503 results about "Mass fraction" patented technology

The invention provides a concrete super-early-strength quick-hardening material, and relates to the field of building materials. The high-strength concrete comprises the following components in percentage by mass: 40%-50% of calcium aluminate, 30%-40% of gypsum, 8%-15% of high aluminum, 1%-3% of an additive, 3%-12% of an exciting agent and 1%-5% of an auxiliary material. According to the super-early-strength quick-hardening material provided by the invention, hour-level strength can be quickly and stably improved, and the strength increasing curve of each age is smooth and stable, so that the requirements of scenes such as road repair and tunnel construction on early strength can be met; it can be guaranteed that the 28-day compressive strength of the material breaks through 70 MPa, the later strength is kept stable, and the long-term safety of an engineering structure is guaranteed; the anti-seepage, anti-freezing and anti-erosion capabilities are realized in a complex environment, the service life of a project can be effectively prolonged, and the maintenance cost is reduced. In addition, the invention further provides a preparation method of the concrete super-early-strength and quick-hardening material, and the preparation method is used for preparing the super-early-strength and quick-hardening material provided by the invention.

The invention relates to a 5xxx series aluminum alloy additive part and a preparation method thereof, relates to the technical field of additive materials, and aims to solve the problem of urgent development of a process capable of effectively improving the strength of the 5xxx series aluminum alloy additive part without any subsequent treatment. According to the main technical scheme, the preparation method of the 5xxx-series aluminum alloy additive part comprises the following steps that 5xxx-series aluminum-magnesium-based aluminum alloy powder and CNT are subjected to powder mixing treatment, and composite powder is obtained; wherein in the 5xxx series aluminum-magnesium-based aluminum alloy powder, the mass fraction of the Mg element is larger than 4% and not larger than 12%, the mass fraction of the Si element is smaller than 0.4%, and the mass fraction of the Cu element is smaller than 0.2%; in the composite powder, the mass fraction of the CNT is greater than 0.5% and not higher than 5%; the composite powder is formed into a blank, and the blank is made into a bar; and the bar is subjected to friction extrusion deposition treatment, and the 5xxx series aluminum alloy additive part is obtained. The method is used for preparing the 5xxx series aluminum alloy additive part with excellent tensile strength and yield strength, and subsequent heat treatment is avoided.

The invention provides a cobalt-containing nickel-based high-temperature alloy GH4098 wide cold-rolled sheet and a manufacturing method thereof. The GH4098 cold-rolled sheet comprises, by mass, 17.50%-19.50% of Cr, 5%-8% of Co, 5.5%-7.0% of W, 3.5%-5.0% of Mo, 2.50%-3.0% of Al, 1.0%-1.5% of Ti, smaller than or equal to 3.00% of Fe, smaller than or equal to 1.50% of Nb, smaller than or equal to 0.30% of Mn, smaller than or equal to 0.30% of Si, smaller than or equal to 0.10% of C, smaller than or equal to 0.015% of S and smaller than or equal to 0.015% of P. The manufacturing method comprises the steps that S1, a plate blank is forged, the forging frequency and temperature are controlled in a light hammer and fast beating mode, and a uniform forged blank is prepared; s2, hot-rolling cogging: heating through a sheath and closing cooling water for rolling to obtain a hot-rolled semi-finished product; and S3, cold rolling machining is conducted, specifically, the wide cold-rolled sheet is manufactured through the repeated cold rolling and intermediate solution heat treatment alternating technology. Through component optimization and process improvement, the strength, plasticity and grain size uniformity of the material are remarkably improved, the manufactured wide cold-rolled sheet is smooth in surface and high in glossiness and can meet the performance requirements in the fields of aerospace and high-end manufacturing, and meanwhile the problems of edge cracking and non-uniform performance in wide plate production in the prior art are solved.

