85results about How to "Guaranteed high temperature strength" patented technology

The invention relates to oxide-dispersion-strengthening ferrite / martensitic steel with the excellent high-temperature strength and the good oxidation resistance and a preparing method of the oxide-dispersion-strengthening ferrite / martensitic steel. The oxide-dispersion-strengthening ferrite / martensitic steel comprises 8% to 10% of Cr, 0.5% to 2% of W, 1.5% to 5.5% of Al, 0.1% to 0.4% of V, 0.1% to 0.5% of Mn, 0% to 1.0% of Zr, 0% to 1.0% of Hf and 0.25% to 0.5% of Y2O3. The content of C and the content of N are controlled to be lower than 0.1%, and at least one kind of the Hf and the Zr is contained; the oxygen content of atomized powder is controlled to be lower than 0.05 wt.%, the atomized powder with the particle size ranging from 50 meshes to 200 meshes is selected to be mechanically alloyed with Al powder, Zr powder, Hf powder and Y2O3 powder, and the size of obtained powder ranges from 90 micrometers to 200 micrometers; silicate glass is used for wrapping, compressing and molding, the pressure is started to be boosted to 120 MPa to 180 MPa at the temperature of 850 DEG C, a two-stage sintering manner in which the temperature ranging from 850 DEG C to 950 DEG C is kept for 1 hour and the temperature ranging from 1050 DEG C to 1150 DEG C is kept for 1 hour is adopted, the tensile strength of the finally-obtained ferrite / martensitic steel at the temperature of 700 DEG C ranges from 250 MPa to 320 MPa, and the ductility of the finally-obtained ferrite / martensitic steel at the temperature of 700 DEG C ranges from 18% to 32%; and the oxidation performance of the dispersion-strengthening steel is also greatly improved on the premise that the high-temperature strength and the high-temperature plasticity are guaranteed, and after 100-h oxidation is carried out at the temperature of 850 DEG C, the oxidation weight increase only ranges from 0.0327 mg / cm<3> to 0.098 mg / cm<3>.

The invention belongs to the technical field of metallurgy, and provides a large-diameter seamless steel tube for high-pressure gas cylinders and a manufacturing method thereof. The large-diameter seamless steel tube for high-pressure gas cylinders comprises the following chemical components in percentage by mass: 0.30-0.60% of C, 0.20-0.50% of Si, 0.20-0.60% of Mn, at most 0.010% of P, at most 0.010% of S, 0.90-1.70% of Cr, 2.50-3.50% of Ni, 0.25-0.55% of Mo, 0.05-0.25% of V and the balance of Fe. The manufacturing method adopts spongy iron and scrap steel as raw materials for steelmaking. The large-diameter seamless steel tube has the advantages of high heat stability, high strength, impact toughness, stable enduring plasticity, high heat resistance, excellent corrosion resistance and excellent fatigue resistance, and the yield strength is not lower than 1000 MPa.

The invention discloses a non-phosphorus and low-carbon alumina-magnesia unburned brick for a stainless steel ladle and a manufacturing method of the brick. The non-phosphorus and low-carbon alumina-magnesia unburned brick comprises the following components by mass percentage: 15-20% of 5-3mm bauxite, 20-25% of 3-1mm bauxite, 10-15% of bauxite less than or equal to 1mm in particle size, 10-15% of 3-1mm fused magnesite, 5-10% of fused magnesite less than or equal to 1mm in particle size, 10-15% of emery powder, 15-20% of spinel powder, 2-5% of aluminum oxide micropowder less than or equal to 25 micrometers, 0.1-2% of silicon carbide additive, 0.1-2% of wetting agent and a phenolic resin binding agent. Compared with the prior art, the brick and the method have the prominent advantages that a burning technology in the conventional method is omitted, energy sources are saved, the brick is free from phosphorus; aluminum and magnesium perform spinel reaction at the high temperature; and the brick is subjected to machine molding in the absence of the phosphorus, has higher density, avoids pollution of molten stainless steel, and has a longer service life.

