5681 results about "Molten steel" patented technology

The invention discloses a method for improving the performance of 700 MPa grade V-N microalloyed high strength weathering steel. The method is specific to the characteristics of the sheet billet continuous casting and tandem rolling technology and metallurgy component, and adopts an electric furnace or a revolving furnace to smelt, refine, continuously cast sheet billet which directly enters into a roller hearth to heat after a casting blank concretes, or soaking furnace, hot rolling, laminar flow cooling and wind-up process flow. The chemical composition of molten steel is :C occupies less than or equal to 0.08Wt. percent, Si occupies from 0.25 to 0.75Wt. percent, Mn occupies from 0.2 to 2.0Wt.percent, P occupies less than or equal to 0.025Wt. percent, S occupies less than or equal to 0.040Wt. percent, Cu occupies from 0.25 to 0.60Wt. percent, Cr occupies from 0.30 to 1.25 Wt.percent, Ni occupies less than or equal to 0.65Wt. percent, V occupies from 0.02 to 0.20Wt. percent and N occupies from 0.015 to 0.030 Wt. percent. The invention takes full advantages of the characteristics of the sheet billet continuous casting and tandem rolling short flow process and adopts the V-N microalloyed technique to produce 700 MPa grade high strength weathering steel under the thinning function of VN and V (C, N) nanometer scale precipitate on crystal grain in casting blank of the sheet billet continuous casting and tandem rolling flow and the theory of precipitation strength. By the optimization design of the metallurgy component of V-N microalloyed 700MPa grade high strength weathering steel, the invention increases the low temperature impact ductility of coil of strip and improves the shaping property.

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 relates to a manufacturing method of thin strip continuously cast and cold rolled non-oriented electrical steel, comprising the following steps: smelting molten steel the temperature and components of which meet the requirements, casting the molten steel into a molten bath formed by a pair of water-cooling crystallizing rolls rotating at high speed, then cooling for the second time, hot rolling, cooling for the third time, coiling, cooling to room temperature, pickling, cold rolling, and finally annealing to obtain the cold rolled non-oriented silicon steel sheet with high magnetic induction and low iron loss. In the invention, the thin strip continuous casting process can eliminate the hot rolling thinning procedure in the traditional process, thus avoiding quality defect caused by the improper hot rolling process, simultaneously reducing the equipment loss, and reducing the maintenance and overhaul costs of equipment; the solidification process is controlled to improve the medium axialite proportion of the casting strip, thus improving the corrugation defect of the product in the cold rolling process; and the range of components of the non-oriented silicon steel smelting is widened by the characteristic of quick solidification of the continuously cast thin strip, and the smelting cost is lowered. The invention has the advantages of short process flow, low energy consumption, high efficiency, low production cost, simple manufacturing method and obvious energy saving and consumption reducing effects.

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.

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.

The invention provides a high-strength cold rolling transformation induced plasticity steel plate and a preparation method thereof. The high-strength cold rolling transformation induced plasticity steel plate comprises the following components by weight percentage: 0.1%-0.5% of C, 0.1%-0.6% of Si, 0.5%-2.5% of Mn, 0.02%-0.12% of P, less than or equal to 0.02% of S, 0.02%-0.5% of Al, less than or equal to 0.01% of N, 0.1%-1.0% of Cu and the rest Fe. The preparation method comprises the following steps of: (a) refining molten steel meeting a component condition, and casting into a blank; (b) rolling, wherein the heating temperature is 1,100-1,250 DEG C, the heat preservation time is 1-4h, the initial rolling temperature is 1,100 DEG C, the final rolling temperature is 750-900 DEG C, the coiling temperature is less than 700 DEG C, the thickness of a hot rolled steel plate is 2-4mm, and the cold rolling accumulated pressing amount is 40-80%; and (c) continuous annealing, wherein the annealing temperature is 700-Ac3+50 DEG C, the heat preservation time is 30-360s, the cooling speed is 10-150 DEG C/s, the aging temperature is 250-600 DEG C, the aging time is 30-1,200s, and the hot roller steel plate is cooled at the speed of 5-100DEG C/s to be at the room temperature. The steel plate disclosed by the invention has the bending strength of 380-1,000 MPa, tensile strength of 680-1,280 MPa and elongation of 15-30%.

