1662 results about "Plastic property" patented technology

The invention discloses multi-source composite expansion super-early-strength concrete and a preparation method thereof. The concrete comprises a cementing material, aggregate, a water reducing agent, water and a multi-source composite expansion system. The expansion system is composed of a plastic expansion agent, a calcium sulphoaluminate early expansion source, a magnesium oxide delayed expansion source and an internal curing material. Through precise component design and function time sequence matching, a cooperative compensation network covering the whole life cycle of the concrete is constructed, a plastic expanding agent inhibits plastic shrinkage, calcium sulphoaluminate compensates early-stage self-shrinkage, magnesium oxide resists medium-and-long-term drying shrinkage, an internal curing material provides continuous moisture guarantee for the above process, and the overall performance of the concrete is improved. And the efficiency of each expansion source is excited and coupled. According to the invention, seamless and accurate shrinkage compensation from a plastic stage to a service later stage can be realized on the premise of ensuring the super early strength characteristic of the concrete, the technical problem that the super early strength concrete is easy to crack due to severe shrinkage is fundamentally solved, and the volume stability and durability of the structure are remarkably improved.

The invention discloses a finite element simulation method for evaluating the reliability of a battery structure, a product and a storage medium. The method comprises the following steps: constructing a battery finite element model comprising a shell and a sealing structure; defining elastoplastic material properties for the shell; applying a pressure load for simulating internal gas production and / or a mechanical load for simulating external impact; after solving, extracting a plastic strain result of the sealing structure area; and evaluating the integrity of the sealing function based on the result. According to the method, the elastic-plastic model is adopted, the limitation that a calculation result is distorted after a material is yielded in traditional linear simulation is overcome, and the plastic failure risk can be accurately predicted; meanwhile, a sealing function failure criterion based on plastic strain is innovatively established, and the problem that sealing performance evaluation of key connection structures such as riveting cannot be achieved is solved. According to the method, a systematic and quantitative safety boundary defining tool is provided for the battery structure design, and the reliability and efficiency of the design are remarkably improved.

The invention belongs to the field of advanced metal plastic processing, and particularly relates to a difficult-to-deform metal ultra-thin strip rolling device and method.The device comprises an uncoiler, a high-strength rolling mill and a coiler which are sequentially arranged, and the inlet side and the outlet side of the high-strength rolling mill are each provided with a pair of equal-diameter rollers; the equal-diameter roller is composed of a copper conductive roller and a ceramic insulating roller, the copper conductive roller on the inlet side and the copper conductive roller on the outlet side are electrically connected to the positive electrode and the negative electrode of the pulse power source respectively, and a strip blank on the uncoiling machine sequentially penetrates through the equal-diameter roller on the inlet side, the high-strength rolling mill and the equal-diameter roller on the outlet side and then is wound on the coiling machine. And a working roll, which is in contact with the strip blank, on the high-strength rolling mill is an insulating ceramic working roll. The pulse current in the method can induce dynamic recrystallization, an ultra-fine grain or nanocrystalline structure is obtained, and the strength and plasticity matching of the product is superior to those of a traditional process. Meanwhile, long-time high-temperature oxidation can be avoided by adopting pulse current to heat the strip blank, and the surface is bright.

The invention discloses an Al-Mg-Zn aluminum alloy plate with excellent strong plasticity and light weight characteristics as well as a preparation method and application of the Al-Mg-Zn aluminum alloy plate. The alloy comprises the following components in percentage by mass: 5.0%-5.5% of Mg, 1.5%-2.0% of Zn, 0.4%-0.5% of Mn, 0.1%-0.3% of Cu, 0.15%-0.25% of Sc, 0.1%-0.15% of Zr, 0.05%-0.15% of Ag, less than or equal to 0.1% of impurities and the balance of Al. The density is not more than 2.63 g / cm < 3 >, the tensile strength is not less than 470 MPa, and the ductility is not less than 23%. The preparation method comprises the steps of high-purity raw material smelting and casting, two-stage homogenization, hot rolling, intermediate annealing, cold rolling, solid solution treatment and single-stage aging. Wherein the total pressing amount of hot rolling is 80-85%, the total pressing amount of cold rolling is 20-35%, and the single-stage aging time is 120-140 DEG C * 16-24 h. The microstructure of the alloy is characterized in that the average size of dispersed AlSc particles is smaller than or equal to 100 nm, the area fraction of deformed grains is larger than or equal to 70%, the average size of nanometer beta-AlMg and T-Mg (Al, Zn) composite precipitated phases is smaller than or equal to 20 nm, the number density is larger than or equal to 1 * 10 < m >, the area fraction of micron-order second phases is smaller than or equal to 0.5%, and the alloy is only formed by impurity Fe. According to the method, the traditional two-stage aging process is simplified, low density, high strength and high plasticity are synchronously improved, and the method is suitable for large-scale industrial application.