The invention relates to a magnesia carbon brick and a preparation method thereof. The magnesia carbon brick is prepared from, by weight, 60%-75% of fused magnesite particles, 10%-30% of fused magnesite fine powder, 5%-10% of carbon, 1%-5% of an antioxidant, 1%-3% of a binding agent and 0.4%-1% of furfural waste liquid. In the preparation process, the fused magnesite particles are placed in a mixing mill to be dry-mixed for 2-15 min, then phenolic resin and the furfural waste liquid are added to continue to be mixed for 5-15 min, then carbon is added to the mixture, mixing is carried out for 5-15 min, finally the fused magnesite fine powder and the antioxidant are added to continue to be mixed for 8-15 min, pug is formed, the rotating speed of the mixing mill is set to range from 950 r / min to 1,000 r / min, mixing time ranges from 10 min to 60 min, and the magnesia carbon brick is prepared after compression moulding and drying solidification. The preparation method is simple, the steps are easy to operate, the uniformity of mixed materials of the magnesia carbon brick is improved, the quality of the mixed materials of the magnesia carbon brick is improved, the labor intensity of workers is lowered, the use amount of phenolic resin is reduced, and due to the addition of the furfural waste liquid, the material mixing process is more even, and phenolic resin is prevented from being caked.

The invention relates to the smelting technology, in particular to silicon iron smelting raw material and a preprocessing method. The preprocessing method comprises the following steps: firstly, silicon contained raw material is mixed with the carbonaceous reducing agent according to a certain ratio; secondly, a 40 to 80 mm oval or oblate pellet is pressed into form through a mechanical way; thirdly, after drying, the percentage of moisture is controlled for less than two percent, and then the raw material can be used as silicon iron smelting raw material. The silicon iron smelting raw material and the preprocessing method have the advantages that the raw material resource is rich, the price is inexpensive, and the energy saving effect is obvious, simultaneously, because a great amount of , the silicon fine powder and siliceous colliery waste are adopted by the technology, the social benefit and the environmental benefit are quite good.

The gas phase medium gasifying nozzle includes gasified medium inlet pipe with flange and corresponding fixed multiple flow channel spray tube with integrated nozzle, and features the equal wall thickness connection between the spray tube and the nozzle with smooth transition, the nozzle with conic outer and inner walls, and nozzle end wall thickness of 1-4 mm. The reasonable arrangement of gasifying nozzles, arced gasifying furnace top and furnace mouth structure forms the optimal flow field and temperature field matching reaching best gasifying effect with effective gas component over 95.5 % and up to 96.3 %. The present invention has prolonged gasifying nozzle life.

The invention relates to a sagger taking alumina sol as a binding agent and used for sintering a lithium battery cathode material and a preparation method of the sagger. The preparation method is characterized by comprising the following steps: firstly mixing 35-45 wt% of mullite, 20-25 wt% of cordierite, 20-25 wt% of magnesium aluminum spinel, 3-7 wt% of alumina sol, 4-7 wt% of Guangxi white clayand 2-7 wt% of silicon powder, and stirring for 8-10 min to obtain a mixture; and then mechanically pressing and shaping the mixture under a condition of 100-120 MPa, drying the mixture for 20-25 h under a condition of 90-110 DEG C, and then keeping the temperature of the mixture for 3-4 h under a condition of 1300-1400 DEG C to prepare the sagger taking the alumina sol as the binding agent and used for sintering the lithium battery cathode material. The preparation method involved in the invention has the characteristics of low production cost, simple process and high yield; and the preparedsagger taking the alumina sol as the binding agent and used for sintering the lithium battery cathode material is large in volume density, high in compressive strength, excellent in thermal shock resistance and good in erosion resistance.