The invention discloses high-strength, high-toughness and high-plasticity martensitic stainless steel, and belongs to the technical field of metallurgy. The martensitic stainless steel comprises the following components in percentage by weight: 0.15 to 0.4 percent of C, 0 to 0.12 percent of N, 0.2 to 2.5 percent of Si, 0.4 to 3.0 percent of Mn, less than or equal to 0.02 percent of S, less than or equal to 0.02 percent of P, 13.0 to 17.0 percent of Cr, 0 to 5.0 percent of Ni, 0 to 2.0 percent of Mo, 0 to 0.3 percent of V, 0 to 0.2 percent of Nb, 0 to 0.05 percent of Ti, 0 to 0.8 percent of Al and the balance of Fe and inevitable impurities. A preparation method comprises the following steps of (1) smelting molten steel according to the set components, and solidifying the molten steel to form an ingot blank by using a continuous casting machine or a casting mold; (2) hot-rolling the ingot blank to form a hot-rolled plate blank; (3) heating the hot-rolled plate blank to 950 to 1100 DEG C, preserving heat for 0.5 to 2 hours, cooling the plate blank to 25 to 200 DEG C, heating the plate blank to 350 to 500 DEG C, preserving heat for 10 to 60 minutes, and air-cooling the plate blank to room temperature. According to the martensitic stainless steel prepared by the method, dispersed remaining martensite is introduced into a microscopic structure, so that the strength, toughness and plasticity of the martensitic stainless steel are greatly improved.

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.

A method of using thin plate adobe continuous casting and rolling to producing thin band steel coil is provided, which belongs to rolling metal at once after continuous casting, in particular relating to thin standard band steel production method. The invention is characterized in that: a conticaster, a swing shear, a roller-hearth type heating furnace, a scale breaker, a vertical miller, 7 mill groups, laminar flow cooling device and reeling machine are connected to a CSP produce line, the produce line adopts reasonable temperature system, rolling equipment, rolling way and combining with cooling after rolling, the molten steel after continuous casting is a casting adobe of 50 to 70mm thick and 900 to 1300 wide, after cutting, heating, scale breaking, proceed continuous rolling to form a thin band of 1.2 to 1.5mm thick and 900 to 1300 wide, then after cooling to reel steel coil. The production flow is short, the equipment is few, the investment is less and the running expense is low; The technics and equipment is reasonable and high efficient, double locomotive and double flow casting, heating by two furnaces, seven rolling machines roll continuously, the production is smooth and saves energy with high production efficiency; the product performance is even and stable, the board shape is regular with high accuracy and good surface quality.

A non-oxide compound magnesite-graphite brick containing carbon less than 6% belongs to a fire resisting material. The material contains magnesia of 75-94%, carbon of 1-5%, non-oxide such as nitride and boride of 0.4-20%, additive of 0-5%, and binder containg carbon. Such magnesite-graphite brick with low carbon has a low heat conductivity, a small acierating to the molten steel and less pollution to the low carbon steel compared to the common magnesite-graphite brick. The magnesite-graphite brick has a good slag resistance because the magnesia is the primary component. And it also has a good heat shock capacity because the carbon is one of the primary components. The carbon prevents said non-oxide from being oxidated. The brick maintains a good heat and shock resistance and slag resistance when reducing the proportion of the carbon because said non-oxide has a low heat expansion and a wet resistance to the slag.

