88results about How to "Improve service performance" patented technology

The invention belongs to the technical field of building materials, and particularly relates to self-healing high-toughness concrete and a preparation method thereof, in particular to a method for realizing self-healing of the high-toughness concrete by utilizing an excessive precursor alkali-activated gel system, and self-repairing of the cracked concrete is realized by excessively preparing a precursor of a gel material. The toughness of the concrete is enhanced in combination with hybrid fibers, so that the novel self-healing concrete which is low in cost and integrates control and repair is realized. When the amount of the polymer precursor is 900 parts, the tensile strength of the concrete can reach 8.9 MPa or above, the compressive strength can reach 100 MPa or above, the self-healing rate of the concrete in 28 days can reach 98%, and the mass loss rate after 50 freezing and thawing cycles is only 0.66%.

The invention discloses a pavement adaptive to a magnetic resonance type dynamic wireless charging system as well as a construction process, a lane and application of the pavement, and belongs to the field of road engineering and road infrastructures. The pavement comprises a lower surface layer, a middle surface layer and an upper surface layer, wherein an input power line of the magnetic resonance type dynamic wireless charging system is distributed on the surface of the middle surface layer, and then a synchronous broken stone sealing layer is adopted to ensure that the input power line is completely embedded; the middle of the upper surface layer is made of pouring asphalt concrete, and two sides are made of wear-resistant asphalt concrete; a transmitting coil of the magnetic resonance type dynamic wireless charging system is embedded in the pouring type asphalt concrete, and the transmitting coil is connected with an input power line. The mechanical compatibility performance of the transmitting coil and the road surface is improved through the special road surface design, the charging efficiency is greatly improved by cooperating with the control system to optimize electric energy input, wireless charging of the vehicle in the high-speed advancing process is finally achieved based on the magnetic resonance coupling principle, and the wireless charging device has the convenient construction technology and the excellent road performance.

The invention relates to the technical field of single-crystal high-temperature alloys, in particular to a control method for dendritic crystal spacing in the growth process of a multi-layer module single-crystal high-temperature alloy. The method comprises the following steps: fixing a pre-prepared multi-layer module single crystal alloy ceramic shell with a graphite center column on a water-cooling copper disc of a liftable bracket of multi-layer module directional solidification equipment; after the mother alloy is smelted, standing is conducted, and the smelting furnace is controlled to pour alloy liquid into the multi-layer module single crystal alloy ceramic shell; and the multi-layer module single crystal alloy ceramic shell filled with the alloy liquid is pulled into the solidification cavity under the driving of the transmission device, so that directional solidification is realized, and the small-dendrite-spacing single crystal high-temperature alloy test bar is obtained. According to the method, under the condition of not changing the casting process, the problems of overlarge dendritic crystal spacing and isotherm inclination caused by the shadow effect of radiation heat dissipation in the directional solidification process of the multi-layer module single crystal high-temperature alloy are solved, and the qualified rate of large-batch production of single crystal blades is effectively increased.

The invention discloses high-strength, high-toughness and high-wear-resistance low-carbon chromium-molybdenum alloy cast steel and a heat treatment process, belongs to the technical field of cast steel and heat treatment, and solves the technical problem that AS-1444-Grade4320 alloy steel subjected to heat treatment is insufficient in comprehensive mechanical property. By properly increasing the contents of C, Si and Mn elements, the upper limit of the body strength is increased, and the alloy structure is improved in cooperation with adjustment of Cr, Mo, Ni and other alloy elements; on the basis of component design, the heat treatment process of normalizing, quenching and tempering is adopted, after heat treatment, the metallographic structure is tempered sorbite, the grain size reaches the level 9, the strength, toughness and wear resistance of the casting are obviously improved, meanwhile, the hardness of the casting is controlled within the reasonable range, the wear resistance of the casting is better matched, and the service life of the casting is prolonged. Comprehensive service performances such as wear resistance and fatigue resistance are improved, and the service life and the use efficiency of the casting are effectively improved.

