762 results about "Brittleness" patented technology

The invention belongs to the technical field of metal composite materials and hydrogen storage and transportation materials, and particularly relates to a high-strength hydrogen-embrittlement-resistant layered metal composite material for hydrogen storage and a preparation method and application of the high-strength hydrogen-embrittlement-resistant layered metal composite material. According to the preparation method, the nickel-saving austenitic stainless steel (NEASS) and the 30CrMo steel are alternately overlapped in a multi-layer mode, and the processes of vacuum electron beam welding, high-temperature hot rolling, accumulative ply rolling, multi-stage heat treatment and the like are combined, so that the composite board with the layer number reaching hundreds of layers, firm interface bonding, excellent mechanical performance and good hydrogen embrittlement resistance is prepared; the technical problem that strength, toughness and hydrogen brittleness resistance of an existing metal material in a high-pressure hydrogen environment are difficult to consider at the same time is solved. The obtained composite material has high strength, high plasticity and excellent hydrogen embrittlement resistance, and is suitable for structural materials of high-pressure hydrogen storage tanks, hydrogen conveying pipelines and other key hydrogen energy equipment.

The invention discloses a deep tunnel surrounding rock mechanical parameter inversion method based on a three-dimensional brittle failure zone contour and sparrow optimization algorithm-information vector machine (SSA-IVM) combined optimization algorithm. The engineering technical problem that due to the fact that excavation instantaneous displacement is difficult to monitor, deep tunnel surrounding rock mechanical parameters are difficult to reasonably obtain through displacement back analysis is solved. The method comprises the following steps: firstly, constructing a tunnel FLAC3D numerical simulation model with the same ground stress condition at the occurrence position of a three-dimensional brittle failure zone; secondly, taking an absolute error between the total number of computational grid units in the actually measured brittle failure zone and the total number of computational grid units entering a plastic state in the range of the actually measured brittle failure zone after calculation of the FLAC3D numerical model as an optimization objective function; and then, by taking the tunnel surrounding rock mechanical parameters as optimization variables and taking a target function reaching a global minimum value as a target, performing global optimization by combining a tunnel FLAC3D numerical model and adopting an SSA-IVM joint optimization algorithm, thereby obtaining reasonable tunnel surrounding rock mechanical parameters.

The invention discloses an annular furnace heat-resistant supporting forged chassis and an additive manufacturing process and a fixing device thereof, and belongs to the technical field of plating of metal materials, and the annular furnace heat-resistant supporting forged chassis comprises the steps that heat-resistant alloy steel base metal with specific components is prepared; carrying out laser texturing and nickel-based alloy bottom layer pretreatment on the surface of the steel plate; performing laser cladding on high-silicon high-temperature alloy powder containing niobium and rare earth elements to form a functional cladding layer, and performing gradient cladding on the edge of the atmosphere guide hole; and finally, carrying out heat treatment and assembling with a fan-shaped refractory brick fixing device. A composite oxide film and a multi-scale strengthening system are constructed, hydrogen resistance and brittleness resistance are effectively achieved, interface thermal stress is relieved, cracking and stripping of a cladding layer are avoided, a fixing device adapts to thermal expansion, the atmosphere is dredged, and the annealing uniformity of a steel coil is improved; the problems of creep deformation, hydrogen embrittlement, cladding layer stripping and thermal stress cracking of a traditional supporting component under the conditions of high temperature, heavy load and nitrogen and hydrogen atmosphere are solved.

The invention relates to the technical field of stainless steel production and manufacturing, and discloses a high-strength corrosion-resistant duplex stainless steel shaft forging method which comprises the steps of blank preparation, homogenization treatment, preheating treatment, multidirectional forging, interrupted cooling, solution treatment, aging treatment and surface finish machining. Uniformity of components in the blank and consistency of temperature distribution are guaranteed, a uniform microstructure basis is provided for subsequent forging, meanwhile, grains are refined through large deformation and multi-pass deformation in multi-directional forging, the strength and toughness of the shaft are improved, brittle phase formation is avoided, and the mechanical property is optimized; by interrupting cooling and solution treatment, controlling the cooling rate and heating parameters in real time, inhibiting harmful phase precipitation and optimizing the austenite-ferrite phase proportion, the shaft has high corrosion resistance, and by means of aging treatment, through a stable structure, the long-term durability of the shaft in a severe environment is guaranteed, and the corrosion weight loss and pitting corrosion risk are reduced.