The invention discloses a super-strength osmosis-resistant high-aluminum brick. The super-strength osmosis-resistant high-aluminum brick is prepared from fused brown corundum, alumina micro-powder, super Guangxi white clay and a specific binder according to a certain ratio, has the characteristics of low porosity, high strength, no adhesion reaction with an aluminum liquid and excellent erosion resistance, can satisfy the severe conditions of the existing aluminum melting furnace, holding furnace and homogenizing furnace, improves a service life of the whole furnace inner liner and improves aluminum liquid quality.

The invention discloses a self-brazing aluminum alloy foil, consisting of the following components in percentage by mass: 0.2-0.4% of Fe, 2.1-2.3% of Si, 1.25-1.45% of Mn, 1.4-1.6% of Zn, 0.3-0.4% ofCu, 0.01-0.02% of Ti, 0.03-0.07% of RE, 0.03-0.07% of Zr, and the balance of Al. The thickness of the self-brazing aluminum alloy foil is 0.05-0.10 mm. The invention further discloses a preparation method for the self-brazing aluminum alloy foil. The self-brazing aluminum alloy foil is a single-layer foil, can implement self-brazing, is high in tensile strength and yield strength after brazing, and is excellent in droop resistance.

The invention discloses zirconium-containing electrothermal alloy. The zirconium-containing electrothermal alloy comprises, by mass, 0-0.03% of carbon, 19-22% of chrome, 3.3-3.6% of aluminium, 0.35-0.43% of zirconium, 0-0.5% of silicon, 0.2-0.6% of titanium, 0-0.5% of manganese, 0-0.004% of magnesium, 0-0.01% of sulphur, 0-0.03% of phosphorus and the balance Fe. The invention further provides a method for preparing the zirconium-containing electrothermal alloy through vacuum induction melting and electroslag remelting. The initial slag system CaF2-CaO-MgO-Al2O3-ZrO2 is extracted during electroslag remelting, in the temperature rise period of the initial stage of remelting, Al2O3 powder is additionally added into the slag, therefore the content of zirconium in ingots is controlled precisely, and the zirconium is distributed evenly. According to the alloy and the preparation method, a right amount of zirconium is added into the electrothermal alloy, so that the high-temperature oxidationresistance of the electrothermal alloy is improved, and the high-quality effect is achieved through process control.

This invention provides a complex type crucible used in magnesium and magnesium alloy smelting. In order to conquer the problem of crucible easy corrosion and penetration, oxidizing desquamation, low quality and short life in high temperature, the crucible in this invention is compounded by ceramic material and double metal crucible made by heat-resisting steel or nickel base high-temperature alloy and carbon steel. The inner layer is the ceramic material that does not react with magnesium and magnesium alloy, central layer is carbon steel material, outer layer is heat-resisting steel or nickel base high-temperature alloy material. The connecting of double metal material is explosive bonding and the high temperature strength and creep resistant capability of crucible is increased, ceramic material form ceramic inner coating on carbon steel surface by spray coating or laser melting and coating technique. The outer layer make crucible not oxidation desquamation in high temperature, carbon steel avoids the high temperature oxidation, ceramic layer prevent crucible corroded by high temperature metal liquor and corrosion gas, the second pollution in smelting process is avoided. It can be used crude magnesium smelting purifying, and smelting preparing, melting and casting of magnesium alloy.

The invention discloses a low-carbon-equivalent steel plate for a nuclear containment as well as a production method of the steel plate. The steel plate comprises the following chemical components inpercentage by mass: 0.09 to 0.13 percent of C, 0.25 to 0.40 percent of Si, 1.00 to 1.35 percent of Mn, less than or equal to 0.010 percent of P, less than or equal to 0.005 percent of S, 0.15 to 0.30percent of Cr, 0.15 to 0.35 percent of Ni, 0.15 to 0.25 percent of Mo, less than or equal to 0.10 percent of Cu, 0.020 to 0.040 percent of Nb, less than or equal to 0.10 percent of V, more than or equal to 0.020 percent of Alt, and the balance of Fe and unavoidable impurities, wherein the carbon equivalent CEV is less than or equal to 0.42 percent. The production method comprises the processes ofsmelting, heating a steel billet, rolling the steel billet and performing heat treatment on the steel plate. The steel plate can meet and simulate the normal-temperature stretching, high-temperature stretching and low-temperature impact properties of the delivery state and the heat treatment state after welding simultaneously, and can be widely applied to nuclear power projects at home and aboard.

