3784results about "Manufacturing converters" patented technology

A device for use in a molten metal pump helps alleviate jams between a rotating rotor and stationary inlet. The device includes an inlet structure including one or more openings and a displacement structure that preferably includes one or more rotor blades. The inlet structure and displacement structure are connected to one another (preferably, but not necessarily, as a unitary piece), thus enabling them both to rotate. A pump including the device is also enclosed. The invention further includes a bearing surface for an impeller or for a device according to the invention, wherein the bearing surface includes grooves that help reduce molten metal build up between the bearing surface of the impeller or device and the bearing surface of a pump chamber.

Improved components for a molten metal pump include a coupling for connecting a rotor shaft to a motor shaft, a rotor shaft and a rotor. The rotor shaft has a first end and a second end wherein the first end optionally has a vertical keyway formed in the outer surface of the shaft. The second end optionally has flat, shallow threads. The coupling can be one-piece or multi-piece, includes a cavity for receiving the first end of the rotor shaft and, if the first end of the rotor shaft has a keyway, the coupling includes a projection in the cavity for being received at least partially in the keyway. The rotor includes a connective portion that connects to the second end of the rotor shaft. If the second end of the rotor shaft includes flat, shallow threads, the connective portion is essentially a bore having flat, shallow threads configured to receive the second end of the rotor shaft. Optionally, the first end of the rotor shaft may have flat, shallow threads in which case the coupling would have a cavity that receives the first end of the rotor shaft, wherein the cavity has flat, shallow threads.

An improved post clamp for a molten metal pump includes a support post clamp that supports the weight of a pump superstructure on the top of the support posts. The clamp preferably includes (a) a bottom flange for connecting to the pump superstructure, (b) a cavity for receiving an end of a support post, wherein the end has a top surface, and (c) a top flange for being positioned above the top surface. In operation the top flange rests on the top surface of the support post thereby supporting at least part of the weight of the superstructure. It is preferred that a plurality of support posts and post clamps according to the invention be used with a molten metal pump wherein the top surface of each support post supports some of the weight of the superstructure. Also disclosed are novel support posts that may be used with the post clamp, and a pump in which the post clamp and/or support posts may be used.

The invention relates to an austenitic stainless steel, a steel tube thereof and a manufacturing method thereof, wherein the austenitic stainless steel and the stainless steel tube comprise the components by mass percent: 0.060-0.14% of C, more than 0 and less than or equal to 0.50% of Si, more than 0 and less than or equal to 1.00% of Mn, less than 0.040% of P, less than 0.015% of S, 17.00-20.00% of Cr, 8.00-11.00% of Ni, 2.50-4.00% of Cu, 0.30-0.60% of Nb, 0.15-0.50% of Mo, 0.15-0.50% of Co, 0.05-0.14% of N, 0.001-0.01% of B, the rest of Fe and unavoidable impurity. The manufacturing method of the steel tube comprises: smelting and pouring to form steel ingots or continuously cast bloom, processing bar material, preparing tubular billet and further processing the steel tube; the method comprises the steps: the heating temperature of processing the bar material is 1250-1270 DEG C, heating temperature of preparing the tubular billet is 1100-1220 DEG C, and the finished product solid solution temperature is 1120-1190 DEG C. The austenitic stainless steel tube has high temperature creep strength and corrosion resisting performance at the high temperature.

A device for submerging scrap metal includes: (a) a drive source, (b) a drive shaft having a first end and a second end, the first end being connected to the drive source, and (d) an impeller connected to the second end of the drive shaft, the impeller preferably having two or more outwardly-extending blades. Preferably, each of the blades has a portion that directs molten metal at least partially downward. The impeller design leads to lower operating speeds, lower vibration, longer component life and less maintenance. Additionally, the impeller preferably has a connective portion. The connective portion is used to connect the impeller to the shaft and preferably comprises a nonthreaded, tapered bore extending through the impeller.

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.

