675 results about "Vacuum induction melting" patented technology

The invention relates to duplex stainless steel powder for laser additive manufacturing and a preparation method and application thereof, and belongs to the technical field of nitrogen-containing stainless steel powder preparation, the duplex stainless steel powder comprises, by mass, 0.09-0.20% of C, 5.00-15.00% of Mn, 1.00-5.00% of Mo, 5.00-15.00% of Ni, 10.00-30.00% of Cr, 0.10-0.40% of N, less than or equal to 0.02% of S, less than or equal to 0.02% of P, and the balance Fe. According to the method, vacuum induction melting and high-pressure inert gas atomization methods are utilized, the conditions such as the adding time of the mixture of the metal manganese particles and the nitrogen-containing alloy particles are controlled, and therefore the purpose of controlling the nitrogen content in the alloy powder is achieved.

The invention discloses a pure smelting method for nickel-based superalloy, which relates to the technical field of metal smelting and comprises the following steps: (1) screening high-purity raw materials; (2) selecting a vacuum induction melting furnace and carrying out vacuumizing treatment; (3) sequentially adding the pretreated raw materials into a vacuum induction melting furnace, and heating and melting the raw materials; (4) carrying out electromagnetic stirring; (5) preparing special electroslag, and drying and crushing the electroslag; and (6) casting the alloy liquid subjected to vacuum melting into a consumable electrode, inserting the consumable electrode into the slag of the electroslag remelting furnace, and electrifying. According to the design scheme, impurities in the nickel-based superalloy are effectively removed, the purity and uniformity of the alloy are improved, the mechanical property and thermal stability of the alloy are improved, the service life is prolonged, and a better purification effect is achieved.

The invention belongs to the technical field of metal material forming, and relates to a high-strength plastic titanium-based composite material annular part and a preparation method and application thereof. The preparation method comprises the following steps: firstly, uniformly mixing titanium alloy powder and reinforced phase powder, then preparing an annular blank according to the technological process of smelting, plasma rotating electrode atomization, degassing seal welding, hot isostatic pressing and ring rolling, and finally, annealing the annular blank to prepare the target annular part. According to the method, the titanium-based composite material powder is prepared by replacing a traditional laboratory small-batch ball milling method with a large-batch mixing method, a vacuum induction melting rod manufacturing method and a plasma rotating electrode atomization method, a reinforced phase can be introduced into a titanium matrix crystal and uniformly distributed, and the method is suitable for industrial large-batch production requirements; the titanium-based composite material annular part is prepared through the technology of powder metallurgy blank making and thermal deformation, and the effects of shortening the machining period and improving the material utilization rate and the forming rate are achieved through the precise size of powder metallurgy forming and the high efficiency of special-shaped ring rolling.

The invention provides a high-temperature alloy for manufacturing a nickel-copper alloy hot extrusion die, which is characterized by comprising the following components in percentage by weight: 0.02 to 0.08 percent of C, less than or equal to 0.15 percent of Si, less than or equal to 0.15 percent of Mn, less than or equal to 0.01 percent of P, less than or equal to 0.01 percent of S, 14.0 to 17.0 percent of Cr, 7.5 to 9.5 percent of Mo, 2.2 to 2.6 percent of Nb, 1.0 to 1.6 percent of Al, 2.2 to 2.8 percent of Ti, 0.005 to 0.015 percent of B, 0.01 to 0.05 percent of Zr, 21.0 to 24.0 percent of Fe and the balance of Ni. The preparation method of the alloy comprises the following processes: firstly, alloy raw materials are subjected to vacuum induction melting and then cast into ingots, then electroslag ingots are obtained through electroslag remelting, then the electroslag ingots are subjected to multi-heating-number forging, and then heat treatment is carried out. The highest use temperature of the alloy reaches 1000 DEG C, and the oxidation rate at 1000 DEG C is as low as 0.08 g / m < 2 >. H; at the temperature of 650 DEG C, the tensile strength reaches 1000 MPa, the yield strength reaches 850 MPa, the fatigue strength is higher than 400 MPa, and the lasting time of the load of 700 MPa reaches 80 h; the service life of a nickel-copper alloy hot extrusion die made of the alloy can reach 25000 times.

