122 results about "Argon flow" patented technology

The invention provides an argon flow and micro-positive pressure linkage control method for an electroslag furnace. The method comprises the steps that the oxygen content and micro-positive pressure signals in the furnace are collected; the future furnace condition is predicted through the deep belief network model; optimizing initial parameters of the fuzzy PID controller in an off-line manner by using a particle swarm algorithm; on the basis of the real-time signal and the prediction result, adaptively adjusting controller parameters on line; and finally, an argon flow and dust removal valve opening control instruction is output in a linkage mode. According to the method, future furnace conditions are predicted through the deep belief network model, the control advancement is realized, and the problem of large lag of the system is solved; offline parameter optimization is carried out on the fuzzy PID controller through a particle swarm algorithm, and excellent initial performance adapting to different working conditions is provided for the fuzzy PID controller; the parameters of the controller are adaptively adjusted through online fuzzy reasoning, so that the system has robustness for coping with a dynamic process; finally, accurate and stable linkage control of the oxygen content in the furnace and the micro-positive pressure is achieved through linkage calculation of the argon flow and a dust removal valve opening instruction.

The invention provides a crystal pulling method for improving the BMD defect density in monocrystalline silicon and a monocrystalline silicon rod, and belongs to the technical field of monocrystalline silicon crystal pulling, and particularly relates to the following steps: stabilizing the oxygen content in a crystal in a relatively high interval by cooperatively regulating and controlling the argon flow, the furnace pressure, the crucible rotating speed, the crystal rod rotating speed and the pulling speed, providing a sufficient oxygen source for generation of BMD defects, and improving the BMD defect density in the monocrystalline silicon on the basis of stabilizing the oxygen content in the crystal in a relatively high interval. In the equal-diameter process, temperature compensation is carried out on a crystal bar through a preset temperature compensation device, diffusion and precipitation of oxygen atoms are effectively promoted to form BMD crystal nucleuses, the BMD body defect density and the axial distribution uniformity are remarkably improved, the specification lower limit of the BMD density is promoted to be improved to 1.0 E + 11 ea / cm < 3 > or above, the internal gettering capacity of a silicon wafer is finally enhanced, and the service life of the silicon wafer is prolonged. And a reliable guarantee is provided for improving the performance and yield of the device.

The invention relates to a production method of nitrogen-containing low-carbon aluminum killed molten steel. The method comprises the following steps: 1) smelting by adopting a top-bottom combined blown converter; (2) the converter smelting process is controlled; (3) controlling the smelting end point of the converter; (4) controlling molten steel sedation; (5) controlling tapping of the converter; and (6) refining of a molten steel argon blowing station is controlled, the molten steel fed with the aluminum wire is subjected to weak stirring, the argon flow is controlled to be 50-100 L / min, the molten steel is subjected to weak stirring for 6-8 min, finished molten steel is obtained, and the finished molten steel comprises, by weight, 0.02%-0.045% of C, smaller than or equal to 0.034% of Si, 0.2%-0.3% of Mn, smaller than or equal to 0.015% of P, smaller than or equal to 0.012% of S, 0.025%-0.06% of Al, 0.0035%-0.0065% of N, smaller than or equal to 0.0035% of T [O] and the balance Fe and residual elements. According to the method, the problem of accurate nitrogen increasing in converter smelting of the low-carbon aluminum killed molten steel is solved, the cleanliness of the molten steel is improved, the argon blowing direct feeding process of the nitrogen-containing low-carbon aluminum killed molten steel is achieved, and the smelting cost is reduced.

The application discloses a low-ash-consumption converter smelting method, adopts single-slag smelting, controls the converter scrap steel ratio in 8% to 26%, controls the top blowing oxygen supply flow in 3.0 to 4.0 Nm 3 / (min·t), controls the bottom blowing argon flow in 0.03 to 0.10 Nm 3 / (min·t); the smelting process is improved by the cooperation of the gun position and the charging; the solid waste slag is added in the converter blowing process, the content of CaO in the slag is controlled in 45% to 55%, and the content of MgO is controlled in 5.5% to 7.5%; meanwhile, the dust removal pressure ball is added to improve the activity of FeO in the slag, and the terminal carbon content of the converter is controlled to be less than or equal to 0.05%. By adding the solid waste slag in the smelting process, the slag needed to oxidize a large amount of iron elements to generate FeO is reduced, so that the total iron content of the slag is reduced; by adding the synthetic slag, the liquidity of the slag is ensured, and the carbon-oxygen reaction is promoted; the total iron content of the low-carbon steel converter terminal slag is stably controlled to be less than 14.5%, the metal yield is provided; the lime addition amount can be reduced, the lime addition amount is controlled to be less than or equal to 10 kg / t, and the cost is reduced.