The invention provides a high-toughness and ultrahigh-strength wear-resistant steel plate and a production method thereof. The steel comprises the following chemical compositions by mass percent: 0.15-0.26% of C, 0.20-0.55% of Si, 1.0-1.60% of Mn, P less than or equal to 0.020%, S less than or equal to 0.010%, 0.00-0.60% of Mo, 0.00-0.50% of Ni, 0.20-1.00% of Cr, 0.01-0.05% of Ti, 0.02-0.04% of Als, 0.0005-0.004% of B and the balance Fe and inevitable impurities. The production method of the steel comprises the following steps: high clean steel smelting, hot metal desulphurizing, converter top-bottom blowing, vacuum processing and blank casting, in particular to plate blank heating, rough rolling, finish rolling and heat treatment technology parameter controlling. The chemical compositionsof the steel contain no V, Mo or Ni, or contain less Mo and Ni, therefore, the steel plate is low in alloy content and fine in toughness and can be widely applied to the mines and construction machinery products, which feature bad working conditions and have high requirements on steel properties.

The invention relates to a high carbon steel wire rod with tensile strength of more than 1,200 MPa and surface shrinkage of more than 35 percent and a preparation method thereof. The high carbon steelwire rod comprises the base components of C, Si, Mn, Cr and the like, selective components of Ni, Cu, Al, B, Ti, Nb, Mo and the like, and the balance of Fe and impurities. The preparation method comprises the following procedures of smelting, casting, rolling and cooling control sequentially, wherein the rolling-starting temperature of the rolling procedure is controlled between 1,000 DEG C and 1,100 DEG C, the spinning temperature is 870-930 DEG C, the cooling controlling procedure is carried out by adopting Steyr cooling control, rapid cooling is adopted before the phase change and at the earlier stage of the phase change, and the slow cooling is adopted at the later stage of the phase change. The high carbon steel wire rod has excellent mechanical performance, less alloy elements and low cost; and meanwhile, the preparation method is realized by only less adjusting the prior production process of the high carbon steel wire rod without nearly adding any production cost.

A weather resistant thick steel plate comprises, by weight, 0.06%-0.9% of C, not more than 0.30% of Si; 1.10%-1.50% of Mn, not more than 0.015% of P, not more than 0.003% of S, 0.035%-0.065% of Als, 0.25%-0.50% of Cu, 0.20%-0.50% of Ni, 0.40%-0.70% of Cr, 0.50%-0.15% of Mo, 0.008%-0.018% of Ti, 0.030%-0.060% of V, 0.015%-0.030% of Nb, not more than 0.0055% of N, 0.001%-0.004% of Ca, 0.0004%-0.0010% of selectively added B, and the balance of Fe and unavoidable impurities. The manufacturing method includes deep desulfurization of molten iron, converter smelting, LF, RH, continuous casting, on-line finishing of slabs, cut-to-length torch cutting of slabs, heating, TMCP, and slow cooling of steel plates. The obtained weather resistant thick steel plate has balanced strong toughness and strong plasticity, low yield ratio, atmospheric corrosion resistance, excellent weldability and fatigue resistance, and is especially applicable to non-coating high-rise building structures and bridge structures.

In accordance with one aspect of an exemplary embodiment, a furnace including a charge well is provided. The charge well comprises an open top chamber including side and base walls of a heat resistant material. An inlet is provided in a side wall of the chamber for receiving molten metal. A ramp is provided adjacent the side wall and an inner wall forms a central cavity. The ramp is disposed between the inner wall and the side wall. The ramp is generally inclined from an intersection with the base wall to adjacent a top surface of the inner wall. The cavity is in fluid communication with an outlet. A passage in the inner wall provides fluid communication between the inlet and the cavity. The inlet and an outlet each receives a conduit and at least one of the conduits can include an elbow joint.

