1424 results about "Ferromanganese" patented technology

A metallurgical V-N microalloying and compound deoxidation cored wire contains a core wire and a cladding steel belt. The technical key point of the cored wire is as follows: the core wire of the cored wire consists of a vanadium-increasing agent, a nitrogen-increasing agent and a deoxidizing nitrogen-fixing agent of which particle sizes are less than 6mm, wherein the vanadium-increasing agent is ferrovanadium, nitrided ferrovanadium or vanadium pentoxide; the nitrogen-increasing agent is ferrosilicon nitride, silicomanganese nitride, ferromanganese nitride, ferrochromium nitride, silicon nitride, aluminum nitride or calcium cyanamide; and the deoxidizing nitrogen-fixing agent contains one or more of aluminum, calcium, magnesium and barium, and can also contain one or more of titanium, zirconium, niobium, manganese, chromium, silicon, carbon and iron. By adopting the cored wire, the V / N ratio of steel can get closer to the optimal proportion, the enhancing function of vanadium can be utilized furthest, vanadium resources can be saved, the recovery rate of nitrogen is high, the nitrogen content is stable, the compound deoxidation function can also be realized, the V-N microalloying cost can be reduced and the quality of steel can be increased.

A DPF with an SCR catalyst and a method for selectively reducing nitrogen oxides with ammonia, filtering particulates, and reducing the ignition temperature of soot on a DPF are provided. The catalyst includes a first component of copper, chromium, cobalt, nickel, manganese, iron, niobium, or mixtures thereof, a second component of cerium, a lanthanide, a mixture of lanthanides, or mixtures thereof, and a component characterized by increased surface acidity. The catalyst may also include strontium as an additional second component. The catalyst selectively reduces nitrogen oxides to nitrogen with ammonia and oxidizes soot at low temperatures. The catalyst has high hydrothermal stability.

The invention discloses a ferromanganese composite oxide catalyst for simultaneous denitrification and mercury removal, the active components of which are MnO2 and Fe2O3, wherein the molar ratio of Mn / Fe is 0.5-5, the catalyst is compounded on the carrier TiO2, and its active components are The total mass fraction of the component is 5% to 40%, and CuO, CeO2, V2O5 and other oxide auxiliary components can also be added, and the addition amount is 0% to 10% of the total mass fraction. The invention also discloses a preparation method of the catalyst, which adopts an impregnation method or a co-precipitation method. The catalyst of the present invention has high activity and selectivity for the catalytic oxidation of nitrogen oxides and mercury, and its temperature adaptability window is wide, which can effectively improve the anti-poisoning performance of the catalyst, and has strong adaptability to harsh operating conditions, and can It is widely used in the catalytic oxidation of pollutants in the flue gas selective catalytic oxidation denitrification and demercuration process, and at the same time, the preparation method of the catalyst of the present invention is simple in process and low in cost.

The present invention discloses one kind of antiwear high-boron cast steel and its preparation process. The antiwear high-boron cast steel has the chemical components including C 0.10-0.50 wt%, B 0.8-5.0 wt%, Cu 0.3-0.6 wt%, Mn 0.8-2.0 wt%, Cr 1.0-2.5 wt%, Si less than 1.5 wt%, Ti 0.08-0.20 wt%, Ce 0.04-0.12 wt%, Mg 0.02-0.18 wt%, N 0.06-0.18 wt%, S less than 0.05 wt%, P less than 0.05 wt%, and Fe and inevitable impurity for the rest. Its preparation process includes smelting in an electric furnace while adding ferromanganese, frrroboron and Al to deoxidize, composite modification of molten steel, fast cooling, and low temperature tempering to eliminate stress. The present invention has simple production process, low production cost and other advantages.

