3320 results about "Decarburization" patented technology

A multi-purpose, multi-oxy-fuel High Temperature Power Burner / Injector / Oxygen Lance, Mechanical System Apparatus Device, for steelmaking from recycled scrap and / or virgin ferrous charge, which can be employed in multi-oxy-fuel (natural gas; pulverized carbonaceous matter; heavy oil), especially by Oxygen Combusted mixture of Natural Gas / Pulverized Carbonaceous Matter in High Temperature Power Burner Mode, for efficient and rapid melting of solid ferrous charge (cold or preheated) in a special steelmaking Metallurgical Furnace or Open Hearth Furnace, Tandem Furnace, BOF, EAF, as its augmenting or only source of thermal energy; more than one Device in Oxygen-Natural Gas / Pulverized Carbonaceous Matter Power Burner Mode, can be employed as the only source of thermal energy in a modified, originally Electric Arc Furnace, as total replacement of Graphite Electrodes and Electric Arc System, the replacement being noticeably more primary energy efficient than the thermal energy provided by Graphite Electrode / Arc System; it also can be employed in an Solid Particles Injector Mode, for injecting of adequately granulated carbonaceous materials or lime into the molten steel for its carburizing or for foamy slag control; further it can be employed in a natural gas shrouded, pulsating oxygen stream, for vertically to the charge oriented soft blow supersonic Oxygen Injection Lance Mode, for decarburization of the molten metal contained in the hearth of the metallurgical furnace and foamy slag control; in one of the embodiments-generally arcuate-pivotally mounted, liquid media cooled composite body, is pivoted into and out of a furnace vessel through a small opening in the shell wall for auto-regulated constant optimal positioning of the Composite Body Tip against solid or molten charge, in each and all multi-purpose modes; furthermore, when inserted into the furnace vessel, the arcuate composite body can be rotated about its longitudinal axis for directing the oxy-fuel high temperature flame towards unmolten charge in the furnace; in an other-generally linear-embodiment, the liquid cooled composite body is attached to the mast type carrier allowing vertical movement of the composite body which enters the furnace vessel through a small opening in the furnace roof; the bimetallic, liquid cooled special tip assembly of both-arcuate and linear embodiments-of the composite body includes easy replaceable, independent, multi-opening nozzles, mounted in a protective, retracted position inside of the liquid cooled special tip assembly.

An improved method and apparatus for metal melting, refining and processing, particularly adapted to steel making in an electric arc furnace. The method provides auxiliary thermal energy to the steel making process, particulate injection for the formation of slag and foamy slag, and oxygen injection for the decarburization of the melt, for the formation of foamy slag and for post combustion burning of carbon monoxide. The burner includes two injection barrels for providing finely pulverized particles and for providing either a supersonic or a subsonic primary flow of an oxidizing gas. The barrels are positioned side by side in a nozzle at the entrance of a flame shaping chamber of a fluid cooled combustion chamber. The nozzle also contains a plurality of fuel orifices for the providing pressurized fuel to the combustion chamber and a plurality of oxidizing gas orifices for providing a secondary flow of an oxidizing gas around the periphery of the nozzle. Because all of the flows of fuel, oxidizing gas and particulates pass through the flame shaping chamber, they are all substantially directed to the same location in the electric arc furnace. The directionality of the flows allows the burner to heat a localized spot of the slag with thermal energy from the oxidation of the fuel, from the oxidation of oxidizable components in the slag or the melt by the lancing of supersonic oxidizing gas, or from any combination of these. Once a spot in the slag is sufficiently heated, a flow of carbon is directed to the localized hot spot in the slag to reduce the FeO, and other oxides, in the slag to carbon monoxide and produce foamy slag. The particulate carbon introduction can be accompanied by further oxidizing gas injection before, during or after the carbon injection.