The invention belongs to the technical field of alloy steel, and relates to composite reinforced high-toughness steel and a preparation method thereof. The steel comprises the following chemical components in percentage by weight: 6.0%-9.4% of Ni, 7.6%-8.9% of Co, 0.8%-3.8% of Cr, 1.0%-2.6% of Mo, 0-0.9% of W, 0.05%-0.60% of V, 0-0.10% of Nb and the balance of Fe. C and Al are added to serve as strengthening elements, and the balance is Fe and impurity elements. When 0.14% < = C < 0.20%, 1.2% < = Al < = 1.6%, 1.0% < = Mo + W / 2 < = 2.0%; when 0.20% < = C < = 0.35%, 0.6% < = Al < = 1.3%, and 2.0% < = Mo + W / 2 < = 3.0%. The alloy is subjected to vacuum induction melting or multi-time melting, homogenizing diffusion annealing and forging rolling to form a material, so that the tensile strength of the steel reaches 2200-2350 MPa or above, the yield strength reaches 2000-2150 MPa or above, and the steel has excellent strength, plasticity and toughness matching and can be used for components such as engine shafts, aircraft landing gears, high-performance shells, frame beams and molds.

The invention discloses a nickel-magnesium intermediate alloy for a high-temperature alloy and a preparation method thereof.The nickel-magnesium intermediate alloy is composed of, by mass, 4%-50% of Mg and the balance Ni and inevitable impurities, and the method comprises the steps that firstly, electrolytic nickel and magnesium ingot raw materials are selected, cut and polished, and ingredients are calculated, weighed and subpackaged; 2, the raw materials are put into a crucible of an induction melting furnace to be smelted, and alloy melt is obtained; and thirdly, a steam suction filtration system is started, the alloy melt is poured into a cast iron ingot mold, and the nickel-magnesium intermediate alloy ingot is obtained after cooling. A proper amount of inert gas is introduced in the vacuum induction smelting process, smelting and pouring in a micro-negative pressure state are guaranteed, impurity introduction in the smelting and pouring processes is reduced by controlling smelting process parameters, meanwhile, gasification loss of the magnesium element is reduced, and the high-strength magnesium alloy with uniform components and high strength is obtained. The nickel-magnesium intermediate alloy is high in cleanliness and low in content of harmful gas elements and inclusions, and is suitable for the field of downstream high-temperature alloys.

The invention discloses an electric engine assembly integral forming process based on precision integral casting, which comprises the following steps: designing a split type precision mold through computer aided design software, and carrying out nitriding treatment to improve the performance; selecting a specific aluminum alloy raw material, performing vacuum induction melting and refining, and injecting the aluminum alloy raw material into a preheated and sprayed mold cavity in a low-pressure casting manner; and demolding after air cooling and water cooling are combined, then after-treatment procedures such as deburring and heat treatment are conducted, and finally detection and assembly are conducted. A conformal cooling water channel design and an ultrasonic-assisted smelting technology are adopted in the process innovation, and the casting process is monitored in real time. According to the process, manufacturing procedures are reduced, compared with a traditional mode, the production efficiency is improved by 30%-50%, the cost is reduced by 20%-30%, the assembling problem is effectively avoided, the sealing performance and reliability of the electric engine are improved, the service life of the electric engine is prolonged, high integration is achieved, and the modern industrial requirement is met.

The invention relates to a high-strength and high-toughness ultra-fine grain titanium alloy material and a preparation method thereof, and relates to the technical field of titanium alloys, the high-strength and high-toughness ultra-fine grain titanium alloy material comprises the following chemical components in percentage by weight: 3.0 to 6.0 percent of Al, 1.0 to 2.5 percent of V, 0.5 to 2.0 percent of Fe, 0.01 to 0.25 percent of B, 0.05 to 0.15 percent of C, 0.05 to 0.10 percent of N, less than or equal to 0.05 percent of H, 0.01 to 0.02 percent of Zr, 0.01 to 0.02 percent of Y, 0.01 to 0.1 percent of Si and the balance of Ti and inevitable impurities. The preparation method comprises the following steps: 1, vacuum induction melting and electron beam cold bed furnace melting; 2, performing homogenization treatment; 3, hot rolling cogging and large-deformation warm rolling are conducted, specifically, hot rolling cogging and large-deformation warm rolling are conducted on the material subjected to homogenization heat preservation treatment; and 4, structure refining heat treatment. The finally prepared high-toughness ultra-fine grain titanium alloy material has excellent mechanical properties, the yield strength is not lower than 1200 MPa, the tensile strength reaches 1400 MPa, and the total ductility is not lower than 8%.