The invention discloses a material with a silver coating for low-temperature brazing of brazing filler metal, and particularly relates to the field of brazing welding, which comprises the following steps: silver amalgam paste is prepared by oscillating and mixing silver powder and mercury according to the mass ratio of 1: 9-0.5: 9.5 in a manner and method for plating silver on the surface of base metal (metal, semiconductor, ceramic or glass); when brazing is carried out, the surface of the silver plating layer of the to-be-welded piece is coated with brazing filler metal, and then heating and pressurizing are carried out in a low-temperature interval of 120-350 DEG C in a vacuum, protective atmosphere or atmospheric environment to complete connection. According to the method, the amalgam reaction and isothermal solidification principles are utilized, a tough welding spot mainly comprising a silver-based solid solution is finally formed, generation of a large number of brittle intermetallic compounds is avoided, a connector has high strength, high reliability and excellent thermal fatigue resistance, and therefore the problems that gold-tin brazing filler metal is high in cost, the brittleness of the welding spot is large, and the welding temperature is high are successfully solved.

An aluminum nitride ceramic welding assembly comprises a first aluminum nitride ceramic piece, a second aluminum nitride ceramic piece and a third aluminum nitride ceramic piece, a second pin hole corresponding to the first pin hole is formed in the welding surface of the second aluminum nitride ceramic piece; two ends of the aluminum nitride ceramic positioning pin are respectively inserted into the first pin hole and the second pin hole; and the slurry layer containing rare earth oxide is arranged on the welding surface of the first aluminum nitride ceramic piece, and the distribution density of the rare earth oxide is gradually reduced from the position close to the first aluminum nitride ceramic piece to the position far away from the first aluminum nitride ceramic piece. High-temperature displacement errors are eliminated by means of cooperative positioning of pin holes in the first aluminum nitride ceramic piece and the second aluminum nitride ceramic piece and aluminum nitride ceramic positioning pins; and meanwhile, generation of brittle phases is inhibited by utilizing a form that the distribution density of rare earth oxides in the slurry layer is gradually reduced from near to far, so that the effects of a high-precision welding interface and joint strength enhancement are obtained, and the reliability and the service life of the aluminum nitride ceramic component are improved.

The invention discloses a high-alloy steel nitriding-laser quenching composite surface strengthening method which comprises the following steps: sequentially polishing the surface of high-alloy steel by using 240-mesh waterproof abrasive paper and 2000-mesh waterproof abrasive paper, then sequentially putting the high-alloy steel into ethanol and acetone for ultrasonic cleaning, and nitriding the pretreated high-alloy steel to form a nitriding layer; and cooling to room temperature along with the furnace under the atmosphere of nitrogen or ammonia gas to obtain the high alloy steel containing the nitriding layer. And blackening treatment is conducted in the atmosphere of argon or nitrogen, then laser quenching treatment is conducted, and high alloy steel surface strengthening treatment is completed. According to the nitriding-laser quenching composite surface strengthening process, the problems that a high alloy steel nitriding layer is shallow (smaller than 0.2 mm), interface brittleness is achieved, and the retained austenite content is high (larger than 20%) are effectively solved, the total treatment time is shorter than or equal to 16 h, the surface hardness of a modified layer is larger than or equal to 600 HV0.1, the thickness of the modified layer is larger than or equal to 1.5 mm, and the nitriding-laser quenching composite surface strengthening process is suitable for preparing key components such as aviation gears and heavy-duty bearings.

The invention relates to the technical field of ceramic products, in particular to a high-temperature-resistant and high-strength domestic ceramic product and a preparation method thereof.The preparation method comprises the following steps that modified alumina fibers, silicon carbide, a dispersing agent, a binding agent and deionized water are subjected to ball milling and mixing, and ceramic slurry is obtained; the modified alumina fiber is obtained by heating alumina-zirconia-lithium scandium silica gel fiber from room temperature to 600 DEG C at a heating speed of 2 DEG C / min, and keeping the temperature for 2 hours; the temperature is increased to 1000 DEG C at the temperature increasing speed of 8 DEG C / min, and heat preservation is conducted for 2 h; and carrying out spray granulation, dry pressing and sintering on the ceramic slurry to obtain the high-temperature-resistant and high-strength domestic ceramic. The alumina fiber is modified; the fracture toughness and the fracture strain of the silicon carbide ceramic can be remarkably improved, and the fracture toughness, the impact strength and the high-temperature strength retention rate of the silicon carbide ceramic can also be improved; and CTE gradient transition is realized, and the problems of high-temperature grain coarsening and brittle phase are solved.