The invention relates to a special flotation column of coal fly ash, an ore pulp distributor is arranged at the top part of a cylinder body of the special flotation column, a plurality of layers of bubble plates are arranged in the cylinder body, a multi-point rotary flow device and a multi-point fly ash overflow hole are arranged at the lower part of the cylinder body, an ore pulp distributing pipe is arranged at the periphery of the ore pulp distributor, a circulating pipeline is arranged at the periphery of the cylinder body, the upper end of the circulating pipeline is connected and communicates with the ore pulp distributing pipe, the lower end is connected and communicates with the rotary flow device, an interface of the ore pulp distributing pipe and a feed and discharge port are respectively connected with the both ends of a circulating pump, a high carbon ash balance overflow plate and a high carbon ash overflow collection port are further arranged at the upper part of the flotation column, and the fly ash overflow hole is provided with a fly ash automatic regulation box by the connection of the pipeline. The special flotation column is applicable to various requirements, the decarburization effect is good, the continuous operation is stable and reliable, the quality of fine coal is high and the processing ability is great, thus saving energy, increasing efficiency and saving investment.

The invention provides an integrated internal circulation type denitrification and decarburization bio-membrane reactor and an operating method thereof. The main body of the reactor consists of an anoxic zone on the lower part, an aerobic zone on the upper part and a settling zone on the periphery of the aerobic zone; a composite filler is filled in the anoxic zone, and a water inlet pipe is communicated with the bottom of the anoxic zone; the aerobic zone is partitioned into a filler zone for adding a carrier on the upper part and a mud-water mixing zone on the lower part by adopting an orifice plate, the anoxic zone and the aerobic zone are partitioned through an impermeable partition plate, and a plurality of aeration pipes are arranged at the bottom of the aerobic zone and provided with air inlet pores; and the settling zone consists of three parts, namely a clean water zone, a contact settling zone and a sludge returning zone which are sequentially arranged from top to bottom, wherein the bottom of the sludge returning zone is provided with a sludge returning seam and communicated with the bottom of the aerobic zone. The reactor realizes zero power consumption in sludge returning, and is compact in structure; and a back flushing system is not required in the contact settling zone, and additional agents and carbon sources are not required, so that the reactor is low in running cost.

The invention discloses a removal technology of removing coal-fired flue gas pollutants and a device thereof. The technology is as follows: an SCR denitration method is first used for removing NOX in the flue gas; then a dust collector is used for removing dusts and ash particles in the flue gas; then a wet calcium-based desulphurization method is used for removing SO2 in the flue gas; then an MEA decarburization process is used for absorbing the SO2 in the flue gas; simultaneously, a pregnant solution of a generated alkanolamine solution is heated, analyzed and regenerated and the generated barren solution of the alkanolamine solution is continuously and cyclically used; and the analyzed CO2 gas with high concentration is produced to be liquid carbon dioxide of industrial grade with high purity after being cooled, gas-liquid separated, dried, compressed and condensed. The device consists essentially of an SCR denitration reactor, the dust collector, a wet calcium-based desulphurization reactor, an MEA decarburization absorption tower, a regeneration tower, a gas-liquid separator, a dryer, a compressor, a condenser and the like which are connected with each other by pipes. The device has simple and compact overall design, low investment and operation costs, and stable and reliable work and can conduct classified integration processing and highly efficient simultaneous removal on every pollutant in the coal-fired flue gas.

An improved method and apparatus for EAF steelmaking wherein the method provides additional thermal energy to the steel making process, carbon injection for the formation of foamy slag, and oxygen injection for the decarburization of the melt, the formation of foamy slag and post combustion burning of carbon monoxide. The apparatus comprises a unique burner configuration which has a central conduit for alternatively supplying fluid hydrocarbon fuel or particulate carbon with a carrier gas which are discharged through a exit opening. The fuel or carbon is mixed with a high speed, preferably supersonic, stream of oxidizing gas. The high speed stream of oxidizing gas is provided by an annular supersonic nozzle which causes the oxidizing gas to surround the fuel or the particulates with an annular flow. The annular nozzle design can be adjusted to direct the flows of particulates and oxidizing gases in the areas and shapes desired for efficient management of the steelmaking process. Optionally, the burner can have another conduit for the secondary supply of a pressurized flow of hydrocarbon fluid fuel to a series of apertures which surround the annular flow. Further, optionally, the burner can have another conduit for the supply of a pressurized flow of a secondary oxidizing gas to a series of apertures which surround the annular flow.