The invention belongs to the technical field of metallurgy and particularly relates to a method for reducing and separating granular iron rapidly at a low temperature. The method comprises the following steps: crushing iron ore, drying, grinding the dried iron ore into fine iron ore powder, adding iron powder, lime powder, ordinary glass powder and fluorite powder into the fine ore powder, spraying with water, mixing, pelletizing or pressing to form pellets; drying the wet pellets, adding reducing coal and a desulfurizing agent, feeding the mixture into a rotary muffle kiln, and carrying out reduction reaction; separating the tail power of a reducing agent from metalized pellets in the high-temperature material from reduction reaction by using a dry magnetic separator; crushing the metalized pellets, and sieving to obtain the granular iron with the size of 3-20mm and the density of 5.8-7.2t / m<3>; polishing the power further, and separating magnetically by adopting a wet process to obtain the high-grade iron powder. The iron ore can be reduced rapidly at a relatively low reducing temperature, the granular iron can be separated, and the yield of the granular iron can be more than 90%. Compared with the Japanese ITmk3 reduction technology, the method provided by the invention can achieve the purposes of saving energy, reducing emission and decreasing carbon to a great extent.

The invention discloses a manufacturing method for double-grain-size-distribution oxide dispersion strengthening ferrite steel, and belongs to the field of metal materials. The double-grain-size-distribution oxide dispersion strengthening ferrite steel comprises the components of (5-10)wt.% of Cr, (1.5-2)wt.% of W, (6-10.5)wt.% of Al, (0.1-0.4)wt.% of V, (0.25-0.5)wt.% of Y2O3 and less than 0.01wt.% of C and N; the oxygen content of atomization powder is less than 0.05wt.%; the atomization powder with the particle size of 200-400 meshes, Al powder with the particle size of 400 meshes and Y2O3powder with the particle size of 20-50 nanometers are mechanically alloyed; the powders are packed and sealed with a low-carbon steel packing sheathe; hot isostatic pressure sintering is performed; the powders are heated, and pressurization is performed at 800 DEG C; and a two-stage sintering mode is adopted. The tensile strength of the obtained strengthened steel is over 820 MPa, and the total ductility is larger than 16%; the tensile strength at 650 DEG C is not lower than 500 MPa, and the total ductility is not lower than 15%.

The invention relates to an electric boosting electrode device, in particular to an electrode device with a cooling and insulating structure, and belongs to the field of glass production tank furnace melting. The electrode device consists of an electrode head (1), an insulated sleeve (2) and a cooling water pipeline (3), wherein the cooling water pipeline (3) is simultaneously used as a lead of the electrode device; and the electrode device is inserted into a specific position in molten glass, the insulated sleeve (2) is connected with the molten glass and the tank bottom (or the tank wall) on the premise of internal cooling, and the insulated sleeve (2) plays a role in protecting the refractory material of the tank bottom (or the tank wall) around the insertion hole of the electrode device under the conditions of high temperature and strong convection around the electrode head (1).