The invention relates to a corrosion-resistant alloy welding wire, in particular to an ERNi CrMo-3 corrosion-resistant alloy welding wire and a preparation method thereof. The steel comprises the following chemical components in percentage by mass: greater than or equal to 64% of Ni, 21%-23% of Cr, 8.5%-10% of Mo, less than or equal to 0.2% of Fe, 0.1%-0.3% of Ti, 0.1%-0.25% of Al, 3.5%-4.15% of Nb, less than or equal to 0.2% of Cu, less than or equal to 0.02% of C, less than or equal to 0.5% of Mn, less than or equal to 0.35% of S i, less than or equal to 0.005% of S and less than or equal to 0.005% of P. By adopting vacuum induction melting and electroslag remelting, the content of all elements in the alloy can be accurately controlled, the content of impurity elements (H, O, N, S, P and the like) is effectively reduced, the content of oxygen and nitrogen is controlled to be not larger than 20 ppm, alloy components are more uniform and stable, and therefore the corrosion resistance and the high-temperature mechanical property of the welding wire are improved.

The invention relates to the technical field of metal processing, and discloses a production method of an ER2209 austenite ferrite duplex stainless steel welding wire, the ER2209 austenite ferrite duplex stainless steel welding wire comprises an adopted vacuum induction melting furnace and a liquid storage tank, the outer side of the vacuum induction melting furnace is provided with a protective shell, one side of the liquid storage tank is fixedly connected with a conveying pump, and the other side of the liquid storage tank is fixedly connected with a vacuum pump. A cooling assembly is arranged in the protective shell. The preparation method comprises the following steps that S1, raw materials are prepared and smelted; s2, cooling the vacuum induction melting furnace; s3, forging is conducted; s4, hot rolling and solution treatment; s5, acid pickling and surface treatment; s6, cold drawing and intermediate annealing; s7, surface copper plating and finish drawing; and S8, winding and packaging. In the acid pickling process of the wire rod, the oxidation degree of the wire rod is detected, meanwhile, the concentration of the acid pickling solution is adjusted according to the actual situation, and the situation that the surface of the wire rod is excessively corroded or is not thoroughly cleaned due to the fact that the concentration of the acid pickling solution is improper is prevented.

The invention provides a directional solidification preparation method of a degradable high-hardness zinc alloy material. The preparation method of the zinc alloy material comprises the machining processes of vacuum induction melting, vacuum directional solidification melting and the like, through the preparation method, growth of Zn + Mg2Zn11 trilobal eutectic and Zn + MgZn2 spiral eutectic is regulated and controlled, microscopic structures are arranged in the specific direction, fine and uniform structure morphology is formed, and the corrosion resistance and the mechanical property of the alloy are improved. The Zn-Mg series alloy prepared by the preparation method disclosed by the invention shows excellent microhardness (181.19 to 243.10 HV). Besides, the corrosion rate of the ideal degradable bone implant is within the range of 0.1 mm / y to 0.5 mm / y, and the corrosion rate of the degradable medical Zn-Mg alloy bone implant material is within the range of 0.0316 mm / y to 0.2280 mm / y, so that the requirement on the corrosion rate in the bone repair process is met; and after the Cu element is added on the basis of Zn-3% Mg, the microhardness of the Zn-3% Mg-Cu-Cu alloy material is improved to about 200HV, and the advantages in the aspect of mechanical support are improved.