The invention provides a method for removing various gaseous pollutants from smoke gas, which is used for solving the problem of limitation of the control and government technology on various pollutants in the smoke gas. The invention utilizes an absorption tower for fully removing SO2, NOX, mercurial vapor and CO2 in the smoke gas, the lower part of the absorption tower is provided an absorptionpulp tank, the middle of the absorption tower is provided with a spraying pipe, the upper part of the absorption tower is provided with an oxidizing agent pipe, the absorption tower is provided with partition boards in the vertical direction, both sides of the partition boards are respectively a desulfurization work section and a denitration and decarburization work section, the upper part of theabsorption tower is a communication oxidization region, the smoke gas enters the desulfurization work section from an inlet of the absorption tower to complete the removal of SO2 and HCL, the smoke gas continuously goes upwards to enter the oxidization region, and NOX is oxidized into water-soluble high oxide in the oxidization region and then enters the denitration and decarburization work section to complete the removal of the NOX, the mercurial vapor and the CO2. The invention breaks through the technical bottlenecks of complicated equipment and high running cost for simultaneously removing various gaseous pollutants from the smoke gas in the prior art. The process method and the device of the invention have the unique novelty.

The invention provides a production method of an ultra low carbon steel. The method comprises the steps of: employing a blowing process for desulfurization and slag removal of molten iron, with control of oxygen blowing time and smelting cycle of a converter, argon bottom-blowing in the whole course, and control of S content in slag lime, [C] content at converter end point, and temperature and oxygen activity at the endpoint, adding lime in a tapping process, and modifying ladle top slag after tapping; employing natural decarburization to control carbon content in an RH, wherein Als in molten steel is less than 0.03% after deoxidation, carrying out vacuum-breaking, adding aluminum powder and top slag modifier into the top slag, blowing argon with stirring, vacuumizing again, and carrying out clean circulation for 2-10 min; and carrying out continuous casting with protective casting in the whole course, wherein a nitrogen increase amount in the molten steel is controlled at less than 2 ppm. The invention can effectively reduce temperature drop in a transmission process, reduce oxygen blowing heating rate in a subsequent RH refining treatment, save energy and shorten the time of refining. Besides, the method can effectively guarantee modification effect of the top slag, prevent nozzle clogging and realize sequence casting. Therefore, the method is particularly applicable to the production of high purity ultra low carbon steel.

The invention provides a method for melting ultra-low carbon steel. The method adopts a desulfuration of molten iron-converter-RH-continuous casting process, wherein a sulfur content in the molten iron is 0.002%-0.006% after desulphurization; converter smelting controls oxygen blowing time, an oxygen gun flow, a bottom-blowing intensity and a smelting period, adopts slag-stopping tapping, steel tapping with a content of C being 0.06%-0.08% and with a temperature of 1650-1680 DEG C, and an oxygen content in the molten iron is 0.03%-0.05%; an RH adopts forced decarburization with a highest vacuum degree of 67-100 MPa and decarburization time of 15-27 min, and a carbon content in the molten iron is 0.0010%-0.0020% and a dissolved oxygen content in the molten iron is 0.025%-0.040% after the decarburization; the molten iron is recycled for 3-5 min after deoxidation by adding aluminium and recycled for another 3-5 min after adding other alloys; a nitrogen content in the molten iron is 0.0015%-0.0035%, and the temperature is 1590-1640 DEG C; and killed steel treatment is carried out for 10-30 min. The method adopts converter tapping with a high carbon and low oxygen content, can use less or not use slag modified agents during the tapping process, accelerates the production rhythm, makes the molten steel cleaner, and reduces the production cost.