The invention relates to the technical field of molten steel refining. The invention discloses an LF furnace dynamic argon blowing method, device and equipment and a medium. The method comprises the steps that the molten steel temperature, the oxygen activity, the average diameter of inclusions and the number of the inclusions are obtained; based on a preset argon flow estimation model, estimating the total argon flow in the current period according to the molten steel temperature, the oxygen activity, the average diameter of the inclusions and the number of the inclusions; and on the basis of a preset argon gas distribution rule, according to the total argon gas flow of the current period, the argon gas flow of each subarea in the current period is obtained, and the argon gas flow of each subarea is adjusted. The total argon flow is calculated according to the molten steel temperature, the oxygen activity, the average diameter of the inclusions and the number of the inclusions in multiple dimensions, the accuracy of the argon flow is improved, then the argon flow of each partition is dynamically adjusted in different periods according to the argon distribution rule, and the stirring uniformity is improved.

A continuous casting long nozzle argon sealing structure, argon blowing control system and control process belong to the technical field of steelmaking, the continuous casting long nozzle argon sealing structure, including long nozzle body and the bowl part outer periphery of its covering shell, the shell is provided with argon inlet, the bowl part outer periphery is provided with annular groove, the volume of the annular groove gradually increases from the argon inlet to its opposite side, the beneficial effects of the present application are that the argon sealing structure designed in the application is simple, the manufacturing cost is low, the argon is uniformly and effectively distributed in the long nozzle circumferential direction, the argon blowing control system and process involved automatically adjust the argon flow of corresponding gear according to the net weight of molten steel in the ladle, the argon blowing effect of molten steel casting process is monitored in real time, the failure rate is reduced, and the quality of molten steel is effectively improved.

The invention relates to the field of semiconductor materials, in particular to a crystal pulling thermal field control method, a crystal pulling thermal field system and application. The crystal pulling thermal field control method comprises the following steps: in an equal-diameter growth stage of czochralski silicon, when the curing rate of a silicon rod is less than or equal to 30%, controlling the argon flow to be 90-120SLPM, and controlling the furnace pressure to be 800-1000Pa. According to the crystal pulling thermal field control method, in the initial stage of equal-diameter growth where the oxygen segregation effect is most sensitive, argon flow and furnace pressure are cooperatively controlled in a specific'low flow-low pressure 'window, and a process environment beneficial to oxygen volatilization instead of entering crystals is actively created. The segregation and doping of oxygen atoms to a solid-liquid interface are effectively inhibited from the aspect of dynamics, and the method is the most critical step for realizing the overall low oxygen content of the silicon rod, especially reducing the oxygen content of the head and improving the axial uniformity.

The present application relates to a kind of multi-scene adaptive intelligent bottom argon blowing control method and system, comprising: the ladle reaches working position after determining gas permeability, receives the signal of sitting ladle, starts blowing argon, infrared thermal imager is opened to monitor picture and determine molten steel surface, fills complete all ladle liquid level area;Intelligent link all refining equipment PLC, according to different stages of metallurgical purpose, determine the bottom blowing stirring power, calculate the bottom blowing gas pressure, bottom blowing gas flow, the naked area of molten steel in continuous video stream, naked edge slag layer height and other related parameters are tracked and calculated in real time, further optimize bottom blowing control;Flow data instruction is issued to bottom blowing PLC, control the pressure and flow size of bottom blowing gas.The present application automatically receives argon blowing state molten steel video image continuously according to the need of on-site production, uses intelligent bottom blowing control to automatically distribute argon flow and pressure, ensure that each furnace reaches better bottom blowing stirring effect, give on-site production guidance, reduce production labor intensity.

The invention provides a tundish argon control system which comprises a control device, a first pipeline control valve, a mass flow meter and a second pipeline control valve, and a purging branch is formed by connecting the mass flow meter and the second pipeline control valve in series. The control device switches a control mode according to a tundish car position signal: a main pipeline control valve is opened when a tundish car starting signal is received, a main pipeline is closed and a purging branch is started after a casting position is reached, and the argon flow is accurately controlled by adjusting the opening degree of a branch control valve. The argon supply opportunity is advanced to inhibit molten steel oxidation, and the argon flow control precision is improved.