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 discloses a process method for cooperatively and continuously processing waste containing iron and/or zinc, lead, copper and tin, and the like and molten steel slag on line, separating and recycling metal such as iron, zinc, lead, copper and tin as well as molten slag. The cooperative processing and recycling method is characterized in that pellets prepared from waste containing iron, zinc, lead, copper, tin and the like, particles, a blocky material containing iron, zinc, lead, copper, tin and the like and high-temperature molten steel slag are added into a reducing, volatilizing and smelting furnace, molten iron, which is obtained by air-blowing, adding of fuels such as coal gangues and flux such as high silicon and high aluminum, high-temperature reducing and volatilizingtreatment, is discharged from an iron outlet of the reducing, volatilizing and smelting furnace; volatilized substances such as zinc and lead and smoke gas are sucked into a dust collector for being collected and utilized; enriched metal such as gold, silver, copper, tin and lead is discharged from a discharge hole in the bottommost part of the reducing, volatilizing and smelting furnace for beingrecycled; and molten slag is discharged through a slag outlet, water slag and the like or the molten slag is returned into a converter for being recycled. Waste containing iron, zinc, lead, copper, tin and the like, molten steel slag and coal gangue waste slag and the like are cooperatively and continuously treated to separate and recycle useful metal, so that remarkable energy-saving environment-friendly social benefits and economic benefits are achieved.

The invention discloses a method of manufacturing a tough steel hot rolled strip coil. The molten steel, waste steel, chromic oxide and molybdenum oxide are mixed into a rotating furnace, and a fluxing medium is added in; the manganese oxide or manganese ore is added in at the earlier stage of blowing; the manganese oxide or manganese ore and the reducing agent are added in by the end of blowing, and nitrogen or argon is blew from bottom during the whole process; tapping is conducted when the components and the temperature of the molten steel are appropriate; during tapping, the composite deoxygener and the reducing desulfurating refining slag are added in the molten steel during tapping, and nitrogen or argon is blew from bottom of a steel ladle during the whole process. The steel ladle adds the metal aluminum in the molten steel from the CAS position to conduct deep deoxidation and microalloying; and then the increasing nitrogen agent, vanadium iron and ferrocolumbium are added in, and nitrogen or argon blowing is kept. The steel ladle is sent to the position of an LF refining furnace, the lime and reducing desulfurating refining slag are added in the LF refining furnace, argon is blew, electricity is supplied, the temperature is raised and argon is blew again, and the calcium line and the boron filament are fed at the later stage of refining; CSP is supplied for continuous casting, and the charging temperature of a cast slab is is more than 950DEG C; the heating temperature, the initial billet temperature, the rolling finishing temperature and the coiling temperature are well controlled. The tough steel hot rolled strip coil manufactured with the method has high strength and good tenacity.

The invention relates to a combination method installation technology for an ultra large steel-smelting converter, belonging to the installation of steel-smelting devices, which is characterized in that respectively installing hydraulic presses and cylindrical safety cushion blocks on the upper portions of four vertical props of a supporting platform relatively to the chassis portions of bearing bases on the driving side and non driving side of the converter, installing pad beams which are respectively indentified with height marks of the chassis of the bearing bases and are integrated together on steel pillars or steel beams of the operational platform on the front of the converter, assembling three components of the converter on charging bays, suspending the three components on the hydraulic presses on the supporting platform and the pad beams which are provided with rolling rods and assembling integrally, regulating the hydraulic presses to make each supporting point with balance force, installing a winding engine and a main pulley block on the advancing end of a ladle car to drag the ladle car and the supporting platform, arranging a single-sheaved block on the driving lateral bearing base which is dragged by a line hook of a steel-melting bay, correcting directions by regulating the rolling rods, and slowly dragging the whole converter to the installation position of the steel-melting bay, which is safe and reliable, and has high effect and strong operability.

