477 results about "Refining (metallurgy)" patented technology

The invention belongs to the field of vanadium metallurgy, and particularly relates to a method for preparing metal vanadium through aluminothermy in cooperation with molten salt electrolysis so as to solve the problem that in the prior art, the production cost of the metal vanadium is high due to the fact that high-temperature and high-vacuum refining is used for removing impurity aluminum. The method comprises the following steps: uniformly mixing a vanadium-containing raw material, metal aluminum and an additive according to a weight ratio of 100: (25-35): (4-8), igniting to carry out aluminothermic reduction reaction, and removing upper smelting slag after a reaction product is cooled to obtain primary metal vanadium; and the primary metal vanadium is subjected to molten salt electrolytic refining in the protective gas atmosphere, and refined metal vanadium is obtained. According to the method, high-temperature or high-vacuum refining is not needed, the high-purity metal vanadium can be prepared only through the two-step operation of aluminothermic reduction and molten salt electrolysis, and compared with an existing vanadium preparation process adopting high-temperature and high-vacuum refining, the energy consumption and the production cost are remarkably reduced.

The invention provides a refining method for increasing nitrogen in the vacuum process of a VD vacuum furnace, and relates to the technical field of ferrous metallurgy, the refining method comprises the following steps: S1, refining molten steel in an LF steel ladle by adopting nitrogen as bottom blowing gas; and S2, the molten steel obtained after LF ladle refining is placed in a VD vacuum furnace, nitrogen serves as bottom blowing gas, the nitrogen flow and the vacuum degree are adjusted in a multi-stage mode, and the nitrogen increasing operation is completed. A multi-stage adjustment mode is adopted, and the nitrogen content in the molten steel is controlled by controlling the nitrogen flow, the vacuum degree and the retention time.

The invention discloses a method for recovering metal from high-nickel copper fire refining slag and application of the method, and relates to the technical field of metal metallurgy. Comprising the following steps: carrying out weak acid arsenic leaching on the copper fire refining slag to obtain arsenic-removed leaching slag and arsenic-containing copper liquid; copper removal is carried out on the arsenic-containing copper liquid to obtain a copper-containing material and copper-removed liquid, and arsenic precipitation is carried out on the copper-removed liquid; the arsenic-removed leaching residues are subjected to oxidation copper leaching to obtain copper leaching residues and a copper sulfate solution, and the copper leaching residues are subjected to reduction vulcanization smelting to obtain nickel matte, tin-antimony smoke dust and smelting residues. According to the method, the cost of separation of copper and arsenic in the raw materials can be reduced, the problem of furnace caking caused in the reduction smelting process is avoided, the obtained copper sulfate solution serves as electrolyte replenishing liquid to be applied to the copper electrolysis process, and the influence on the self-purification process of electrolyte is small. According to the method, nickel and copper are enriched in matte nickel through reduction vulcanization smelting, then copper-nickel separation is conducted through the post-treatment process, the post-treatment process is shorter, nickel recovery is achieved while copper recovery is guaranteed, and better economic benefits are achieved.

The invention relates to the technical field of chemical metallurgy, and discloses a preparation and purification method of high-purity sponge vanadium, which comprises the following steps: preparing a vertical vacuum reduction furnace, adding a reducing agent, discharging air in the furnace, and introducing shielding gas; heating, adding vanadium chloride for smelting, taking out, putting into a distillation furnace, and carrying out heating and heat preservation treatment; and finally, putting the product into a crucible in an electron beam furnace, vacuumizing, heating and smelting, introducing protective gas into the electron beam furnace after smelting, and cooling to room temperature to obtain a sponge vanadium product. The high-purity sponge vanadium is prepared by adopting a novel vanadium chloride metal thermal reduction-distillation method, and the sponge vanadium is further purified through vacuum electron beam refining, so that the common technical problems of long flow, low product purity and the like of a traditional method for preparing the high-purity metal vanadium are solved.

The invention relates to the technical field of ferrous metallurgy, in particular to a production and manufacturing method of a low-cost high-elongation 600MPa-grade steel plate, which is characterized in that raw materials comprise the following chemical components in percentage by weight: 0.111 to 0.173 percent of C, 0.13 to 0.43 percent of Si, 1.325 to 1.565 percent of Mn, less than or equal to 0.018 percent of P, less than or equal to 0.008 percent of S, 0.020 to 0.060 percent of Alt, 0.0225 to 0.0435 percent of Nb, less than or equal to 0.0070 percent of N and the balance of Fe; the manufacturing method comprises the following steps of top-bottom combined blown converter, LF refining, VD vacuum refining, slab continuous casting, two-stage controlled rolling and subsection cooling.