The invention discloses a high-performance N-type skutterudite thermoelectric material barrier layer with a composite structure and a preparation method thereof, and belongs to the technical field of thermoelectric conversion. The preparation method comprises the following steps that a Mo target is installed at a radio frequency target position, a W target is installed at a direct current target position, a skutterudite wafer substrate is fixed to a substrate, and the substrate is heated and vacuumized; and the argon flow is set and introduced, bias voltage is started, radio frequency and direct current power supplies are synchronously started to pre-sputter the target material, then radio frequency sputtering of the Mo connecting layer and direct current sputtering of the W barrier layer are sequentially carried out, and the W-Mo composite barrier layer is prepared. The method is used for solving the technical problems that due to the limitation of the high melting point of refractory metal W, a compact tungsten barrier layer is difficult to prepare through a common sintering process, the diffusion capacity of barrier elements is reduced, mismatch of thermal expansion coefficients of the metal W and a skutterudite matrix is large, and the barrier layer is prone to failure in a thermal cycle service environment.

The invention relates to a preparation method of a niobium diselenide lubricating film serving for current-carrying friction. The niobium diselenide lubricating film is prepared by adopting a radio frequency magnetron sputtering method. Sputtering gas is argon, a sputtering target material is niobium diselenide, the niobium diselenide thin film which is compact in structure and has good mechanical performance, electrical performance and lubricating performance is prepared by changing argon flow and substrate negative bias pressure, stable lubrication in 100 thousand cycles can be achieved in the atmospheric environment, and the friction coefficient is 0.08. Under a current-carrying friction working condition, compared with a traditional molybdenum disulfide film, the contact voltage is only 1 / 4, and the wear rate is reduced by more than half. The technology can be widely applied to antifriction and wear-resistant treatment of electric contact sliding parts in the fields of aerospace, electric power systems, semiconductor manufacturing and the like.

The invention provides a crucible feeding method in monocrystalline silicon preparation and application, and relates to the technical field of semiconductor material manufacturing. Specifically, when the charging amount of the granular silicon in the crucible is less than or equal to 200kg, firstly, a small material is charged into the bottom of the crucible, then the granular silicon is charged into the middle of the upper part of the small material, then the space between the granular silicon and the wall of the crucible is filled with blocky silicon, and finally, the blocky silicon is flatly laid on the upper part of the granular silicon; when the charging amount of the granular silicon in the crucible is greater than 200kg, firstly charging a small material into the bottom of the crucible, then paving the granular silicon on the upper part of the small material, and finally paving the small material on the upper part of the granular silicon; in addition, the argon flow in the re-feeding stage is controlled to be higher than the argon flow in the initial charging stage. According to the invention, the sputtering phenomenon in the process of initially charging the granular silicon can be effectively reduced, the sputtering of the granular silicon is obviously reduced by measures of improving the charging mode, optimizing the heating process, controlling the melt state and the like, and the quality of monocrystalline silicon is improved.

This invention discloses a method and system for preventing electrode breakage in refining furnaces using quantitative bottom blowing of hot slag with low current, belonging to the field of metallurgical technology. The method includes: pouring circulating hot slag at a temperature not lower than 1450℃ into the ladle to soften the crusted slag layer; quantitatively adjusting the bottom blowing argon flow rate, extracting the argon pore opening diameter using a visual sensor and establishing a calculation model to maintain liquid level stability; switching the electrode raising and lowering to manual mode, setting a low arc-starting current of 10000 amperes, and using a laser reference to control the three-phase electrode flatness error within ±5mm; acquiring electrical and acoustic signals at a period of not less than 100 milliseconds to construct a multi-dimensional model to determine successful arc ignition; after stabilization, increasing the power at a preset slope and switching back to automatic mode. Through hot slag modification, quantitative bottom blowing, low-current arc ignition, and multi-dimensional monitoring, the risk of electrode breakage in the early stages of arc ignition is significantly reduced, improving the safety and stability of the refining process.