The invention discloses a ceramic bonded WC hard alloy and a preparation method thereof, WC hard alloy powder is prepared from W powder, Ti powder, Zr powder and C powder, the mass fraction of the W powder is 85-90 wt.%, the mass fraction of the Ti powder is 2-2.5 wt.%, the mass fraction of the Zr powder is 4-4.5 wt.%, and the mass fraction of the C powder is 6-6.5 wt.%. The W powder, the Ti powder, the Zr powder and the C powder are mixed in a mechanical alloying (MA) mode through a one-step method, the novel high-entropy ceramic combined WC hard alloy composite material is prepared through the SPS sintering technology, the sintering temperature is reduced through vacancy energy in a system, sintering is promoted, introduction of oxygen is reduced, the hardness, fracture toughness, corrosion resistance and other performance of a sintered body are improved, and the service life of the high-entropy ceramic combined WC hard alloy composite material is prolonged. Meanwhile, the technological process is simplified, and the production cost of the hard alloy material is reduced.

The invention relates to a method for improving early-stage performance of an all-solid-waste cementing material, and aims to improve the early-stage performance of the cementing material. At present, the early strength (1d strength) of an all-solid waste cementing material is generally low, but the characteristic is closely related to construction efficiency and is a key limit for large-scale application of the all-solid waste cementing material. Sintering is not included in the working procedures, and the product does not contain cement clinker. The method comprises the following steps: selecting industrial solid wastes such as steel slag, blast furnace water slag, iron alloy slag, silicomanganese slag, industrial byproduct gypsum, sintering fly ash, fly ash, calcined coal gangue and the like as raw materials; the industrial solid waste is subjected to independent or mixed grinding treatment; by optimizing the raw material ratio and introducing key component minerals, the specific surface area of the cementing material is increased, and active sites of the key minerals are dissociated and exposed. The mass of the introduced key components for optimizing the raw material ratio accounts for less than or equal to 15% of the total mass of the cementing material, the mass fraction of the key and active minerals is increased by less than or equal to 10%, and the early strength of the all-solid waste cementing material is increased by 30%.

The invention relates to the technical field of powder metallurgy materials, and discloses a binding-phase-free hard alloy and a preparation method thereof.The binding-phase-free hard alloy comprises, by mass, 75-80 parts of WC; 8 to 12 parts of TiC; 5 to 8 parts of TaC; 3 to 5 parts of ZrC; 1.5 to 2.5 parts of HfC; 0.8 to 1.2 parts of rare earth oxide; the preparation method comprises the five key steps of core-shell structure composite powder preparation, high-energy beam melting gradient accumulation, microwave-magnetic field composite field activation, multi-stage pressure plasma sintering and staged variable-rate gradient cooling. And component gradient design is cooperated with a multi-field coupling process. Through collaborative design of a core-shell structure hard phase and a gradient composite phase, and in combination with a multi-field coupling activated sintering and gradient cooling process, the problem of obdurability balance of the non-binding-phase hard alloy is solved, the microstructure stability is optimized, and the comprehensive performance and the process controllability are improved.

The invention discloses a post-combustion effect simulation method introducing chemical reaction analysis. The post-combustion effect simulation method comprises the steps that detonation energy, detonation products, mass fraction and related thermodynamic parameters are obtained according to the detonation process of explosives; obtaining an energy release parameter containing a chemical reaction source item; establishing a combustion analysis and calculation model introduced with a chemical reaction source item after the explosion of the closed space; solving the initial temperature and initial pressure of the equivalent gas mass of the explosive; inputting related parameters into a combustion analysis and calculation model after explosion in a closed space in which chemical reaction is introduced, and solving to obtain an energy release rate; and the specific heat energy of the post-combustion effect is obtained through calculation, the JWL state equation is modified, and the implosion response of the closed space considering the post-combustion effect is simulated. The method has the advantages that the calculation model including the chemical reaction source item is introduced, the explosive initiation process can be accurately and effectively simulated, the post-combustion reaction starting and ending time and the energy release rate are obtained, and the simulation result is accurate.