The invention discloses a magnesium alloy micro-scale plastic deformation behavior quantitative prediction method and system. The method comprises the following steps: obtaining grain orientation distribution data of a magnesium alloy material; obtaining initial parameter values of four deformation modes of base plane slippage, cylindrical surface slippage, conical surface slippage and stretching twinning; importing the grain orientation distribution data and the initial parameter values of the four deformation modes into a magnesium alloy micro-scale plastic deformation behavior quantitative prediction model, and sequentially carrying out the following calculation steps: calculating Schmidt factors of the four deformation modes; calculating starting stress values of the four deformation modes; starting the deformation mode with the minimum starting stress value; calculating a starting stress difference between adjacent crystal grains; calculating a deformation transfer factor between adjacent crystal grains; and calculating a deformation response indication factor. The method can predict the starting deformation mode of each grain of the magnesium alloy and the stress-strain transfer behavior of the adjacent grains, further quantitatively analyze the formation position and expansion path of the strain band in the microscale, and provide a basis for optimizing the alloy performance.

The invention provides an integral forming method and device for a pressure accumulator diaphragm capsule, and the method comprises the following steps: sleeving a movable female die into a pipe blank part, and adjusting the distance between the movable female die and a fixed female die; a high-pressure fluid medium is introduced through an internal flow channel of the connecting rod, and the pressure and loading time of the high-pressure medium are regulated by a pressure regulating device; the positions of the movable core head, the fixed sealing head, the pre-expansion limiting die and the movable female die are kept immovable, and the pressure regulation and control device is adjusted to unload the pressure of the high-pressure medium; the pre-expansion limiting die is separated in the radial direction and rotates to be separated from the pipe blank part; the movable female die moves in the axial direction to form a single waveform; the movable female die moves progressively in the axial direction, and the movable core head moves in the axial direction as well; and forming of a second waveform and a subsequent waveform is completed. According to the method, the defects of welding deformation, weld joint gouges, weld joint surface oxidation color, weld joint black spots and joint internal oxide inclusion caused by a traditional welding method are overcome, the quality control difficulty in the production process is reduced, and the production efficiency and the production quality of the diaphragm capsule are remarkably improved.

The embodiment of the invention provides a forming method of a nanocrystalline special-shaped thin-wall part and the nanocrystalline special-shaped thin-wall part, and relates to the technical field of precision forming. The forming method comprises the steps that a polymer prepolymer and a metal ion solution are mixed, metal ions are made to generate nano conductive particles in situ through a liquid phase reaction, and the nano conductive particles are formed; adding micron conductive particles into the polymer prepolymer containing the nano conductive particles, and performing uniform ultrasonic dispersion to obtain polymer conductive slurry; a curing agent is added into the polymer conductive slurry, the mixture is poured to the surface of the original template after being evenly stirred, demolding is conducted after curing forming, and a polymer core mold with an original template structure is obtained; immersing the polymer core mold serving as a cathode into the electroforming solution, reducing metal ions in the electroforming solution into metal atoms through electrodeposition, and depositing the metal atoms in the core mold cavity until the core mold cavity is fully cast; and the nanocrystalline special-shaped thin-wall part is demolded from the core mold cavity, and the nanocrystalline special-shaped thin-wall part is obtained. The preparation cost can be reduced, and the performance can be improved.

The invention discloses a femtosecond laser strengthening method for improving the surface integrity of a laser cladding high-temperature alloy, and belongs to the technical field of laser cladding postprocessing, and the femtosecond laser strengthening method comprises the following steps: S1, selecting a proper high-temperature alloy as a base material, and cleaning and pretreating the surface of the base material; s2, a cladding laser is started to clad the base material; S3, a femtosecond laser system is set, and the optimal light beam quality and energy density are obtained; according to the method, the cladding surface is strengthened through femtosecond laser, the defects of cracks, air holes and the like appearing on the material surface after laser cladding are effectively removed, the surface integrity is greatly improved, premature failure caused by the problems of stress concentration and the like in the using process of components can be prevented through elimination of the surface defects, the service life of the components is prolonged, and the production cost is reduced. The safety and stability of the key hot end component are guaranteed, and the surface integrity of the high-temperature alloy component can improve the service performance and reliability under extreme loads such as high temperature, high flow speed and high pressure in the fields of aerospace and the like.