This invention provides a high-strength, high-ductility austenitic stainless steel and its production method. The composition is: C 0.045%-0.085%, N 0.10%-0.40%, Si 0.90%-1.55%, Cr 16%-20.1%, Ni 7.5%-12.5%, Mn 1.5%-3.5%, Mo 1.5%-3.0%, Nb 0.08%-0.22%, Ti 0.015-0.065%, O≤0.005%, P≤0.003%, S≤0.003%, with the remainder being Fe and unavoidable impurities. Compared with existing technologies, this invention obtains a reasonable grain size and second-phase particles through nitrogen, titanium, and niobium alloying, combined with low-temperature rolling and appropriate annealing and aging heat treatment, thus developing an austenitic stainless steel with excellent mechanical properties. It achieves excellent ductility at a high strength level, with a strength-ductility product as high as 60 GPa·s.

The invention discloses an ultrahigh-strength maraging steel wire as well as a preparation method and application thereof, and belongs to the field of steel product manufacturing. The steel wire alloy comprises the following components in percentage by weight: 0.02%-0.05% of C, 0.10%-0.35% of Si, 0.20%-0.60% of Mn, 0.60%-2.50% of Cr, 18.5%-22.0% of Ni, 8.0%-13.0% of Co, 1.2%-2.0% of Ti, 3.0%-5.5% of Mo, 0.10%-0.50% of Al, less than or equal to 1.50% of Cu, less than or equal to 1.50% of Nb, less than or equal to 0.05% of V, less than or equal to 0.04% of N, less than or equal to 0.02% of La + Ce and the balance of Fe and inevitable impurity elements. And the equivalence ratio Nieq / Creq of nickel to chromium is greater than or equal to 1.80. The steel wire provided by the invention has ultrahigh strength, excellent toughness and plasticity, wear resistance, heat resistance, drawing performance and bending and twisting performance.

The invention relates to the technical field of metal plastic forming, in particular to a reverse stretching forming method of an aluminum lithium alloy skin. According to the method, through the reverse stretch forming technology, it is ensured that materials flow uniformly in the stretching process, precise attachment is achieved step by step, and the method is particularly suitable for stretch forming of aluminum-lithium alloy and variable-curvature skin. According to the skin part self-adaptive wrinkle removing mold, the skin part self-adaptive wrinkle removing mold is innovatively designed, the self-adaptive wrinkle removing function of the mold is achieved, and the tool design structure is optimized. According to the process, the part appearance precision is remarkably improved, the gap control requirement in a file is met, and the formed part is smooth in appearance and free of quality problems such as wrinkles and orange peel defects on the surface.

The invention discloses a thermomechanical treatment method for manufacturing a high-performance ribbed shell section, and belongs to the technical field of high-performance precision plastic forming manufacturing. According to the method, firstly, through high-temperature multidirectional forging cogging, medium-temperature rectangular ring rolling and high-temperature in-mold forging and rolling composite forming, near-net forming of the ribbed shell section, coarse crystal phase crushing and refining and grain refining are achieved; and finally, through the design of solid solution, in-mold cold rolling and aging, the problem that cold deformation is discontinuous and uneven due to a split mold structure in an existing ring piece cold bulging process is solved, accurate shape correction, residual stress reduction and performance improvement are achieved, and the product quality is improved. And the high-performance near-net plastic forming and high-performance manufacturing requirements of a key structural part, namely a ribbed shell section, of an aerospace carrier are met.

The invention discloses a high-strength and high-plasticity copper alloy and a preparation method thereof. The high-strength and high-plasticity copper alloy is prepared by mixing Cu-Al pre-alloyed spherical powder and CuO powder according to the mass ratio of (100-150): 1, wherein the Cu-Al pre-alloyed spherical powder and the CuO powder are different in particle size range. The solid solution state Al element part in the high-strength plastic copper alloy is oxidized into Al2O3 through CuO, and the Al2O3 exists in a Cu matrix. The preparation method comprises the following steps: (1) mixing Cu-Al pre-alloyed spherical powder with CuO powder, and drying; (2) cold isostatic pressing treatment; (3) vacuumizing, sintering at a high temperature in a protective atmosphere, and cooling; (4) vacuumizing, reducing in a reducing atmosphere, and cooling; and (5) after preheating, the copper alloy reduction blank is placed in a rotary forging die, rotary forging and air cooling are conducted, and the copper alloy is obtained. The high-strength plastic copper alloy is good in conductivity and mechanical property and high in plasticity. The method is simple in process, environmentally friendly, low in cost and suitable for industrial production.