The invention provides a dephosphorization method of semi-steel. The method comprises the following steps: adopting a six-hole oxygen gun to perform sectional smelting through a way of adjusting the oxygen supply strength of the oxygen gun, namely first dephosphorization smelting, adding a first batch of slag-making materials, controlling the oxygen supply strength of a top-blowing oxygen gun at 2.83-3.21Nm3/(t steel. min), simultaneously bottom-blowing nitrogen, smelting and deslagging; performing second dephosphorization smelting, adding a second batch of the slag-making materials, controlling the oxygen supply strength of the top-blowing oxygen gun at 3.58-4.07Nm3/(t steel. min), bottom-blowing the nitrogen during the time period from the beginning of the second dephosphorization smelting to carbon catching, bottom-blowing argon during the time period from the carbon catching to the terminal point of converting, smelting, stopping slag, tapping for getting molten steel with the content of a phosphorus element, which is not more than 0.008% by weight percentage, and performing the operation of remaining the slag after the tapping. By adopting the method, the dephosphorization effect is good, the dephosphorization efficiency is high, the smooth operation of the smelting process of a converter can be ensured, the steel-making production cost can be reduced and the semi-steel can be adopted for producing low-phosphorus steel with high grade and high added value.

A conticasting and tandem rolling technology for manufacturing the high-strength and-weatherability Ti-microalloyed steel plate includes such steps as smelting, refining, conticasting, solidifying, heating, hot rolling, laminar flow cooling and coiling. Its advantages are high strength, high shaping performance, high weatherability and high weldability.

The invention provides a method for smelting high-carbon steel from semi-steel. The method adopts the semi-steel after extraction of vanadium as a raw material, and comprises the following steps of: adopting a low vanadium extraction process during smelting of a vanadium extraction converter to ensure that the carbon content of the semi-steel after the extraction of vanadium is not smaller than 3.70 weight percent, and the temperature of the semi-steel is not lower than 1,290 DEG C; adding active lime into the converter according to a standard of 10 to 15 kg in a ton of steel, adding high-magnesium lime into the converter according to a standard of 7 to 10 kg in a ton of steel, shaking the converter back and forth to ensure that the active lime and the high-magnesium lime are uniformly mixed with steel slag in the converter, then adding the semi-steel into the converter, and adding a ferro-silicon alloy into the converter, wherein the added amount of the ferro-silicon alloy can ensure that the initial alkalinity of furnace slag is 2 to 3; performing converting, and pouring out the furnace slag when the temperature of a molten pool is raised to be 1,400 to 1,500 DEG C; adding active lime into the converter according to a standard of 12 to 18 kg in a ton of steel and adding high-magnesium lime into the converter according to a standard of 9 to 12 kg in a ton of steel to perform secondary slagging; performing converting, and adding manganiferous iron ore into the converter to ensure that the alkalinity of the furnace slag is 4 to 5 and a CaO-SiO2-FeO-MnO low-melting-point slag system is formed; adding a cooling agent into the converter after converting for 3 to 5 minutes, and continuously converting until target molten steel and terminal furnace slag are obtained; and tapping. According to the method, dephophorization and carbon maintenance can be realized at the same time.

The embodiment of the present invention discloses a termination point prediction method and a system for converter steelmaking. The method includes the following steps: collecting current production parameter information in converter steelmaking and current flame information at the mouth of a converter as independent variables; creating a neural network, and training the created neural network with a training sample made up of the independent variables; and predicting the termination point of converter steelmaking by the neural network obtained after the training according to the independent variables, so as to obtain a termination point time prediction result, a carbon content prediction result and a molten steel temperature prediction result. Therefore, with the technical scheme provided by the embodiment of the present invention, by obtaining the production information of the converter and the flame information at the mouth of the converter in real time, the steelmaking terminationpoint time, the molten steel temperature and the carbon content can be analyzed precisely online in real time, so as to precisely control the process to improve the automation and the production efficiency of converter steelmaking and lower the cost.

The invention discloses a method for producing high-strength low-carbon bainite steel based on thin slab continuous casting and rolling process. The method includes the following steps: melting by using a rotary furnace or an electric furnace, refining molten steel in an LF furnace after the component analysis, performing the composition adjustment, continuously casting thin slabs, directly heating the thin slabs at the temperature of 950-1100 DEG C in a roller-hearth heating (soaking) furnace at a temperature not less than 1150 DEG C, controlling the tapping temperature of heated thin slabs in a range from 1050 DEG C to1160 DEG C, rolling by using a continuous rolling mill to produce plates, finishing at a temperature of 840-860 DEG C, performing laminar cooling, and coiling with a down coiler at a temperature of 550-600 DEG C to produce the steel coil. The method can produce non-tempered high-strength steel based on thin slab continuous casting and rolling process, and has the advantages of simple metallurgical composition of steel, low cost of alloying production, and stability in high toughness and good forming and welding properties of the steel coil.