The invention discloses a Cr-rich multiphase six-element non-noble metal high-entropy alloy and a preparation method thereof, and belongs to the technical field of magnetic high-entropy alloys. The preparation raw materials comprise 65 to 70 at.% of Cr, 1 to 5 at.% of Fe, 1 to 5 at.% of Co, 1 to 5 at.% of Ni, 10 to 15 at.% of Al and 10 to 15 at.% of Mo, and the total amount is 100 at. The preparation method comprises the following steps: (1) uniformly mixing the raw materials; (2) continuously introducing argon; (3) raising the temperature at a constant speed, synchronously increasing the argon flow velocity, keeping the temperature at 1200 DEG C for 16 hours, and reducing the argon flow velocity; (4) cooling at a constant speed, synchronously increasing the argon flow velocity, keeping at 900 DEG C for 10 hours, and reducing the argon flow velocity; and (5) cooling at a constant speed, keeping the argon flow speed, and rapidly cooling to room temperature. According to the preparation method, a precise six-element non-noble metal element doping strategy is combined with a one-step heat treatment and staged rapid cooling process, so that cooperative regulation and control of high Curie temperature Tc and low saturation magnetization Ms are realized at low cost, and the key bottlenecks of high magnetic loss, poor magnetic stability and the like of a traditional magnetic material are effectively broken through; and a material basis is provided for development of new-generation high-frequency and high-temperature magnetic devices.

The utility model discloses an argon pressure reducer which comprises a device body, an air inlet is formed in the side surface of the device body, an air outlet is formed in the lower surface of the device body, a barometer head is arranged on the upper surface of the device body, a meter barrel is arranged on one side of the barometer head, and a floating column is arranged in the meter barrel. And fan blades are arranged in the device main body and are positioned below the meter barrel. According to the pressure reducer, the fan blades are additionally arranged in the pressure reducer, argon can drive the fan blades to rotate in the flowing process in the pressure reducer, then a power source is provided for use of the wind power lamp, along with rotation of the fan blades, light of the wind power lamp is turned on to illuminate the meter barrel, and therefore workers can observe the height of the floating column conveniently; therefore, the flow and pressure conditions of the gas can be known, an auxiliary lighting device is not needed, and the practicability of the pressure reducer is greatly improved.

This invention discloses a method for producing high-nitrogen steel with nitrogen enhancement, comprising: Step 1, converter smelting: using bottom blowing mode with nitrogen blowing throughout the process; Step 2, refining LF furnace: the LF furnace is bottom-blown with nitrogen before the third power supply and bottom-blown with argon after the third power supply. Slag formation, deoxidation, and alloying are performed during the refining LF furnace process, and the composition of the molten steel is controlled and tested; Step 3, refining RH furnace: nitrogen is used as the vacuum treatment driving gas, and the nitrogen content is controlled by adjusting the high and low vacuum times. After RH furnace vacuum breaking, calcium treatment is performed, carbonized rice husks are added to cover the molten steel surface, and argon flow is adjusted for soft blowing. Samples are taken to confirm the nitrogen content; Step 4, continuous casting: continuous casting is performed using a continuous casting machine. This application achieves precise control and stable maintenance of the nitrogen content in high-nitrogen steel by using nitrogen blowing throughout the converter process, nitrogen enhancement in the refining LF furnace before the third power supply, and nitrogen enhancement in the refining RH furnace, thus meeting the quality requirements of high-nitrogen steel. The production process is simple, which is beneficial for improving production efficiency and reducing production costs.

This invention relates to a method for preparing a hole transport layer in a perovskite solar cell and its application. The method requires no annealing throughout and specifically includes: S1. Using a nickel target, a first nickel oxide layer is prepared on a substrate surface by magnetron reactive sputtering at a pressure of 0.2–0.4 Pa and an argon gas flow rate of 200–600 sccm, wherein the argon to oxygen flow rate ratio is 20–30%; S2. Using a nickel oxide ceramic target, a second nickel oxide layer is obtained by magnetron physical sputtering at a pressure of 0.3–0.5 Pa and an argon gas flow rate of 200–600 sccm, wherein the oxygen to argon flow rate ratio is 1.5–5%. The technical problem to be solved is how to provide a method for preparing a hole transport layer that combines nickel reactive sputtering with nickel oxide ceramic target physical sputtering using magnetron sputtering equipment, requiring no annealing throughout the process, significantly reducing preparation costs, and forming a film structure more conducive to hole transport.