The invention relates to a preparation method of an alumina ceramic shell for monocrystal blades. Ethyl silicate slurry is utilized to prepare a shell, of which the layer structure is provided with at least five layers. The method comprises steps as follows: 1) the first layer of the shell uses ethyl silicate slurry prepared by one of the following two schemes: Scheme 1: adding fused alumina fine powder with the particle size of 1000-230# into ethyl silicate, wherein the viscosity is fai4 by flow cup viscosity, and the flow clean time is 57-62 seconds; Scheme 2: adding ZrSO4 powder with the particle size of 200-325# into ethyl silicate, wherein the viscosity is fai4 by flow cup viscosity, and the flow clean time is 65-70 seconds; 2) the ethyl silicate slurry for the rest layers of the shell except the first layer satisfies the formula and preparation sequence requirements of the Scheme 1, wherein the viscosity of the mixture obtained by stirring is fai4 by flow cup viscosity, and the flow clean time is 30-35 seconds; and after the slurries are sequentially coated on the wax mold, the shell is roasted at 500-1000 DEG C DEG C for 3-15 hours, and is cooled in the furnace. The method provided by the invention can be utilized to obtain the excellent-performance ceramic shell which has the advantages of moderate thickness, favorable thermal shock resistance and good air permeability.

The invention discloses a shell making process of a silica sol shell with high deshelling property. The shell making process comprises the following steps: S1, uniformly mixing powder with silica solwith stirring, and adding a wetting agent and a defoamer to form a first mixture; S2, immersing a wax mold into the first mixture, taking the wax mold out, scattering sand into the wax mold, and drying to obtain a first-layer mold shell; S3, repeating the step S2 until second to sixth layers of mold shells are obtained; S4, drying the wax mold including the first to sixth layers of mold shells tocomplete sealing; S5, calcining the wax mold including the first to sixth layers of mold shells to obtain a mold shell casting. According to the shell making process of the silica sol shell with highdeshelling property disclosed by the invention, fully-calcined aluminosilicate refractory sand powder, free iron and hard kaolinite with low diaspore content is taken as a main material of the silicasol shell, and is combined skillfully with quartz sand, so that the high-temperature strength of the mold shell is ensured, and the retained strength after mold shell pouring can be lowered greatly.

The invention relates to a carbon composite fireproof material for blast furnace iron runner and a preparation method thereof. The material is made of graphite (C), Al, Si, SiC, corundum, magnesite, and vf-SiO2, wherein the weight ratio of the total weight of graphite (C), Al, Si, and SiC to the total weight of corundum, magnesite, and vf-SiO2 is 1:1. The material is prepared by the following steps: adding silica sol accounting for 10% of the total weight of raw materials, blending, forming, carrying out a hardening treatment, grinding, and finally packaging into bags so as to obtain the finished products. The casting material for blast furnace iron runner maintains the characteristics of high temperature strength, scrubbing resistance, and corrosion resistance of common fireproof material and at the same time has a certain degree of toughness like metal materials. During the melt iron discharging process, the material is subjected to cool-heat circulation, can tolerate fierce temperature fluctuation impact, can maintain a stable volume, and is not easy to peel off, so the service life of the iron runner is prolonged.

The invention relates to the field of seamless steel tube manufacturing, in particular to a strengthening method of the surface of a piercing plug of a seamless steel tube rolling mill. The strengthening method comprises the following steps that 1 flaw detection is conducted on the outer surface of the plug to detect whether the plug is damaged or not; 2 abrasive blasting processing and polishing processing are conducted on the outer surface of the plug which is confirmed not damaged through flaw detection; 3 the plug with abrasive blasting processing and polishing processing conducted is cleaned so as to remove dirt on the surface of the plug; 4 an abrasion-resistant layer is welded onto the outer surface, with the dirt removed, of the plug; 5 grinding is conducted on the welded surface of the plug. The strengthening method of the surface of the piercing plug of the seamless steel tube rolling mill has the advantages that according to the technology, welding strengthening is conducted on the surface of the plug on the basis that the comprehensive mechanical performance of a common plug is not influenced, the welding material is formed by adding hard alloy phase into a cobalt base, the surface of the plug is strengthened in a welding mode, metallurgical bonding of the super abrasion-resistant layer and a base of the plug is guaranteed, the mechanical performance of a plug body is not changed and after a strengthened part is abraded due to use, the part can be repaired multiple times.