The invention provides a high-carbon high-chromium high-niobium cast iron self-protection flux-cored wire. The flux-cored wire has a steel belt as an outer skin. The flux core comprises the following components in weight percentage: 10 to 30 percent of ferroniobium, 20 to 30 percent of high carbon ferrochrome, 0.1 to 3 percent of V, 0.2 to 3 percent of W, 0.6 to 0.8 percent of ferromanganese, 0.2 to 0.8 percent of 75 ferrosilicon, 20 to 30 percent of chromium carbide, 5 to 12 percent of graphite, 1 to 10 percent of aluminum-magnesium alloy, 1 to 5 percent of silicon carbide and 1 to 3 percent of ferroboron; and the percentage of a counter weight is between 46 and 54 percent. The high-carbon high-chromium high-niobium cast iron self-protection flux-cored wire has the advantages of high hardness, good wear resistance, good oxidation resistance and strong shock resistance, and is widely applied to grinding rolls and grinding disks of coal grinding machines in thermal power plants and cement plants, material charging equipment in blast furnaces(material charging slots, receiving cones, material storage areas and sieve plates), slag vertical mills, hammer heads and rollers of crushers and sintering equipment workpieces in steel plants.

The preparation method for high specific capacity and specific power manganous ferrous lithium silicate with formula as Li2MSiO4(M=Mn(1-x)Fex, 0íœxíœ1) / C as anode material for lithium cell comprises: mixing the lithium salt, manganous salt, ferrite and normal silicate ester into water-alcohol system, heating to obtain the mixed predecessor; then, grinding with sugar to mix and treat at high-temperature in nitrogen. Wherein, there is 84~97% silicate and 3~16% carbon. This invention is simple and convenient to operate, and has high performance-price ratio.

The invention relates to a method for the catalytic decomposition of N2O in a gas containing N2O in the presence of a catalyst, wherein the catalyst comprises a zeolite that has been loaded with a first metal selected from the group of noble metals consisting of ruthenium, rhodium, silver, rhenium, osmium, iridium, platinum and gold, and with a second metal selected from the group of transition metals consisting of chromium, manganese, iron cobalt, nickel and copper, and wherein the loading of the zeolite with metals has been obtained by first loading the zeolite with the noble metal and then with the transition metal, as well as a catalyst for this method and a method for the preparation of this catalyst.

The invention discloses a preparation method of wear-resistant high-chromium cast iron and belongs to the technical field of metal materials. According to the preparation method, common scrap steel, carburant, ferrochromium, ferromolybdenum, copper plates, ferrochromium nitride, ferrosilicon, ferromanganese, ferroboron and aluminum are smelted in an electric furnace so as to form the wear-resistant high-chromium cast iron. The molten wear-resistant high-chromium cast iron comprises the following chemical components in percentage by mass: 3.0-3.5% of C, 18-25% of Cr, 0.3-0.5% of Mn, 0.3-0.5% of Si, 0.18-0.25% of N, 0.5-0.8% of Mo, 0.2-0.4% of B, 0.08-0.12% of Al, 0.5-1.0% of Cu, less than 0.05% of S, less than 0.05% P and the balance of Fe. Molten iron is treated with an inoculator when taken out from the electric furnace, and is treated with a suspending agent when poured, so as to obtain fine solidification structures. Therefore, the wear-resistant high-chromium cast iron has excellent properties.

The self-protective high chromium cast iron cored build-up welding wire has metal powder core comprising nickel powder 6-8 wt%, middle carbon manganese iron 8-10 wt%, No. 45 ferrosilicon 9-12 wt%, high carbon ferrochromium 65-75 wt%, metal Cr powder 18-21 wt%, ferromolybdenum 5-7 wt% and Al-Mg powder 1.5-2.5 wt%, and with one welding wire filling amount of 0.49-0.53. The present invention makes it possible to use the welding wire in submerged arc welding without needing added flux and protecting gas, results in raised comprehensive welding performance and raised welding quality, and may be applied widely in build-up welding field requiring high antiwear, anticorrosive and anticracking performance.