The invention relates to normalized high-strength medium-carbon acid-resistant container steel and a preparation method, and belongs to the technical field of steel manufacturing. The acid-resistant container steel comprises the following chemical components in percentage by mass: less than or equal to 0.20% of C, less than or equal to 0.55% of Si, 1.20-1.70% of Mn, less than or equal to 0.025% of P, less than or equal to 0.010% of S, less than or equal to 0.050% of Nb, less than or equal to 0.050% of V, less than or equal to 0.030% of Ti, more than or equal to 0.020% of Al, less than or equal to 0.0060% of Ca and a matrix element Fe. A proper amount of Nb (niobium), V (vanadium) and Ti (titanium) alloy elements are added to replace a traditional Cu (copper) and Ni (nickel) alloy combination, and the alloy component cost is greatly reduced while high strength and acid resistance are guaranteed.

The invention relates to the field of test and analysis of impurity element content of primary magnesium ingots, in particular to a method for testing impurity element content of primary magnesium ingots by ICP (inductively coupled plasma) spectrometry, which comprises the following steps: firstly adding H2O2 into a magnesium ingot sample to infiltrate the sample, then adding HCl at an interval of less than 1 minute to carry out first reaction, carrying out first heating after the reaction is finished, and then carrying out second heating, cooling to 20-30 DEG C, transferring to a volumetric flask, and fixing the volume by using third-level water to obtain a sample solution; establishing a working curve by using an ICP spectrometer and a standard solution; testing the sample solution; the ratio of the mass of the magnesium ingot sample to the volume of H2O2 to the volume of HCl is 1: (3-10): (30-54), the method fills the standard vacancy of ICP spectrometry analysis of the silicon element in the primary magnesium ingot, a reliable basis is provided for chemical component analysis of the primary magnesium ingot, the test result is surface, and the method for testing the mass fraction of the impurity elements in the primary magnesium ingot provided by the invention has the advantages of high analysis precision, simple operation, high accuracy and high reliability. The analysis period is short, and related chemical varieties are few.

The invention discloses a biomass fuel rod and a production method and application thereof, and belongs to the technical field of biomass fuels, the biomass fuel rod comprises the following components by mass: 60-80 parts of a biomass raw material, 10-20 parts of a binder, 1-5 parts of a combustion improver, 3-8 parts of a sulfur and chlorine fixing agent, 1-3 parts of a denitration agent, and 2-5 parts of an ash content regulator. The production method specifically comprises the following steps: (1) pretreatment: crushing a biomass raw material until the particle size is less than or equal to 2mm, and carrying out pretreatment by adopting baking semi-carbonization; (2) mixing: sequentially adding a binder, a combustion improver, a sulfur-fixing and chlorine-fixing agent, a denitration agent and an ash content regulator which are ground until the particle size is less than or equal to 2mm, and stirring and mixing for 5-10 minutes; (3) forming: carrying out extrusion forming by adopting a twin-screw extruder under the pressure of 15-25MPa and the temperature of 80-100 DEG C to obtain a fuel rod with the density of 1.2-1.4 g / cm < 3 >; the production method is simple and easy to implement, the combustion performance of the produced fuel rod is good, and the combustion efficiency and the environmental protection property are improved.

The invention discloses a fixed flash welding process for an R350HT high-strength heat-treated steel rail containing trace alloying elements, which comprises the following steps: preparing a steel material of the steel rail, the chemical components of the steel material meeting the European standard EN13674 requirements, and the chemical components of the steel material in industrial production comprise the following components in percentage by mass: 0.76-0.80% of C; 0.50 to 0.58% of Si; 1.0 to 1.20 parts of Mn; p < = 0.020; s is less than or equal to 0.025; the steel rail comprises the following components in percentage by mass: 0.10-0.15% of Cr, 0.01-0.03% of V and the balance of Fe, a proper amount of the steel rail is added according to the limitation of residual elements of the components, and the components are subjected to smelting, continuous casting, steel billet slow cooling, rolling, heat treatment and the like to produce the steel rail. The size of a steel rail continuous casting billet is 280 mm * 380 mm, and the rolling section is 60E1.