The invention relates to a novel method for realizing helical carbon growth by using an electro-deposition nickel catalyst, which comprises the following steps: (1) cutting a copper foil into a required size, and sequentially carrying out ultrasonic cleaning in ethanol and acetone to obtain a sample; (2) carrying out electro-deposition on the sample in a nickel plating electrolyte; (3) placing the Cu foil sample plated with the Ni film on a quartz boat, placing the quartz boat at the central position of a horizontal tube furnace, and introducing argon before heating; and (4) raising the furnace temperature, after the temperature is stable, introducing acetylene as a carbon source, maintaining the argon flow, reacting for several minutes, generating a carbon micro / nano coil on the surface of the Ni catalyst, stopping supply of acetylene after deposition is finished, and naturally cooling the sample to room temperature under the condition of continuously introducing Ar atmosphere so as to avoid oxidation. According to the method disclosed by the invention, extensible, repeatable and high-yield synthesis of the carbon micro / nano coil is realized, and a new technical approach is provided for high-performance electromagnetic wave absorption and preparation of a multifunctional composite material.

The application discloses a preparation method of an electrolytic alkaline water nickel-based electrode and belongs to the technical fields of electrolytic hydrogen production and material surface engineering. The electrolytic alkaline water nickel-based electrode is prepared by adopting pure nickel as an outer skin of a flux-cored wire, and the inner part is wrapped with 5-20 wt.% aluminum powder and 1-5 wt.% zinc powder. The specific steps include: cleaning and grit blasting the surface of a substrate; preparing an array of welding spots on the pretreated surface of the substrate by adopting a pulsed metal-arc additive process, and the process parameters are as follows: current 100-120 A, voltage 22-23 V, argon flow rate 15 L / min, dry elongation 10-11 mm, welding speed 15-35 mm / s, and pulse frequency 10-50 Hz; and the obtained electrode sample is placed into a mixed solution of potassium hydroxide and potassium sodium tartrate for water bath heating, so that the electrolytic alkaline water nickel-based electrode is obtained. The electrolytic alkaline water nickel-based electrode has high double-layer capacitance and low hydrogen production overpotential, and has good electrocatalytic performance.

The invention relates to a preparation method of a copper seed layer, and the preparation method comprises self-ionization plasma sputtering, and when the copper seed layer is deposited, the argon flow is 1sccm to 10sccm, the direct current sputtering power is 10kW to 20kW, the radio frequency bias power is 150W to 250W, and the initial temperature is 20 DEG C to 30 DEG C. The preparation method provided by the invention is carried out under the condition of relatively low initial temperature, so that damage and stress accumulation of high temperature to silicon dioxide are avoided; the method is carried out under the condition of high direct-current sputtering power, sputtering particle energy can be balanced, and compact deposition of Cu atoms is promoted. Due to the arrangement of radio frequency bias power, Ar atom bombardment can be enhanced, Cu atoms are migrated to low-energy crystal lattice sites, and surface protrusions are reduced; plasma can be stabilized by setting the argon flow, and uniform deposition of the copper seed layer is ensured. Therefore, according to the preparation method provided by the invention, the TSV electroplating quality can be improved, and the SIP interconnection reliability is improved.

The invention discloses a production method of a peritectic steel continuous casting sheet billet. The technical problem that when an existing sheet billet continuous casting machine is used for producing the peritectic steel continuous casting sheet billet with the w [Al] in the steel being 0.022%-0.042%, the corner crack occurrence rate of the continuous casting sheet billet is high is mainly solved. According to the technical scheme, the production method of the peritectic steel continuous casting sheet billet comprises the steps that (1) a top-bottom combined blowing converter is adopted for smelting, argon is blown from the bottom in the whole smelting process, and the argon flow is 0.05-0.10 Nm < 3 > / (min.t); (2) controlling the smelting end point of the converter; 3) immediately tapping after the converter blowing is finished; 4) transporting molten steel in the steel ladle to an argon blowing station, and uniformly stirring the molten steel; (5) transporting the molten steel in the steel ladle to an LF furnace to carry out molten steel temperature regulation and control and component regulation and control; and 6) carrying out slab continuous casting on the molten steel to obtain a continuous casting slab. The corner crack occurrence rate of the peritectic steel continuous casting sheet billet produced through the method is smaller than or equal to 0.41%.