The invention relates to high-strength rare earth ytterbium heat-resistant steel and a manufacture method thereof. The heat-resistant steel comprises the following chemical components by mass percentage: 0.05-0.12% of C, 0.2-1.5% of Si, 0.5-1.7% of Mn, less than or equal to 0.045% of P, less than or equal to 0.030% of S, 24.0-26.0% of Cr, 19.0-22.0% of Ni, 0.03-0.6% of Yb, and the balance of Fe and the unavoidable impurity element; and the following condition should be simultaneously satisfied: Creq / Nieq is less than or equal to 1.165, Creq is Cr+1.5Si, and Nieq is Ni+30C+0.5Mn. By adding rare earth ytterbium, crystal boundary intensity is increased, the method provides favorable condition for increasing carbon content in the heat resistant steel, so that the high temperature intensity and service life of the steel are increased, the reasonable manufacturing process condition is cooperated, under guarantee of mechanical properties, the grain size of the heat-resistant steel can reach 4-6 grade, and the steel antioxidation performance is increased.

The invention discloses special casting materials for triangular area prefabricated components of an electric arc furnace roof. The special casting materials are prepared from the following raw materials: 20-35 parts of highly pure aluminum bauxite, 10-25 parts of tabular corundum, 15-32 parts of chromium corundum, 3-5 parts of spinel fine powder, 1.5-2.5 parts of kyanite, 5-9 parts of active aluminum oxide micro powder, 1-3 parts of chromium oxide green fine powder, 2-4 parts of silicon micro powder, 3.11-5.25 parts of a bonding agent, 0.03-0.06 part of organic fibers and 0.5-1 part of stainless steel fibers. According to the special casting materials disclosed by the invention, scientific grain size distribution is adopted for main body granules, so that the triangular area prefabricatedcomponents are guaranteed to have good high temperature strength and good hot vibration stability; materials of the spinel micro powder, pure calcium aluminate cement, active aluminum oxide and chromium oxide green and the like, which are added, are compounded, and after casting moulding and baking, a high-strength low-temperature solidified combination liner is formed, so that the compactabilityand the volume stability of the prefabricated components are guaranteed; the chromium corundum (Al2O3+Cr2O3 greater than or equal to 95%) in the raw materials is slag for smelting electrofusion chromium metal; through the use of the raw materials, the cost of products can be reduced, discharge of industrial waste can be reduced, and cyclic utilization of the industrial waste can be effectively realized.

The invention discloses a long-service-life high-strength hot-corrosion-resistant nickel-based superalloy. The nickel-based superalloy comprises the following components in percentage by weight of 18.0%-19.9% of Cr, 18.0% to 25.0% of Co, 1.6%-2.8% of Al, 3.1%-4.5% of Ti, 0.1%-0.5% of Ta, 3.1%-4.9% of W, 0%-1.20% of Mo, 0.7%-1.7% of Nb, 0.005% to 0.15% of C, 0.003%-0.03% of B, 0.005% to 0.08% of Zr, and the balance Ni. Through component design optimization of the alloy, the thermal corrosion resistance and the high-temperature strength of the alloy are guaranteed, and meanwhile the long-life structure stability of the alloy is improved. The alloy disclosed by the invention is suitable for manufacturing hot-end parts of gas turbines and can be used for thousands of hours for a long time in agas corrosion environment.

The invention discloses an alloy material of a valve and the valve. The alloy material of the valve is prepared from, by weight, 0.45%-0.55% of C, 0-0.45% of Si, 8.00%-10.00% of Mn, 0-0.050% of P, 0-0.030% of S, 25.00%-27.00% of Cr, 3.50%-5.0% of Ni, 0.40%-0.60% of N, 0.80%-1.50% of W, 1.80%-2.50% of Nb and the balance Fe. The oxidation resistance, the high-temperature strength and the creep resistance of the alloy material can meet the actual working condition requirements of an exhaust valve, and the cost is not increased substantially. Besides, the alloy material is particularly applicableto preparation of hollow valves.