The application discloses an easy-to-cut steel with excellent plasticity and drilling performance and a preparation method thereof, and the preparation method comprises the following steps: converter smelting, LF refining, continuous casting, hot rolling and air cooling line cooling; in the continuous casting step, the water quantity of a crystallizer is 130-140 m 3 / h, and the secondary cooling water quantity is 0.8-1.0 L / kg; in the air cooling line cooling step, the cooling speed is 1-1.5 DEG C / s from the spinning temperature to greater than 650 DEG C, and the cooling speed is 2-4 DEG C / s in the range of 650 DEG C-500 DEG C; under the condition of not adding easy-to-cut elements and increasing production cost, the plasticity and drilling performance of the easy-to-cut steel are significantly improved by controlling the manganese sulfide inclusion size, hardness and structure of the rolled material.

The invention discloses a manufacturing method for preventing a single-board guitar panel from recessing, and relates to the technical field of manufacturing for preventing the single-board guitar panel from recessing, and the method comprises the steps: carrying out the finite element stress simulation of a three-dimensional digital model of the single-board guitar panel, and determining a high-stress region in a stress state; according to the distribution characteristics of the high-stress area, generating a structure model of the bionic support network through topological optimization; preparing a lightweight support net with a bionic structure by adopting an additive manufacturing process based on the structure model; the method comprises the following steps: placing a to-be-processed veneer panel on a rigid mold with a preset curved surface, and carrying out plastic pre-deformation on the to-be-processed veneer panel under the action of vacuum negative pressure to obtain a pre-formed panel; a lightweight supporting net is fixed to a high-stress area on the inner side of the preformed panel; the modularized metal framework with preloaded stress is installed at a preset position in the guitar body to form a reverse acting force system which resists the downward sinking of the panel; and carrying out integral curing treatment on the guitar body provided with the supporting net and the metal framework to complete integrated manufacturing.

The invention discloses a manufacturing process of an NO7718 nickel base alloy nut for nuclear equipment. The manufacturing process comprises the steps of material preparation, hot forging, shot blasting, solid solution heat treatment, physical and chemical detection, finish machining, precipitation hardening heat treatment and detection packaging. The hot forging near-net forming technology is adopted, the shape of the nut blank is directly obtained through plastic deformation, the cutting allowance of machining is greatly reduced, a large number of raw materials are prevented from becoming sweeps, the material utilization rate is remarkably increased, and the raw material cost is effectively reduced; by accurately controlling the initial forging temperature, the final forging temperature and the cooling speed of hot forging as well as subsequent solution treatment and precipitation hardening treatment, grains can be refined, and the precipitation form and distribution of a strengthening phase can be controlled, so that the microstructure of the material is optimized, and the material obtains more excellent comprehensive mechanical properties such as higher strength, plasticity and toughness cooperation; and the harsh working condition requirements of nuclear equipment can be better met. The process provided by the invention ensures the stability and consistency of product performance.

The invention discloses an electric auxiliary roll forming device, and relates to the technical field of annular part plastic processing, the electric auxiliary roll forming device comprises a rolling device and an electric auxiliary device, the rolling device is provided with a conductive core roller and a feed roller, the core roller is sleeved with a to-be-formed annular blank, and the core roller and the feed roller are oppositely arranged on the annular inner side and the annular outer side of the annular blank; the axes of the ring blank, the core roller and the feeding roller are located on a first plane, a common vertical line of the axes of the ring blank, the core roller and the feeding roller is arranged on the first plane, and the feeding direction of the feeding roller is consistent with the common vertical line; the electric auxiliary device comprises a first carbon brush and a second carbon brush, the first carbon brush and the second carbon brush are suitable for being electrically connected with two electrodes of an external power source respectively, the first carbon brush makes contact with the axial end of the core roller, the first carbon brush is electrically connected with the core roller, the second carbon brush makes contact with the axial end of the feeding roller, and the second carbon brush is electrically connected with the feeding roller. Compared with the prior art, the annular part can be electrically heated in an auxiliary mode, and the performance of the plastically-machined annular part is good.