The invention discloses a pickling-free cold heading Kovar alloy wire production process which comprises the following steps: S1, raw material preparation: preparing the following raw materials in percentage by mass: 41.5% of Ni, 0.5% of Co, less than or equal to 0.03% of C, less than or equal to 0.05% of Mn, less than or equal to 0.05% of Si, less than or equal to 0.02% of P, less than or equal to 0.02% of S and the balance of Fe; mixing the materials, and carrying out vacuum induction melting and electroslag remelting to prepare an alloy ingot; the alloy cast ingot is subjected to hot rolling treatment to form a hot-rolled wire rod with the diameter being 12.0-16.0 mm; s2, peeling treatment is conducted, specifically, surface layer defects of the hot-rolled wire rod in the step S1 are removed through a peeling machine; s3, dry-type drawing treatment is conducted, specifically, the hot-rolled wire rod treated in the step S2 is subjected to dry-type drawing through a dry-type drawing die to form an alloy wire; s4, intermediate annealing treatment is conducted, specifically, the alloy wire in the step S3 is placed in an annealing furnace, sufficient hydrogen is input into the annealing furnace, intermediate annealing is conducted under the hydrogen protection atmosphere, the annealing temperature is 950-1100 DEG C, and the annealing walking speed is 3-5 m / min; the surface quality and the size consistency of the wire can be improved, meanwhile, the defects of environmental pollution, hydrogen embrittlement and the like are reduced, and the use requirements of high-end precise cold heading parts are met.

The invention discloses a preparation method of high-sphericity titanium-based corrosion-resistant high-entropy alloy powder, and relates to the technical field of metal powder preparation, and the preparation method is technically characterized by comprising the following steps that S1, titanium-based high-entropy alloy raw materials are smelted into melt in a vacuum induction smelting furnace, and the titanium-based high-entropy alloy raw materials comprise, by atomic percent, 30%-40% of Ti, 5%-15% of Al, 3%-10% of Cr, 2%-8% of Nb and 1% of Mo; the method has the technical effects that dendritic crystal growth is inhibited and heavy element segregation is eliminated through the synergistic effect of low-frequency and high-frequency magnetic fields, so that the powder composition segregation index of the embodiment is superior to that of a contrast, the element distribution uniformity is improved by multiple times, and the hollow powder rate is remarkably reduced compared with that of a magnetic-field-free process.

The invention relates to corrosion-resistant austenitic stainless steel for spent fuel aftertreatment and a preparation method of the corrosion-resistant austenitic stainless steel, belongs to the field of nuclear materials and technologies, and solves the key problem that existing domestic commercial austenitic stainless steel is prone to intergranular corrosion in a nitric acid medium in a special spent fuel aftertreatment environment. The stainless steel comprises the following components in percentage by weight: 15.0 to 20.0 percent of Cr, 12.0 to 18.0 percent of Ni, 3.0 to 6.0 percent of Si, 0.05 to 2.0 percent of Mn, 0.05 to 2.0 percent of W and Mo, 0.20 to 0.20 percent of N, 0.20 to 0.20 percent of Nb and V, 0.05 to 0.05 percent of rare earth element RE and the balance of Fe and inevitable impurity elements: less than or equal to 0.010 percent of C, less than or equal to 0.005 percent of P, less than or equal to 0.005 percent of S, less than or equal to 0.005 percent of O and less than or equal to 0.005 percent of B. The preparation method of the stainless steel comprises the steps of vacuum induction melting, vacuum consumable remelting, thermal machining and solution treatment.