The invention relates to a coating material for preventing carbon deposition for a coke tank lining plate. The coating material comprises the following raw materials in percentage by weight: 20-30% of mullite aggregate, 5-15% of silicon carbide, 5-12% of mullite micro-powder aggregate, 5-10% of andalusite, 25-35% of mullite, 5-15% of silicon carbide, 0.1-5% of boron nitride, 1-5% of metal silicon powder, 1-8% of organic silicone resin solution, 3-8% of microcrystalline glass powder, 5-15% of silica sol with a silicon oxide content of 32-40%, and 0.01-1% of sodium polyacrylate. The use method comprises the following steps of: arranging a stainless steel wire mesh after anchoring nails are nailed at a to-be-smeared coke pot lining plate part; welding the stainless steel wire mesh to the anchoring nails in parallel; coating the stainless steel wire mesh with the coating material until the stainless steel wire mesh is completely coated; collecting pulp by using plastic fiber cloth; naturally air-drying; heating; preserving heat; and keeping for later use. The service lifetime of the coke pot lining plate can be prolonged from 3-6 months to at least 7 months by the coating material, and the temperature of the outer surface of the coke pot shell is reduced by 150-300 DEG C.

The invention discloses a preparing method of high-performance easy-to-demold resin sand for nodular cast iron. The resin sand is prepared from 40-50 parts of forsterite powder, 3-5 parts of silica sol, 1-3 parts of boron glass powder, 0.01-0.02 part of sodium lignin sulfonate, 5-9 parts of pyrophyllite powder, 2-4 parts of phenolic resin powder, 5-8 parts of pyrite powder, 4-7 parts of gypsum powder, 2-4 parts of epoxy resin powder, 0.3-0.5 part of samarium oxide, 1-3 parts of alumina whiskers, 1-3 parts of a graphene PVA emulsion, 2-4 parts of boron nitride, 1-3 parts of ferric oxide, 1-2 parts of silicon carbide, 1-3 parts of fused alumina zirconia powder, 0.2-0.5 part of cerium oxide and 0.4-0.8 part of a vulcanizing agent. According to the resin sand, through the reasonable cooperation of the components, the content of resin and a curing agent is reduced, the performance of the resin sand is improved, the ash content and water content of the resin sand are reduced, and therefore the quality of a casting is improved, the gas volume is reduced, meanwhile the quality of reclaimed sand is improved, and good circulation is formed.

The invention discloses high-melting-point Kelvin structure lattice metal as well as a preparation method and application thereof, and belongs to the technical field of lattice metal preparation. Theproblems that the application working condition is limited due to the fact that anisotropy generally exists in an existing lattice metal unit structure and the application range is narrow due to low-melting-point lattice metal are solved. According to the high-melting-point Kelvin structure lattice metal as well as the preparation method and the application thereof provided by the invention, adaptive design of a casting process is carried out on the basis of Kelvin structure lattice units, a novel ceramic preform material with high-temperature strength and removal performance is developed, andhigh-melting-point Kelvin structure lattice metal is prepared by combining indirect three-dimensional (3D) printing with a precision casting process. The high-melting-point metal is mainly made of steel and iron materials and a high-temperature alloy. The high-melting-point Kelvin structure lattice metal prepared by the method has isotropic mechanical properties, and has higher strength, rigidityand temperature resistance, and the application space of the lattice metal is greatly expanded.

The invention provides a preparation method of a clay quartz crucible for high-temperature alloy casting. The preparation method comprises the following steps: preparing pug, refining the pug, molding, drying and sintering. The pug comprises a basic material and water, and the basic material comprises the following components in percentage by mass: 25-30% of ball clay powder; 40-50% of quartz glass powder; 20-25% of white corundum powder; and 1%-5% of mullite powder. According to the clay quartz crucible, the raw material variety, the adding proportion and the raw material granularity are reasonably controlled; the adverse effect of clay on the thermal stability of the crucible is avoided, the problem that a pure quartz crucible cannot be plastically formed is solved, the requirements of high-temperature alloy on the use temperature and thermal shock resistance of the crucible are met, meanwhile, the sintering temperature of the crucible is 500 DEG C lower than that of a traditional magnesium crucible, and the sintering condition is easier to meet.