The invention relates to the field of metal materials, and provides a high-speed extrusion low-alloying high-toughness magnesium alloy and a preparation method thereof. The alloy is prepared from the following components in percentage by mass: 0.7 to 1.2 percent of manganese, 0.2 to 0.8 percent of aluminum, 0.4 to 1.2 percent of zinc, 0 to 0.25 percent of additive elements, less than or equal to 0.05 percent of inevitable impurities and the balance of magnesium, the additive element is one or any combination of silver or rare earth, the content of the silver is 0-0.25%, the content of the rare earth is one or combination of cerium or scandium, the content of the cerium is 0-0.25%, the content of the scandium is 0-0.25%, and the total content of alloying elements in the alloy system is less than 3.5%. The preparation method comprises the steps of smelting, gravity casting and high-speed extrusion. The low-cost multi-element microalloyed magnesium alloy is prepared, meanwhile, high-speed extrusion forming of the alloy material is achieved, and long-time heat treatment is not needed before extrusion machining. Wherein the extrusion speed reaches 12-60 m / min, the elongation of the magnesium alloy profile is larger than or equal to 18%, the ratio of the yield strength to the total element content is larger than or equal to 132 MPa / wt.%, and compared with the prior art, the performance is remarkably improved.

The invention relates to the field of composite material structure design and manufacturing, in particular to an intelligent design method for a SiC fiber reinforced metal matrix composite material pipe structure based on data driving. Firstly, to-be-designed structure parameters in a pipe structure are defined as design variables; then performing test design, and obtaining a plurality of structural parameter combinations to be subjected to analogue simulation based on a test design algorithm; then data acquisition is carried out, analogue simulation is carried out on structure parameter combinations obtained through test design based on a finite element calculation method, and the service performance of the pipe structure corresponding to each structure parameter combination is obtained; carrying out model training; solving based on an optimization algorithm to obtain an optimal structure parameter combination; and finally, result verification is carried out, a corresponding SiC fiber reinforced metal matrix composite pipe structure is prepared, a service performance test is carried out, and a design result is verified. According to the method, the development period of the composite tubular structural member can be effectively shortened, and the service performance of the composite tubular structural member is improved.

The invention discloses a hydrogen engine powder metallurgy valve seat ring and a preparation method thereof, and belongs to the technical field of powder metallurgy manufacturing, the valve seat ring is composed of a Fe-based alloy matrix and a working face magnetron sputtering plating layer, and the valve seat ring is prepared from, by mass, 0.6%-1.2% of C, 4.0%-7.0% of Cr, 0.8%-1.2% of Ti, 0.8%-1.2% of Nb, 2.5%-5.8% of V, 2.0%-4.0% of W, 3.5%-7.0% of Mo, 2.0%-2.5% of Co, 1.5%-2.0% of Mn, 1.0%-2.0% of Al and the balance Fe. 1.0%-1.5% of a solid lubricant and the balance of Fe, and the particle size is 100-120 meshes. The hydrogen engine powder metallurgy valve seat ring has the advantages that the hydrogen engine powder metallurgy valve seat ring is prepared through the warm pressing-die wall lubrication technology and the like, has excellent hardness and strength, high compactness, corrosion resistance, high abrasion resistance, high-temperature performance, hydrogen embrittlement resistance and hydrogen corrosion resistance and is suitable for hydrogen engines of automobiles, ships, military heavy equipment and the like.

The invention relates to a tapered roller bearing installation and adjustment experiment system and method. The system comprises a system host and tapered roller bearing installation and adjustment experiment units. The tapered roller bearing installation and adjustment experiment unit comprises at least two sets of tapered roller experiment bearings, two sets of cylindrical roller accompanying bearings, an axial force loading device, an axial force detection device and a radial loading device, and the axial force detection device is installed on the axial force loading device; the axial force loading device comprises an axial loading head and a loading sleeve; and the axial loading head is connected to the outer end face of the first loading sleeve, extends out of the outer end part of the installation and adjustment experiment unit and is connected with an external end cover. The system takes a tapered roller bearing as a representative object, comprises a hardware unit and a software unit, and detects force and displacement parameters through a high-precision sensor to realize high-precision measurement and precise regulation, and a software system can also form a load-displacement curve of the bearing, and compares the load-displacement curve with a simulation result to verify the accuracy of load-deformation adjustment.

