81results about How to "Lower tapping temperature" patented technology

The invention discloses a method for producing thick-walled and large-diameter acid-resistant and corrosion-resistant pipeline steel by using high-phosphorus molten iron. For Grade B-X70M acid-resistant and corrosion-resistant pipeline steels with a thickness of 35mm-40mm and a width of 3500mm-5000mm, the smelting process of the present invention is BOF→RH→LF→CCM→billet heating→rolling, using ultra-low carbon, ultra-low phosphorus and sulfur, The design of low manganese content reduces the segregation of the slab center, reduces the formation of MnS inclusions, eliminates the accumulation of carbides in the core, reduces the grain size of the rolled plate through TMCP rolling, eliminates or reduces the band structure, and ensures the acid resistance of the product. Corrosion performance, so as to achieve acid and corrosion resistant pipeline steel matrix to meet the acid and corrosion resistance.

The invention discloses a high-silicon-molybdenum ductile iron material and a preparation method thereof. The high-silicon-molybdenum ductile iron material comprises the following components in percentage by weight: 2.90 to 3.35 percent of C, 4.40 to 4.80 percent of Si, 0.50 to 0.75 percent of Mo, 0.30 to 0.50 percentage of Cr, 0.20 to 0.45 percent of V, 0.10 to 0.30 percent of Mn, 0.04 to 0.07 percent of Mg, less than or equal to 0.07 percent of P, less than or equal to 0.02 percent of S, and the balance of Fe. For the high-silicon-molybdenum ductile iron material, the tensile strength is more than or equal to 710 MPa, the yield strength is more than or equal to 500 MPa, the extensibility is more than or equal to 10 percent, and the hardness is 230 to 265 HBW5/750. The high-silicon-molybdenum ductile iron material also contains a trace amount of Sn and Sb. The high-silicon-molybdenum ductile iron material eliminates fragmental graphite and graphite deterioration layers, ensures the spheroidization grades of the parts with different wall thicknesses, and the defects of microscopic shrinkage and the like are overcome.

The invention relates to a bottom dusting electrical furnace steelmaking process. The technical scheme includes that the bottom of an electrical furnace 1 is provided with 1-6 bottom guns 3 based on electrical furnace steelmaking method with precharing system, current-carrying gas is adopted to blow powder into a metal pool by 1-6 bottom guns 3, and blowing amount of powder is 20-100wt% of addition when the powder is added into the furnace; wherein, the bottom guns 3 are arranged symmetrically or asymmetrically 0-0.7 time of furnace bottom radius away from the furnace bottom center; the bottom gun 3 is in contact or non-contact structure; the current-carrying gas is one of Ar, N2, natural gas, O2 and CO2; the powder is one or more than one of ground quick lime, limestone powder, ferric oxide powder, concentrate fines, carbon dust, dolomite powder, flousper powder, calcium carbide powder and alloy powder; powder granularity is 0.01-0.10mm; blowing technological parameters include that pressure is 0.3-1.2MPa, gas supply flow is 0.1-1.0Nm3/t steel and powder gas ratio is 4-10. The invention has the characteristics that stirring effect is enhanced, metal material yield is improved and residue material utilization ratio is improved, duration of heating is shortened and steel quality is improved.

The invention relates to a converter less-slag smelting method. The converter less-slag smelting method uniformly adopts a less-slag single-slag mode under the conditions of high iron consumption or low iron consumption and complex molten iron silicon change. The converter less-slag smelting method comprises the following process flows of: finishing tapping, remaining slags, adjusting the slags, splashing the slags, adding scrap steel, mixing molten iron, conducting calculation, conducting blowing, controlling an end point and tapping. In the smelting process, the lance position and the oxygen supply intensity are controlled by referring to the CO value; the end oxidizability is effectively controlled through heat balance accurate calculation; the molten steel oxidizability is reduced through process low lance position control; the alloying cost is effectively reduced; and meanwhile, the final slag oxidizability is reduced; the slag splashing furnace protection effect is promoted; and the furnace condition maintenance cost is effectively reduced.