The invention belongs to the technical field of aluminum-based composite materials, and particularly relates to a heat-resistant cyclic wear-resistant aluminum-based composite material and a preparation method thereof.Based on the total mass of the aluminum-based composite material, the heat-resistant cyclic wear-resistant aluminum-based composite material comprises an aluminum alloy matrix and a SiC particle reinforcement with the mass fraction of 15%-25%, and the SiC particle reinforcement is a mixture of micron-sized particles and submicron-sized particles; the particle size of the micron-sized particles is 10-100 [mu] m, the particle size of the submicron-sized particles is 0.3-0.8 [mu] m, the addition amount of the submicron-sized particles accounts for 0.1-2% of the total mass of the composite material, and the composite material has good wear resistance and good heat-resistant cycle performance at the normal temperature of minus 300 DEG C. The prepared SiC particle aluminum-based composite material brake disc can avoid excessive decline of material hardness, wear resistance and friction coefficient caused by thermal cycle in a repeated braking process.

Provided is a production process of an S355J2 hot rolled H-beam for a Ce-containing beam-column member, relating to the production of hot-rolled H-beams. The production process can ensure the performance of the hot-rolled H-beam with multiple classes from one steel grade, and achieve low cost, stability, uniformity, consistency, and narrow composition control of various elements. In the S355J2 hot-rolled H-beam for a Ce-containing beam-column member, a hot-rolled H-beam is prepared from the following compositions by mass fraction: 0.18%-0.20% of C, 0.25%-0.30% of Si, 1.22%-1.27% of Mn, less than or equal to 0.025% of P, less than or equal to 0.025% of S, 0.008%-0.011% of Nb, 0.008%-0.012% of V, 0.004%-0.008% of N, 0.0015%-0.0055% of Ce, less than or equal to 0.015% of Al, and the rest of Fe and inevitable impurities.

The invention discloses a low-cost smelting method for normalizing and rolling H-shaped steel for ocean engineering. The smelting process comprises the steps of blast furnace molten iron, molten iron pretreatment, converter smelting, LF refining and special-shaped blank continuous casting. The steel comprises the following chemical components in percentage by mass: 0.08%-0.14% of C, 0.25%-0.35% of S i, 1.30%-1.50% of Mn, less than or equal to 0.02% of P, less than or equal to 0.010% of S, 0.05%-0.09% of V, 0.015%-0.035% of Nb and the balance of Fe and impurities, and the total mass fraction is 100%. The prepared H-shaped steel not only has very high yield strength and tensile strength, but also has very good impact toughness.

The invention discloses a high-temperature speckle preparation method suitable for a silicon carbide ceramic-based composite material, which is characterized by comprising the following preparation steps: S1, weighing 0.1-5g of metal oxide powder, 0.05-0.5 g of stabilizer solution with the mass fraction of 1-5% and 5g of water; s2, magnetically stirring the system at 25 DEG C for 2-48 hours; s3, spraying the speckle liquid obtained in the step (2) on the surface of the SiC ceramic-based composite material by using a spray gun, and drying; and S4, carrying out a mechanical test. The speckle prepared by the method has excellent temperature resistance and high adhesive force, and is not easy to oxidize, deform or fall off.