The invention relates to high-strength-and-toughness low alloy wear resistant steel and a manufacturing method thereof, belonging to the technical filed of metallurgy. The high-strength-and-toughness low alloy wear resistant steel comprises the following components by weight percent: 0.15-0.20% of C, 0.1-0.5% of Si, 1.2-1.6% of Mn, less than or equal to 0.015% of P, less than or equal of 0.005% S, 0.02-0.04% of Al, 0.016-0.022% of Ti, 0.16-0.20% of Cr, 0.16-0.22% of Mo, 0.001-0.0015% of B and the balance of Fe, and simultaneously the carbon equivalent Ceq (%) is less than or equal to 0.55. The manufacturing method comprises the following steps: smelting molten steel and pouring into a slab, and carrying out rough rolling after heating and heat insulation; and then carrying out complete quenching treatment, or sub-temperature quenching treatment, or carrying out the complete quenching treatment and then carrying out the sub-temperature quenching treatment, and adopting low temperature tempering to eliminate stress after the quenching. The method of the invention ensures higher hardness, simultaneously can obviously improve the impact toughness of steel plates, increase the impact resistance of the steel plates, and prolong the service life of mechanical equipment, and can obtain wear resistant steel plates with different strength and toughness grades by using the steel with same components and different quenching processing methods.

The invention discloses a heavy reduction technology for improving center segregation and center porosity of super-thick slabs. The heavy reduction technology is characterized in that the oil cylinder pressure of hydraulic cylinders on three sectorial sections of solidification tail ends of the continuous casting slabs ranges from 1800KN to 2500KN; and according to the solidification characteristics of steel types, the superheat degree of molten steel is controlled between 10-35 DEG C, the casting speed of a casting machine is controlled between 0.6 meter/minute and 1.0 meter/minute, the specific water flow of a secondary cooling zone is controlled between 0.4 and 0.6 liter/kilogram, large pressure is applied to one sectorial section to achieve the reduction of 5.0-12.0 millimeters, and the other two sectorial sections are slightly pressed to achieve reductions of 2-3 millimeters. The heavy reduction technology can be implemented to improve the quality of the super-thick slabs which further can be used for substituting for static ingots to produce super-thick steel plates with the thickness of 100millimeters and more, and the heavy reduction technology can achieve the high production efficiency and is environment-friendly.

The invention provides a method to produce ultra low phosphorus steel by out-of-furnace dephosphorization, in particular to a controlling method to control phosphorus in steel during ultra low phosphorus steel production process. The invention is done according to the following steps: (1) when converter tapping, the weight percent of end phosphorus content is less than 0.013 percent and dephosphorization flux is added along with steel flow stream to ladle at the same time; (2) slag-stopping and non-deoxidation tapping is adopted; (3) after tapping, remove dephosphorization flux in the ladle; (4) after flux removal, refining treatment such as heating, deoxidation alloying and desulphurization; (5) continuous casting is done. The invention is convenient for operation, high efficiency of dephosphorization, short time consumption, and stable dephosphorization effect which can satisfy dephosphorization requirement of different content ultra low phosphorus molten steel by dephosphorization during the tapping without increase treatment time.

The invention discloses a smelting process of high-carbon bearing steel. High-alkalinity refining slag with the alkalinity value of 6-9 is obtained through adding conditioned slag and a deoxidizing agent, so that relatively good desulfuration and deoxidization effects are achieved, the content of S can be reduced to about 0.002%, and the content of O can be reduced to be less than 7ppm. Meanwhile, in order to avoid brittle impurity generation caused by overhigh alkalinity of refining slag, the content Al of the molten steel is strictly controlled in a smelting process, enough aluminum blocks for deoxidizing are added at one step in a tapping process, and no aluminum is replenished in the subsequent process, so that a deoxidized product is prevented from being floated; the content of Al in the refining slag is controlled at about 0.010%, so that secondary oxidation caused in a pouring process is reduced. On the other hand, the value of CaO/Al2O3 in the refining slag is controlled at about 1.7, so that the melting point of slag is relatively low, the flowability of the slag is relatively good, the steel slag is easy to separate, and the slag rolling and reduction reaction of molten steel in a vacuumizing process are reduced. Therefore, D-type inclusions in the bearing steel are effectively prevented from being increased, and the rating standards of inclusions in the bearing steel are reached.