The invention discloses a forming method of a titanium alloying high-boron stainless steel slab, which comprises the following steps: (1) melting molten steel through vacuum induction according to set components, and pouring to obtain an induction cast ingot; the alloy comprises the following components in percentage by mass: 0.2-2.5% of B, 0.5-5.0% of Ti, 17.0-21.0% of Cr, 10.0-16.0% of Ni, 0.5-2.5% of Mn, 0.1-1.5% of Si, less than or equal to 0.07% of C, less than or equal to 0.04% of P, less than or equal to 0.03% of S, less than or equal to 0.1% of N and other inevitable impurities, and the balance of Fe. (2) electroslag remelting is conducted on the induction cast ingot, an electroslag ingot is obtained, after diffusion annealing is conducted on the electroslag ingot at the temperature of 1100-1220 DEG C, hot forging cogging is conducted, and a thick plate intermediate billet is obtained; and (3) the thick plate intermediate blank is subjected to hot rolling and solution treatment with the single-pass rolling reduction being 3%-18%, and the titanium alloying high-boron stainless steel plate blank is obtained. In order to solve the problems that the high-boron stainless steel plate blank is small in specification, difficult to machine and limited in industrialization, the alloy component design is optimized, the forming process of titanium alloying, electroslag, hot forging and hot rolling is provided, and an effective technical route is provided for industrial production of the large-size and thick-specification plate blank.

The invention discloses a production process of a novel copper-based alloy bimetallic synthesis material, and relates to the field of alloy materials.The production process comprises the steps that a copper-nickel alloy is selected as a base material, a titanium alloy is selected as a functional layer, and stress distribution of a bonding layer is designed and optimized through gradient component distribution; preparing a copper-nickel alloy liquid by utilizing vacuum induction melting, supporting and fixing a core rod through three points, and controlling temperature and flow velocity for pouring to form co-growth crystals; the surface of the base material is cleaned through a sand blasting process, a Cu-Ti nano coating is coated through a PVD technology, and a nanoscale convex-concave structure is formed; building a mathematical model of a temperature field and a component diffusion field, and optimizing and combining area temperature distribution and diffusion behaviors through simulation analysis; through gradient temperature control annealing treatment, residual stress is eliminated, and diffusion is promoted; the bonding performance is evaluated by combining shear strength and microhardness tests; and dividing the production process based on the modular design. The method can be widely applied to the industrial fields with high-temperature, high-strength and corrosion-resistant requirements.

The invention discloses austenite hydrogen-resistant stainless steel and a preparation method thereof, and belongs to the field of metal materials. The austenitic hydrogen-resistant stainless steel comprises the following chemical components in percentage by mass: less than or equal to 0.06% of C, less than or equal to 1.00% of Si, 3.00-5.00% of Mn, 19.50-22.00% of Cr, 11.00-13.00% of Ni, 1.50-2.00% of Mo, 1.50-3.50% of Cu, 0.20-0.30% of V, 0.10-0.23% of Nb, 0.30-0.40% of [N], less than or equal to 0.01% of P, less than or equal to 0.004% of S, less than or equal to 0.003% of [O] and the balance of Fe. The preparation method comprises the steps of vacuum induction melting, high-temperature homogenization, forging, hot rolling and heat treatment. The method solves the problems that traditional austenitic stainless steel is poor in hydrogen embrittlement resistance and an existing process is difficult to consider precise regulation and control of high purity, low impurities and hydrogen trap elements at the same time.

The invention discloses a platinum-based alloy baffle material for an airspace engine, and belongs to the technical field of precious metal alloy materials. By optimizing alloy components and the preparation method, the problems that platinum-based alloy is insufficient in high-temperature mechanical property, rare earth elements are seriously burnt and the like are successfully solved, and a new-generation platinum-based high-temperature structural material with excellent high-temperature mechanical property and oxidation resistance is developed. The material comprises the following components in percentage by mass: 25.0%-30.0% of Ir, 0.10%-1.00% of Sm, 0.10%-1.00% of Ce and the balance of Pt, the preparation method comprises the following steps: weighing a mixture of platinum, iridium, samarium and cerium metals, and sequentially carrying out pre-alloying, vacuum induction melting, pouring, solution treatment and aging treatment, thermoplastic processing, cutting and surface treatment to obtain the platinum-based alloy baffle material for the airspace engine. The tensile strength of the material reaches 48 MPa at the temperature of 1500 DEG C, and the lasting creep life exceeds 54 h under the stress of 50 MPa; under severe thermal shock and cavitation conditions, the surface of the alloy is kept intact, and the 10h oxidation weight gain is lower than 1.6 mg / cm < 2 >.