The invention discloses a (FeNiMnCrV) Nx multilayer structure hydrogen resistance coating of a skin-like structure, and the (FeNiMnCrV) Nx multilayer structure hydrogen resistance coating is sequentially divided into a FeNiMnCrV sputtering layer, a (FeNiMnCrV) Nx foundation layer, a CrN middle layer, a (FeNiMnCrV) Nx-CrN circulation layer and a (FeNiMnCrV) Nx capping layer from bottom to top on the surface of a base material, hydrogen traps are generated between the interfaces, so that a large number of hydrogen atoms can be captured; obvious potential energy difference exists at different positions, and a rough energy rugged landscape is generated during hydrogen migration, so that hydrogen migration can be greatly inhibited; and the electron interaction between hydrogen and different metal elements is utilized to generate a remarkable local capture effect and limit long-range hydrogen transportation, so that most of hydrogen atoms are prevented from continuously permeating downwards, hydrogen absorption and hydrogen resistance are combined, and the hydrogen permeability is greatly reduced.

The invention discloses modified high-carbon alloy steel and a preparation method and application thereof, and belongs to the technical field of high-carbon alloy steel for aluminum alloy forming dies. The preparation method disclosed by the invention comprises the following steps: carrying out electroslag remelting on a high-carbon alloy steel rod to obtain a casting blank; carrying out thermoplastic deformation on the casting blank to obtain a blank; the blank is annealed, so that carbides in the blank are eliminated or become fine particles, spherical graphite can be separated out, and the modified high-carbon alloy steel is obtained; the particle size of the fine particles is smaller than 10 microns. According to the method, coarse and large carbides which are difficult to eliminate in the high-carbon aluminum alloy forming die steel containing strong carbide forming elements such as Cr, Mo and V or medium-strong carbide forming elements are subjected to rapid and basic graphitization through a thermoplastic deformation and high-temperature graphitization combined process; the technical problem that carbide decomposition and graphite precipitation control are difficult to realize in the existing method is solved.

This invention provides a low-cost, bimodal particle size distribution titanium-based powder for additive manufacturing, titanium-based parts, and a method for preparing the same. The method utilizes two different medium particle sizes D... 50 Using near-spherical titanium-based powder as raw material, a near-spherical bimodal particle size distribution titanium-based powder with good uniformity is obtained by wet mixing of suspension and rotary degreasing in a furnace. Various near-spherical bimodal particle size distribution titanium-based powders can also be prepared. The difference between these powders lies in the different particle size ratios and mass ratios of the two raw material powders used. The bulk density and flowability of each bimodal powder are tested to determine the range of particle size ratios and mass ratios of the two powders in near-spherical bimodal particle size distribution powders with high bulk density and flowability. This guides the preparation of high-quality near-spherical bimodal particle size distribution titanium-based powders for additive manufacturing. Ultimately, additive manufacturing technology is used to prepare high-performance, low-cost titanium-based parts to meet the stringent performance requirements of titanium components in high-end fields such as aerospace.

This invention discloses a multi-process synergistic method for strengthening and toughening titanium alloys. The method includes: firstly, pre-treating the titanium alloy surface with sandblasting; then, subjecting the pre-treated titanium alloy to solid embedding carburizing treatment; subsequently, under inert atmosphere protection, sequentially subjecting the carburized titanium alloy to solution treatment, rapid cryogenic treatment, and aging treatment; and finally, shot peening the surface of the heat-treated titanium alloy. This invention solves the problem in existing technologies where a single process is insufficient to synergistically improve the strength and toughness of titanium alloys, achieving a synergistic match between high strength and high hardness on the surface of the titanium alloy material and high toughness in the matrix.