The invention discloses a production process of a 65 Mn spring steel wire rod and a 65 Mn spring steel wire rod. According to the invention, advantages of a device of a high line set are utilized, a finish rolling and reducing-sizing mills adopt 8+4 type, through optimization of a heating cycle process before rolling, a rolling control process and a cooling control process, only 8 front finish rolling machines and 2 reducing-sizing mills are utilized, so that surface decarburization of a spring is reduced and is even removed, and the fatigue life of a finished spring is prolonged; the amount of scales is reduced and the metal yield is improved; a metallographic structure is improved and a high sorbite rate is obtained, so that the production process has conditions to cancel a lead patenting process at the earlier drawing stage, the production processing cost is reduced, and the metallographic structure and the comprehensive performance of a hot-rolled wire rod for the 65 Mn spring steel are optimized. According to the invention, the microstructure quality and the mechanical property of the produced hot-rolled wire rod with phi6.5 mm for the 65 Mn spring steel reach the standard of the conventional 65 Mn spring steel after lead hot-rolled wire rod for the 65 Mn spring steel, the conditions to cancel the lead patenting process at the earlier drawing stage by a downstream user can be satisfied, a processing process is reduced for a user, and the production cost is reduced.

The invention belongs to the gas separation technology area, it relates to a decarbonization solution which recycles or removes the carbon dioxide gas from the mixed gas which contains carbon dioxide, said invention specially relates to an ethoxyl ethylenediamine decarbonization solution. Its characteristic lies in: the invention has designed a new compound decarbonization solution which is composed of the main absorption component, the aid absorption component, the activation component, the corrosion inhibitor, the oxidation inhibitor and the water. Among, the main absorption component is AEE, the aid absorption component is AMP, MDEA and TEA, the activation component is MEA, DEA and PZ, the corrosion inhibitor is vitriol sour sodium, the oxidation inhibitor is the sodium sulfite and the cupric acetate. The effect and the profit of the invention are that it can be used in recycling many kinds of chemical industry reaction exhaust, the carbon dioxide of the combustion flue gas and the mixed gas, may also used in removing the carbon dioxide of town gas, the natural gas and so on, the merit of the decarbonization fluid is that the absorption capacity is big, purification is high, desorption rate is big, regeneration energy consumption is low.

A method for producing ultra-low-carbon steel belongs to steel-making technology field. The process route is: molten iron desulfuration preprocess -converter smelting -RH vacuum process -slab continuous casting. The iron desulfuration preprocess applies blowing magnesium granules for desulfuration; the converter smelting terminal carbon content and oxygen activity of molten steel; applying slag dam operation when tapping without deoxidation; the ladle furnace proceeds operation of top slag modification and temperature controlling; RH vacuum processing to control the maximum vacuum; applying Al for deoxidation when the decarburization is finished, and alloying if the deoxidation is finished and assuring the deep vacuum processing time after the deoxidation; calming the molten steel when the vacuum is finished; applying non-carbon covering agent and non-carbon protection slag in the slab casting process; the continuous casting process uses full protection casting, and the casting process controls a reasonable pulling speed according to slab section. The advantages are: the invention resolves problem of nozzle clogging and improves castability of the ultra-low-carbon steel and implements multi-furnace continuous casting, and the components of carbon, phosphorus, sulphur and nitrogen of the completed product conforms smelting request of the ultra-low-carbon steel.

A method of manufacturing a grain-oriented steel sheet including hot-rolling a slab prepared using molten steel containing, by mass%, C of not more than about 0.08 %, Si of about 1.0 to about 8.0 % and Mn of about 0.005 to about 3.0 %; optionally annealing the hot-rolled steel sheet; performing cold rolling once, or twice or more with intermediate annealing therebetween; performing primary recrystallization annealing in a low- or non-oxidizative atmosphere and adjusting the C content in the steel sheet after primary recrystallization annealing to be held in the range of about 0.005 to about 0.025 mass%; performing secondary recrystallization annealing; decarburization annealing; and, preferably, performing additional high-temperature continuous or batch annealing. A grain-oriented electrical steel sheet having a sufficiently high magnetic flux density and a low iron loss can be advantageously obtained even when it is manufactured without using an inhibitor.

