973 results about "Vacuum induction furnace" patented technology

The invention relates to high-temperature alloy technology, and in particular provides an isometrical cast nickel-base high-temperature alloy with low density, high incipient melting temperature and good casting property and a preparation process thereof, which can be used for floating tile materials of a combustion chamber. The alloy comprises the following compositions by mass percentage: 0.03 to 0.06 percent of C, 5 to 12 percent of Cr, 5.5 to 6.5 percent of Al, 3 to 8 percent of Co, 3 to 7 percent of W, 2 to 4 percent of Mo, 1.6 to 3.2 percent of Nb, 0.01 to 0.03 percent of B, 0.008 to 0.025 percent of Y and the balance of Ni. A vacuum induction furnace is adopted to smelt a master alloy, and a smelting crucible is a CaO crucible or a MgO crucible; and the operation process comprises the following steps: putting alloying elements such as carbon, chromium, cobalt, tungsten, molybdenum and niobium in proportion and a nickel plate into the crucible; melting the alloy when the vacuum degree reaches between 50 and 0.1 Pa; and after completion of the melting, refining for 30 to 300 seconds at a temperature of between 1,550 and 1,600 DEG C, cutting off electricity, forming a film, breaking the film to add Al and Al-Y and Ni-B interalloy for uniform stirring, and casting a master alloy pig at a temperature of between 1,450 and 1,500 DEG C. The invention solves the problems of low incipient melting temperature, poor plasticity and inoxidability and the like of the nickel-base high-temperature alloy.

The invention relates to a directional-freezing heat-proof corrosion-resistant nickel base cast superalloy with low cost and excellent performance. The cast superalloy has the chemical composition range by weight percentage as follows: C is 0.04 to 0.09; Cr is 14.5 to 15.3; Co is 9.0 to 9.9; W is 4.7 to 5.9; Mo is 1.6 to 2.3; Al is 2.8 to 3.3; Ti is 4.2 to 5.0; Hf is 0.3 to 0.6; Ta is 0.3 to 1.5; B is 0.06 to 0.10; Y (adding quantity) is 0.015; Mn is less than or equals to 0.2; Si is less than or equals to 0.2; P is less than or equals to 0.008; S is less than or equals to 0.008; Fe is less than or equals to 0.5; the other weight percentage is composed of Ni. A vacuum induction furnace is adopted to smelt master alloy, and the directional-freezing is performed in a liquid-metal-cooled (LMC) furnace to prepare columnar grain alloy; the vacuum degree of a directional furnace is less than or equals to 5*10<-4>mmHg, the casting temperature ranges from 1480 to 1570 DEG C, the drawing velocity is 3 to 15mm/min, the temperature gradient is 95 to 145 DEG C/cm, and the temperature of melting tin ranges from 250 to 350 DEG C. The invention provides the heat-proof corrosion-resistant superalloy, which contains Ta, does not contain alloying elements that are Re (with low cost), Nb, Zr and Ce, and has a stable microstructure. Compared with cheC88 Y-BN, the tensile-strength (using Delta (b) and Delta0.2 to represent) is increased more than 30 percent, the plasticity is improved obviously, the lasting temperature is risen by 30 DEG C under the same stress condition, and the cast superalloy is applied to manufacture turbine blades of a combustion turbine which is used under 930 DEG C.

The invention belongs to the technical field of rolled steel, and in particular relates to a manufacturing method of a spray formed high-vanadium high-speed steel composite roller. The high-vanadium high-speed steel comprises the following chemical components in percentage by mass: 1.7 to 1.8 percent of C, 1.2 to 1.6 percent of Si, 5.0 to 6.0 percent of Cr, 1.2 to 1.4 percent of Mo, 0.5 to 0.6 percent of Mn, 8.0 to 10.0 percent of V, and the balance of Fe; and the roller core is made of ball milling cast iron. The invention also discloses a preparation method of the radiation roller. The preparation method comprises the following steps of: preheating the roller core to a certain temperature by using an induction coil, simultaneously smelting the high-speed steel of the outer layer in a vacuum induction furnace, atomizing the high-speed steel molten metal flow by adopting a spray forming method and using nitrogen, and depositing the molten metal on the rotary roller core for compounding. The outer texture of the compound roller is uniform, rough eutectic carbides and texture segregation are eliminated, and good metallurgical combination is formed between the roller core and a spraylayer; and the spray formed compound roller has high hardness on the surface, good abrasion resistance, improved fatigue performance and longer service life, and has higher and better economic benefits as equipment is mature.