The invention discloses a high-dispersion and small-particle-size alpha-MoC1-x / SiO2 catalyst as well as a preparation method and application thereof. The catalyst is composed of alpha-MoC1-x nanoparticles dispersed on a silicon dioxide carrier, the alpha-MoC1-x / SiO2 catalyst is generated in a three-dimensional SiO2 confined network in a limited manner, wherein the three-dimensional SiO2 confined network is constructed by in-situ polycondensation of silica sol under the condition that the pH value is 2.3-2.8, and the molybdenum content is 30-60%; the average particle size of the alpha-MoC < 1-x > nanoparticles is 1.0-2.2 nm, and the alpha-MoC < 1-x > nanoparticles are highly dispersed in the SiO2 confinement structure; the alpha-MoC1-x nano-particles are face-centered cubic phase molybdenum carbide, and the mass fraction of the face-centered cubic phase molybdenum carbide is larger than or equal to 90 wt%. The alpha-MoC1-x / SiO2 obtained by the invention can realize higher methanol selectivity and intrinsic activity under the condition of 140-180 DEG C, and can stably operate for 100 hours. The invention provides a novel small-particle-size and high-dispersion molybdenum carbide catalytic material and a preparation strategy thereof for preparing methanol through low-temperature and high-selectivity CO2 hydrogenation.

The invention relates to the technical field of building material preparation, and discloses an aluminate material compounded alkali-free accelerator which comprises the following components in parts by mass: 6-12 parts of an aluminate-based material, 4-10 parts of a sulphoaluminate-based material, 8-18 parts of a regulator, 20-40 parts of aluminum sulfate and 50-70 parts of water, the preparation method comprises the following steps: sequentially adding the sulphoaluminate-based material, the aluminate-based material, the regulator and the aluminum sulfate, and carrying out multi-stage stirring. When the mixing amount of the prepared accelerator is 6%-8% of the mass of cement, the initial setting time is 120-180 seconds, the final setting time is 200-300 seconds, the strength in 6 hours is larger than or equal to 1.1 MPa, and the strength in 1 day is larger than or equal to 9 MPa. According to the formula, the setting performance and strength development of the accelerator are optimized, the adaptability and construction efficiency of cement are improved, the problems that a traditional accelerator is poor in adaptability, long in setting time and slow in strength development are solved, and the requirements for rapid construction and high strength are met.

The invention relates to the technical field of building engineering materials, in particular to an inorganic grouting material with adjustable curing time and a use method thereof. The inorganic grouting material provided by the invention comprises a main material and an adjusting material, the main material comprises the following components in parts by mass: 50-70 parts of sulphoaluminate cement clinker, 10-20 parts of quartz powder, 10-20 parts of gypsum, 3-5 parts of nano volcanic ash, 0.5-1 part of a water reducing agent and 0.1-1.5 parts of a retarder; the adjusting material comprises a composite coagulant and hydroxypropyl methyl cellulose. Through innovation of a material formula and innovation of a construction process, the problem that the grouting effect is poor due to the fact that a traditional grouting material cannot change the solidification time according to variable underground grouting scenes and requirements is solved; accurate grouting can be achieved under the conditions of different grouting depths, different crushing degrees, different diffusion radiuses, different mixing water temperatures, different coal and rock mass temperatures, different water inflow and the like.

The invention discloses a solid solution strengthening type difficult-to-deform nickel-based high-temperature alloy strip and a preparation process thereof, and belongs to the technical field of nickel material processing. The solid solution strengthening type difficult-to-deform nickel-based high-temperature alloy strip prepared by the invention comprises the following components in percentage by mass: 0.07 to 0.08 percent of carbon, 0.33 to 0.35 percent of silicon, 0.46 to 0.48 percent of manganese, 21.7 to 22.3 percent of chromium, 0.05 to 0.06 percent of cobalt, 0.34 to 0.36 percent of aluminum, 1.30 to 1.31 percent of molybdenum, 0.26 to 0.27 percent of iron, 13.85 to 13.86 percent of tungsten, 3.23 to 4.40 percent of titanium and the balance of nickel. The preparation method comprises the following steps: melting silicon, manganese, chromium, molybdenum, iron, cobalt, tungsten and nickel in a vacuum induction melting furnace, refining and deoxidizing; after deoxidation, adding carbon, aluminum and titanium under the conditions of argon protection and laser irradiation, stirring, discharging, casting, solidifying and homogenizing; and then cogging forging is carried out, after high-temperature rolling is carried out under the electric pulse condition, first-time solid solution heat treatment, acid pickling, cold rolling annealing and finished product heat treatment are sequentially carried out, and the solid solution strengthening type difficult-to-deform nickel-based high-temperature alloy strip is obtained.