The invention relates to a steel wire rod for a non-quenched and tempered fastener, a production method of the steel wire rod and the fastener, and the steel wire rod is characterized in that through component design, an element B is added on the basis of strengthening elements such as carbon, silicon and manganese, so that excellent hardenability and plasticity of steel are guaranteed; the tensile strength of the steel wire rod obtained through the production process of converter smelting, LF refining, bloom continuous casting, cogging, steel wire rod rolling and offline salt bath of the steel wire rod is 1050-1250 MPa, and the percentage reduction of area is 65-70%; the steel wire rod is subjected to drawing and cold heading to produce the fastener, thermal refining can be omitted, the technical requirements of the 12.9-grade fastener can be met, and the production cost and the carbon emission are effectively reduced.

The invention discloses a wire feeding mechanism for a steel ball cold header, and belongs to the technical field of metal plastic processing equipment.The mechanism comprises a workbench, a straightening mechanism, a first driving assembly and a feeding roller assembly, and the straightening mechanism is used for straightening a steel ball through cooperation of a rotatable diameter adjusting disc, pressing assemblies distributed in the circumferential direction and a connecting mechanism; and the feeding roller assembly is provided with a rotatable rotary table mechanism, a plurality of guide rolling wheels with different sizes are installed on the rotary table mechanism, switching is driven through a second driving assembly, locking is achieved through a limiting assembly, and the feeding roller assembly is driven by a first driving assembly to rotate. According to the straightening device, the straightening function of synchronous aligning and the driving function of rapid roller changing are integrated, and the adaptability and the production efficiency of the straightening device to wires with different diameters are improved.

The invention discloses an annealing treatment method for low-carbon steel, and relates to the technical field of metallurgical engineering. Comprising the following steps that steel to be annealed is placed in an annealing furnace with the preset temperature to be subjected to annealing treatment, and the annealing furnace comprises a heating section, a heat preservation section and a furnace cooling section which are continuously arranged in the moving direction of the steel; the preset temperature of a heating area is 690-715 DEG C, the preset temperature of a heat preservation area is 750 DEG C, and the preset temperature of a furnace cooling area is 730-525 DEG C; and the residence time of the steel in a heating section, a heat preservation section and a furnace cooling section is adjusted, the residence time of the steel in the heating section is 1.3-1.6 h, the residence time of the steel in the heat preservation section is 3.0-3.6 h, the residence time of the steel in the furnace cooling section is 2.9-3.5 h, and the cooling rate is 64-77 DEG C / h. By means of the method, the plasticity and toughness of the large-specification low-carbon steel can be remarkably improved, and the cold forging machining performance of the large-specification low-carbon steel is ensured.

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.

The invention discloses a composite beam plastic flexural capacity correction calculation method considering interface slippage. The method is suitable for a hogging moment area of a steel-concrete composite beam reinforced by an external prestress carbon fiber reinforced composite material rib. The method comprises the following steps: firstly, determining basic static boundary parameters and a shear connector constitutive model; in the iterative calculation, solving a temporary bearing capacity by utilizing an axial force and moment balance equation, and calculating interface slippage along the beam length and a deformation loss item at the support based on internal force distribution; then determining a rigidity degradation coefficient according to the average slip amount, and dynamically reducing the static yield bending moment to reconstruct the plastic hinge length; and finally, constructing a corrected deformation coordination equation, deducting a deformation loss item in geometric deformation calculation to obtain the real elongation of the in-vitro CFRP rib, and updating a stress parameter until a result is converged. According to the method, by introducing a deformation loss item and a rigidity degradation mechanism, deviation caused by traditional rigid connection assumption is corrected, and accurate prediction of the ultimate bearing capacity is achieved.

A kind of titanium alloy plate local heat / electricity / ultrasonic multi-field coupling assisted progressive forming device and its use method, relate to a kind of titanium alloy plate progressive forming device and its use method.The present application is to solve the technical problems of the existing titanium alloy plate progressive forming method relatively slow heating speed, high energy consumption, poor product quality.The device of the present application realizes two-stage heating by local non-contact heating and pulse current self-resistance heating, improves the heating rate, improves the material plasticity by the "electroplasticity" effect generated by pulse current, reduces the material deformation resistance by the "ultrasonic softening" effect generated by ultrasonic field, improves the formability, and improves the forming quality by multi-field coupling.The present application realizes the reduction of material deformation resistance and plasticity by the coupling of heat, electricity and ultrasonic multi-energy field in the deformation process of sheet metal, and significantly improves the formability of material.