The invention provides high-boron high-chromium low-carbon high-temperature-resistant wear-resisting alloy steel and manufacturing method thereof. The chemical content of the alloy steel includes, by weight, 0.10%-0.5% of C, 3%-26% of Cr, 0.5%-4% of W, 0.5%-1.2% of Si, 0.5%-1.5% of Mn, 0.7%-3.5% of B, 0.3%-2.6% of Cu, 1.5%-2.4% of Al, 0.8%-1.6% of Ti, 0.02%-0.15% of Ca, 0.03-0.25% of Ce, 0.02%-0.18% of N, 0.05%-0.3% of Nb, 0.12%-0.25% of Mg, 0.04%-0.13% of K, 0.05%-0.12% of Ca, 0.06%-0.15% of Ba, less than 0.03% of S, less than 0.04% of P and the balance Fe and unavoidable impurity elements. After steel scrap and ferrochromium are melted in an electric furnace, a copper plate, silicon iron and ferromanganese are added to the electric furnace, after content is qualified through pre-furnace adjustment, the temperature of a melt rises to 1560-1620 DEG C, calcium-silicon alloy and deoxidation aluminum are added, ferrotitanium, ferroboron and metal aluminum are sequentially added and poured out of the furnace after being melted, granular rare earth magnesium alloy with a diameter of less than 12mm and a composite inoculant composed of metal cerium, Si3N4, VN, Nb and K are placed at the bottom of a steel ladle after being roasted, metaphoric inoculation processing is carried out on smelt liquid steel in a in-ladle pouring mode, the liquid steel pouring temperature ranges from 1400 DEG C to 1450 DEG C, and a casting piece undergoes air cooling for 2-4 hours at the temperature of 920-1150 DEG C.

The invention provides a high-strength abrasion-resisting steel plate and a production method thereof. The chemical components of the high-strength abrasion-resisting steel plate include, by weight, 0.25-0.30% of C, 0.3-0.5% of Si, 0.40-1.00% of Mn, 0.6-1.2% of Cr, 0.15-0.4% of Mo, 0.01-0.03% of Nb, smaller than or equal to 0.50% of Ni, smaller than or equal to 0.50% of Cu, 0.0005-0.0022% of B, 0.025-0.04% of Ti, 0.020-0.045% of Als, smaller than or equal to 0.015% of P and smaller than or equal to 0.005% of S, wherein Ti/N is greater than or equal to 3.4. During refining, molten steel [N] is controlled to be smaller than or equal to 0.0080%, [O] is controlled to be smaller than or equal to 0.0020%, it is ensured that the effective boron content is 0.0010-0.0020%, and stacking for slow-cooling is performed for 48 hours or more after continuous casting. Two-stage rolling control is adopted, the finish rolling temperature at the first stage is 980-1050 DEG C, out-line quenching is conducted on plate blanks with the thickness greater than 50 mm at the second stage, swinging is performed at the low-pressure section of a quenching machine, on-line quenching is conducted on plate blanks with the thickness smaller than or equal to 50 mm, and residual heat is utilized to perform self tempering. The high-strength abrasion-resisting steel plate has lower carbon and manganese contents and good weldability, the surface hardness is greater than 550 HB, and the toughness at the low temperature of -40 DEG C is greater than 30 J, and the maximum thickness can be up to 120 mm.