The invention belongs to the field of production of ultrahigh-strength plastic alloy steel, and relates to a preparation method of micro/nano-structure ultrahigh-strength plastic stainless steel containing Nb. The preparation method comprises the steps of: firstly preparing materials according to a composition proportion, adding 0.05-0.15% of Nb element on the basis of 316L austenitic stainless steel, then carrying out vacuum induction furnace smelting, casting blank forging, forged piece hot rolling and solution treatment, carrying out cold deformation on the steel plate which undergoes the solution treatment with deformations of 40%, 60%, 80% and 90% and with single reduction in pass controlled within 3-10% to prepare steel plate with different cold deformations, annealing the steel plate which undergoes the cold deformation with heating rate controlled at 50-200 DEG C/s, with heating temperature within 750-950 DEG C and with heat preservation time within 5-100s, and cooling to the room temperature at a cooling rate of 50-400 DEG C/s to obtain a superfine austenite structure with micro-nano scale. The obdurability of the material is synchronously improved. The yield strength of the final product can be up to 750-800MPa, the strength of extension is up to 1100-1200MPa and the percentage of elongation is 35-45%.

The invention discloses a process for preparing Cu-Cr-Zr alloys applicable to contact lines. The process comprises the following steps that alloys comprising 0.30 to 0.50 percent of Cu, 0.10 to 0.15 percent of Cr, 0.01 to 0.02 percent of Zr and Si are melt in a vacuum induction furnace, wherein alloy elements, namely Cr, Zr and Si, are added by master alloys; fine casting-state crystal grains and oversaturated matrix tissues having secondary dendritic crystal spaces are obtained by controlling solidification velocity and cooling velocity; rolling in fit, drawing deformation and annealing thermal treatment to the fine casting-state crystal grains and oversaturated matrix tissues are carried out so as to control deformation degrees and parameters for the thermal treatment; and the strain-hardening effect and the precipitation strengthening effect are organically combined. Therefore, the alloys have the advantages of excellent tensile strength, electrical conductivity and high-temperature resistant softening capacity and lower cost under the conditions of simplified process and the simpler apparatus and components, and are applicable to industrial production.

The invention relates to the field of single crystal superalloys, particularly to a high-strength hot-corrosion-resistant Ni-based single crystal superalloy and a preparation method, and is mainly applied to high-temperature components applied to various marine environments and turbine high-temperature components of ground industrial gas turbines. The superalloy comprises chemical components in percentage by weight as follows: 11-15% of Cr, 5-9% of Co, 0.5-2.0% of Mo, 3.0-5.0% of W, 4.5-7.0% of Ta, 3.5-5.6% of Al, 2.3-3.7% of Ti and the balance of Ni. A vacuum induction furnace is used for smelting, a mother alloy is cast firstly, and then the high-strength hot-corrosion-resistant single crystal superalloy is prepared according to a single crystal growth technology and a heat treatment system. The Cr and refractory metallic elements with higher content are selected, but the content of the Ti element is reduced. Meanwhile, the crystal boundary is eliminated through a single crystal technology, so that the hot corrosion resistance, the high-temperature mechanical property and the structure stability of the alloy are further improved.

The invention provides a preparation process for preventing the formation of surface impure crystals and recrystallization on a mono-crystal hollow turbine blade. According to the preparation process, a spherical wax piece is arranged at an exposed part (tail end) of a positioning platinum wire; a thin wax film is brushed on the other exposed parts; the exposed part is covered with a fireproof material which is the same as a mold shell material in a shell making process; after de-waxing, an end part spherical cavity and a platinum wire face micro-gap are formed; a heat insulation cavity is formed by the cavity and the side micro-gap in a vacuum induction furnace in a mono-crystal preparation process; a heat bridge effect of the exposed platinum wire part is avoided so that an alloy is prevented from partial overcooling and the formation of impure crystal is inhibited; and furthermore, the cavity and the platinum wire side micro-gap provide a releasing space to the deformation of the platinum wire and the partial residual stress is prevented from occurring, and the recrystallization is prevented from occurring in a post heat treatment process of the blade.