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 relates to a high strength foundry air cooling bainite wear resistant steel that the chemical constituents is 0.32-0.65 C, 0.8-3.0 Si, 1.2-3.0 Mn, 0.5-0.8 Cr, 0.3-0.8 Cu, 0.001-0.008 B, 0.18-0.35 Al, 0.05-0.15 Y, 0.05-0.20 Ti, 0-0.12 Mg, 0-0.12 Ca, 0-0.15 Zn, and 0.10<Mg+Ca+Zn<0.25, the else is Fe and trace impurities. The process includes the following steps: smelting waste steel, pig iron, ferrochrome iron and copper board, adding ferrosilicon and ferromanganese preliminary deoxidation into melting down and alloying; heating to 1600-1660 degree centigrade after adjusting the constituents adding aluminum deoxidatioin and alloying and blast furnace tapping; putting the compounding modification particle of Yt, boron, titanium, magnesium, calcium, and zinc on the bottom of pouring ladle, taking modification process to the molten steel; molding the molten steel after modification process into normal matrix for casting. The invention could prolong the useful life of antifriction component, improve working efficiency, and have good economic benefit.

The invention relates to a composite roll for centrifugally casting high-chromium cast iron and a preparation method thereof, belonging to the technical field of the steel rolling. The composite roll comprises a roll external layer and a roll core. The chemical components of the materials of the roll external layer in terms of the percentage by weight are as below: 25-28 of alloy scrap iron of a high-nickel-chromium infinite chilled iron roll, 28-30 of carbon ferrochrome, 1.5-2.5 of mid-carbon ferromanganese, 2.5-3.5 of ferroboron, 0.5-0.8 of silicon-calcium-barium alloy, 0.2-0.4 of aluminum, 0.3-0.5 of ferrotitanium, 0.2-0.4 of rare earth ferrosilicon, 0.10-0.15 of zinc, 0.15-0.18 of magnesium and the balance of low-carbon waste steel sheet. The roll core is high-strength alloy cast iron or low-alloy ductile cast iron. The roll external layer and the roll core are formed through centrifugal composite casting. The roll has low production cost, contains a small number of impurities and has high degree of purity; the hardenability, the mechanical performance and the thermal fatigue of the roll can be improved; and the roll has long service life and low production cost.

The invention relates to an abrasion-resisting surfacing flux-cored wire for a coal milling roller, which is composed of high carbon ferro chrome 45-65%, chromium carbide 8-20%, chromium metal 5-15%, flake graphite 3-8%, high carbon ferromanganese 3-6%, 75# ferrosilicon 5-7%, ferroboron 5-15%, aluminum magnesium alloy 2-5% and an agglutinant 2-8%. The diameter of a welding wire is phi 3.2-phi 4.0mm, welding wire metal is a low carbon steel strip, and 49%-53% of cored powder by mass is filled in the formed low carbon steel strip. No protective gas is additionally arranged outside the flux-cored wire, and the manufacturability is good in the self protection open arc welding. During the welding, the arc is stable, the spatter lose rate is low, molten slag is little, the welding can be continuously performed, the welding joint is attractive in forming, the self-protection effect is good, and no air holes is on the surface of the flux-cored wire. The hardness of the abrasion-resisting surfacing flux-cored wire for the coal milling roller reaches above 62 HRC after multilayer surfacing by metal piling, the evenness of the whole hardness is + / -2HRC, and the performance resistant to abrasion of low-stress grinding materials is good.

The invention belongs to the technical field of lithium ion batteries and specifically relates to a high-safety lithium manganese iron phosphate battery. The high-safety lithium manganese iron phosphate battery comprises a positive plate, a negative plate, an isolating membrane, an electrolyte and a battery shell, wherein the positive plate includes a positive pole current collector and a positive pole active material layer which is coated on a surface of the positive pole current collector; the positive pole active material layer includes the following components by weight percentage: 90wt%-96wt% of positive pole active material, 1.5wt%-5wt% of positive pole conductive agent and 2wt%-5wt% of positive pole binding agent; the positive pole conductive agent is a mixture of conductive carbon black and at least one of a carbon nano tube or graphene; and the ratio of the conductive carbon black to at least another conductive agent is 1wt%:0.5wt% to 4wt%:1wt% based on the weight percentage in the positive pole active material layer; the isolating membrane is one of a polyolefin film or a non-woven cloth film; and the electrolyte is a high-temperature-resistant electrolyte. Compared with a nickel cobalt lithium manganate ternary battery and a lithium iron phosphate battery, the high-safety lithium manganese iron phosphate battery has relatively high weight specific energy and relatively high safety performance at the same time, has a long cycle life and is suitable for popularization and application in the field of new energy vehicles.