The invention belongs to the technical field of high-temperature alloy heat treatment, and discloses a method for improving the hot working performance of a nickel-based high-temperature alloy for a molten salt reactor by combining pre-deformation and homogenization. The method comprises the steps that raw materials of the nickel-based superalloy for the molten salt reactor to be improved are sequentially subjected to vacuum induction melting, pouring and electroslag remelting refining treatment, and an electroslag remelting refined alloy cast ingot is obtained; the electroslag remelting refined alloy cast ingot is sequentially subjected to heating, heat preservation and pre-deformation treatment and is air-cooled to the room temperature, and a pre-deformed cast ingot is obtained; and the pre-deformed cast ingot is subjected to homogenization treatment and air cooling to the room temperature, and the method is completed. The method is a novel heat treatment process combining pre-deformation and high-temperature homogenization, the hot working performance of the alloy is optimized, the high-temperature alloy uniform in structure and excellent in mechanical property is obtained, and application in the field of high-temperature molten salt energy systems is met.

The invention belongs to the technical field of metallurgy, and particularly relates to ultrapure 316L stainless steel and a vacuum induction melting preparation method thereof. The preparation method comprises the following steps: firstly preparing NiCa intermediate alloy through vacuum induction melting, then preparing 316L alloy through vacuum induction melting, firstly adding Al for deoxidation, then adding the refined NiCa intermediate alloy for high-temperature refining for Al removal, and finally performing low-temperature refining for Ca removal and further deep deoxidation and desulfurization. According to the method, various impurity elements such as Al, O and S and inclusions of the ultra-pure 316L stainless steel can be removed only through a vacuum induction melting method, extra technological processes such as electroslag or self consumption are not needed, equipment investment is simple and convenient, large-scale industrial application can be achieved easily, and an effective way is provided for purification preparation of the ultra-pure 316L stainless steel.

The invention relates to the technical field of high-temperature alloys, and particularly discloses a smelting preparation process of a large-specification bar capable of resisting the temperature of 800 DEG C. The invention discloses a smelting preparation process of a large-specification bar resistant to the temperature of 800 DEG C. The smelting preparation process specifically comprises the following steps of vacuum induction smelting, annealing, first-time vacuum consumable smelting, electrode forging, second-time vacuum consumable smelting, consumable ingot homogenizing annealing and bar forging in sequence. According to the method, the large-size bar resistant to the temperature of 800 DEG C is prepared through the process, the bar quality is improved, the prepared large-size bar has excellent tensile property and high temperature resistance, the occurrence probability of black spots and white spots is reduced, and meanwhile homogenization control over bar components is achieved.

The invention relates to the technical field of materials, in particular to high-strength high-toughness corrosion-resistant maraging stainless steel and a preparation method thereof.The stainless steel comprises, by mass, 11.0%-13.5% of Cr, 9.5%-10.5% of Ni, 0.5%-1.25% of Mo, 0.2%-1% of Al, 0.5%-1.0% of Ti, 0.2%-1.0% of Nb, 0.1%-0.8% of Cu, smaller than or equal to 0.20% of Mn, smaller than or equal to 0.01% of P, smaller than or equal to 0.01% of S, smaller than or equal to 0.20% of Si, smaller than or equal to 0.01% of O, smaller than or equal to 0.01% of C and the balance Fe. The preparation method of the high-strength, high-toughness and corrosion-resistant maraging stainless steel comprises the steps of vacuum induction melting and consumable melting or vacuum induction melting furnace electroslag remelting, homogenization treatment, forging, rolling and heat treatment. According to the martensitic precipitation aging stainless steel prepared through the preparation method, on the basis that the tensile strength and the hardness exceed 1900 MPa and 52 HRC correspondingly, the ductility, the percentage reduction of area and the impact toughness are remarkably improved and exceed 15%, 50% and 60 J / mm < 2 > correspondingly, and the martensitic precipitation aging stainless steel has the advantages of being low in preparation cost, high in strength, high in yield ratio, good in toughness, high in corrosion resistance and the like.