The present application relates to the technical field of metallurgy, and particularly relates to a production method of a large-wall-thickness pipeline steel with improved carbon dioxide corrosion resistance and strength and toughness, and specific measures include: (1) controlling the bottom blowing mode and end point requirement in the converter process; (2) controlling the tapping time and replacing the tapping hole opportunity in the tapping process; (3) feeding the CAS aluminum wire and controlling the CAS argon blowing time; (4) controlling the top slag addition amount, heating time and outgoing mode in the LF refining process; (5) controlling the wire feeding parameters, soft blowing time and outgoing requirement of RH in the RH refining process; (6) controlling the precision requirement, casting speed fluctuation and crystallizer liquid level fluctuation of the continuous casting equipment in the continuous casting process to obtain the casting blank. Through controlling the parameters of each process in the smelting and rolling process, the present application realizes the whole-process steel cleanliness control and ladle grain refinement, and further improves the strength, low-temperature toughness, HIC resistance and carbon dioxide corrosion resistance of the large-wall-thickness pipeline steel.

The invention belongs to the technical field of metallurgy, and particularly relates to ultrapure 316L stainless steel and a vacuum induction melting preparation method thereof. The preparation method comprises the following steps: firstly preparing NiCa intermediate alloy through vacuum induction melting, then preparing 316L alloy through vacuum induction melting, firstly adding Al for deoxidation, then adding the refined NiCa intermediate alloy for high-temperature refining for Al removal, and finally performing low-temperature refining for Ca removal and further deep deoxidation and desulfurization. According to the method, various impurity elements such as Al, O and S and inclusions of the ultra-pure 316L stainless steel can be removed only through a vacuum induction melting method, extra technological processes such as electroslag or self consumption are not needed, equipment investment is simple and convenient, large-scale industrial application can be achieved easily, and an effective way is provided for purification preparation of the ultra-pure 316L stainless steel.

The invention relates to the technical field of metallurgy, in particular to a production method for reducing casting blank cracks, which comprises the following procedures: (1) pre-desulfurizing molten iron; (2) smelting in a converter; (3) LF refining; (4) RH refining; (5) slab continuous casting; and (6) hot charging and rolling. By optimizing the chemical components and the mass percentage of the continuous casting billet and regulating and controlling the technological parameters of multiple procedures such as converter smelting, LF refining, RH refining, slab continuous casting and hot charging rolling, the austenite grain size in the microstructure of the surface layer of the continuous casting billet is refined, the high-temperature plasticity of the continuous casting billet is improved, and cracks on the surface of the continuous casting billet are reduced.

The invention provides a method for removing trace impurity elements from high-purity rubidium salt, which belongs to the technical field of metallurgy and comprises the following steps: dissolving the high-purity rubidium salt with deionized water to obtain a high-purity rubidium salt solution; adding a precipitator into the high-purity rubidium salt solution to carry out selective precipitation reaction of rubidium to obtain a rubidium-containing precipitation product, and preliminarily removing impurity elements such as sodium, potassium and cesium; the rubidium-containing precipitation product is filtered and then subjected to roasting treatment, the rubidium-containing precipitation product is subjected to a decomposition reaction, and a roasted product is obtained; an acidic transformation agent is added into the roasted product for a transformation reaction, and a rubidium salt solution is obtained; impurity elements such as sodium, potassium and cesium in the product are further removed through a recrystallization refining method, and the rubidium salt product with the purity reaching 99.9% or above is obtained. The method can effectively remove trace impurity elements in the high-purity rubidium salt, and has the advantages of short flow, few procedures and high product purity.

The invention discloses a method for cascade recovery of tellurium from a complex tellurium-containing material. The method comprises the steps of acid pickling, reduction neutralization, pyrogenic transformation, leaching and neutralization. According to the method, through cooperative treatment of a wet process and a pyrogenic process, the problem of slag phase wrapping is effectively solved, and tellurium with different valence states in a complex tellurium-containing material is converted into high-quality tellurium neutralization slag in a gradient mode. The selenium removal rate is not lower than 95%, the tellurium recovery rate reaches up to 90% or above, efficient separation of selenium and tellurium is achieved, and the produced tellurium dioxide neutralization slag can be used for further purification and refining.