The invention discloses a method for preparing low-cost neodymium iron boron (NdFeB) by adding a heavy rare earth oxide into an ingot recasting sheet, which comprises the following steps of: putting didymium, boron, aluminum, copper, niobium, cobalt and iron into a vacuum induction furnace in an ingredient proportion, introducing argon. and refining and casting into a casting sheet; putting the casting sheet into a hydrogen breaking furnace to break the hydrogen; adding 1.04 to 5.05 weight percent of the heavy rare earth oxide in a powder weight ratio; stirring two kinds of powder in a mixer, pulverizing with an airflow grinding machine, and putting the powder into a mold of a molding press; orienting in a magnetic field and performing compression molding; putting blanks into an isostatic pressing machine for pressing, and making into green bodies after maintaining the pressure; and sintering the green bodies in a vacuum sintering furnace at the temperature of between 1,000 and 1,100 DEG C to prepare the NdFeB magnets. The ingot is modified into a casting sheet, so the coercive force of the magnet can be effectively improved. By adding heavy rare earth elements which are better distributed in the crystal boundary and on the grain crystal edge at the pulverizing stage, the capacity of improving the coercive force is far higher than that of directly adding the heavy rare earth elements at the smelting stage; and the formula cost can be reduced by replacing high-price heavy rare earth raw materials by lower-price heavy rare earth oxides.

The invention discloses a manufacturing method of a soft magnet silicon-aluminum alloy magnetic powder core with small amounts of rare earth element cerium or lanthanum, which comprises the following steps: 1) smelting industrial pure iron, polycrystalline silicon, pure aluminum, cerium-iron alloy or lanthanum-iron alloy in a vacuum induction furnace into FeSiAl alloy cast ingots with small amounts of cerium or lanthanum, wherein the alloy cast ingots comprise the components of 9.0-9.8% of Si, 5.4-6.0% of Al, 0.02-0.25% of Ce or La, 0.006-0.015% of C, 0.008-0.010% of O2, 0.008-0.028% of S, 0.03-0.035% of P and balance of Fe; and mechanically crushing into FeSiAl alloy powder, carrying out high-heat treatment in a shielding gas atmosphere, and then screening; 2) carrying out surface passivation treatment on the FeSiAl alloy powder with phosphoric acid and alcohol, then adding 0.20% of kaolin, 0.20% of lubricant and 0.50% of parting compound, uniformly mixing, and carrying out pressure forming; and 3) carrying out heat treatment and surface spraying. The invention can increase the resistivity of the magnetic core and reduce the high-frequency eddy current loss, and has lower magnetic core loss. Besides, the invention improves the temperature stability of the magnetic permeability, and enables the decline of the magnetic permeability to be less than 3% when the working temperature rises to 125 DEG C.

The invention discloses an iron-based nanocrystalline soft magnetic alloy with electromagnetic interference resistance and a preparation method thereof. The general formula of the iron-based nanocrystalline soft magnetic alloy with electromagnetic interference resistance is Fe100-x-y-z-wSixAlYNizMw, wherein M is selected from at least one of Mo, Cu, Cr, Nb, Ti and Zr, x, y, z and w are respectively used as the weight percents of Si, Al, Ni and M, 100-x-y-z-w is the weight percent of Fe, x is not less than 2 and not more than 10, y not less than 2 and not more than 8, z is not less than 1 and not more than 5 and w is not less than 0.5 and not more than 1. Pure metal raw materials are blended according to the general formula and placed in a vacuum induction furnace for smelting to obtain a master alloy; then the master alloy is smelted by an electric arc overflow type rapid quenching furnace and quickly and continuously cast to the surface of a chilling copper roller to obtain thin strips or sheets which are subject to ball milling flattening treatment to obtain flattening powder; and finally mixing and processing the flattening powder and a caking agent into a sheet-shaped flexible material for resisting electromagnetic interference. The invention has controllable process parameters and is suitable for quick and continuous production of industrial scale; and an obtained magnet has extremely-high magnetic conductivity and the magnet shielding effect is improved.

The invention discloses a preparation method for electromagnetic wave interference resistant iron silicon aluminum nickel alloys. The invention comprises the following steps: firstly, ferrum, aluminum, silicon and nickel with a purity more than 99.9 weight percent are taken as raw materials and laid into a medium frequency vacuum induction furnace for smelting, and a master alloy is obtained; secondly, the master alloy after smelting is laid into a quick quenching device; an alloy ingot casting is quickly poured on a water-cooling roll wheel which rotates at high speed after arc remelting under the protection of high purity inert gases, and a quickly condensed sheet band or a quickly condensed sheet is obtained; thirdly, the sheet band or the sheet is laid into a ball mill for ball milling flat processing, and flat powder is obtained; fourthly, the flat powder is laid into a stainless steel tube which is then vacuumized and filled with high purity inert gases for protection, and then the stainless steel tube is laid into a tube furnace for heating, heat preservation and cooling along with the furnace; fifthly, the flat powder and binding agents are mixed and milled for processing the sheet. The preparation method for the electromagnetic wave interference resistant iron silicon aluminum nickel alloys adds adequate nickel into Sendust alloys, thereby the processability of the alloys is improved; the ball milling time is reduced; the cost of industrial production is saved; simultaneously the magnetic conductivity can be improved and the magnetic shielding effect can be improved.