The invention discloses a process for producing an anti-acid pipeline steel by Ruhrstahl Heraecus (RH)-ladle furnace (LF)-RH refining. In the process, the composition of molten steel is controlled by converter smelting and RH-LF-RH refining process, so as to produce a low-carbon low-sulfur anti-acid (hydrogen-induced cracking HIC and stress corrosion cracking SCC resistant) pipeline steel. The specific flow is as follows: pre-desulphuzation of molten steel - converter smelting-primary RH vacuum refining - LF refining desulphuzation - secondary RH vacuum refining - continuous casting. By the secondary RH vacuum refining process, the decarburization burden of the converter and the oxidability of the molten steel can be reduced, and the adverse effect caused by recarburization in the LF refining process can be eliminated; furthermore, the use of a strong deoxidizer is reduced, the production is stabilized, and the composition of the molten steel is ensured to be controlled within a production target stably to meet the control requirements of the anti-acid pipeline steel on the low-carbon low-sulfur and high-purity composition. The carbon content of the finished steel produced by the process of the invention can be stably controlled to be 0.03% to 0.04%, and the sulfur content is stably controlled to be less than or equal to 0.0010%.

The invention discloses a method for producing high-corrosion-resistance steel through twin-roll thin-strip continuous casting. The method comprises the following steps of (a) smelting: carrying out smelting according to the following chemical components in percentage by weight, 0.02-0.06% of C, 0.1-0.5% of Si, 0.4-1.7% of Mn, smaller than or equal to 0.02% of P, 4.0-6.0% of Cr, 1.0-3.0% of Ni, smaller than or equal to 0.007% of S, 0.004-0.010% of N, smaller than 0.001% of Als, greater than 250 of Mn/S, 0.007-0.020% of total oxygen [O]T and the balance of Fe and inevitable impurities; (b) continuous casting: adopting a twin-roll thin-strip continuous casting process; c) protecting in a lower closed chamber; d) online hot rolling; e) cooling after rolling: cooling the rolled strip steel ina gas atomization cooling manner; and f) strip steel coiling: directly coiling the cooled hot-rolled strip steel into a coil after the end with poor quality of the cooled hot-rolled strip steel is cutoff by an end shear, and controlling the coiling temperature of the hot-rolled strip to be 600-700 DEG C.

The invention discloses a converter later-stage low-temperature tapping efficient dephosphorization method. The method comprises the following steps that Si, Mn and part of iron in slag are oxidized by adopting high lance position and large oxygen flow in the early stage of blowing; with the continuation of oxygen blowing, CO gas generated by chemical reaction of carbon and oxygen enables the early-stage slag to be prone to emerge, the lance position is raised, and the oxygen flow is reduced; the lance position is lowered in the middle stage of blowing; in the middle and later stages of smelting, the lance position is increased for slag adjustment, a part of sinter is added in multiple batches, the dephosphorization effect of the slag is good, and meanwhile good thermodynamic and dynamic conditions are achieved; and then a sublance is put down for TSC, and in the later stage of smelting, the final TSO temperature is controlled to be 1590-1620 DEG C . According to the method, an in-furnace efficient dephosphorization production process under a converter end-point low-temperature tapping condition is provided, and by reducing tapping end-point temperature, the distribution ratio of phosphorus in slag and steel in the later stage of smelting of a converter is increased, and therefore the dephosphorization efficiency in the later stage of smelting is improved.

The invention provides a method for calculating tapping time of a steelmaking converter, which belongs to the field of ferrous metallurgy and comprises the following steps: determining a converter profile, a structural size, a converter tapping tilting mechanism type, working characteristics and a rotating speed range; calculating each inclination angle of the converter from tapping to ending, thevolume of molten steel and slag in the converter corresponding to each subdivided liquid level height, and the mass of the molten steel; calculating the corresponding tapping molten steel mass flow and outflow time further, and building a basic database; and in combination with a tilting operation system in the converter tapping process, calculating the tapping time. According to the invention, the influences of the irregular structural shape of the converter, the size of the tapping hole, the weight of molten steel and slag loaded in the converter, the tapping tilting angle, the tilting speed and other operation systems are fully considered. The method is reliable in theory, practical and accurate in calculation, and lays an important foundation for influence factor analysis of the tapping time of the converter, optimization of a tapping operation system, reduction of tapping temperature and other process optimization.