The invention relates to the technical field of metal material production, in particular to a hot rolling method for improving the impact stability of low alloy steel and medium and wide strip steel. The method comprises the following steps: 1) smelting and refining: adding a titanium alloy after deoxidation, controlling the argon flow to stabilize the Ti element yield, deeply desulfurizing by adopting high-alkalinity and high-reducibility slag, and controlling [S] to be less than or equal to 0.005%; 2) continuous casting: controlling [N] to be less than 50ppm by adopting protective casting; and (3) rolling and cooling are conducted, specifically, the finish rolling temperature and the laminar cooling rate are controlled, and the coiling temperature is accurately controlled by regulating and controlling side spraying, air sweeping and cooling strategies. The method systematically solves the technical problems of unstable impact performance and generation of bainite and other abnormal structures caused by component fluctuation and inaccurate process control of the aluminum-containing low alloy steel. And the prepared medium-wide strip steel is uniform in full coil performance, the longitudinal impact energy at 0 DEG C is stable and is not lower than 100J, and the product quality is remarkably improved.

The invention relates to the technical field of bonding wire processing, and particularly discloses a production method of a silver-based alloy wire, which comprises the following steps: fusing a part of silver raw material and alloy element raw material into intermediate alloy, and smelting the intermediate alloy and the remaining silver raw material to obtain the silver-based alloy wire. The silver-based alloy wire is prepared through the procedures of directional solidification continuous casting, heavy drawing / medium drawing, first-time annealing, fine drawing, second-time annealing, superfine drawing, third-time annealing and coil dividing and winding; in the directional solidification continuous casting process, vacuumizing is conducted, argon is injected, and then smelted metal liquid is dragged under the medium-frequency electric induction frequency of 4-6 kHZ and the argon flow of 0.1-0.2 L / min till the end; a water-based lubricant for wire drawing is further adopted in the superfine wire drawing procedure, and the concentration of the water-based lubricant is 3.0-4.0%. According to the silver-based alloy wire production method, the quality of the silver-based alloy wire is obviously improved by adjusting technological parameters of all the steps in the silver-based alloy wire production method.

The present application belongs to the technical field of argon arc welding control, and particularly relates to a manual tungsten argon arc welding external control device and a control method. The control device and the control method are characterized by the welding circuit on-off module for controlling the on-off of the welding circuit, the argon on-off module for controlling the on-off of the argon, the delay closing module for controlling the on-off of the argon flow, the delay on module for controlling the on-off of the welding circuit, the DC-DC power module for supplying power to each component, the high-frequency coupler and the high-frequency arc starting module for realizing high-frequency arc starting, and the switch module for controlling the switch of the device. The control device can control the arc starting, argon and electricity required in the manual tungsten argon arc welding process, and can solve the problem that the welding machine position needs to be frequently moved in the manual tungsten argon arc welding with large distance and frequent change of the welding field. The ordinary direct current welding machine with the step-down output external characteristic can have the manual tungsten argon arc welding function, so as to improve the welding quality, safety, save argon, improve the utilization rate of the welding equipment and the like.

The invention relates to the technical field of preparation of single crystal silicon rods, and discloses a method for preparing an N-type single crystal silicon rod from large-proportion granular silicon, which comprises the following steps: melting a silicon material and a dopant in a crucible, and pulling a single crystal; the silicon material comprises N-type granular silicon and a circulating material, and the ratio of the N-type granular silicon to the circulating material is (55-65): (35-45); operating parameters are set in the material melting and supplementing process, the temperature ranges from 1300 DEG C to 1600 DEG C, the argon flow ranges from 150 slpm to 160 slpm, the dry pump opening degree ranges from 25% to 30%, and the furnace pressure ranges from 10 Torr to 15 Torr. The preparation method is low in cost, and the prepared silicon single crystal rod is good in quality.

The application relates to the technical field of steelmaking secondary refining process, in particular to a method for RH vacuum calcium treatment. The method comprises the following steps: according to the content of sulfur in molten steel, setting the adding amount of high-efficiency calcium-iron alloy; under the condition of setting the vacuum degree, adding the high-efficiency calcium-iron alloy with the set adding amount into the molten steel, and controlling the total argon flow of the vacuum chamber to carry out homogenization calcium treatment operation; under the condition of setting the time, carrying out soft blowing operation on the molten steel after calcium treatment, and controlling the argon flow of the ladle bottom blowing to promote the floating of inclusions. The application solves the technical problem of smoking in the existing RH vacuum calcium treatment process.