The invention relates to a high strength low alloy hot rolling ferrite bainite weathering resistant steel and a production method thereof. The steel comprises the components by weight percent: 0.05-0.10% of C, 0.30-0.45% of Si, 1.00-1.50% of Mn, less than or equal to 0.015% of P, less than or equal to 0.01% of S, 0.50-0.70% of Cr, 0.20-0.30% of Ni, 0.20-0.40% of Cu, less than or equal to 0.05% ofAl, 0.01-0.025% of Ti, 0.03-0.05% of Nb and the rest of Fe and impurities; and the yield strength is more than or equal to 450MPa, and the welding cold crack susceptibility coefficient is less than orequal to 0.2. The invention has the advantages of low cost, high strength, low yield ratio, high weatherability, excellent weldability and low temperature toughness, simple process flow of the preparation technique and easy operation. Therefore, the invention can be widely applied to the fields such as bridges, buildings, containers, railway coaches, etc.

Disclosed are couplings for use in devices positioned in a molten metal bath. One is a rigid coupling that may include a counterweight, the coupling to reduce nonconcentric movements during rotation of a shaft, particularly a rotor shaft. Another coupling uses magnetic force, rather than a direct physical connection, to form a driving connection between a drive shaft (such as a motor drive shaft) and a driven shaft (such as a rotor shaft). In the event the rotor is jammed, the increased torque creates an overload that disconnects the drive shaft from the driven shaft in order to help prevent damage to the rotor, driven shaft, drive shaft and other components. Also disclosed is a coupling to transfer gas into a shaft, the coupling having a non-threaded internal surface to help prevent gas leakage and thus assist in preventing any resulting damage to the coupling and shaft.

The invention discloses a producing method of clean steel, which can further enhance the cleanliness and comprise the following steps of: pretreating with molten iron for desulfurizing until [S] is not more than 0.010%; then delivering to a converter for smelting; dephosphorizing and controlling sulfur; controlling finished molten iron in the converter to be with [P] of not more than 0.0080% and [S] not more than 0.010%; adding a ladle slag modifying agent to ladles in a steel tapping process for regulating and modifying the ladle slag, wherein after treating, in the molten iron, [P] is not more than 0.0060% to 0.0080%, [S] is not more than 0.0080% and roughing slag quantity is not more than 0.5%; controlling refined finished slag components in LF (Low Frequency) refining, wherein soft argon blowing time of the molten iron is not less than 5 minutes after LF refining, and the composition is qualified when [S] is not more than 0.0020%; carrying out VD (Vacuum Degassing) refining to ensure that [H] is not more than 1.5ppm; and continuously casting, wherein a double-layer high-alkalinity covering agent is adopted as a middle ladle, a seal ring and a long water gap are additionally arranged for argon-blowing protective casting, which is carried out at constant speed, and overheat delta T of the molten iron ranged from 15 DEG C to 30 DEG C. Under the condition that the producing cost is not increased basically, the cleanliness of the clean steel is further enhanced by the control of each procedure junction point, and the clean steel comprises the following components by weight percent: S not more than 20ppm, P not more than 100ppm, TO not more than18ppm, H smaller than 2.0ppm, N not more than 35ppm, and A, B, C and D types of impurities not more than 0.5 grade.

An apparatus and method are disclosed in which ultrasonic vibration is used to assist the degassing of molten metals or metal alloys thereby reducing gas content in the molten metals or alloys. High-intensity ultrasonic vibration is applied to a radiator that creates cavitation bubbles, induces acoustic streaming in the melt, and breaks up purge gas (e.g., argon or nitrogen) which is intentionally introduced in a small amount into the melt in order to collect the cavitation bubbles and to make the cavitation bubbles survive in the melt. The molten metal or alloy in one version of the invention is an aluminum alloy. The ultrasonic vibrations create cavitation bubbles and break up the large purge gas bubbles into small bubbles and disperse the bubbles in the molten metal or alloy more uniformly, resulting in a fast and clean degassing.