The invention discloses a smelting process for regulating and controlling C-class and D-class inclusions of heavy rail steel through magnesium treatment, and belongs to the technical field of ferrous metallurgy. Smelting is carried out according to given components and a production process, the smelting process comprises the steps of converter smelting, LF refining, VD vacuum treatment, magnesium treatment and continuous casting, and the generation type and distribution of inclusions in the heavy rail steel are accurately regulated and controlled mainly by adding a proper amount of magnesium-containing cored wires in the last stage of smelting. Most inclusions in the heavy rail steel exist in the form of fine dispersed calcium-silicon-magnesium-aluminum-oxygen composite inclusions. According to the smelting process, large-size C-class and D-class inclusions with the size larger than 10 micrometers can be eliminated, intragranular acicular ferrite can be induced to be formed in the solidification process, grains are refined, the performance is improved, and the performance and quality of the heavy rail steel are improved.

The invention relates to the technical field of ferrous metallurgy, in particular to a smelting method for silicon deoxidation of low-carbon low-silicon aluminum killed steel. The method comprises a converter, an alloy fine adjustment station, RH refining and continuous casting. A strong bottom blowing mode is adopted in the later stage of converter blowing, and high-carbon ferromanganese, a ferrosilicon deoxidizing agent and lime are sequentially added during tapping; and after temperature measurement and sampling in the alloy fine tuning station, the steel ladle is transported to RH refining. And the RH executes different treatment modes according to Si and C components of the alloy fine tuning station, such as oxygen blowing decarburization and desilicication, direct aluminum particle addition alloying or vacuum reserved oxygen decarburization and the like. Through cooperation of silicon pre-deoxidation and aluminum final deoxidation, the oxygen content of RH entering molten steel and consumption of an aluminum deoxidizing agent are reduced, and the cleanliness of the molten steel is improved; different treatment modes shorten the treatment period, reduce the final temperature of the converter, meet the low-carbon and low-silicon requirements, reduce the production cost and improve the production efficiency.

The invention belongs to the field of ferrous metallurgy, and relates to a rare earth microalloyed plateau weather-resistant high-performance structural steel plate and a preparation method thereof. The steel comprises the following components in percentage by weight: 0.03%-0.05% of C, 0.15%-0.25% of Si, 1.30%-1.60% of Mn, less than or equal to 0.013% of P, less than or equal to 0.005% of S, 0.020%-0.045% of Nb, 0.006%-0.020% of Ti, 0.5%-1.0% of Ni, 0.15%-0.20% of Cr, 0.10%-0.30% of Cu, 0.001%-0.003% of Zr, 0.001%-0.010% of RE and the balance of Fe and inevitable impurities. The preparation method comprises the steps of molten steel converter smelting, RH and LF refining, continuous casting, casting blank heating, rolling and the like. According to the high-performance structural steel plate, ReH is larger than or equal to 420 MPa, Rm is larger than or equal to 525 MPa, the ductility is larger than or equal to 30%, the yield ratio is smaller than or equal to 0.80, the longitudinal impact energy at the temperature of-60 DEG C is larger than or equal to 250 J, the comprehensive mechanical property is excellent, the relative corrosion rate is smaller than or equal to 50% compared with traditional Q355 carbon steel, and the high-performance structural steel plate has the advantages of being resistant to low-temperature freezing and thawing, resistant to corrosion and resistant to environment-sensitive fracture.

The invention belongs to the technical field of ferrous metallurgy, and particularly relates to a molten steel smelting method adopting fluoride-free refining slag in LF (ladle furnace) refining, which comprises the following steps: taking a slag sample from the LF refining slag refined by fluorine-containing refining slag, analyzing the components of the slag sample, calculating the metallurgical properties including melting point and viscosity of the slag sample by using FactSage software, and calculating the content of the fluoride-free refining slag according to the calculation result. The composition of the fluoride-free refining slag system replacing the fluorine-containing refining slag is obtained through phase diagram calculation; obtaining the molten steel oxygen content and temperature at the converter smelting end point, and determining the amount of slag needing to be added according to the molten steel oxygen content and temperature at the converter smelting end point; lime and synthetic refining slag are added in the converter tapping process for slagging to achieve first modification; and in the LF refining process, residual lime and synthetic refining slag are added for slagging to realize secondary modification, a slag system is adjusted to a required fluoride-free refining slag system composition, and LF refining is realized by adopting molten steel of fluoride-free refining slag for smelting.