The application discloses a method for preventing steel penetration between plate surfaces of a submerged nozzle quick-change mechanism, 1) under the premise of stable refractory material quality, the nozzle baking method is changed, rapid baking is adopted during baking, the total baking time is controlled to be 1.5-2.5 h, the temperature reaches the range of 1000-1100 DEG C, and the nozzle temperature before use is ensured to be greater than or equal to 950 DEG C; 2) argon is used for sealing between plates of the submerged nozzle quick-change mechanism in a tundish, and the argon flow is controlled to be 10 L / min; 3) a heat insulation steel plate is installed at the lower part of the submerged nozzle quick-change mechanism, 4) the inspection and maintenance of the submerged nozzle quick-change mechanism are well done, all threads and machining holes of a main frame are inspected, and compressed air is used for cleaning; the main frame cooling channel is inspected by using compressed air, and if the channel is blocked, the channel is required to be thoroughly cleaned; 5) the compression force of the spring must be tested after the quick-change mechanism is taken offline each time.

The invention discloses a multistage coating oxygen-mediated annealing preparation method based on RAFM steel / titanium nitride, and belongs to the technical field of coating preparation. The method comprises the steps that a TiN coating is deposited on the surface of a low-activation ferrite / martensitic steel matrix through magnetron sputtering, a pure titanium target material is used, the nitrogen-argon flow ratio is 1: 13-1: 18, the background vacuum degree is 4-6 * 10 <-5 > Pa, the deposition time is 60-90 min, and extra active heating is not applied to the matrix in the deposition process; placing the deposition coating sample in a quartz tube for packaging, wherein the gas pressure in the tube provides a trace oxygen atmosphere; and then annealing treatment is conducted at the temperature of 800-1000 DEG C, and heat preservation is conducted for 90-120 Through oxygen-mediated element diffusion and reaction, a multi-stage composite structure sequentially comprising an inner oxide layer, an Fe inner enrichment layer, a TiN layer, an Fe outer enrichment layer and an outer oxide layer from a matrix to the outside is formed in the TiN coating in situ. The method is simple in process, a transition layer does not need to be additionally deposited, and the prepared multi-stage coating is well combined with a matrix interface, has excellent thermal shock resistance and can bear more than 30 times of thermal shock cycles.

The invention discloses a production method of extremely-low-sulfur silicon killed steel, and relates to the technical field of molten steel refining. The method comprises the following steps: firstly, controlling the final temperature and the final carbon and sulfur content of molten steel in a converter, then adding silicon-calcium-barium and lime in the tapping process, and transferring a steel ladle to an LF (Ladle Furnace) after the tapping is finished; the method comprises the following steps: controlling the flow rate of ladle bottom blowing argon in an LF refining furnace, stirring, breaking slag, adding silicon-calcium-barium, adjusting the flow rate of ladle bottom blowing argon, adding fluorite and lime, carrying out electric arc heating, sampling, measuring the temperature, adjusting the components and temperature of molten steel, carrying out electric arc heating again, feeding nano high-calcium wires, adjusting the flow rate of ladle bottom blowing argon, and carrying out soft blowing. And getting out of the station to obtain the extremely low-sulfur silicon killed steel molten steel. The purpose of stably controlling the sulfur content of the silicon killed steel in the LF refining furnace is achieved, and the sulfur content of the molten silicon killed steel can be controlled to be 0.005% or below.

The present application relates to the technical field of catalytic synthesis, and particularly relates to a method for preparing N-formamide by catalytic oxidation of N-heterocyclic compounds, comprising the following steps: firstly, N-heterocyclic compounds, methanol (MeOH) and acetonitrile (MeCN) are mixed and added into a pressure tube provided with a magnetic stirrer, and continuous stirring is carried out under argon flow (99.999%); then, Cu(NO3)2 is added, and stirring is continued for 2 minutes; then, 2mmol of H2O2 is added, argon is closed, and a polytetrafluoroethylene plug is used to quickly block; then, the reaction mixture is continuously stirred at room temperature for 13 hours; after the reaction is completed, the mixture is concentrated by a rotary evaporator; and the concentrated mixture is purified by a silica gel column chromatography to obtain a product; the method has the advantages of low cost, simple operation, high atomic economy, mild reaction conditions, low energy consumption, high substrate universality and the like.