The invention discloses a hypoeutectic high-chromium white cast iron, which comprises the following components calculated according to mass fraction: 1.9-2.4 of C, 16-22 of Cr, less than or equal to 0.8 of Si, less than or equal to 0.7 of Mn, 0.5-1.0 of Ni, 1.0-1.7 of Mo, less than 0.04 of S, less than 0.06 of P, 0.05-0.4 of RE, 0.5-1.0 of Cu, 0.05-0.15 of Zn, 0.1-0.3 of V and the balance of Fe. The preparation method comprises the following steps of: defining the mixture ratio according to the requirement of mass fraction and mixing; mixing scrap steel and pig iron in an intermediate-frequency induction furnace and heating the mixture to be melt; after molten iron is smelt, sequentially adding high carbon ferro-chrome, manganese iron, nickel and molybdenum and smelting again; feeding a zinc ingot with small granularity and rare earth or vanadium at the bottom of a casting ladle, covering a steel sheet or scrap iron and compacting; pouring the molten iron into the casting ladle and carrying out metamorphism and deslagging treatment; casting the molten iron and forming to obtain a hypoeutectic high-chromium white cast iron piece; then placing the hypoeutectic high-chromium white cast iron piece into a heat treatment furnace for thermally treating; and quenching and tempering to obtain a hypoeutectic high-chromium white cast iron material with the hardness of 60-66HRC (Hardness Rockwell) and the impact ductility of 10-14J / cm<2>. The hypoeutectic high-chromium white cast iron has the advantages of low cost, high wear resistance and reliable use safety. In addition, the preparation method of the hypoeutectic high-chromium white cast iron is simpler, and is easy in operation and strong in practicability.

The invention relates to a low-carbon ferromanganese production method using low-grade manganese mineral powder. The low-grade manganese mineral powder which has rich reserves is heated by a micro-wave oven, reduced by carbon, smelted at high temperature, purified by magnetic separation to directly prepare low-carbon ferromanganese. And the production method saves sintered agglomeration process with large energy consumption and serious pollution. The low-carbon ferromanganese with high purity is made through the steps that: the material is carefully chosen, crushed, fine- grinded, sieved, mixed, stirred, preheated by the micro-wave oven, pre-reduced through carbon monoxide, finally reduced, smelted at high temperature, cooled under the protection of nitrogen and purified by magnetic separation. The preparation method has the advantages of short technological process, less using equipment, being suitable for large- scale industrialization production, the yield rate can reach 98 percent, wherein manganese content is 75 percent and iron content is 20 percent, and the content of carbon is less than 0.5 percent; the content of harmful material sulfur is also less than 0.5 percent; the content of phosphor is less than 0.2 percent. The products have the advantages of low carbon, low phosphor and sulfur containing, no agglomeration, no pollution to environment. The method is the ideal ferromanganese direct production method using low-grade manganese mineral powder and fills up a scientific research blank in the field in China.

The invention relates to a welding drug core welding wire used to repair the working layer of cold rolling middle roller. Wherein, said welding wire comprises coat and drug core; said drug core comprises medium-carbon ferromanganese at 1.2-1.6%, high carbon ferro-chrome at 6.0-8.0%, ferro-molybdenum at 1.0-3.0%, ferro-vanadium at 0.7-1.5%, ferrocolumbium at 0.06-0.16%, ferrotungsten at 1.0-2.8%, ferrotitanium at 0.05-0.09%, nickel at 0.7-1.2%, silicon iron at 0.80-1.5%, rare-earth at 1.0-5.0%, derbyshire spar at 4.5-10.5%, and the left is iron powder. The invention has simple method, and the rigidity is HRC55-59, without crack.