The present invention provides a method for preparing a high temperature resistant cladding of a quartz optical fiber with integrated strengthening and toughness, which mainly solves the problems that the melting point of the optical fiber metal cladding is low, the environmental adaptability is poor, and the metal cladding has a great influence on the macrobending loss characteristics of the optical fiber. The scheme adopted by the present invention includes a BN inner cladding and an outer cladding; wherein the BN inner cladding is prepared by a chemical vapor deposition method, and the outer cladding is prepared by a polymer-derived ceramic method; by adding the modified SiCw to a precursor solution, after ultrasonic cleaning, the SiCw with amino groups grown is placed in the precursor solution for immersion, and then solidified and cracked to obtain a quartz fiber coated with a BN / SiBCN-SiCw double cladding; the method of the present invention improves the strength and toughness of the quartz optical fiber simultaneously, realizes the purpose of integrated strengthening and toughening of the quartz optical fiber, and also improves its service ability in harsh environments.

The invention provides a variable-cross-section thin-wall revolving body product forging forming method and die. The method comprises the steps that a blank is put into a furnace to be heated, and a first forging die is assembled on a first forging press after being preheated; an upper punch of the first forging die ascends, and the heated blank is placed in a first cavity; the upper punch is pressed downwards, and the blank is forged into a required shape; the upper punch ascends again, and the lower ejector rod ejects the forge piece out and enters the furnace again for heat compensation; a second forging die is preheated and then assembled on a second forging press, the forge piece obtained after heat compensation is placed in a lower die, and an upper die moves downwards to be closed to press the forge piece; the left punch and the right punch move to the stop position, so that the forge piece is completely formed; and the left punch and the right punch are withdrawn, the upper die ascends to expose a formed product, the product is taken out, and flashes are polished cleanly. Compared with the prior art, more materials are saved, the mold utilization rate is better, comprehensive benefits are higher, continuity of a product flow line can be better achieved, and the service performance of a product is improved.

The invention belongs to the technical field of material composite reinforcement, and particularly relates to a construction method of maraging steel with a gradient nanostructure. A gradient nanostructure layer with a certain depth is formed on the surface of the maraging steel by utilizing a surface nanocrystallization technology, and the surface of the maraging steel is remarkably strengthened. The core of the method lies in that rigidity compensation is provided in the treatment process to intensify the surface plastic deformation degree, and temperature field acceleration interface segregation and interface structure adjustment are provided. And finally, a gradient nanostructure layer with the obvious strengthening characteristic is obtained on the surface of the maraging steel, and the anti-fatigue performance of the maraging steel is greatly improved.

The invention discloses a method and a device for controlling residual stress of a powder plasma surfacing layer of an air valve face, belongs to the field of welding additive manufacturing, is used for inhibiting residual tensile stress in the powder plasma surfacing layer of the air valve face, and particularly relates to a pressurizing device for the powder plasma surfacing layer of the air valve and a surfacing residual stress control strategy. The surfacing layer pressurizing device is composed of an air valve rod clamping device, a rotary table, an air valve end face pressurizing device and an air valve face pressurizing device, and loads applied to an air valve are controlled in the welding process and after welding. The surfacing layer residual stress control strategy comprises the steps of range and process determination of a cleaning area, dynamic pressure calculation in the surfacing process and after-welding load application and force application position determination.

The invention discloses a special ultrahigh corrosion-resistant high-pressure cast aluminum alloy for marine equipment and a preparation process of the special ultrahigh corrosion-resistant high-pressure cast aluminum alloy. The aluminum alloy is designed by taking aluminum as a matrix and synergistically adding silicon, magnesium, various transition elements and rare earth elements of cerium and lanthanum in a specific proportion. The preparation process sequentially comprises the steps of smelting and refining, high-pressure die casting, heat treatment and surface treatment. Through the unique component design and the systematic combination of the whole-process technology, the high-pressure casting manufacturability of the alloy is kept, meanwhile, the marine corrosion resistance and the mechanical property are comprehensively improved, and the alloy is suitable for structural parts such as marine ship engine parts in the severe environment.