The application belongs to the technical field of high-performance tool coating, and relates to a design method of a cross-scale biomimetic gradient coating based on a multi-principal-element high-entropy system, which sequentially forms a high-entropy alloy plastic layer, a high-entropy alloy / high-entropy ceramic strong and tough layer and a nanocrystalline high-entropy ceramic superhard layer on the surface of a tool base body, constructs a gradient transition structure, matches the high-entropy alloy plastic layer with a bonding phase of the tool base body, optimizes the high-entropy alloy / high-entropy ceramic strong and tough layer material, improves the interface bonding force, adopts thermal-mechanical coupling calculation to optimize the gradient transition design, constructs an atomic model and optimizes the microstructure based on molecular dynamics simulation, establishes a finite element model to simulate thermal cycles and mechanical loads, optimizes the interface performance, constructs a mathematical model by using a BP neural network and a particle swarm optimization algorithm, and realizes the gradual transition design of the tool base body and the coating. The application solves the problems of large brittleness, insufficient adhesion and limited thermal stability of the tool coating interface, and improves the interface bonding performance of the coating, the stability and durability of the coating tool.

The invention discloses a high-strength and high-plasticity low-melting-point aluminum alloy brazing material and a preparation method and application thereof, and relates to the technical field of solder manufacturing. The low-melting-point aluminum alloy welding flux is prepared from the following components in percentage by weight: 10 to 14 percent of Si, 4 to 20 percent of Cu, 0.04 to 0.25 percent of Eu, 0.78 to 0.82 percent of Fe, 0.13 to 0.17 percent of Mn, 0.08 to 0.12 percent of Mg, 0.18 to 0.22 percent of Zn and the balance of aluminum and inevitable impurities. The Al-Si-Cu ternary alloy is constructed to form a low-melting-point eutectic phase, the melting point of the material is effectively reduced, meanwhile, Eu atoms are doped, the aluminum matrix is subjected to the pressure stress effect, the interplanar spacing is reduced, the grain size of the matrix aluminum phase is reduced, the elemental Si phase is refined, the eutectic Al-Si phase content is increased, and precipitation of the brittle Al2Cu phase is restrained; therefore, the aluminum alloy solder has high tensile strength and elongation after fracture under the condition that the melting point is low.

Solid powder and an organic carrier are matched according to the mass ratio of (82-86): (14-18), silver powder and titanium dihydride powder which form the solid powder are matched according to the mass ratio of 96: 4, and a solvent, a thickening agent and a dispersing agent which form the organic carrier are matched according to the mass ratio of (91-95): (2-6): (1-5). According to the Ag-Ti soldering paste, silver powder and titanium dihydride powder serve as solid phases and are matched with a specific organic carrier, by optimizing the rheological property and the vacuum brazing technology, TiH2 is decomposed to generate active Ti atoms, the active Ti atoms react with AlN ceramic to generate a continuous TiN reaction layer, and high-strength and low-defect connection of an AlN ceramic base material and an oxygen-free copper metal copper layer is achieved; a traditional Cu element is abandoned in a soldering paste system, generation of a brittle phase is avoided, and the reliability of a connector under the extreme working condition is improved; when applied to preparation of the ceramic copper-clad plate, the film has the advantages of strong silk-screen printing adaptability, uniform film thickness and low voidage.

The invention belongs to the technical field of dissimilar metal welding, and particularly relates to a laser welding-brazing method for titanium steel dissimilar metal connection. According to the laser welding-brazing method, the laser is adopted as a welding heat source, and laser welding combining brazing and fusion welding is achieved by comprehensively regulating and controlling the filling material, the laser beam position and welding parameters. By the adoption of the welding mode, metallurgical regulation and control of welding seams can be effectively achieved, generation of brittle intermetallic compounds is restrained, a high-quality welding joint with excellent strength and plasticity is obtained, the tensile strength of the welded joint is 317.6 MPa and reaches 82.71% of that of steel base metal and 75.44% of that of titanium base metal, the joint coefficient is 0.83, equal-strength matching is basically achieved, and the welding quality is improved. The welding problem of the titanium steel dissimilar metal is effectively solved, technical support can be provided for matched use of titanium alloy and traditional steel and iron materials, and development of the transportation tool lightweight technology is further promoted.