The invention provides a method for inhibiting cracks of an additive manufacturing nickel-based superalloy and application of the method. The method comprises the steps that a selective laser melting technology is adopted, nickel-based alloy powder is subjected to 3D printing, so that the nickel-based alloy powder is formed layer by layer, and a printing component is obtained; wherein during printing, interlayer rotation is carried out, and after printing of each layer is completed, the layer is subjected to same-path instant remelting with the same laser scanning path and the same 3D printing process condition; the printing component is subjected to sectional type heat treatment, the sectional type heat treatment comprises a first stage, a second stage and a third stage, the heat treatment temperature of the first stage is 650-850 DEG C, the heat treatment temperature of the second stage is 950-1200 DEG C, and the heat treatment temperature of the third stage is 650-850 DEG C, so that the nickel-based superalloy is obtained. According to the method, the crack inhibition effect of the additive manufacturing nickel-based superalloy can be improved, and the strength and plasticity of the additive manufacturing nickel-based superalloy are improved.

This invention relates to the field of metallic materials technology, and more particularly to a negative enthalpy duplex stainless steel material and its preparation method, which possesses high strength, high plasticity, and high corrosion resistance. The negative enthalpy duplex stainless steel material is Fe... a Cr b Ni c Mo d Mn e C f Si g Ti h Al i V j Wherein, a, b, c, d, e, f, g, h, i, and j correspond to the mass percentages of each element: a = 60-70 wt%, b = 15-20 wt%, c = 10-15 wt%, d = 0-5 wt%, e = 1-5 wt%, f = 0.015 wt%, g = 0-1 wt%, h = 0-3 wt%, i = 0-0.5 wt%, j = 0-0.5 wt%, and d, g, h, i, and j are not zero. This series of negative enthalpy duplex stainless steel materials all contain ferrite and austenite in their structure, and the microstructure and mechanical properties of the alloy can be controlled by adjusting the proportions of different metal elements. This series of negative enthalpy duplex stainless steel materials exhibits high strength and high ductility. Simultaneously, negative enthalpy duplex stainless steel materials exhibit excellent corrosion resistance.

The invention discloses a TC11 titanium alloy thick-wall pipe diameter forging process parameter optimization method, which relates to the technical field of metal plastic forming process optimization, and comprises the following steps: clearly defining a structure defect problem caused by non-uniform deformation energy in diameter forging of a specific pipe blank and an optimization target; constructing a simulation model to calculate forming sizes and internal deformation energy distribution under different process parameters; training a neural network agent model embedded with a deformation energy uniformity optimization target; using the model to drive a multi-objective optimization algorithm, and automatically searching an optimal process parameter combination; and selecting and outputting a final optimal process parameter from an optimization result. According to the method, the quantitative index reflecting the deformation energy distribution uniformity is embedded into the process optimization model, so that the internal deformation energy distribution of the material can be collaboratively optimized while the macroscopic size is optimized, and the problem that the recessive factor which affects the final structure performance of the component is difficult to effectively evaluate and actively regulate and control in the process design stage in the existing method is solved.

The invention discloses high-strength heat-resistant aluminum-copper alloy powder, a 3D printing application method and an aluminum product. Relates to the technical field of metal material and additive manufacturing, in particular to a high-strength heat-resistant aluminum alloy material suitable for selective laser melting. The alloy powder is composed of Cu, Sc, Ni, Ce, Si, Mn, Ti, Fe and Al, the content of Cu ranges from 5 wt% to 15 wt%, the content of Sc ranges from 0.3 wt% to 2 wt%, the content of Ni ranges from 0.5 wt% to 5.5 wt%, the content of Ce ranges from 0.5 wt% to 5.5 wt%, and an Al7Cu4Ni eutectic phase is generated in situ in the printing process. And through a multi-element synergistic strengthening mechanism, the solidification interval is effectively reduced, cracks are inhibited, and meanwhile fine grain strengthening and precipitation strengthening are achieved. After SLM forming and low-temperature heat treatment, the obtained aluminum product has ultrahigh strength, good plasticity and excellent heat resistance, the tensile strength exceeds 650 MPa, the hardness exceeds 180 HV0.2, the ductility exceeds 7%, and the aluminum product meets the requirements for light high-strength heat-resistant components in the high-end fields such as aerospace and the like.