The application discloses a kind of surface micro-arc oxidation dense ceramic film aluminum alloy and its preparation method.After annealing treatment of aluminum alloy base material, it is in turn treated by oil and grease removal, micro-arc oxidation and drying, and obtained;The conditions of the annealing treatment are as follows: temperature is 200-300 DEG C, time is 50-80 min;The conditions of the micro-arc oxidation are as follows: current density is 8-10 A / dm 2 , time is 15-20 min;The method forms dense ceramic film on the surface of alloy base material through the synergistic effect of annealing and maintenance oxidation, which can effectively improve the comprehensive performance of the material;The aluminum alloy obtained by the technical scheme of the application has excellent corrosion resistance and wear resistance, and solves the corrosion problem of aluminum alloy welding structure in high temperature, high humidity and high salt mist environment.

The invention discloses a silver-copper composite strip for an automobile fuse and a preparation method of the silver-copper composite strip, the silver-copper composite strip is formed by arranging silver and copper alternately, a silver-copper alloy transition layer is arranged between the silver and the copper, and the thickness of the silver-copper alloy transition layer is 1.0-3.0 microns. A silver-copper alloy transition layer with uniform and controllable thickness is formed through thermal diffusion, so that smooth transition and firm metallurgical bonding of electrothermal properties among layers are realized, and the comprehensive service performance of the composite strip is remarkably improved; and secondly, the preparation method is high in automation degree, the processing process is simple and stable, large-batch continuous production is easy to realize, the production cost is reduced, and the production efficiency is improved.

The invention relates to the technical field of saggers, in particular to a sagger for solid-phase sintering of a high-nickel NCA ternary lithium battery positive electrode and a preparation method of the sagger. The preparation method comprises the following steps: S1, mixing and grinding bauxite fine powder, active Al2O3 micro powder, pyrophyllite fine powder, Si powder and boric acid to obtain mixed powder; s2, adding silica sol and stirring to obtain slurry; s3, performing spray granulation on the slurry to obtain a microsphere material; s4, performing high-temperature heat preservation on the microsphere material in a nitrogen atmosphere, cooling and sieving to obtain a sintered microsphere material; s5, magnesium aluminate spinel particles, mullite fine powder, the sintered microsphere material, talc fine powder and cerium oxide fine powder are mixed and subjected to ball milling, and a mixture is obtained; s6, adding paper pulp waste liquid, mixing, sealing and ageing to obtain an aged material; and S7, after compression molding and drying, high-temperature heat preservation is conducted, and the saggar is obtained after cooling. And the prepared sagger is good in integrity, high in yield, excellent in sintering performance, high in thermal shock resistance and high in resistance to corrosion and permeability of a high-nickel NCA ternary lithium battery positive electrode material.

The application relates to the technical field of hoisting belts, and provides a flexible bearing material for a fatigue-resistant high-strength hoisting tool and a preparation method thereof. The material takes UHMWPE fibers or aramid fibers as a substrate, is activated by low-temperature oxygen plasma, is sequentially subjected to glycidyl methacrylate grafting to introduce epoxy sites, end-amino hyperbranched PAMAM chain extension to construct a multistage active interface, is subjected to a silane coupling agent containing a benzotriazole group to construct a weather-resistant layer, is then loaded with a negative nano-titanium dioxide and polyethylene imine composite system, and is finally crosslinked and solidified by ethylene glycol diglycidyl ether. The application strengthens the interface bonding force through a multistage covalent bonding surface modification structure, simultaneously improves the fatigue resistance, weather resistance and wear resistance of the material, and solves the problems of weak interface bonding of existing hoisting bearing materials, easy wear and aging in cyclic service, and short fatigue life.

The present invention provides a bearing lubricating material based on modified polytetrafluoroethylene and modified carbon fiber, which is prepared by mechanical blending, pre-pressing, sintering and other processes with modified polytetrafluoroethylene resin as a polymer matrix, fluorosilane modified carbon fiber as a main reinforcing filler, and a small amount of lubricating filler and functional filler as a modified component. The polytetrafluoroethylene resin is polymerized and modified, so that its processing performance is greatly improved on the basis of maintaining the original physical and chemical properties of polytetrafluoroethylene; the carbon fiber is activated and grafted with fluorosilane to improve the interface bonding between the carbon fiber and the polytetrafluoroethylene resin; on this basis, combined with the introduction of lubricating fillers and functional fillers and the control of component content, the mechanical strength, tribological properties, thermal conductivity and dimensional stability of the composite material are comprehensively improved, and the application of the lubricating components of inlaid and liner polytetrafluoroethylene / metal composite sliding bearings can effectively improve their service performance and service life.