The application provides a ferrite bainite steel and a preparation method thereof, and belongs to the field of steel preparation. The chemical composition of the ferrite bainite steel includes, in mass fraction, C: 0.18% to 0.22%, Si: 1.3% to 1.8%, Mn: 2.0% to 2.5%, P: less than or equal to 0.01%, S: less than or equal to 0.01%, N: less than or equal to 0.004%, and the balance of Fe and inevitable impurities. The metallographic structure of the ferrite bainite steel includes, in volume fraction, ferrite bainite: 50% to 65%, tempered martensite: 25% to 30%, MA island: 1% to 3%, and residual austenite: 7% to 10%. By reducing the coarse MA island and unstable blocky residual austenite, the crack initiation source is avoided, and the technical problems of poor hole expansion and elongation of the ferrite bainite steel in the prior art are solved.

The present invention relates to the field of catalytic hydrogenation, and specifically relates to a preparation method and an application method of a ruthenium-based hydrogenation catalyst. The technical key points are as follows: Ni(NO3)2·6H2O and (NH4)H2W 12 O 40 ·xH2O are used to modify the Al2O3 support by the precipitation deposition method and then calcined to obtain a metal-modified support; then, ruthenium is loaded on the metal-modified support by the impregnation method and then calcined, and the hydrogenation catalyst is obtained after hydrogen reduction; wherein, the mass fraction of ruthenium is 0.5%, the mass fraction of Ni is 0.5 - 2.5%, the mass fraction of W is 0.5 - 2.5%, and the remaining components are the alumina support. In the present invention, ruthenium and alumina are respectively used for the selection of the active component and the support, and together with the auxiliaries nickel and tungsten, the synergistic effect among several metal elements improves the dispersion degree of the active component.

The invention relates to an anti-ablation functional powder gradient composite material as well as a preparation method and application thereof. The anti-ablation functional powder gradient composite material comprises a fiber woven framework, anti-ablation functional powder and ablation-resistant resin, the concentration of the anti-ablation functional powder in the composite material is distributed in a gradient descending manner from the surface to the inside along the normal direction of the ablation surface; based on 100 wt% of the total mass of the anti-ablation functional powder and the anti-ablation resin, the mass fraction of the anti-ablation functional powder is 2 wt%-20 wt%. According to the anti-ablation powder gradient composite material, the anti-ablation functional powder distributed in a gradient descending mode is constructed from the surface to the interior in the normal direction of the ablation face, the mechanical performance is guaranteed, and meanwhile the performance requirements of structural function integrated components such as ablation resistance, heat protection and high strength are met; the problems that a surface anti-ablation coating is prone to falling off, and the powder content affects the mechanical property of a composite material are solved.

The invention relates to a neodymium-iron-boron magnet and a preparation method thereof. The preparation method comprises the following steps that first auxiliary alloy powder RexMy and heavy rare earth powder are mixed to obtain diffusion alloy powder; mixing the second auxiliary alloy powder RexMy with the neodymium-iron-boron main alloy powder to prepare a neodymium-iron-boron matrix; placing the diffusion alloy powder on the surface of the neodymium-iron-boron substrate, and performing diffusion treatment and tempering treatment to obtain a neodymium-iron-boron magnet; wherein Re is selected from Pr and / or Nd, M is selected from at least one of Al, Cu or Ga, x and y are mass fractions, x is larger than or equal to 50% and smaller than or equal to 80%, y is larger than or equal to 20% and smaller than or equal to 50%, the mass fraction of first auxiliary alloy powder RexMy in the diffusion alloy powder is W1, the mass fraction of second auxiliary alloy powder RexMy in the neodymium iron boron matrix is W2, and the ratio of W1 to W2 is 10: 1-25: 1. According to the preparation method of the neodymium-iron-boron magnet, the intrinsic coercive force of the neodymium-iron-boron magnet can be improved, and the utilization rate of heavy rare earth elements can be effectively increased.