The invention belongs to the field of metallurgy, and relates to a method for producing low phosphorus steel by smelting semisteel, which solves the technical problem of controlling the steelmaking end point of a converter within 0.006 percent. The method is mainly realized by adjusting slag-making parameters of the converter smelting by adopting a single slag method, which comprises that: the slag-making materials added in the converter slag-making process consist of 40-50kg of active lime, 20-30kg of high-magnesium lime and 15-25kg of composite slag former based on per ton of tapping molten steel; and the slag-making materials are added in twice. In addition, by controlling an oxygen supply system and an end point control system, the dephosphorization rate of the converter can reach over 92 percent; molten steel containing less than 0.006 percent of phosphorus is obtained; steel ladle slag de-P and alloy re-P are controlled within 0.002 percent. The method can stably produce finished low phosphorus steel containing less than 0.010 percent of phosphorus, and is characterized by simple operation method, small investment on equipment and low production cost.

PCT No. PCT/AT97/00201 Sec. 371 Date May 15, 1998 Sec. 102(e) Date May 15, 1998 PCT Filed Sep. 12, 1997 PCT Pub. No. WO98/12359 PCT Pub. Date Mar. 26, 1998In a process for working up combustion residues and slags from waste incineration plants or steel works slags, the slag is charged at a slag layer height of above 1.2 m into a converter (1), in which the molten slag is reacted with a metal bath (4) through which oxygen is blown. The oxygen is introduced into the bath (4) for cooling the submerged tuyeres (7, 8) in the form of air or along with CO2 or water vapor.

A metal scrap submergence device comprising an open top chamber including walls of a heat resistant material, an inlet positioned in a side wall of the chamber, an outlet positioned in the base of said chamber, and a ramp adjacent said side wall of the chamber. The side wall further includes a feature affecting molten metal flow. The feature can include, for example, a baffle, a vane, a passage, a diverging or converging shape and combinations thereof. Similarly, the molten metal flow can be affected by slanting the ramp inwardly or outwardly.

The invention discloses a production method of low-silicon and low-carbon deep punching/drawing steel, bottom-blowing argon is performed in the whole process of converter smelting, and a single slag/double slag technique is adopted to pour out the dephosphorized slag, high-basicity slag is produced in later period, the dualistic basicity of final slag R is more than 3.5, the terminal temperature of molten steel is 1620 DEG C to 1650 DEG C, and tapping ( P ) is less than 0.012 percent. The molten steel is refined by adopting low-silicon and low-carbon high-basicity reductive slag in a LF furnace refining station, thus to manufacture reductive slag for desulphurisation, and the ( Al ) in the molten steel is less than 0.005 percent. The molten steel refined by the LF furnace is vacuum-treated by a RH vacuum furnace, the carbon and the silicon in the molten steel is circularly removed, the molten steel is continuously casted into a casting blank through a CSP sheet bar conticaster, the casting blank is sent into CSP sheet bar heat continuous rolling mill and rolled into a coiled sheet after being heated in a roller hearth soaking furnace, a hot rolled coiled sheet is coldrolled into cold rolled coiled sheet through a cold tandem mill or a single mill after being acidwashed, and leveled through a leveling machine after being annealed by a cover furnace, and a leveling divided coil is stretched and divided. The production method has the advantages that the production cost of the working procedure is saved, the consumption of the refractory consumption of the converter is reduced, the equipment investment is saved, the process of the production technique is steady and smooth, the n value of the cold rolled plate is bigger than 0.23, the r value thereof is bigger than 2.1, and the deep punching performance and the extensibility are good.

A process for energy- and emission-optimized iron production and an installation for carrying out the process. A first partial amount of a generator gas produced in a melter gasifier is used as a first reducing gas in a first reduction zone. A second partial amount is fed to at least one further reduction zone as a second reducing gas. In addition, after CO₂ scrubbing, a partial amount of top gas removed from the first reduction zone is admixed with the generator gas after the latter leaves the melter gasifier, for cooling the generator 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.

A container does not need a member such as a stoke and the like that are exposed to the molten metal therein, thus the necessity to replace the parts such as the stoke and the like can be eliminated. In addition, there is no structure like the stoke in the container, the operability for the preheating is improved thus the preheating can be performed effectively. In addition, since a flow passage is formed inside the lining with high heat conductivity, inner heat of the container is easily conducted to the flow passage. Thus, the decrease in temperature of the molten metal that flows inside the flow passage can be suppressed to the utmost.