The invention relates to the technical field of electronic packaging and welding, and particularly discloses Ag-Cu-Ti-based composite brazing filler metal and a preparation method and application thereof. The composite material comprises the following components in percentage by weight: 87%-96.5% of Ag-Cu28 alloy powder, 3%-8% of TiH2 and 0.5%-5% of a reinforcing phase, and the reinforcing phase is Ag-coated titanide or ceramic particles. According to the method, the comprehensive welding performance of the brazing filler metal is improved by adopting a method of coating the reinforcing phase with Ag, and meanwhile, the negative influence caused by adding the reinforcing phase is overcome. Aggregation of reinforced phase particles can be reduced through Ag coating, uniform distribution of the reinforced phase fine particles in the brazing filler metal is achieved, and generation of large brittle phases is greatly reduced. And meanwhile, the fluidity of the brazing filler metal is enhanced, the joint filling capacity of the brazing filler metal is improved, and the welding voidage of a connector is effectively reduced. In addition, the Ag coating can avoid the reaction between the reinforcing phase and the Ti element, and the influence of the reinforcing phase on the melting point of the brazing filler metal is reduced.

The invention relates to the technical field of alloy materials, in particular to a tungsten-zirconium active material and a preparation method thereof. The tungsten-zirconium active material provided by the invention is prepared from the following elements in percentage by mass through a specific preparation method: 55-85% of W, 10-35% of Zr and 3-30% of other elements, and the other elements are more than two of Ti, Nb, Hf and Mo. The content of W is controlled to be 55-85%, so that the density of the material is 11 g / cm < 3 > or above, the high strength of the material is ensured, and the material has kinetic energy penetration capacity; the content of Zr is 10% or above, and it is guaranteed that the material has certain activity; and the addition of other elements such as Ti, Nb, Hf and Mo inhibits the generation of a W2Zr brittle phase, so that the plasticity of the tungsten-zirconium active material is improved. And by combining with a specific preparation method, the prepared tungsten-zirconium active material has high plasticity while having high strength and high density.

The invention relates to a low-stress chemical mechanical etching process suitable for fragile materials, which belongs to the technical field of etching processing of fragile materials and comprises a precise chemical mechanical polishing machine, a polishing pad, a polishing solution conveying and managing system and end point detection equipment. The precise chemical mechanical polishing machine comprises a multi-zone pressure controllable polishing head, a high-precision rotating speed control system and a real-time thickness measuring system, a polishing pad is a polishing disc made of porous polyurethane materials, and the polishing liquid conveying and managing system comprises a multi-channel metering pump system and a stirring and temperature control unit. And the end point detection equipment comprises a surface profilometer, an atomic force microscope and a transmission electron microscope. According to the method, through fine cooperation of chemical reaction and mechanical grinding, microcrack initiation and propagation in the polishing process are effectively inhibited, surface and subsurface damage of the fragile material is remarkably reduced, the machined surface which is ultrahigh in smoothness and free of damage is obtained, and meanwhile the high material removal rate is kept.

The invention discloses a design method capable of giving consideration to both toughening and crack path controllability for a brittle material, and belongs to the technical field of fracture mechanics and artificial intelligence crossing, and the method comprises the steps: employing an input coding method based on space-response double-domain fusion to carry out feature extraction; introducing a channel attention mechanism to perform weighted fusion on the extracted double-domain features, and generating prediction results for different key tasks; evaluating the reliability of a prediction result by adopting a phase field verification and closed-loop adaptive optimization mode, and carrying out iterative training and optimization on the neural network; and taking the optimized neural network as a fitness evaluation function of double-target genetic optimization, and performing multi-target optimization on defect generation parameters. According to the invention, through fusion of the spatial domain and the response domain, geometric morphology and dynamic response characteristics are cooperatively extracted, and the prediction precision of complex fracture behaviors is improved; through non-dominated sorting multi-objective optimization under physical constraints, a high-toughness and path-controllable optimal solution is output, and brittle materials are pushed to cross an active controllable fracture design.