The invention relates to a method for preparing a titanium aluminum intermetallic compound from a hydrogenated titanium-aluminum alloy through a short process. High-purity aluminum and titanium sponge serve as raw materials and are smelted into titanium-aluminum alloy cast ingots in a vacuum consumable electrode electric arc kish furnace or a vacuum induction furnace, the cast ingots are then crushed to be powder in a coarse mode, the powder is subjected to hydrogen treatment to obtain brittle hydrogenated alloy powder, and then the alloy powder is grinded to be microfine titanium-aluminum alloy powder by using vortex air flows; rough bodies are formed by manufacturing the hydrogenated alloy powder and subjected to a dehydrogenation reaction in the sintering and heating process, the alloy powder after the dehydrogenation reaction is high in surface activity and easy to densify through sintering, and the titanium aluminum intermetallic compound product is finally obtained and is high in purity, low in oxygen content and high in relative density. The method is short in technological process, high in operation stability, high in repeatability and capable of achieving mass continuous production; the prepared titanium-aluminum alloy powder has the advantages of being high in purity, low in oxygen content, small in particle size, narrow in size distribution, good in evenness and the like and is suitable for compression molding, injection molding and gelcasting molding.

The invention relates to a crucible for vacuum induction melting and a manufacturing method thereof. The crucible is tied on a bottom brick in an induction coil of a vacuum induction furnace. The crucible is characterized by being designed as a double-layered composite structure, wherein the inner layer is an inner shell which is used for melting and made of high-chemically stable crucible material with low decomposing pressure; and the outer layer is an outer shell which is made of low-cost crucible material and has the functions of heat insulation and support. The manufacturing method comprises the following steps in sequence: (1) paving a layer of outer shell material of the crucible at the bottom of the tied crucible, paving a layer of inner shell material of the crucible, and rammingthe material of the crucible; (2) mounting a graphite core, and placing a thin cylinder between the graphite core and an asbestos insulation layer; (3) tying the inner and outer shells of the crucible, and adding the inner shell material of the crucible between the graphite core and the thin cylinder and ramming the inner shell material of the crucible, and then adding the outer shell material ofthe crucible between the graphite core and the asbestos insulation layer; and (4) roasting the induction coil by electrifying the induction coil, and extracting the graphite core after cooling. The crucible manufactured by the manufacturing method of the crucible for vacuum induction melting has low cost.

A preparation method of easy welding high strength toughness X80 pipe line steel for magnesium treatment belongs to the production field of low alloy high strength steel, including first preparing materials according to constituent mixing rate, then smelting in a vacuum induction furnace, forging casting blank and controlling rolling and cooling. The preparation method is characterized in that the heating temperature is 1170-1230 DEG C prior to forging blank residues; the thermal time is 60-120min; and the beginning temperature of coarse rolling is 1100-1180 DEG C; the finishing temperature of coarse rolling is no less than 980 DEG C, the temperature-holding thickness of intermediate blank is 45-50mm; the beginning temperature of finish rolling is no more than 880 DEG C; the finishing temperature of finish rolling is 780-810 DEG C; the pressing rate of finish rolling is more than 3T (T: target thickness of finished products); and the target thickness of finished products is 10-15mm. After finish rolling, the product rapidly enters ACC for cooling control, with the cooling speed being 15-35 DEG C/s. the self-tempering temperature is 400-550 DEG C. The produced high strength toughness X80 pipe line steel has typical acicular ferrite tissue, as well as favorable comprehensive mechanical property and high input energy welding property.