The invention provides a metallurgical composite pelletizing prepared through a twice pelletizing method, as well as a preparation method and an application thereof. The pelletizing is provided with a pelletizing shell formed by a central pelletizing core and a pellet material coating the outside of the pelletizing core. The internal pelletizing core of the formed pelletizing is in a reducing atmosphere, the outside of the formed pelletizing is in an oxidizing atmosphere, and the metallurgical composite pelletizing undergoing twice pelletizing satisfies the metallurgical requirements. The pelletizing core takes an iron-containing material and reducing coal dust or coke powder as raw materials in which adhesive and waste fly dust are added, and is obtained by means of disk pelletization or pressure pelletization. The pelletizing shell takes the iron-containing material and the pelletizing core as raw materials in which the adhesive is added, and is obtained by means of disk pelletization and taking the pelletizing core as the center of the sphere. Various metallurgical performance indexes of the composite pelletizing are highly better than normal pellets. The composite pelletizing not only realizes the harmlessness and the recycling of the waste fly ash, but also can greatly improve the technical and economic indexes of iron making blast furnaces. In addition, the composite pelletizing not only achieves such social benefits as energy conservation, emission reduction, environment protection and environment pollution treatment, but also can create considerable economic benefits.

The invention discloses a converter smelting endpoint molten steel carbon and temperature control system and a method thereof, and belongs to the technical field of converter steelmaking automation control. The converter smelting endpoint molten steel carbon and temperature control system comprises hardware equipment and a software processing module, and is characterized in that: the hardware equipment comprises converter sublance measuring equipment and converter exhaust gas analysis equipment; the software processing module comprises a converter production process data acquisition module, a converter smelting endpoint carbon calculation module, a converter smelting endpoint temperature calculation module, and an information display module; the software processing module is operated on a computer; and the hardware equipment and the software module are connected with a converter production process database through an Ethernet to realize data interaction. The control system and the method thereof have the advantages of accurately controlling the converter smelting endpoint molten steel carbon content and the molten steel temperature, along with stable operation, cost conservation, and wide application range.

The X65 pipeline steel for use in acid condition consists of C 0.02-0.05 wt%, Mn 1.20-1.50 wt%, Si 0.10-0.50 wt%, S not more than 0.0020 wt%, P 0.004-0.012 wt%, Nb 0.05-0.07 wt%, Ti 0.005-0.025 wt%, Mo 0.050-0.195 wt%, Cu not more than 0.35 wt%, Ni not more than 0.35 wt%, N not more than 0.0080 wt%, Ca 0.0015-0.0045 wt% and Ca/S not less than 2.0 except Fe. Its making process includes the following steps: smelting in a converter or an electric furnace; secondary steel making including LF desulfurizing + RH vacuum deairing and Ca treatment; continuous casting; rolling with initial rolling termination temperature of 940-1020 deg.c and finish rolling termination temperature of 780-840 deg.c; and winding at 500-580 deg.c. The X65 pipeline steel has low manufacture cost, high HIC resistance, high dynamic tear resistance and high impact toughness.

The invention discloses a low cost yield strength 700MPA level non-tempering processing high strength steel plate, which is characterized by, in terms of mass, comprising 0.05-0.10% of C, 0.1-0.4% of Si, 1.5-2.0% of Mn, less than 0.015% of P, less than 0.01% of S, 0.3-0.8% of Cr, 0.09-0.15% of Ti, 0.04-0.08% of Nb, less than 0.005% of N, less than 0.002% of O, and balance of Fe and unavoidable impurities. The manufacturing method of the steel plate comprises technological steps of smelting, rough rolling, fine rolling, reeling and cooling to obtain the steel plate with yield strength of 700-780MPa, tensile strength of 800-860MPa and elongation Delta larger than or equal to 18%. The yield strength 700MPA level non-tempering processing high strength steel plate simultaneously has abrasive resistance and better low temperature toughness, toughness and crispiness transition temperature is at around negative 40 DEG C, specific energy of shock at normal temperature can reach as high as 120J.