The invention belongs to the technical field of ferrous metallurgy, particularly relates to a method for determining the LF refining slag amount of ultralow-sulfur pipeline steel, provides a molten iron-free pretreatment-single slag method ultralow-sulfur pipeline steel production process, and establishes an optimal refining slag system of the ultralow-sulfur pipeline steel. According to the method, the sulfur capacity of a refining slag system is calculated through a KTH model, the sulfur distribution ratio of the refining slag is further obtained by combining current molten steel components, the theoretical adding amount of the refining slag is accurately obtained according to the requirements of the sulfur distribution ratio, the molten steel amount, the LF refining station entering sulfur content and the LF refining station exiting sulfur content, and a refining slag amount rapid calculation model based on LF station entering sulfur content classification is provided. And when the sulfur content of the entering molten steel is less than or equal to 0.030 wt%, the optimal desulfurization efficiency of the LF is ensured based on the LF slag system optimization and accurate slag quantity control technology, stable production of the ultra-low sulfur steel can be realized under the condition of no molten iron pretreatment, and the sulfur content of a finished product is controlled within 10ppm.

The invention relates to a process for preparing a phosphor copper rod by using a phosphonate-amide composite purifying agent as a quenching aid, and belongs to the technical field of non-ferrous metallurgy. Phosphorus pentoxide and sodium carbonate are mixed and decocted into fused salt, the fused salt is cooled and ground and then added into a corundum crucible together with scrap copper to be rapidly heated, compressed air is blown in, and slagging-off is conducted after heat preservation and standing; blowing mixed gas into the melt for reduction refining; adding calcium boride into the melt for refining; the refined copper liquid is subjected to continuous casting and continuous rolling; rapidly immersing the phosphorus copper rod subjected to continuous casting and rolling into a quenching aid solution, and carrying out quenching treatment; and the quenched phosphor copper rod is blow-dried and dried, and the high-conductivity phosphor copper rod is obtained. The high-purity phosphorus copper rod prepared by the method is excellent in key indexes of copper content, phosphorus content and conductivity, and meets the expected requirements of high purity and high conductivity.

The invention belongs to the field of ferrous metallurgy, and discloses an RH refining oxygen blowing decarburization method which comprises the following steps: dynamically adjusting the oxygen blowing flow and the oxygen blowing lance position according to the ratio of the content of carbon to the content of oxygen in RH incoming steel; the oxygen blowing amount is determined according to the initial values of the carbon and oxygen contents in the RH entering steel and the target values of the carbon and oxygen contents after decarburization is finished; a gradient lifting gas flow system is adopted in the RH decarburization process, the oxygen blowing opportunity of RH decarburization and the vacuum pressure in the oxygen blowing process are controlled, and when RH decarburization is finished, molten steel is controlled to be low in oxygen activity. According to different RH entering molten steel components, the oxygen blowing flow and the oxygen blowing lance position are dynamically adjusted, the gradient gas flow increasing system is adopted, the RH decarburization oxygen blowing opportunity, the oxygen blowing process vacuum pressure and decarburization ending molten steel oxygen activity control are combined, the oxygen utilization rate can be effectively increased, the decarburization period is shortened, and the decarburization efficiency is improved. The problem of molten steel recarburization caused by molten steel splashing due to too violent carbon-oxygen reaction is solved, RH efficient decarburization is achieved, the steel ladle top slag oxidability is reduced, and the molten steel cleanliness is improved.

The invention relates to the technical field of metallurgy and chemical industry, in particular to a silicon-manganese alloy smelting method which comprises the following steps of raw material pretreatment, gradient reduction smelting, tapping and refining and flue gas slag cooperative treatment. In the silicon-manganese alloy smelting process, lanthanum-cerium oxide in the rare earth composite material reacts with impurities such as sulfur, phosphorus and oxygen in a melt at high temperature to form a high-melting-point compound which is separated along with slag, the impurity content is effectively reduced, meanwhile, rare earth elements are segregated at the grain boundary, atomic diffusion migration is inhibited, the alloy grain size is remarkably refined, and the alloy yield is improved. And the rare earth composite material optimizes the alloy solidification structure through the double effects of chemical purification and physical modification, the problems of impurity segregation and insufficient toughness in the traditional silicon-manganese alloy smelting process are solved, and the mechanical property of the silicon-manganese alloy is remarkably improved.