The invention provides an aluminum-vanadium-niobium-chromium intermediate alloy as well as a preparation method and application thereof. The aluminum-vanadium-niobium-chromium intermediate alloy comprises the following components in percentage by mass: 15%-22% of V, 1%-7% of Nb, 5%-11% of Cr and the balance of Al and inevitable impurities. The preparation method of the aluminum-vanadium-niobium-chromium intermediate alloy comprises the following steps: firstly, respectively preparing three binary intermediate alloys, namely primary alloys, by utilizing an aluminothermic reduction method; then, the primary alloy is refined through vacuum induction melting, and a secondary alloy is obtained; and finally, the secondary alloy and metal aluminum are subjected to vacuum induction melting, and the aluminum-vanadium-niobium-chromium intermediate alloy is prepared. The aluminum-vanadium-niobium-chromium intermediate alloy has the advantages of being uniform in component, low in element segregation and low in impurity content, and has very good application prospects and large-scale industrial popularization potential in the field of titanium alloy production through the additive manufacturing technology.

The invention belongs to the technical field of vacuum centrifugal casting and vacuum induction melting, and particularly relates to a complex thin-wall casting vacuum induction remelting pouring temperature gradient control device and method, and the device comprises a calculation system, a temperature measurement mechanism, a rapid induction remelting mechanism and a bottom pouring crucible; the calculation system is used for achieving simulation calculation of rapid induction remelting and bottom pouring of the alloy ingot, and the temperature measuring mechanism outputting target remelting characteristic parameters is used for measuring temperature changes and temperature gradient distribution of the top, the middle and the bottom of the alloy ingot in the remelting process in real time. The rapid induction remelting mechanism is used for melting the alloy ingots and achieving the melting sequence of the alloy ingots from top to bottom and from outside to inside. By means of the high-temperature alloy remelting device, the problem that in the high-temperature alloy remelting process, due to the fact that the temperature gradient is disordered, alloy is completely melted or part of alloy liquid flows out from the bottom firstly is effectively solved, and casting defects are reduced.

The invention discloses special hot work die steel for large-scale integrated die casting and a preparation method of the special hot work die steel, and belongs to the technical field of hot work die steel. The steel comprises the following chemical components in percentage by mass: 0.28%-0.35% of C, 0.01%-0.025% of La, 0.01%-0.02% of Ce, 0.4%-0.45% of Mn, 0.1%-0.2% of Si, 4.5%-5.5% of Cr, 1.50%-2.00% of W, 2.2%-2.8% of Mo, 0.8%-1.2% of V, 1.0%-1.5% of Co, 0.1%-0.3% of Nb and the balance of Fe and impurities (S and P are less than or equal to 0.015%). The preparation method comprises the composite processes of vacuum induction melting and electroslag remelting purification, hydrogen firing high-temperature homogenization and three-upsetting and three-drawing multi-directional forging, spheroidizing annealing and subzero treatment, step quenching and double tempering, multi-element co-permeation, supersonic particle bombardment surface nanocrystallization and plasma boriding. The rare earth element La / Ce refined grain boundary is combined with multi-element alloy strengthening and surface nanocrystallization-boronizing synergistic treatment, so that the hardness, impact toughness and thermal fatigue life of the die steel are remarkably improved, and the die steel is suitable for high-temperature, high-pressure and high-wear working conditions of a large integrated die-casting die.

The invention discloses a smelting method of a large-size Fe-based high-temperature alloy for a gas turbine. The smelting method comprises the following two steps: casting a metal raw material into a 710mm electrode bar through a vacuum induction furnace, and then feeding the electrode bar into a consumable electrode vacuum furnace for remelting to produce a 810mm steel ingot. According to the method, the vacuum induction melting and vacuum consumable remelting (VIM and VAR) combined process is adopted for smelting, so that the burning loss of the Ti element can be effectively controlled to ensure that the content of the Ti element reaches the standard, excessive generation of Ti-series carbonitride can be avoided, and the negative influence on the purity of the molten steel is fundamentally avoided.