The invention discloses 350 DEG C-resistant thermosetting polyimide aerogel and a preparation method thereof, and relates to polyimide aerogel and a preparation method thereof. The problems that existing polyimide aerogel is low in temperature resistance and high-temperature strength are solved. The 350 DEG C-resistant thermosetting polyimide aerogel is prepared from tertiary amine, aromatic diamine, aromatic dianhydride, an end-capping reagent and a solvent, the preparation method comprises the following steps: 1, weighing; 2, adding a solvent and p-phenylenediamine into a three-necked bottle for reaction under the conditions of nitrogen atmosphere, certain temperature and stirring, heating, adding aromatic dianhydride, fluorenyl-containing diamine and tertiary amine, stirring for reaction, finally adding an end-capping reagent, cooling and standing; 3, freeze-drying; and 4, carrying out thermal imidization reaction.

The invention relates to oxide-dispersion-strengthening ferrite / martensitic steel with the excellent high-temperature strength and the good oxidation resistance and a preparing method of the oxide-dispersion-strengthening ferrite / martensitic steel. The oxide-dispersion-strengthening ferrite / martensitic steel comprises 8% to 10% of Cr, 0.5% to 2% of W, 1.5% to 5.5% of Al, 0.1% to 0.4% of V, 0.1% to 0.5% of Mn, 0% to 1.0% of Zr, 0% to 1.0% of Hf and 0.25% to 0.5% of Y2O3. The content of C and the content of N are controlled to be lower than 0.1%, and at least one kind of the Hf and the Zr is contained; the oxygen content of atomized powder is controlled to be lower than 0.05 wt.%, the atomized powder with the particle size ranging from 50 meshes to 200 meshes is selected to be mechanically alloyed with Al powder, Zr powder, Hf powder and Y2O3 powder, and the size of obtained powder ranges from 90 micrometers to 200 micrometers; silicate glass is used for wrapping, compressing and molding, the pressure is started to be boosted to 120 MPa to 180 MPa at the temperature of 850 DEG C, a two-stage sintering manner in which the temperature ranging from 850 DEG C to 950 DEG C is kept for 1 hour and the temperature ranging from 1050 DEG C to 1150 DEG C is kept for 1 hour is adopted, the tensile strength of the finally-obtained ferrite / martensitic steel at the temperature of 700 DEG C ranges from 250 MPa to 320 MPa, and the ductility of the finally-obtained ferrite / martensitic steel at the temperature of 700 DEG C ranges from 18% to 32%; and the oxidation performance of the dispersion-strengthening steel is also greatly improved on the premise that the high-temperature strength and the high-temperature plasticity are guaranteed, and after 100-h oxidation is carried out at the temperature of 850 DEG C, the oxidation weight increase only ranges from 0.0327 mg / cm<3> to 0.098 mg / cm<3>.

The invention discloses a gypsum shell low in retained strength and a preparing method of the gypsum shell. Gelatin is contained in the gypsum shell. The method comprises the steps that gypsum powderand filler are evenly mixed; after water is heated, the gelatin is added in the water, uniform mixing is conducted, and a transparent solution is obtained; gypsum powder and filler mixed powder is added in the transparent solution, and slurry is obtained; the slurry is poured into a die; after the slurry in the die is hardened, the die is dismounted, standing is conducted at the room temperature,and a wet gypsum shell is obtained; and the wet gypsum shell is naturally dried and roasted, and the gypsum shell low in retained strength is obtained. The gypsum shell is low in retained strength andeasy to clean, the preparing method is simple, and the production efficiency is high.