The invention discloses a technological method for producing high-purity low-iron aluminum sulfate by using coal ash and comprehensively utilizing the coal ash, comprising the following steps of: carrying out mechanical activation, flotation decarburization, magnetic separation for deferrization, aluminum extraction with sulfuric acid, solid-liquid separation, concentration of aluminum sulfate crude liquor, organic alcohol alcoholization for acid rinse, organic alcohol alcoholization for deferrization and aluminum sulfate dewatering and drying on the coal ash to obtain the high-purity low-iron aluminum sulfate with low Fe content. The invention solves the problems on impurity removal and purification of the aluminum sulfate in the recycling process of the coal ash, simplifies the process flow, reduces the energy consumption, solves the technical problem of overlarge accumulation of secondary residue quantity, achieves high extraction ratio of aluminum contained in the coal ash, and realizes the recycling of organic alcohol and sulfuric acid and the comprehensive utilization of side products including unburnt black, magnetic iron powder, iron-containing aluminum sulfate crystals, high-silicon-dust active mineral blending materials or novel silicon-magnesium cement, and the like. The technological method has the advantages of simple process, short flow, easiness for control of a production process, high aluminum extraction ratio, low impurity content of products and stable quality.

The invention discloses a heating method used for preventing the high carbon strip billet from decarburizing. The strip billet is heated in the heating furnace, and the heating process comprises the preheating period, heating period, and heat soaking period. The invention is characterized in that the micro positive pressure and the weak oxidizability environment are adopted during the heating process to heat the strip billet. In the invention method, the heating time is reduced, the standing time of the billet in the high temperature area is reduced, the depth of the decarburizing layer on the surface of the billet can be controlled in a shallow scope, the metal recovery ratio is enhanced; the fuel consumption is reduced, the energy is economized; and compared with the method of coating a protecting layer on the surface of the billet, the cost and the labor intensity are reduced.

The invention relates to a hardening and tempering high-strength steel plate for wood based panel equipment and a production method of the steel plate, and belongs to the field of manufacturing low-alloy high-strength structural steel. The steel plate consists of the following chemical components in percentage by weight: 0.18 to 0.24 percent of C, 0.20 to 0.50 percent of Si, 0.80 to 1.20 percent of Mn, more than or equal to 0.02 percent of P, more than or equal to 0.01 percent of S, 0.20 to 0.50 percent of Mo, 0.20 to 0.50 percent of Ni, 0.70 to 1.00 percent of Cr, more than or equal to 0.003percent of B, 0.017 to 0.030 percent of Nb, 0.040 to 0.050 percent of V, 0.017 to 0.026 percent of Ti, and the balance of Fe and inevitable impurities. The production method of the steel plate comprises the following steps of: electric furnace smelting, vacuum decarburization / vacuum arc decarburization (VD / VOD) furnace vacuum decarburization, ladle furnace (LF) furnace refining, continuous casting (die casting), billet steel (ingot) clearing, heating, plate rolling, hardening and tempering, steel plate checking and polishing, tempering, sampling inspection, and warehousing. The hardening andtempering high-strength steel plate for the wood based panel equipment adopts Cr-Ni-Mo-B system micro-alloy elements for composite strengthening, and acquires good obdurability matching through a reasonable heat treatment process, and simultaneously the welding performance of a thick plate is not reduced.

The invention relates to a coating material for metal heat treatment process, especially a protective coating material for preventing oxidation / decarburization of steel workpieces during heat treatment heating. Composed of binder and its formula by weight percentage is: 10-20% glass powder, 33-30% quartz sand, 23-20% silica sand, 24-20% Al2O3, 2-10% C; this high-efficiency self-stripping High-temperature anti-oxidation / decarburization coating material, widely applicable to anti-oxidation / decarburization of various steels when heated at 800-1200°C / 4-10 hours, and can be naturally peeled off in the subsequent cooling process. The surface of the steel workpiece after heat treatment still has the original metallic luster, and the surface layer of the steel workpiece still maintains the original chemical composition; this coating material is easy to use, has excellent anti-oxidation / decarburization effects, strong natural peeling ability, and wide applicability .