The present invention relates to a catalyst for concurrently removing CO, CH, NOx and PM, and a preparation method thereof, and belongs to the field of an atmosphere pollution treatment technology and environment protection catalysis materials. According to the catalyst, a solid solution of rare earth and a rare metal zirconium, a perovskite-type composite oxide and a small amount of a noble metal are adopted as active components, a self-made honeycomb ceramic is adopted as a carrier, the total loading amount of the solid solution of the rare earth and the rare metal zirconium, and the perovskite-type composite oxide in the active components is 5-20% of the mass of the catalyst, the loading amount of the noble metal is 0.01-1% of the mass of the catalyst, a general formula of the active components is AgqE1-qAyZr1-yBCOx, E is a noble metal, A and B are rare earth, C is a transition metal, y is more than 0 and less than 1, q is more than 0 and less than 1, E is one or two selected from noble metals such as platinum (Pt), palladium (Pd) and rhodium (Rh), A and B are two selected from rare earth such as lanthanum (La), cerium (Ce), praseodymium (Pr) and neodymium (Nd), and C is one selected from transition metals such as copper (Cu), cobalt (Co), manganese (Mn), iron (Fe) and nickel (Ni).

The invention relates to a wear-resistant overlaying flux-cored wire. The wear-resistant overlaying flux-cored wire comprises a low-carbon steel outer layer and a flux core inner layer, wherein the filling coefficient of a flux core is 45-55 percent, and the overlaying flux-cored wire is characterized in that the flux core comprises the following components in parts by weight: 1-6 parts of microcrystalline graphite, 1-4 parts of aluminum-magnesium alloy, 1-2 parts of fluoride, 1-2 parts of silicate, 1-3 parts of titanate, 1-2 parts of carbonate, 30-80 parts of high carbon ferro-chrome, 15-45 parts of metal chromium carbide, 5-10 parts of electrolytic chromium powder, 3-6 parts of high carbon ferromanganese, 1-4 parts of rare earth ferrosilicon, 2-6 parts of ferrosilicon, 4-10 parts of ferromolybdenum, 5-10 parts of ferrotungsten, 5-10 parts of ferrovanadium, 4-10 parts of ferrocolumbium, 4-10 parts of ferrotitanium and 1-4 parts of ferroboron. The wear-resistant overlaying flux-cored wire has the advantages of good hardness, wear resistance and anti-cracking performance.

The invention discloses a low-temperature steel flux cored wire. Flux core of the flux cored wire comprises the following raw materials by weight percentage: 28 to 33 percent of rutile, 1 to 3 percent of aedelforsite, 14 to 18 percent of silicon-manganese alloy, 16 to 21 percent of ferrous powder, 2 to 4 percent of nickel powder, 1 to 2 percent of cryolite, 5 to 7 percent of feldspar, 1.5 to 2.5 percent of ferrotitanium, 0.5 to 1 percent of ferroboron, 5 to 6 percent of mid-carbon ferromanganese, 2.5 to 4 percent of magnesite, 4 to 6 percent of quartz and 1.5 to 3.5 percent of fluorite. Compared with the similar product of the prior art, the flux cored wire belongs to the meta-acid slag series, and has the advantages of good electric arc stability, less splash, easy slag removal, good low-temperature impact ductility, good low-temperature crack resisting performance, high efficiency and low cost.

A battery with a high capacity and superior cycle characteristics, and an anode active material used for it are provided. An anode active material contains tin as a first element, a second element, and a third element. The second element is at least one from the group consisting of boron, carbon, aluminum, and phosphorus, and the third element is at least one from the group consisting of silicon, magnesium, titanium, vanadium, chromium, manganese, iron, cobalt, nickel, copper, zinc, gallium, zirconium, niobium, molybdenum, silver, indium, cerium, hafnium, tantalum, tungsten, and bismuth. The content of the second element in the anode active material is from 9.8 wt % to 49 wt %.