The present invention provides a method for preparing D2 steel bars and wires by an arc continuous casting and rolling process, and belongs to the technical field of continuous casting and rolling of cold working die steel. The present invention melts, refines and degasses the raw materials for preparing D2 steel to obtain molten steel; the molten steel enters the continuous casting tundish, and a covering agent is added to the molten steel; the molten steel in the continuous casting tundish enters the crystallizer for solidification, and a continuous casting billet is continuously pulled out by continuous casting; the continuous casting billet is sequentially subjected to a first annealing, a continuous rolling and a second annealing to obtain D2 steel bars and wires. The present invention adopts a continuous casting + continuous rolling process to refine the thickness of the eutectic carbide network and improve the uneven distribution of eutectic carbides; at the same time, the macroscopic segregation of the steel billet is reduced, and the uniformity of the organization is improved. The obtained D2 steel bars and wires have an excellent low-magnification organization level, and have good service performance and service life. At the same time, the present invention adopts a continuous casting + continuous rolling process to prepare D2 steel bars and wires with a short production process, which can save production procedures, save energy and reduce consumption, and reduce costs and increase efficiency.

The application discloses an aero-engine hot-end component full-life-cycle management method and system, and belongs to the technical field of aero-engines.The system constructs a full-life-cycle closed loop system of material gene optimization-precision forming process-service health monitoring-life prediction and active repair, can realize service life improvement of more than 200% of the aero-engine hot-end component, and improves the production yield rate from the conventional 60% in the industry to more than 90%.The application fills the core short board of short life, poor reliability and low yield rate of the aero-engine hot-end component in China, breaks through the core technical bottleneck of the "industrial crown pearl" of the aero-engine, and is 100% domestically produced and controllable in material and process, and can be widely applied to scenes such as army armed helicopter turboshaft engines, military unmanned aircraft turbojet / turbofan engines and the like.

The application relates to the technical field of part machining, in particular to a connecting hole surface rolling device and a rolling method. The connecting hole surface rolling device comprises a mandrel, a sleeve and a plurality of rolling balls, the sleeve is sleeved on the mandrel, and the plurality of rolling balls are uniformly and intervally arranged on the sleeve. The mandrel can move along the axial direction and rotate along the circumferential direction, the mandrel has an equal-diameter section, a variable-diameter section and a limiting ring which are sequentially connected from top to bottom, the cross-sectional area of the variable-diameter section gradually increases from top to bottom, the sleeve can move on the equal-diameter section and the variable-diameter section, and the limiting ring limits the sleeve from separating from one end of the variable-diameter section away from the equal-diameter section. The sleeve penetrates the connecting hole of a workpiece from top to bottom, the workpiece drives the sleeve to move to the equal-diameter section, so that the rolling balls roll against the hole wall of the connecting hole. The sleeve penetrates the connecting hole from bottom to top, the workpiece drives the sleeve to move to the variable-diameter section, so that the outer circumferential surface of the mandrel forces the rolling balls to press against the hole wall of the connecting hole, and the rolling pressure of the rolling balls against the hole wall of the connecting hole gradually increases from top to bottom.

The invention discloses a laser shock marking method for a gear transmission component. The laser shock marking method comprises the steps that the to-be-marked position of the gear transmission component is determined; forming a light-transmitting restraint layer capable of allowing high-amplitude plasma shock waves to propagate on the surface of the position to be marked; adjusting the distance between the position to be marked and the laser to a preset distance; performing laser impact marking on the to-be-marked position based on a laser; a pit is introduced into the surface of the position to be marked based on laser spot impact induced plastic deformation; and forming a mark based on continuous lap joint of the pits. According to the impact marking method, an absorption layer is not used in the marking process, the marking efficiency is improved, the marking width is increased, the mechanical property of the material is greatly improved, and the fatigue life of the material is greatly prolonged.