shorter time. According to the method, the problems of low production efficiency and high cost caused by pouring stopping are solved, the production continuity is improved, and the overall production cost of double-roller cast rolling is reduced.