The present invention discloses a continuous casting technology, which can greatly reduce defects of a cogged ingot of bloom continuous casting. A technical scheme of the present invention is: the continuous casting technology of the cogged ingot comprises double cooling of solidified shell, wherein the solidified shell goes through five shower cooling areas in sequence to be twice cooled. Cooling intensity in cooling direction of five shower cooling areas is as following: 151 to 1941 / (min is multiplied by m 2 ), 24 to 501 / (min is multiplied by m 2 ), 23 to 351 / (min is multiplied by m 2 ), 12 to 191 / (min is multiplied by m 2 ) and 8 to 111 / (min is multiplied by m 2 ). The present invention gradually reduces the cooling intensity of the solidified shell with the solidified shell thickening, thereby effectively reducing inside and outside difference in temperature of the solidified shell, decreasing heat stress of the solidified shell and reducing defects of the bloom continuous casting. The present invention is especially suitable for the cogged ingot of bloom continuous casting with a cross of 450mm multiplied 360mm that is made up of medium-carbon ferromanganese such as 35Mn2 and 37 Mn2.

The invention discloses a method for preparing hypereutectic high chromium white cast iron. According to the method, steel scrap, pig iron, high carbon ferro-chrome, ferromanganese and ferrosilicon are taken as smelting raw materials. The method comprises the following steps of: preparing the following chemical compositions in percentage by weight: 3.0 to 4.5 percent of C, 15 to 35 percent of Cr, 0.5 to 1.5 percent of Mn, 0.5 to 1.5 percent of Si, less than 0.06 percent of P, less than 0.06 percent of S and the balance of Fe; melting the raw materials in an electric furnace, deoxidizing, quickly pouring a casting fluid in the furnace into a casting ladle; when the temperature is reduced to 1,300-1,350DEG C, pouring the casting fluid into a sand mould for forming; heating a cast in the electric furnace to the temperature of between 700 and 1,000DEG C, keeping the temperature, quickly taking out of the furnace, and forging on a forging machine for forging deformation treatment; and tempering the forged piece to obtain the hypereutectic high chromium cast iron.

The invention provides a novel process for a formula of a slag-free flux-cored wire, and relates to a welding material. The manufacturing method adds the combination of molybdenum powder, nickel powder and rare earth silicon to a formula of raw materials, eliminates mineral powder in a common formula, and optimizes the proportion of various types of metal powder in the formula. According to the formula, the welding material comprises the following components: 4 to 8 parts of micro carbon ferrochromium, 12 to 18 parts of low carbon ferromanganese, 56 to 67 parts of iron powder, 2 to 6 parts of molybdenum powder, 0.1 to 0.4 part of ferroboron, 2 to 5 parts of rare earth silicon, 1 to 3 parts of ferrosilicon, 2 to 3 parts of ferrotitanium, 2 to 3 parts of sodium fluoride, 3 to 7 parts of ferroaluminum, 1 to 3 parts of aluminum to magnesium powder and 4 to 8 parts of nickel powder. The invention improves the toughness, strength and anti-fatigue performance of welding seams and thins welding-seam grains by adding the combination of molybdenum powder, nickel powder and rare earth silicon into the raw materials of the formula, eliminating the mineral powder in the common formula, and optimizing the proportion of various types of metal powder in the formula. Meanwhile, slagging on the surfaces of the welding seams is avoided, and welding efficiency is raised by 20 percent compared with slag-type processes.

The invention provides a high-strength and high-toughness metal powder type flux-cored wire with no need of being pre-heated before welded. Steel skin is 79-84% of a total weight of a welding wire and a flux core is 16-21% of the total weight of the welding wire. The steel skin is manufactured by using a cold rolling carbon steel strip and comprises the following components: 0.02-0.055% of C, 0.005-0.0085% of Si, 0.15-0.35% of Mn and the balance of iron; and the flux core comprises the following components: 12-18% of nickel powder, 2-4% of manganese powder, 3-7% of silicon iron, 2-6% of ferro-molybdenum, 0.8-2.5% of ferrotitanium, 1-5% of mid-carbon ferromanganese, 0.8-2.5% of potassium fluosilicate and rear earth oxide in sum, and the balance of iron powder. The flux-cored wire provided by the invention has the advantages of good welding process, high melting efficiency and less slag quantity; the yield strength of deposited metal can be more than 590 MPa; the impact rigidity at a temperature of -50 DEG C can be more than 70J; and the diffusible hydrogen is in an ultralow hydrogen level.