The present invention involves performing a rolling process on a steel sheet while maintaining the temperature of the steel sheet within the range not lower than a ductile-brittle transition temperature but not higher than a non-uniform deformation occurrence temperature. This cold rolling method is for performing a rolling process on a steel sheet S by means of a plurality of rolling stands std arranged in the conveying direction of the steel sheet S while supplying a rolling oil to each of the plurality of rolling stands std. The method comprises supplying at least a portion of the rolling oil recovered from a rolling stand std disposed on a downstream side in the conveying direction of the steel sheet S among the plurality of rolling stands std, to a prescribed number of the rolling stands std including the rolling stand std disposed most stream in the conveying direction of the steel sheet S.

The invention provides a metal fracture ductile-brittleness identification method and device, equipment and a medium, relates to the technical field of material failure analysis, and aims to solve the problem of how to accurately identify metal fracture ductile-brittleness. The metal fracture toughness and brittleness identification method comprises the steps of obtaining a to-be-predicted microscopic feature image data set of a metal fracture surface; inputting the to-be-predicted microscopic feature image data set into a pre-trained microscopic feature recognition model to determine the number corresponding to each microscopic feature contained in the to-be-predicted microscopic feature image data set; and inputting the number corresponding to each microscopic feature contained in the to-be-predicted microscopic feature image data set into a pre-trained regression prediction model to determine the ductile brittleness of the metal fracture.

The invention provides a high-thermal-conductivity flexible epoxy composite material as well as a preparation method and application thereof, and belongs to the field of high polymer materials. The composite material disclosed by the invention is prepared by adding polydopamine modified BN and FG which are jointly used as fillers into an epoxy matrix and adopting polyether amine as a curing agent. The polydopamine modified BN and the FG are jointly used, so that a synergistic interaction effect can be achieved in the aspects of heat-conducting property, dielectric property and mechanical strength. The epoxy composite material disclosed by the invention can obtain excellent heat-conducting property, dielectric property and insulating property under the compatibility of specific raw materials. And when the curing agent with a long molecular chain is adopted, the epoxy composite material can obtain excellent flexibility, and the problem of brittleness of the existing epoxy composite material is solved. A research basis is provided for preparation and performance research of the flexible epoxy composite material, and the flexible epoxy composite material has a good application prospect.

The invention discloses a method for diffusion bonding of titanium alloy and stainless steel by using an intermediate layer, which is characterized in that a layer of Ta material and a layer of Ag material are sequentially arranged between a titanium alloy workpiece and a stainless steel workpiece as the intermediate layer, and diffusion welding is realized by heating and pressurizing. The method is applied to diffusion welding connection between Ti alloy and stainless steel, and the problems of brittle phase generation, residual stress concentration, insufficient connection strength and the like caused by large thermal expansion coefficient difference and high interface reaction activity of dissimilar materials can be effectively solved. And the connection residual stress can be better reduced, the connection strength is improved, and the joint interface quality and the overall mechanical property are improved.

The invention discloses a preparation method of an SMC graphene composite material civil air defense door, which comprises the following steps: S1, preparing a mould pressing sheet, cutting the sheet into blocks according to the pressing process requirement, and weighing; s2, a mold is preheated, the preheating temperature of the mold is controlled to be 140-150 DEG C, and the preheating time is 20-30 min; s3, mold material spreading is conducted, specifically, a release agent is evenly sprayed on the inner surface of the preheated mold, and then the weighed sheets are laid in a cavity of the mold; s4, the mold is closed; s5, heat preservation pressing is conducted, specifically, the pressure in the mold is controlled to be 8-12 MPa, the temperature in the mold is controlled to be 160-180 DEG C, and the pressing time is 60 min or above; s6, the mold is opened; and S7, product shaping is conducted, and the SMC graphene composite material civil air defense door is obtained. The civil air defense door prepared through the method is high in strength and good in toughness, graphene can make up for the defects that an SMC material is poor in toughness and high in brittleness, and therefore the performance of the civil air defense door is improved.

This invention discloses a micro-wedge splitting test device and a method for testing fracture parameters of quasi-brittle materials. The device includes a micro-sample, a groove on the upper part of the micro-sample, and a force-transmitting component. The force-transmitting component comprises a wedge, a roller, and a force-transmitting block connected in sequence. Compared with existing standard wedge splitting test devices, the ratio of the fracture cross-section to the volume of the micro-sample increases by more than 1.8 times, and the ratio of the shoulder width to half-width of the micro-sample decreases by less than 10%. By controlling the ratio of fracture cross-section to sample volume and the ratio of sample shoulder width to sample half-width, the device can reduce the size of the wedge splitting test device while ensuring that the crack forms and propagates stably at the center. Furthermore, by limiting the load rate to approximately 0.1 mm / min, the device ensures stable energy release during the micro-splitting test, making the micro-wedge splitting test device suitable for testing the fracture performance of small-sized functional components.