The invention discloses a SiC reinforced CrMnFeCoNi high-entropy alloy composite material and a preparation method thereof, and belongs to the technical field of composite materials and preparation thereof. The composite material disclosed by the invention comprises the following components in percentage by mass: 95 to 99.5 percent of CrMnFeCoNi high-entropy alloy and 0.5 to 5 percent of SiC, the preparation method comprises the following steps: S1, carrying out ball milling on CrMnFeCoNi high-entropy alloy powder in an argon atmosphere; s2, SiC powder is added into the CrMnFeCoNi high-entropy alloy powder obtained after ball milling in the step S1, ball milling continues to be conducted in the argon atmosphere, and composite material powder is obtained; and S3, the composite material powder prepared in the step S2 is subjected to vacuum hot pressing sintering, and a SiC reinforced CrMnFeCoNi high-entropy alloy composite material block is obtained. Through the step-by-step ball milling process, the negative influence generated by a brittle phase is reduced, and meanwhile, the strength of the composite material is remarkably improved, so that the comprehensive performance of the composite material is in a rising trend, and the comprehensive performance of the composite material is at a better level.

The invention belongs to the field of geological dating, and particularly relates to an improved method for determining the U-Pb age of micron-sized sphene. According to the invention, the matrix effect related to the dating Fe2O3 content of sphene is confirmed; a large number of tests show that the 206Pb / 238U ratio obtained by the TIMS (TIMS (Thermal Ionization Mass Spectrometer)) and SIMS (Secondary Ion Mass Spectrometer) of the sphene standard sample is strongly correlated with the Fe2O3 mass fraction, so that a simplified method for directly correcting the 206Pb / 238U ratio of an unknown sample is established, and the 207Pb / 235U age is corrected by adopting a similar principle. The deviation between the age of the sphene after correction and the reference age is reduced from 12.3% to 0.4%, which indicates that the corrected age result is more accurate; by adopting the method, the natural sphene with the Fe2O3 content of 0.019-38.31% can be accurately obtained, and the method has the advantages of high accuracy and simple correction process.

The invention provides a method for determining the ball diameter and grading of an ore grinding medium in fine grinding operation, which adopts two or more ore grinding medium ball diameter theoretical calculation methods, and comprises the following steps: calculating the theoretical ball diameter of the ore grinding medium of each size fraction of materials to be ground, and preliminarily determining the ball diameter and ball ratio of a mill by referring to the granularity composition and mass fraction of the materials to be ground; and then verifying and optimizing through an ore grinding test, and finally determining the technical scheme of reasonable initial ball loading and accurate ball supplementing and adding of the mill. The method comprises the steps of size fraction analysis and grouping of the materials to be ground, theoretical ball diameter calculation, ore grinding test verification, determination of the initial ball loading scheme of the mill and determination of the ball supplementing and adding scheme of the mill, theoretical calculation and test verification optimization are included, the implementation method is simple, the application range is wide, and the process effect is good.

The application discloses a low-grade lepidolite flotation combined collector and application thereof, and belongs to the technical field of mineral processing. The lepidolite flotation combined collector SDI-101 of the application is composed of a cationic collector and an anionic collector, and includes the following raw materials in mass fraction: 20%-80% of an amine collector and 20-80% of an amino carboxylic acid collector. The combined collector is used to cooperatively improve the flotation efficiency of the low-grade lepidolite ore. In the case that the Li2O grade of the lepidolite raw ore is lower than 0.5%, a lepidolite concentrate with a Li2O grade of about 2% and a recovery rate of more than 80% can be obtained through a 'one-roughing-one-cleaning-one-scavenging' flotation process. The lepidolite combined collector of the application is applicable to the low-grade lepidolite ore, and the raw ore does not need desliming treatment. The lepidolite combined collector of the application has the advantages of strong collecting property and adaptability, can effectively improve the grade and recovery rate of the lepidolite concentrate, and promotes the efficient use of lepidolite resources.