The invention belongs to the field of nickel-based deformed high-temperature alloys, particularly relates to a nickel and cobalt-based high-temperature alloy containing rare earth elements and a preparation method thereof. The nickel and cobalt-based high-temperature alloy is mainly suitable for parts used at high temperature (700-750 DEG C) and under high stress such as turbine disks and blades of aircraft engines. The alloy comprises the following components in percentage by weight: 15-30 percent of Co, 11-17 percent of Cr, 4-6.5 percent of Ti, 1.0-3.0 percent of Al, 0.5-2.5 percent of W, 1-3 percent of Mo, 0-2 percent of Re, less than 0.1 percent of C, less than 0.1 percent of Zr, less than 0.1 percent of B, 0.01-0.5 percent of RE and the rest of Ni. The alloy is smelted with a vacuum induction furnace or a vacuum consuming furnace, is cast into a master alloy with chemical ingredients which are consistent with requirements and is thermally processed. The alloy has excellent processing performance, room temperature to high temperature tensile strength and equivalent durability to a high-performance cast and forged high-temperature alloy TMW.

A crucible for smelting Ti and Ti-alloy in vacuum induction furnace is prepared from boron nitride and flux.

The invention relates to a method for adding a nitrogen element into smelting molten steel of a vacuum induction furnace. The method comprises the following steps of: when a steel grade into which the nitrogen element is needed to be added is smelted in the vacuum induction furnace, adding nitrogen-containing iron alloy which does not damage the quality of molten steel into a hopper; and after the molten steel is subjected to high vacuum refining and deoxidized fully, introducing argon into the furnace and an ingot mold, adding the nitrogen-containing iron alloy for deoxidizing finally, tapping and pouring. The method is simple and reliable; and after furnace charges are molten completely, refined and deoxidized, and the nitrogen-containing iron alloy is added under the protective atmosphere of the argon and is deoxidized finally, the molten steel is tapped and poured, so the aim of adding the nitrogen element accurately at low cost is fulfilled, the content of the nitrogen element can be controlled accurately, and the recovery rate is stabilized to be over 65 percent.

The invention relates to high-strength high dampness and heat sea atmospheric environment resistant weathering resistant steel and a preparing method, and belongs to the technical field of weathering resistant steel. The steel comprises, by weight, 0.01%-0.03% of C, 0.30%-0.50% of Si, 0.60%-0.80% of Mn, 0.90%-1.10% of Cu, 2.80%-3.20% of Ni, 0.20%-0.40% of Mo, 0.25%-0.35% of Sn, 0.05%-0.10% of Sb, not larger than 0.03% of Cr, not larger than 0.02% of Nb, not larger than 0.01% of P, not larger than 0.01% of S, 0.03%-0.05% of RE and the balance Fe. On the basis of a Cu-Ni-Mo alloy system, the Sn, the Sb, the Nb, the RE and other microalloy elements are added, and the Cr content in the weathering resistant steel is greatly reduced. A steel ingot meeting the composition design scope is smelted through a vacuum induction furnace, through the follow-up forging and hot rolling, the weathering resistant steel with the strength of extension larger than or equal to 750 MPa, the yield strength larger than or equal to 650 MPa and the ductility larger than or equal to 15% is finally obtained; the corrosion resistance is reduced by more than 30% compared with a Q450NQR1 traditional weathering resistant steel; and the high-strength high dampness and heat sea atmospheric environment resistant weathering resistant steel is prepared and has the excellent mechanical property.

The invention belongs to the field of nonferrous metal processing, and provides a preparation method for a titanium-nickel memory alloy sheet. The preparation method mainly comprises the steps of smelting, annealing, forging, hot rolling, cold rolling and annealing, acid pickling and inspection; a vacuum induction furnace graphite crucible is adopted for smelting in the smelting step, firstly, a small amount of Ti-Ni mother alloys with the same mass percent as smelting materials is prepared and is placed in the vacuum induction furnace graphite crucible, after power is supplied and smelting iscompleted, a Ti-Ni alloy molten pool is formed, melting the ni alloy molten pool, then crushed materials of sponge titanium and electrolytic nickel are slowly added into the molten pool for smelting,and a titanium-nickel ingot is formed, wherein the chemical components of the titanium-nickel ingot is ensured to comprise 54.5%-55.5% of Ni, less than or equal to 0.04% of C, less than or equal to 0.005% of H, less than or equal to 0.050% of O, less than or equal to 0.04% of N and the balance Ti. According to the method, the problem of poor plasticity of a common titanium-nickel memory alloy sheet at the room temperature is solved, defects of cracking, peeling, folding, oxidizing and impurity pressing are overcome, the mechanical property is improved, meanwhile, the cost is reduced, and theyield during batch production is improved.