The invention discloses a boron-contained centrifugal composite high-speed steel roller, which comprises an outer layer of the high-speed steel roller, a middle layer of the high-speed steel roller and a core of the high-speed steel roller. The manufacturing method includes steps of smelting, interrupted front treatment, roller pouring, annealing, rough machining, double tempering, finish machining and testing. By the method, three-layer composite roller technology is adopted in the boron-contained centrifugal composite high-speed steel roller, composite ability of the outer layer of the high-speed steel roller and the core of the high-speed steel roller is increased, the roller is less prone to spalling, high in rigidity and accident resistant ability, fine in abrasion resistance, safe in use, low in energy consumption and short in cycle in heat treatment, oxidation and decarburization of the roller and roller breakage in use are avoided. The manufacturing method is simple and hot quenching process is omitted.

The invention relates to a method for separating and purifying hydrogen from water gas by pressure swing adsorption. Raw material gas is sequentially subjected to a PSA-1 (Pressure Swing Adsorption) decarburization working procedure, a PSA-2 CO purification working procedure and a PSA-3 H2 purification working procedure. Six adsorption beds ABCDEF of a primary adsorption tower T1, seven adsorption beds ABCDEFG of a secondary adsorption tower T2 and eight adsorption beds ABCDEFGH of a tertiary adsorption tower T3 are mainly provided. Backward discharge gas in the PSA-3 H2 purification working procedure is used as the outward blowing gas for the PSA-1 decarburization working procedure, thereby increasing the hydrogen yield by about 3%; forward discharge gas recovered by the six beds of PSA-1 is circularly purified at the inlet of a raw material gas compressor, thereby reducing the loss of effective components in the decarburization working procedure; the content of methane in the process product gas generated by the seven beds of PSA-2 is decreased to 0; and the yield of the product CO is improved to be above 80%.

The invention provides an iso-butane, n-butane and butylene separation and purification method. C4 raw materials are successively put into a C3 decarburization tower, a C5 decarburization tower, an iso-butane tower, an n-butane tower and a stripping tower to obtain high-purity iso-butane, n-butane and butylene. Solvents are cyclically utilized. The iso-butane, n-butane and butylene separation and purification method has the technical advantages that not only can equipment investment be reduced, but also the advantages of extractive distillation are used and the energy consumption is reduced.

The invention relates to a process for smelting ultra-low-carbon steel, which comprises melted iron pretreatment desulfuration, converter smelt, LF furnace refining, RH vacuum process and continuous casting procedure in turn. Converter smelt tapping adopts non deoxidization tapping, steel which is tapped off is refined by LF ladle furnace before carried out melt iron vacuum decarburization processing, wherein refining is mainly used to proceed modifying property processing and further desulfuration and heating for top slag of melted iron, and the melted iron is reinforced with positive oxygen blowing decarburization after shifted into a RH vacuum container. The process can control carbon, nitrogen and sulfur in steel to preset objects which are required, and has excellent castability when a casting machine casted, thereby realizing casting by several furnaces.

The present invention relates to metal material, and especially cold forging steel coil for fastener and its production process. The superfine crystal microalloyed medium carbon steel coil has the alloy elements including: C 0.10-0.25 wt%, Si not more than 0.08 wt%, Mn 0.80-1.70 wt%, P not more than 0.035 wt%, S not more than 0.035 wt%, V, Nb, Ti and Al trace quantity, and Fe for the rest. Its production process includes the following steps: smelting in a converter, external refining, casting blank; heating to 1100 deg.c in a heating furnace; rolling at 750-830 deg.c, finish rolling in a TMCP process and rolling in a two phase region and great deformation quantity; controlled cooling and spinning; cooling and bundling at temperature lower than 500 deg.c. The cold forging steel coil is used in producing fastener directly in a cold header, has simple technological process, low cost, less pollution and raised production efficiency.