The invention discloses a fifth-generation nickel-based single-crystal high-temperature alloy with a high-stability structure, which comprises the following components in percentage by mass: 2.5 to 4.5 weight percent of chromium, 6 to 10 weight percent of cobalt, 3 to 5 weight percent of tungsten, 1 to 3 weight percent of molybdenum, 5 to 6.5 weight percent of rhenium, 5 to 7 weight percent of aluminum, 7 to 10 weight percent of tantalum, 0 to 0.2 weight percent of hafnium, 3.6 to 5 weight percent of ruthenium, 0 to 0.05 weight percent of carbon, 0 to 0.03 weight percent of yttrium and the balance of nickel. The total mass fraction of rhenium, tungsten and molybdenum in the alloy is rhenium + tungsten + molybdenum less than or equal to 13.5%, and the mass fraction proportional relation of tungsten and molybdenum is tungsten / molybdenum gt; 2.2, the mass fraction proportion relation of tantalum and aluminum is that tantalum / aluminum is greater than or equal to 1.1. The invention further discloses a heat treatment process of the fifth-generation nickel-based single-crystal high-temperature alloy with the high-stability structure. The nickel-based single-crystal high-temperature alloy with high temperature bearing capacity is developed on the basis of high-temperature stability of a structure by synergistic stability elements and strong promotion of TCP phase precipitation element content, the temperature bearing capacity reaches the level of a typical fifth-generation single-crystal high-temperature alloy, and the endurance life is larger than or equal to 1000 h at the temperature of 1100 DEG C / 137 MPa.

The invention discloses a two-dimensional near-free-surface underwater explosion cavitation forecasting method, and relates to the technical field of explosion.The method comprises the steps that a mixed fluid is regarded as a mixture of multiple fluid media, and a multiphase compressible fluid motion control equation related to state parameters of the mixed fluid before the mixed fluid reaches an equilibrium state and the mass fraction of the fluid media of all phases is constructed; then constructing a thermodynamic state equation of any k-phase fluid medium based on an NASG equation, and constructing a cavitation phase change equation after the mixed fluid completes phase change relaxation to reach an equilibrium state by considering the phase change process of a liquid phase and a steam phase when a flow field changes; and solving an equation set formed by a multiphase compressible fluid motion control equation, a thermodynamic state equation of each phase of fluid medium and a cavitation phase change equation in each cycle step to obtain a numerical forecasting result. According to the method, cavitation is regarded as the continuous accumulation process of the steam phase content in the mixed fluid, the physical essence is better met, and therefore the forecasting result is more accurate.

The invention relates to 750MPa-grade high-strength steel with high comprehensive formability and a preparation method, and belongs to the technical field of steel preparation. The high-strength steel comprises the following chemical components in percentage by mass: 0.04%-0.08% of C, less than or equal to 0.2% of Si, 1.4%-2.0% of Mn, less than or equal to 0.01% of P, less than or equal to 0.005% of S, 0.02%-0.05% of Al, 0.02%-0.06% of Nb, 0.08%-0.15% of Ti, 0.1%-0.3% of Mo, less than or equal to 0.004% of N and a matrix element Fe, the microstructure of the high-strength steel comprises, by volume fraction, 60%-80% of ferrite and 20%-40% of bainite. Through reasonable component design, a metallographic structure of a target proportion is obtained, so that the obtained high-strength steel has relatively high elongation and hole expansion rate, and has excellent comprehensive forming performance.