The invention discloses a forging forming process for an aluminum casting chassis supporting arm implanted with a steel plate framework, and relates to the technical field of metal composite material forming. The method comprises the following steps: 1, pretreating a steel plate framework; 2, assembling the mold; 3, performing semi-solid extrusion; 4, sequentially carrying out segmented heat treatment of solid solution at 535 DEG C for 2 hours, water quenching and aging at 175 DEG C for 8 hours; and 5, the cooling rate is controlled to be 5 DEG C / min under a 0.15 T rotating magnetic field, and solidification is completed. Through a quadruple synergistic mechanism of micro anchoring structure-gradient coating-semi-solid extrusion-segmented heat treatment, the shear strength of a composite interface reaches 60-105 MPa, the tensile strength of a final component reaches 311-322 MPa, the fatigue life is prolonged to 120 million times from 500 million times, the lightweight target that the weight is reduced by 50% compared with that of a pure steel part is achieved, and the production cost is reduced. The defects of insufficient strength, infirm aluminum / steel interface bonding, pore shrinkage and brittle phase of a traditional aluminum casting piece are overcome.

The invention relates to the technical field of black metal materials, in particular to saw blade steel with excellent repeated welding performance and a manufacturing method of the saw blade steel. The high-strength and high-toughness steel comprises the following chemical components in percentage by weight: 0.46%-0.55% of C, 0.3%-0.8% of Si, 0.4%-0.6% of Mn, less than or equal to 0.025% of P, less than or equal to 0.010% of S, 0.0010%-0.0020% of B, 0.10%-0.20% of Zr, 0.24%-0.35% of Co, 1.2%-1.5% of Co / (C / 10 + Mn / 5 + 60B) and the balance of Fe and inevitable impurities. According to the method, Zr, B and Co are added, and the processes of converter smelting, VD refining, continuous casting, slab heating, rolling and heat treatment are carried out, so that the steel strength and sufficient hardenability are guaranteed, the brittleness of a welding part and a heat affected zone is reduced, and the repeated welding performance of the saw blade steel is improved.

The invention belongs to the technical field of mechanical manufacturing and material science, and particularly relates to an artificial intelligence chip inductor powder mold surface strengthening treatment method and system, which comprises the steps of mold matrix mechanical shock strengthening pretreatment, preparation of a gradient diffusion layer, a toughness bonding layer and a superhard wear-resistant layer in sequence without breaking vacuum, and post-treatment. The system is integrated vacuum treatment equipment and realizes continuous treatment without breaking vacuum. Surface mechanical shock strengthening is introduced in the pretreatment stage of a mold base body, and a strengthening layer with a fine grain structure, high-density dislocation and remarkable residual compressive stress is formed on the surface layer of the mold. According to the strengthening layer, the fatigue strength and the plastic deformation resistance of the mold base body are effectively improved, a tough bearing substrate is provided for growth of the subsequent surface strengthening layer, and therefore the problem that the binding force between a traditional strengthening layer and a brittle base body is insufficient is fundamentally solved, and the fatigue fracture resistance of the whole mold structure is remarkably improved.

This invention relates to a method for preparing ultra-pure smelting of high-strength and high-toughness special steel at ultra-low temperatures. The chemical composition (wt%) is controlled as follows: C≤0.01%, Si≤0.05%, Mn≤0.05%, S≤0.005%, P≤0.005%, Ni: 17.5~18.5%, Co: 8.0~9.0%, Mo: 3.0~3.8%, Al: 0.05~0.15%, Ti: 0.20~0.35%, H≤1.0 ppm, O≤16 ppm, N≤15 ppm, with the balance being Fe and other unavoidable impurities. Core Technology: A five-element synthetic slag system of CaO-SiO2-Al2O3-MgO-CaF2 is introduced during the VIM stage. Utilizing the high-speed directional solidification effect of VAR steady-state remelting, and through matching the smelting environment and cooling rate, the coarse, brittle titanium sulfide phase is transformed into finely dispersed Al-Mg-Ti-S-O multiphase composite oxides. This achieves composite modification of inclusions and reduces their number density from 45 inclusions / mm². 2 Reduced to 8.5 pieces / mm 2 It effectively eliminates the hazards of large particles >4μm. The average grain diameter of the original austenite is refined from 42.37μm to 26.38μm, the elongation of the material reaches 21.06%, and the impact energy is as high as 143.63J, significantly improving the resistance to brittle fracture and possessing extremely high engineering application value.