The invention discloses a production method for reducing flaw detection defects of wind power gear steel, and belongs to the technical field of ferrous metallurgy. According to the method, an electric furnace-LF-VD-continuous casting process route is adopted, the mass fraction of an aluminum element Al in molten steel is controlled to be not lower than 0.018% in the LF refining process, and the mass fraction of [Al] is controlled to be higher than 0.010% all the time in the VD vacuum treatment process. And after VD vacuum breaking, aluminum is supplemented in time, the mass fraction of Al is increased to 0.015%-0.020%, calcium treatment is reasonably carried out, and the mass fraction of Ca in molten steel is controlled to be 0.0006%-0.0009%. By accurately controlling the component change of the molten steel in the VD process, the formation of CaO-MgO-Al2O3-SiO2 inclusions with high SiO2 content is effectively inhibited, the large-size ultrasonic flaw detection defects in the wind power gear steel are remarkably reduced, and the internal quality of the steel is improved. The method is simple in process and remarkable in effect, and has a good industrial application prospect.

The invention discloses a method for refining and homogenizing crystal grains of a 9%-12% Cr steel thick-wall large forge piece, and belongs to the field of ferrous metallurgy. According to the method, the large forge piece is heated to be close to the critical point of the complete austenitizing temperature in a stepped mode, the large forge piece is subjected to heat treatment by regulating and controlling dispersive precipitation of carbides in an initial structure and uniform nucleation of austenite and / or introducing a small amount of undissolved ferrite, residual precipitated phases and multi-phase interfaces and controlling the cooling speed; nucleation particles of pearlite transformation in the vibration heat preservation process are remarkably increased, uniform distribution of granular pearlite in the supercooled austenite is promoted, structural inheritance is cut off and eliminated, and the purpose of grain refining and homogenizing after performance heat treatment is achieved. According to the method, the grains of the thick-wall large forge piece are refined to 5 grades or above, the cross section grain size difference is within 2 grades, a series of problems that in the production process, grass waves exist in ultrasonic flaw detection, the grain size is unqualified, and the low-temperature impact toughness does not reach the standard can be solved, the product percent of pass and the production efficiency are remarkably improved, and meanwhile the production energy consumption is reduced.

The invention discloses a technological method for regulating and controlling the melting point and viscosity of aluminum deoxidized steel refining slag based on rare earth cerium, and belongs to the technical field of ferrous metallurgy refining. The redox characteristic of Ce and slag system structure modification are combined, the limitation of traditional single component adjustment is broken through, and the composite oxide effect of Ce is utilized: Ce generates CeO2 and Ce-Al-O composite oxide at high temperature, so that the liquidus temperature of a slag system is remarkably reduced, and the melt structure is optimized; by limiting the addition amount of Ce and balancing the cost and performance, the situation that the oxidability of a slag system is out of control due to excessive Ce is avoided, and the thermodynamic stability of the slag system is improved; the addition of Ce inhibits the generation of high-melting-point calcium aluminate and promotes the formation of a low-melting-point phase; by adding Ce, melting point reduction, viscosity optimization and molten steel purification are achieved at the same time, the additive is superior to an existing single-function additive, traditional fluorite is replaced, and fluorine pollution is reduced. The invention aims to provide the same environment-friendly and efficient method capable of accurately regulating and controlling the physicochemical properties of the slag.

The invention relates to the technical field of metallurgy, and discloses a preparation method of a low-nitrogen-content and low-impurity high-purity vanadium-aluminum alloy, which comprises the following steps: step 1, controlling the purity, granularity and content of raw materials; 2, baking the raw materials and mixing the raw materials; step 3, charging; step 4, smelting; step 5, coarse crushing; sixthly, sand blasting treatment is conducted; and step 7, crushing, refining, screening, detecting and packaging. According to the method, the content of the added aluminum oxide cooling material is controlled, the vacuum environment is applied to the smelting process, argon is introduced until the pressure in the furnace is-0.08 MPa after vacuumizing is stopped, volatilization of elements in the alloy is reduced, and the beneficial effect that the loss of reaction heat and the influence of impurities such as oxygen and nitrogen in air on the purity of the alloy are avoided is achieved.