The invention discloses a coal-fired fluidized bed micro oxygen rich combustion CO2 emission reduction method and a coal-fired fluidized bed micro oxygen rich combustion CO2 emission reduction system for solving the problem of low-cost CO2 emission reduction of an industrialized coal-fired boiler. A micro oxygen rich combustion mode using mixed gas of air, oxygen and recycled smoke as a combustion aid is adopted, wherein the mixed gas contains about 25 percent of oxygen, 30 to 40 percent of recycled smoke and the balance of air; and in the micro oxygen rich combustion mode, the concentration of the CO2 gas in the generated smoke is 30 to 40 percent, and the CO2 in the smoke is removed by adopting a physical adsorption technology. The invention also provides a system device for implementing the method. By considering oxygen making cost, energy consumption and optimal comprehensive effect of separating CO2 by physical adsorption and combining the micro oxygen rich concept and the circulating fluidized bed combustion technology, desulfuration, denitration, decarburization and zero pollution emission at lower cost can be realized. The invention has the advantages of good economic efficiency, simple process, low energy consumption, high automation degree in operation process and the like.

The invention discloses a method for producing cold-rolled steel strips. The method comprises the following steps of: performing krypton (KR) desulfurization treatment, converter dephosphorization-less slag decarburization and relative humidity (RH) light treatment on molten iron, and performing continuous casting to obtain a high-purity plate blank; heating the plate blank, performing rough rolling and precision rolling to obtain a hot-rolled plate, cooling the hot-rolled plate and coiling the hot-rolled plate into a hot-rolled coil; and performing cold rolling, annealing and flattening on the hot-rolled coil, and coiling the hot-rolled coil into a finished product. By the method for producing the cold-rolled steel strips, the cold-rolled steel strips which have high drawing property and good welding performance and can be used for flux-cored wires can be produced, the production requirement of the flux-cored wires is met, splash in the welding process is reduced, seams with good welding quality are obtained, and the automation level of welding is improved.

The invention relates to a control method for surface decarburization and ferrite distribution of a steel disc bar of a spring. The method comprises the steps of raw material preparation,smelting in a converter, LF (Ladle Furnace), VD (Vacuum Degassing) treatment, continuously casting, flaw detection and coping, heating, rolling, spinning, wind cooling by stelmor, intensively coiling, detecting and putting in a storeroom, rolling wire rods to be 8-18 mm in diameter, ensuring that the tensile strength (ob) is 950-1100MPa and the percentage reduction of area (Z) is 30-50 percent after aging treatment, and organizationally adding a small amount of dispersedly distributed into sorbite. Compare with other processes, the strength is decreased to a certain extent, the reduction of area is improved to a certain extent, the variation range of the strength and reduction of area is smaller, the performance is more stable, pulling and reeding operation is facilitated, the production cost of spring steel is lowered, and the service life of the spring steel is prolonged.

A smelting method for a low-silicon ultralow-sulphur steel belongs to the metallurgy technical field. The smelting process for producing low-silicon ultralow-sulphur steel comprises: molten iron 'complete-three-removal' pretreatment, decarburization converter smelting, and LF refining process. In order to ensure that silicon increase in molten steel during deep desulphurization is prevented, the sulphur content in molten steel for refining pull-in is firstly decreased by KR molten iron desulphurization pretreatment, and the pressure for LF deep desulphurization is reduced; then the silicon content in molten iron in a decarburization converter is decreased by desilication pretreatment in a dephosphorization converter to ensure the alkalinity of the slag in the decarburization converter is more than 4.0. The advantages are that the problem of the easy increase of silicon during the LF refining desulphurization process in the prior art is solved; the refining time is shortened; and the production efficiency is improved.