The invention relates to a manufacturing technique of an automotive vanadium titanium cast iron brake drum with high strength and high abrasive resistance, and particularly relates to a preparation method of a vanadium titanium cast iron brake drum. The preparation method comprises the following steps: melting base iron, namely b y taking vanadium titanium pig iron, steel scrap, foundry returns, a carburant, ferrosilicon, ferromanganese and ferrochrome as furnace charge, adding the carburant to the furnace bottom; smelting the furnace charges by using a medium-frequency induction furnace to prepare the base iron; heating and purifying molten iron in an overheating manner after the molten iron is molten down, and then carrying out heat preservation at 1520-1530 DEG C; and carrying out drossing, adding a slag conglomeration agent to the surface to carry out heat preservation after drossing, and then adding a little of furnace charge, and adjusting the ingredients and the like of the molten iron. A little of furnace charge is added at the later smelting stage to increase the heterogeneous core technology, so that the chilling tendency of the molten iron is relieved, the graphitization ability of the molten iron is improved, and the inoculation effect is improved. A secondary inoculation treatment process of a launder and a pouring cup is adopted, so that the inoculation effect is improved, the graphite form is improved, carbide and ferrite are removed, and the content of pearlite is improved.

The invention discloses a low-hydrogen basic electrode for welding FV520 (B) stainless steel, comprising a core wire and an electrod covering, wherein the electrode covering comprises the following materials in weight percentage: 35%-45% of marble, 18%-26% of fluorite, 6%-9% of quartz, 3%-6% of zircon sand, 6%-12% of rutile, 1%-3% of ferrosilicon, 6%-10% of ferrotitanium, 5%-11% of low-carbon ferromanganese, 1%-3% of rare-earth ferrosilicon and 0.5%-1.5% of sodium carbonate, and the sum of the weight percentages of the components is 100%. Compared with the traditional special imported electrode for the FV520 (B) stainless steel, the electrode made of the electrode covering has the advantages of favorable arc stabilization performance, good fluidity of a molten bath, less splash and dust, easier slag removal after welding, uniform slag coverage, and delicate and attractive welding joint formation. The content of diffusible hydrogen generated by using the developed electrode for depositing metal is effectively controlled and meets the requirements of low-carbon contents.

The invention relates to the technical field of metallurgy, and in particular relates to a preparation method of IF (Interstitial Free) steel containing phosphorus, silicon and manganese. The preparation method comprises the following steps: sequentially performing predesulfurization and slagging-off treatment on molten iron to obtain first molten iron; performing dephosphorization converter smelting on the first molten iron to obtain semi molten steel; performing decarbonization furnace smelting on the semi molten steel to obtain first molten steel, or, performing conventional converter smelting on the first molten iron to obtain the first molten steel; performing temperature adjustment and decarbonization on the first molten steel by virtue of an RH (Ruhrstahl-Heraus) furnace, and introducing ferrophosphorus and micro carbon ferromanganese; then supplementing ferrophosphorus and micro carbon ferromanganese into the first molten steel, adding a ferro-silicon alloy at the same time, and adjusting components of the first molten steel to obtain second molten steel with qualified carbon content and silicon-manganese-phosphorus content; transferring the second molten steel to a continuous casting process and pouring into a middle ladle, and casting the second molten steel to obtain an IF steel plate slab. The preparation method of the IF steel containing phosphorus, silicon and manganese, disclosed by the invention, can be used for reducing the time and load for adjusting the components, shortening the smelting time in the RH furnace and increasing the production efficiency and the plate slab quality.