The method for producing cold-rolled non-oriented electrical steel by using sheet bar and adopting continuous casting and continuous rolling process includes the following steps: a). utilizing the following components: C is less than or equal to 0.005%, Si is less than or equal to 3.5%, Mn is less than or equal to 1.5%, Al is less than or equal to 1.5%, P is less than or equal to 0.2%, S is less than or equal to 0.010%, N is less than or equal to 0.005%, O is less than or equal to 0.02% and the rest is iron and smelting; b). continuous casting, continuously casting molten steel to obtain sheet bar; c). heating, the temperature of sheet bar before which is fed into the furnace is 700-900deg.C, retaining said temperature for 30s-5min; heating sheet bar in ferrite phase area and heating temperature is less than or equal to 1120deg.C; d). hot-rolling, rolling in ferrite phase area, final rolling temperature is 800deg.C-950deg.C; e). coiling, coiling temperature is 500deg.C-900deg.C; and f). normalizing treatment or non-annealing treatment, acid-pickling, first cold-rolling or secondary cold-rolling with intermediate annealing to target thickness, then making final annealing so as to obtain the invented product.

The invention relates to a calcium magnesium RH dip pipe hot spray repair material used for high-performance smelting silicon steel and a preparation method, and is characterized in that the invention adopts high-purity magnesium gravel and synthesis magnesium calcium as main components; more than one of organic addition agents of woodiness calcium sulphonate, modified starch ether, and the like are used in composite mode to substitute low-melting harmful plasticizers of soft clay, water glass, and the like used by conventional spray repair material to realize good spray repair adhesiveness and good high-temperature performance of the spray repair material. The invention uses two ultra fine powder of ultra fine MgO micro powder, SiO2 micro powder and calcium hydroxide micro powder in composite mode to act slushing enhancement effect, further improves adhesiveness and agglutinating property of the material, and enhances high temperature strength of the material. Provided spray repair material has high hot strength, good high-residue erosion resistance performance and good molten steel erosion resistance performance; spraying and repairing a dip pipe can make the service life be more than one furnace when a RH device smelts low sulphur special silicon steel, thus satisfying the requirements of the smelting of the special silicon steel.

The invention provides a converter dephosphorizing and steelmaking method. The method comprises the following steps of: a, adding slag making materials which consist of active lime, high-magnesium lime and a composite slagging agent into a converter molten pool; blowing and slagging by a dephosphorizing oxygen lance oxygen blowing process and an inert gas bottom blowing process to remove phosphorus in molten steel; and pouring 60 to 80 percent of slag out when the molten pool temperature in a converter is between 1,420 and 1,450 DEG C, the alkalinity of the slag is between 2.0 and 2.5 and the total iron content in the slag is between 10 and 15 weight percent; and b, adding the slag making materials into the converter molten pool; blowing and slagging by a normal oxygen lance oxygen blowing process and the inert gas bottom blowing process to further remove the phosphorus in the molten steel; pouring the slag out when the molten pool temperature in the converter is between 1,680 and 1,700 DEG C, the alkalinity of the slag is between 3.2 and 4.2 and the total iron content in the slag is between 16 and 23 weight percent to obtain the molten steel with the phosphorus element content of not more than 0.009 weight percent. By the method, the dephosphorizing efficiency and the dephosphorizing effect of the converter are improved, and the production cost is reduced.

The invention belongs to the field of metallurgy, is a process for producing pipeline steel by converter-RH-LF-continuous casting, comprising converter process and terminal control, oxygen-remaining steel-tapping process, RH decarburization desaeration process, RH deoxidation alloying process and LF desulfurization process. By using RH oxygen-remaining natural decarburization, the invention can reduce the burden of converter decarburization and lower the oxidizability of molten steel, better meet the quality requirements of X70, X80 pipeline steel to low carbon and high purity. Pipeline steel produced by the converter-RH-LF-continuous casting has carbon content stably controlled in a range of 0.035% to 0.050% in accordance with objective composition requirement, no more than 0.006% of N, no more than 0.0003% of H, 0.013% of P, 0.002% of S, no more than 1.5 levels of inclusion thick series and no more than 1.5 levels of inclusion fine series.