The invention discloses a zinc-plated hot-formed steel plate or steel strip with excellent cold bending performance and a manufacturing method thereof. The zinc-plated hot-formed steel plate or steelstrip comprises a base plate with a surface decarburization layer thickness of 20 [mu]m or below and a zinc coating with an adhesion amount of 10-100 g / m<2> on the base plate. The constituent weight percentage of the base plate is C: 0.1-0.8%, Si: 0.05-2.0%, Mn: 0.5-3.0%, P: <=0.1%, S: <=0.05%, Al: <=0.1%, N: <=0.01%, and the balance Fe and unavoidable impurities. The average size of original austenite grains of the base plate is 15 [mu]m or below. The hot-formed steel plate or steel strip has a continuous and complete coating, no cracks extending to the base plate and excellent cold bending performance on the basis of meeting the conditions that the tensile strength of the base plate after hot-forming is 1500 MPa and the elongation after breaking is 5%.

The invention relates to a control method for preventing nozzle clogging in a casting process of ultra-low carbon-aluminium deoxidized molten steel, and belongs to the technical field of a steelmaking technology. The technical scheme is that a process path of molten iron desulfurization treatment, converter smelting, converter steel tapping, Rheinstahl Heraeus (RH) vacuum treatment, and continuous casting of a dual-flow slab is adopted to smelt ultra-low carbon steel, so that the castability of the ultra-low carbon-aluminium deoxidized molten steel is improved; the oxygen content of the molten steel of a converter blowing end-point, the carbon content and the temperature of the endpoint are reasonably controlled; a favorable condition is provided for RH vacuum decarburization; pouring is protected in a continuous casting manner; secondary oxidization of the molten steel is prevented by adopting blowing-argon sealing protection of a long-nozzle and a submersed nozzle; secondary oxidization of the molten steel is prevented by using an alkaline covering agent; an occluded foreign substance in the molten steel is well adsorbed; the castability of the ultra-low carbon-aluminium deoxidized molten steel is improved; the targets of no choking of the submersed nozzle and no change of the submersed nozzle in a complete multi-furnace continuous casting process are achieved. Thus, the effect on a casting blank caused by replacement of the submersed nozzle is avoided.

A method and an apparatus for advantageously introducing a flame and a high velocity oxidizing gas into a furnace for metal melting, refining and processing, particularly steel making in an electric arc furnace. The steel making process of an electric arc furnace is made more efficient by shortening the time of the scrap melting phase and introducing an effective high velocity oxidizing gas stream into the process sooner to decarburize the melted metal. In one implementation of an apparatus, improved efficiency is obtained by mounting a fixed burner / lance closer to the hot face of the furnace refractory at an effective injection angle. This mounting technique shortens the distance that the flame of the burner has to melt through the scrap to clear a path to the molten metal and shortens the distance the high velocity oxygen from the lance travels to the slag-metal interface thereby increasing its penetrating power. The method additionally includes supplying a plurality of reaction zones with the high velocity oxidizing gas to decarburize the melted metal. The plurality of reaction zones increases the surface area available for the reaction thereby allowing a more rapid rate of decarburization and a more homogenous metal bath. The reaction zones are supplied with the high velocity oxidizing gas according to an oxygen supply profile which is related to the carbon content of the metal bath. In this manner an optimal amount of oxygen can be introduced into the metal bath to shorten the decarburization process without producing excessive oxidation of the metal bath and excessive free oxygen in the furnace.

The invention provides a full production process of a low-temperature oriented silicon steel, relates to the technical field of metallurgy, and aims at solving the technical problems of high slab heating temperature, short service life of a heating furnace, energy waste, low converter smelting designation hit rate of the oriented silicon steel due to narrow range of requirements on C and other chemical element contents, and the like of traditional cold-rolled oriented silicon steel. The full production process of the low-temperature oriented silicon steel comprises the following steps: molteniron pre-treatment, converter treatment, RH (Ruhrstahl-Heraeus) vacuum treatment, slab continuous casting, hot charging and hot delivery, slab heating, hot rolling, primary cold rolling, primary decarbonization and annealing, secondary cold rolling, low-temperature recovery annealing and magnesium oxide coating, high-temperature cover furnace annealing, stretching and insulating layer coating, aswell as slitting, packaging and storing to finally produce the low-temperature oriented silicon steel.