The application discloses a kind of plasma spraying self-reduction TiC / Ti composite coating and its preparation method and application, belong to thermal spraying coating field, TiC powder, deionized water and binder are mixed and stirred and ball milled, and TiC spherical powder is prepared by spray granulation;Using plasma spraying process, TiC spherical powder is sprayed on substrate, so that TiC occurs self-reduction reaction to generate Ti metal phase, and forms plasma spraying self-reduction TiC / Ti composite coating on substrate;In plasma spraying self-reduction TiC / Ti composite coating, Ti metal phase is distributed between TiC ceramic phase, and forms layered inlay structure.The application uses TiC powder as raw material, and generates Ti metal bonding phase in situ by adjusting and controlling plasma spraying process parameters during spraying process, avoids additional metal bonding phase and subsequent annealing treatment, simplifies process flow and reduces cost.The bonding strength of the prepared plasma spraying self-reduction TiC / Ti composite coating can reach 52.40 MPa at most, which significantly improves the problem of large brittleness and poor interface bonding of traditional TiC coating.

The invention discloses a method and system for evaluating the dynamic brittleness of an underground gas storage, and the method comprises the steps: carrying out an indoor experiment on a cover rock sample, and obtaining a dynamic brittleness-plasticity characteristic containing a rock fatigue damage state; forming a static brittle-plasticity curve based on the logging curve of the sampling well; homing the sampling depth in the static brittle-plasticity curve, and constructing a mathematical correlation model representing two brittle-plasticity relationships through dynamic and static brittle-plasticity characteristics under different sampling depths; based on pre-stack seismic data of the underground gas storage where the sampling well is located, a static brittle-plasticity data body is obtained, and the static brittle-plasticity data body is converted into a dynamic brittle-plasticity data body through the data association model. According to the invention, the three-dimensional dynamic brittle-plasticity attribute of the cap layer can be obtained.

The invention provides a method for reducing internal cracks of a soft reduction continuous casting billet, which comprises the following steps: S1, establishing a three-dimensional finite element model comprising a casting billet and a pair of reduction rollers, and the three-dimensional finite element model is used for simulating stress distribution in a deformation process when the casting billet is subjected to soft reduction processing under the reduction rollers; s2, a three-dimensional finite element model is adopted, and the shear stress distribution condition of the casting blank within the brittleness temperature range under each set of soft reduction machining parameters is simulated; the maximum chamfering angle corresponding to the situation that the longitudinal corner of the machined casting blank does not collapse serves as the optimal chamfering angle; and S3, a three-dimensional finite element model is adopted, the tensile stress distribution condition of the casting blank in the brittleness temperature range under the soft reduction machining parameters is simulated, and the chamfer length when the maximum tensile stress in the brittleness temperature range is minimum is taken as the optimal chamfer length. By optimizing the chamfering structure of the casting blank, solidification of the edge blank shell is effectively avoided, and the internal defect rate of the casting blank is reduced.

The application discloses a rare earth high-strength dual-phase steel and a forming method and application thereof, and belongs to the technical field of dual-phase steel. The forming method of the rare earth high-strength dual-phase steel comprises the following steps: converter smelting, LF refining, RH refining, adding cerium iron and yttrium iron at the end of the RH refining or before continuous casting, continuous casting, three-stage hot rolling, cold rolling and three-stage annealing. The rare earth high-strength dual-phase steel has good cold stamping formability, high weldability, no rare earth element segregation, no cracking of steel forming, high yield, and can be directly used to prepare automobile bodies after cold stamping forming at normal temperature. There is no rare earth inclusion or coarse carbon nitride brittle bulk agglomerate on the surface layer of the weld, the rare earth element is in a dispersed distribution state, has excellent dispersion strengthening effect, the weld is not prone to cracking, and the mechanical properties of the weld are superior to those of the base material.