The invention discloses a high-cleanliness pipeline steel smelting process. The process route comprises molten iron pouring, molten iron pretreatment, converter smelting, tapping, deoxidizing, alloying, LF refining furnace, treating with calcium, RH vacuum furnace and continuous casting and is characterized by comprising the following specific steps: firstly, converter smelting process; secondly, refining furnace smelting process; and thirdly, continuous casting process. The invention belongs to a steel-making process in the field of metallurgy and relates to a method for smelting and controlling a high-cleanliness pipeline steel. By molten iron desulphurization pretreatment, optimizing a converter tapping and deoxidizing system and a slagging system, LF refining furnace deep deoxygenation and reducing slag manufacturing processes, RH high-vacuum-degree degassing and inclusion removal process, the pouring is protected by the continuous casting in the whole process so that the composition of a casting billet is uniform, the contents of harmful elements such as S, P, O, N and H are low, the non-metallic inclusions are effectively controlled, the casting billet is good in internal quality and the production of high value-added ultra-low sulfur steel is ensured.

Exemplary embodiments of the invention provide a molten metal containment structure including a refractory molten metal containment vessel having an external surface, and a metal casing for the vessel having an internal surface at least partially surrounding the external surface of the vessel at a distance therefrom forming a spacing between the vessel and the casing. The spacing includes an unobstructed upwardly extending gap that is vented to the exterior of the structure by upper and lower openings in the casing. A layer of insulating material is preferably positioned in the spacing between the internal surface of the casing and the external surface of the vessel, with the layer of insulating material being narrower than the spacing at least at upwardly extending sides of the casing, thereby forming the unobstructed gap. The vessel may be a metal conveying trough, a housing for a metal filter, a container for a metal degasser unit, a crucible, or the like.

The invention discloses an on-line dynamic optimization control method for a converter steelmaking process based on data driving. The method comprises the following steps: building an off-line prediction model database; building a liquid steel temperature prediction model and a carbon content prediction model by use of a data driving method to obtain a corresponding relationship between operating variables and the temperature and carbon content of liquid steel in the converter steelmaking process; selecting a melt data unit matched with the information of the current converter steelmaking production process and determining a control reference curve of the liquid steel temperature and carbon element content; building a real-time dynamic optimization model of the converter steelmaking process and determining an optimized set value unit of each operating variable; and selecting the set value of each operating variable from the optimized set value unit so as to carry out control operation. The method disclosed by the invention can be used for realizing real-time on-line control over the converter steelmaking process and providing convenience for an operator to set selection conditions according to actual working conditions, thus the production efficiency of a steelmaking plant is improved.

The present invention belongs to the field of iron and steel smelting technology, and is especially boron steel producing process in a converter. The production process includes the steps of smelting in a converter, deoxidizing and refining in a ladle, and boron alloying. The boron steel producing process has low oxygen content in molten steel after refining, high boron steel yield of 69.4-91.8 %, and excellent application foreground.

The invention provides hot-rolled H-steel for a low temperature-resistance structure and a preparation method for the hot-rolled H-steel. The hot-rolled H-steel for the low temperature-resistance structure comprises the chemical components in weight percentage: 0.12-0.22 percent of C, 0.10-0.40 percent of Si, 1.1-1.50 percent of Mn, not greater than 0.025 percent of P, not greater than 0.025 percent of S, 0.01-0.05 percent of V and the balance of Fe and trace impurity. According to the hot-rolled H-steel for the low temperature-resistance structure, mainly through reducing sulphur content and employing vanadium for microalloying without adding other elements, immersion-type flat water gap fully-protective casting is adopted in the continuous casting process. Because of the complexity of a beam blank continuous casting machine, aluminium deoxidation is not adopted. Therefore, the low temperature-resistance steel provided by the invention is good in mechanical property, and the average longitudinal impact power is 90J at the temperature of -20 DEG C.