The invention discloses a method for supplying heat in a converter by using a carbon-based heating agent. Specifically, the method comprises: after scrap steel is added to the converter, firstly adding the carbon-based heating agent and then adding iron. In this way, the temperature rising rate is increased after the heating agent is added and the heat utilization rate is higher. In the steelmaking process of the converter, if the amount of scrap steel is increased, it is obvious that the heat is insufficient; if a heat source is not added, the converter tapping temperature is inevitably lowered, and then temperature is increased in a finery. The method supplies the heat in the converter by using the heating agent so as to reduce electrodes and power consumption in the finery, and therebyreduce costs relatively.

The invention discloses a continuous-casting sealed pouring device and a technological method for protecting the pouring by using same. The device comprises a ladle and the like. The ladle and a crystallizer are respectively arranged above and below a tundish. The lower outer surface of the ladle down nozzle is spherical, and the ladle down nozzle and the tundish down nozzle are respectively muff-coupled with a ladle immersion argon-sealing sleeve and a tundish immersion argon-sealing sleeve. Seal washers are installed between the ladle immersion argon-sealing sleeve and the ladle down nozzle and between the tundish immersion argon-sealing sleeve and the tundish down nozzle. A circle of inner grooves, a first argon through-hole and a second argon through-hole are arranged at the upper parts of the ladle immersion argon-sealing sleeve and the tundish immersion argon-sealing sleeve, wherein the first argon through-hole and the second argon through-hole are vertically communicated with the grooves. The device and technological method provided by the invention are characterized in that the sealing performance of molten steel is improved in the pouring process; the secondary oxidation is avoided; the content of impurity in the steel is reduced; the tapping temperature in a converter is reduced; and the molten steel quality is effectively ensured.

The invention relates to a high-strength fire-resistant and weather-resistant steel plate/strip and a production method thereof. The steel plate/strip comprises the following chemical components in percent by weight: 0.02-0.06% of C, 0.1-0.55% of Si, 0.4-1.7% of Mn, less than or equal to 0.03% of P, less than or equal to 0.007% of S, 0.30-0.80% of Cr, 0.10-0.60% of Cu, 0.20-0.60% of Mo, 0.01-0.08%of Nb, 0.004-0.010% of N, less than or equal to 0.001% of Als, 0.007-0.020% of total oxygen [O]T and the balance Fe and inevitable impurities, wherein Mn/S is greater than 250; and Pcm is smaller than or equal to 0.27%. The production method comprises the following steps of: selectively adding micro-alloy elements such as Mo/Nb/Cr into steel, and controlling the alkalinity of slag, the type and melting point of inclusions in the steel, the content of free oxygen in molten steel and the content of acid-soluble aluminum Als; then casting a cast strip through double-roller thin strip continuouscasting, and then feeding the cast strip into an on-line rolling mill for hot rolling; and after rolling, cooling the strip steel in a gas atomization cooling mode, and finally coiling the strip steeldirectly into a steel coil.

The invention belongs to the technical field of steel and iron metallurgy, and discloses a channel-type induction-heating ladle device and heating method. The channel-type induction-heating ladle device and heating method are used for heating molten steel in a ladle and reducing the cooling of the molten steel during steel and iron production. The channel-type induction-heating ladle device comprise the ladle, a ladle cover, an iron core, a coil and a water cooling or air cooling device, wherein a channel is arranged in the ladle, and capable of horizontally penetrating through the side wall of the ladle and perpendicularly penetrating the center of the ladle; the iron core penetrates through the channel and surrounds one side of the ladle; the coil is wound around the iron core on the outer side of the ladle; the axis of the coil and the that of the iron core are kept perpendicular; and the coil is connected with the water cooling or air cooling device. The channel-type induction-heating ladle heating method comprises the following steps: (1) conveying the ladle to a refining or pouring station; (2) starting the water cooling or air cooling device to cool the coil, so as to prevent the coil from overheating during the subsequent power-on operation; (3) introducing an alternating current into the coil, so as to generate variable magnetic flux in the iron core, wherein the current magnitude reaches 1-10000 A and the frequency reaches 1-10000 Hz; and (4) after the refining or pouring operation is completed, stopping the power-on operation, shutting down the water cooling or air cooling device, and proceeding with the next working procedure.