The present application relates to high-temperature alloy smelting technical field, specifically relates to a kind of high-aluminum titanium cast nickel-based high-temperature alloy purification smelting method.The pure smelting method, step one, low calcium nickel alloy preparation;Step two, pure smelting: batching and furnace charging, melting period, refining period, alloying period, calcium treatment purification period and casting period;Pure smelting process is carried out in vacuum induction melting furnace, 2 / 3 low calcium nickel alloy is directly loaded into magnesium oxide crucible when furnace charging, and the remaining 1 / 3 low calcium nickel alloy is added in calcium treatment purification period.The present application prepares a kind of component accurately controllable "low calcium nickel alloy" as master alloy by pre-preparation, is added in key smelting stage, solves the problem of calcium element direct addition, realizes the deep deoxidation denitrogenation desulfurization of alloy melt, significantly reduces the oxygen, nitrogen, sulfur impurity content in alloy, to improve the purity and comprehensive mechanical properties of alloy.

The invention discloses a method for reducing impurity element sulfur in cast high-temperature alloy return scraps, and belongs to the technical field of metal material smelting. The method comprises the following steps: carrying out vacuum induction melting on pretreated cast high-temperature alloy return scraps of the same mark to obtain a return scrap alloy induction ingot; surface oxide skin of the obtained return scrap alloy induction ingot is removed, a primary shrinkage cavity in the upper end is cut off, then the return scrap alloy induction ingot and an auxiliary electrode are coaxially welded, and a consumable electrode is obtained; and after the consumable electrode is baked, electroslag remelting is conducted under the protective atmosphere, and an electroslag ingot is obtained. On the basis of vacuum induction melting, the protective atmosphere electroslag remelting technology is further adopted for conducting deep purification melting treatment on the return scrap alloy ingot, the content of the impurity element S in the return scrap alloy ingot can be reduced to 0.5 ppm or below, and the content of the impurity element S in the return scrap alloy ingot reaches the level lower than the content of the element S in a new material; and the high-temperature oxidation resistance and corrosion resistance of the alloy can be obviously improved, and the fatigue, durability and other mechanical properties of the alloy are improved.

The invention provides a preparation method of a GH706 high-temperature alloy large-size bar billet, which comprises the following five steps: (1) a GH706 high-temperature alloy ingot prepared by a triple smelting process of vacuum induction melting, protective atmosphere electroslag remelting and vacuum consumable remelting comprises the following chemical components in percentage by weight: 0.025%-0.060% of C, 14.50%-17.50% of Cr, 39.00%-44.00% of Ni, 1.50%-2.00% of Ti, 2.50%-3.30% of Nb + Ta, 0.15%-0.50% of Al and the balance of Fe and inevitable impurities; the balance is Fe and other micro trace elements; (2) high-temperature homogenization treatment; (3) cogging and forging: carrying out high-temperature cogging and forging on the cast ingot for 2-3 heating numbers, wherein the forging modes are upsetting and drawing-out; (4) intermediate billet forging: performing medium-temperature multi-heating-number upsetting and octagonal drawing on the intermediate billet subjected to cogging forging; according to the preparation method of the GH706 high-temperature alloy large-size bar billet, the technical problem that the structure uniformity is difficult to control due to end face cracking, low forging yield and severe temperature rise in the cogging process of a large-size cast ingot is solved, and the preparation method has high application value in industrial actual production.

The invention discloses a vacuum induction melting furnace for alloy melting, and relates to the technical field of melting furnaces. The vacuum induction smelting furnace for alloy smelting comprises a smelting furnace body, a heating unit, a crucible, a bottom support, a mold base, a vacuum control unit, a feeding unit, a discharging control unit and a proportional control mechanism. According to the smelting furnace, the feeding unit is additionally arranged on the smelting furnace main body, the feeding unit is convenient for storing various raw materials and controlling discharging, the tedious operation of opening the furnace for adding the raw materials for many times is avoided, time and labor are saved, alloy smelting can be continuously and stably carried out, the discharging amount of the two raw materials is controlled through the design of the discharging control unit and the proportion control mechanism, and the smelting efficiency is improved. Quantitative supply is achieved, the discharging proportion of the two raw materials is accurately controlled through the proportion control mechanism, operation is easy and convenient, errors are not prone to occurring, the requirement for accurate proportion of different alloy components can be met, and stability and consistency of alloy quality are guaranteed.