The present application provides a full-process intelligent refining system applied to an LF refining furnace, which relates to the field of iron and steel metallurgy and includes: a slag-making control module that calculates the addition amount of slag-making agent; a temperature prediction module that predicts and controls the molten steel temperature in real time; a blowing argon control module that establishes a relationship model between the exposed area of molten steel and the bottom blowing argon gas flow rate; a wire feeding prediction module that calculates the feeding amounts of aluminum wire and calcium wire; an alloy calculation module that automatically controls the alloy addition amount; a machine-assisted module that collects data and performs sampling and slag sticking work; a main control module that is used to control the system operation; and a server for data storage and interaction. The present application uses technologies such as statistical methods and mechanism calculations to establish mechanism models for each refining process, predict and automatically control the refining process, effectively improving the hit rate of alloy components and the temperature compliance rate, and at the same time reducing alloy consumption and power consumption.

The invention belongs to the technical field of ferrous metallurgy, and particularly relates to a production method of low-silicon sulfur-added high-aluminum gear steel which comprises the following chemical components in percentage by weight: 0.15%-0.20% of C, 0.06%-0.12% of Si, 1.35%-1.55% of Mn, 0.035%-0.055% of S, 1.10%-1.20% of Cr, 0.035%-0.055% of Al, 0.012%-0.016% of N, less than or equal to 0.0010% of O and the balance of Fe and inevitable residual elements. The overall process route of the production method comprises the steps of converter primary smelting, tapping pre-calcification and sulfurization, LF refining slagging, RH vacuum treatment and continuous casting protection pouring. By optimizing the composition of the refining slag, controlling the sulfur content in stages and co-processing calcium and aluminum, the continuous casting castability problem of the low-silicon sulfur-added high-aluminum gear steel is effectively solved, and the liquid level fluctuation percent of pass of a crystallizer is greater than 99%.

The invention relates to a method for preparing rare earth steel by refining prefabricated slag of a CaO-Al2O3-REO-MgO slag system, belongs to the technical field of ferrous metallurgy, and solves the technical problem of how to prepare the rare earth steel by refining the prefabricated slag of the CaO-Al2O3-REO-MgO slag system so as to improve the rare earth yield. The invention discloses a method for refining and preparing rare earth steel by using prefabricated slag of a CaO-Al2O3-REO-MgO slag system. The method comprises the following steps: S1, paving a deoxidizing agent, the prefabricated slag and lime at the bottom of a steel ladle before tapping, and tapping; s2, slag adjustment operation of the LF furnace; step S3, alloying is carried out; s4, treating white slag for more than or equal to 20 minutes, and performing calcium treatment; s5, argon blowing is carried out, and an LF furnace station is left; s6, RH treatment is carried out; s7, adding a rare earth iron alloy; s8, vacuum breaking is carried out after vacuum circulation, and the robot leaves the RH station; s9, a tundish covering agent is scattered on the surface of the molten steel; and S10, the surface of the molten steel is protected through continuous casting crystallizer casting powder. The yield of the rare earth elements is 40% or above.

The invention relates to an RH vacuum tank system and a combustion heating operation method, and belongs to the field of ferrous metallurgy vacuum treatment equipment. The system comprises a vacuum tank, a hot bent pipe, a top lance device, a vacuum air pump system and an automatic control system, the hot bent pipe is connected with the vacuum tank, and an automatic ignition device, an infrared temperature measuring device, a video monitoring device and a thermocouple are integrated in the hot bent pipe; the top lance device is of a water-cooling multi-layer sleeve structure, multiple stations are switched through a top lance rotating frame and a lifting trolley, and vacuum sealing is maintained. The method is based on multi-sensor cooperative control, low-temperature ignition, high-temperature spontaneous combustion and molten steel heating modes are automatically executed according to the temperature of a refractory material at the bottom of a tank and the temperature of molten steel, and combustion stability is ensured by dynamically adjusting the flow of fuel gas and oxygen. According to the scheme, through closed-loop ignition control, inert gas protection and intelligent monitoring, the safety is remarkably improved, and the gas explosion risk is avoided; full-automatic operation and precise temperature control are combined, the molten steel quality and the production efficiency are improved, and the device is suitable for refining production of high-value-added steel such as silicon steel and automobile sheets.