The invention discloses a steel-making alloy on-line baking method. A combustor along the tangential direction of the circumferential direction of a furnace body is arranged on a furnace body of an alloy baking furnace; a high-temperature airflow produced by the combustor bakes and heats an alloy along the tangential direction of the circumferential direction of the furnace body; and the baked alloy is discharged from a discharge hole of the furnace body so as to be directly added into a steel ladle. According to the steel-making alloy on-line baking method provided by the invention, the heating uniformity is effectively improved, the temperature of the whole alloy in the furnace body is ensured to be increased by heating, the baking and heating efficiency is improved, and the alloy can bequickly heated so as to meet the demand, so that the molten steel quality can be improved, the tapping temperature is reduced, the production energy consumption is effectively reduced, the service life of a converter is prolonged, the production efficiency is improved, the production cost is reduced, and the product economic benefit is improved.

The invention discloses a control method of steel inclusions for a railway bogie. According to the method, through pretreatment of molten iron, the content of slag in the molten iron and the low sulfur content are effectively reduced, the heat source of a converter is guaranteed, and the smelting pressure of the converter is relieved; through smelting of the converter, the original oxygen contentof the molten iron is effectively reduced, oxide inclusions generated after the molten iron reaches a steel ladle are greatly reduced, and the number of the inclusions generated in the molten iron ina smelting process is reduced; through a refining treatment mode, the inclusions are denatured, and solid inclusions mainly containing CaO-CaS are generated; and a high overheating degree and weak cooling mode is adopted for continuous casting, it is guaranteed that the molten iron effectively floats and is adsorbed at a ladle, a tundish, a cleaner and a solidification tail end in a casting process, a quite small amount of inclusions are gathered in the center of a casting blank, the purity of the molten iron is effectively improved, and the anti-fatigue characteristic of a product is improved.

The invention discloses an intelligent smelting system and an operation method thereof, and relates to the technical field of casting. The system comprises AGV transfer equipment, automatic pouring equipment, automatic box pressing equipment, a spheroidizing baking ladle, automatic box turning equipment, casting head removing equipment, shakeout equipment, shot blasting equipment and power and free equipment. The interior of the automatic pouring equipment comprises a barrel-shaped pouring ladle, a tilting mechanism, a transverse moving mechanism, a lifting mechanism, a pouring vehicle body, a rail system, a control and operation system, a safety system and a cable device, and the interior of the automatic box pressing equipment comprises a stand column, a cross beam, a lifting mechanism, a box pressing mechanism, a transverse moving mechanism and a lifting and transverse moving driving mechanism. The production area is compactly arranged, so that equipment is reasonably arranged, the number of production equipment can be reduced, the process route can be shortened, and the requirements of efficiency improvement, cost reduction and environment-friendly production are met.

The invention discloses a method for reducing iron consumption. The method specifically includes the following steps that 35-45 wt% of slag is poured into a furnace; qualified molten iron is introduced into the heating furnace for heating; the molten iron after heating in the above step is put into an oxygen top-blowing converter, and qualified steel scrap is added into the oxygen top-blowing converter at the same time; a slag-forming material is added for gun drop blowing, and the gun position in the blowing process needs to be specifically adjusted according to different silicon amounts in the molten iron. According to the method for reducing the iron consumption, by ensuring that the temperature of the molten iron is 1290 DEG C to 1320 DEG C, physical heat of the molten iron is stabilized, the heat balance of the converter is ensured, and correspondingly the consumption of the molten iron in a steel making process of the converter is reduced. By adding a carbonaceous heat-generatingagent into the converter, an important way of increasing the heat of the converter and increasing a cold-to-material ratio is achieved, the surplus heat is increased, the adding proportion of the steel scrap is increased, and thus the consumption of the molten iron is reduced; during gun drop blowing, the phenomena that the adding amount of the steel scrap is large and the steel scrap cannot be blown thoroughly are ensured, the operation is stable, and a better use prospect is brought.