The present invention relates to the technical field of metallurgy. Disclosed are a manufacturing method for and use of a corrosion-resistant and low-temperature-resistant continuous-cast steel billet for a wind turbine. The manufacturing method comprises the following steps: carrying out electric furnace steelmaking, carrying out LF refining, carrying out VD vacuum treatment, carrying out continuous casting by means of three-stage vibration crystallization, i.e., non-sinusoidal, sinusoidal and non-sinusoidal vibration crystallization, and carrying out gradual slow-cooling aging, i.e., strong, medium and weak slow-cooling aging, to obtain a continuous-cast steel billet for a wind turbine. According to the present invention, by means of composition and process control, a specific microstructure can be formed. On one hand, a continuous-cast billet is manufactured by means of three-stage vibration crystallization, i.e., non-sinusoidal, sinusoidal and non-sinusoidal vibration crystallization, in a crystallization process; and on the other hand, in the present invention, by means of gradual slow-cooling, i.e., strong, medium and weak slow-cooling, a characteristic composite microstructure having a 0.1-5.5 μm (Nb, V, Ti)CN phase and a 0.3-3.8 nm dispersed copper-rich nanophase is finally formed, and the composite microstructure has excellent low-temperature impact resistance and multiple biological corrosion resistance.

The invention relates to the technical field of metallurgy, in particular to microstructure regulation and control wind power main shaft steel and a heat treatment preparation method and application thereof. The wind power main shaft steel is prepared through the processes of smelting, LF refining, VD refining, continuous casting and rolling, profiling forging and performance heat treatment. The wind power main shaft steel comprises C, Si, Mn, Nb, Cr, Mo, Al, V, Ti, N, P, S, Fe and inevitable impurities. According to the wind power main shaft steel, the proportion of small-angle grain boundaries smaller than 10 degrees is larger than 65%; and a micro-nano-sized (Nb, V) N precipitated phase exists at the grain boundary. The tensile strength of the wind power main shaft steel exceeds 900 MPa, the elongation exceeds 14%, and the wind power main shaft steel has good performance.

The invention relates to a method for preparing metallic titanium through two-step electrolysis in halide molten salt, and belongs to the technical field of metallurgy. The method comprises the following steps: by taking fluorine-chloride mixed molten salt as primary electrolytic molten salt, adding TiO2 into the fluorine-chloride mixed molten salt, uniformly mixing, heating the fluorine-chloride mixed molten salt containing TiO2 to the electrolytic temperature of 650-850 DEG C in an inert atmosphere, inserting a cathode and an anode, carrying out primary molten salt electrolysis, taking out a cathode product, and carrying out secondary electrolytic treatment on the cathode product to obtain the TiO2 / TiO2 composite material. Performing vacuum distillation or washing on the cathode product to remove impurities, and drying to remove attached electrolyte to obtain a primary electrolytic product crude titanium; the method comprises the following steps: by taking primary electrolysis product crude titanium as a soluble anode, high-purity metal titanium as a cathode and chloride molten salt as secondary electrolysis molten salt, heating the chloride molten salt to the electrolysis temperature of 550-750 DEG C in an inert atmosphere, inserting the cathode and the anode, performing electrolytic refining, and washing the electrolysis product with diluted hydrochloric acid and deionized water to remove impurities, thereby obtaining the low-oxygen metal titanium powder. A low-melting-point molten salt system is adopted in two-step electrolysis, and energy consumption can be effectively reduced.

The invention relates to a preparation method of ultralow-carbon ultralow-sulfur low-nitrogen steel, and belongs to the technical field of ferrous metallurgy. The method comprises the following steps: smelting a raw material containing waste steel in an electric furnace to obtain first molten steel; the first molten steel is subjected to sectional type LF refining, and second molten steel with the preset sulfur content is obtained; wherein the sectional type LF refining comprises LF refining of a light desulfurization section, a slagging-off section and a deep desulfurization section for spraying calcium oxide powder which are arranged in sequence, and the temperature of the first molten steel in the light desulfurization section is controlled; and the second molten steel is subjected to RH vacuum smelting, decarburization and denitrification are conducted, oxygen blowing operation is conducted in the RH vacuum smelting process, and the ultralow-carbon ultralow-sulfur low-nitrogen molten steel is obtained. The ultralow-carbon ultralow-sulfur low-nitrogen molten steel is prepared from the following components in percentage by mass: less than 20 ppm of oxygen, less than 0.0030% of nitrogen, less than 0.0030% of sulfur and less than 0.0020% of carbon.