The invention provides a method for establishing a nonlinear constitutive model of low-temperature marine steel, and relates to the technical field of ships and materials. A heterogeneous time series data set is provided for model construction through multi-type sample multi-axial load tests and full-field strain acquisition; nonlinear mapping of deformation activation energy about temperature and microscopic state variables is established by taking a crystal plasticity theory as a framework, and the defect that a low-temperature dislocation evolution rule cannot be reflected due to the fact that a traditional model solidifies physical parameters into constants is overcome; a damage evolution operator jointly induced by stress triaxial degree and a principal stress threshold is embedded, Bayesian inference is adopted to carry out parameter joint calibration, model dynamic calibration and parameter continuous optimization are realized through a simulation and experiment closed-loop iteration mechanism, and finally a digital design evaluation model capable of being under untested extreme working conditions is produced. And an engineering tool taking physical interpretability and probabilistic safety margin into consideration is provided for the ice-resistant design of the polar region ship.

The invention discloses a beam-column joint with a replaceable self-resetting bionic plastic hinge and application, the beam-column joint comprises a steel beam, an upper prefabricated column, a lower prefabricated column and a connecting joint for connecting the upper prefabricated column, the lower prefabricated column and the steel beam, and the replaceable self-resetting bionic plastic hinge is connected between an overhanging beam on one side of the connecting joint and the steel beam; the replaceable self-resetting bionic plastic hinge comprises a torsion amplification damper which is connected to the end faces of the upper and lower flanges of the pair of connecting beam sections and is connected by a rotating arm, a self-resetting device which is arranged on the butt-joint end faces of the upper and lower flanges of the pair of connecting beam sections, and a pair of friction hinges which are arranged at the butt-joint ends of the pair of connecting beam sections and are mutually nested and wrapped to form rotation. The beam-column joint not only has excellent energy dissipation performance, but also can concentrate post-earthquake damage, protect a main body structural member from being damaged, and improve the anti-seismic performance of the beam-column joint; meanwhile, the replaceable self-resetting bionic plastic hinge is connected with the steel beam and the joint core area through high-strength bolts and lug plates, mounting and dismounting are easy, and the replaceable function after an earthquake can be achieved.

The invention relates to special-corrosion-resistant martensitic heat-resistant steel and a preparation method thereof, belongs to the technical field of nuclear heat-resistant steel, and solves the problems of poor oxidation corrosion resistance, low strength and poor impact toughness and plasticity of ferrite / martensitic steel in high-temperature liquid lead bismuth in the prior art. The heat-resistant steel comprises the following chemical components in percentage by mass: 0.10-0.13% of C; 0.9 to 1.4 percent of Si; mn: 0.5 to 0.7%; 8.5 to 9.0 percent of Cr; 0.4 to 0.6 percent of W; 0.7 to 0.8 percent of Mo; 0.25 to 0.40 percent of Ni; 0.15% to 0.20% of V; 0.05 to 0.07 percent of Nb; the content of N is 0.045 to 0.065 percent; compared with the prior art, the heat-resistant steel disclosed by the invention has the advantages that a compact Si-rich oxide layer is ensured to exist in the heat-resistant steel by increasing the content of Si, so that the high-temperature liquid lead / lead bismuth corrosion resistance of the material is improved; by adjusting the content of Mn, Cr, Ni, W, Mo and other elements, it is ensured that the material has a single martensite structure, the heat-resistant steel has good room-temperature and high-temperature mechanical properties at the same time, and the heat-resistant steel is suitable for lead-cooled fast reactor structural materials.

The application discloses a micro-nano circular plate fracture analysis method considering coupling of surface effect and plastic zone, and firstly establishes a three-dimensional curved surface coordinate system suitable for a surface layer, and then further corrects a Dugdale cohesion force model according to a superposition principle after considering surface correlation of the plate, and then simplifies the Dugdale cohesion force model into a hyper-singular integral equation by using Hankel transformation, and finally obtains influences of the surface effect on the plastic zone size and crack surface displacement by numerically solving the hyper-singular integral differential equation.The method can accurately capture the nonlinear coupling relationship between the crack size, the surface shear modulus, the torsional displacement and the stress intensity factor under the micro-nano scale, effectively corrects calculation deviation generated by traditional classical theory when the surface effect is ignored, ensures the accuracy of the fracture analysis under different scales, and realizes more accurate and more comprehensive theoretical description of the elastic-plastic fracture behavior of the micro-scale material.

The invention discloses a modeling and analysis method for a metal matrix composite crystal plasticity finite element, and particularly relates to the field of metal matrix composites for spaceflight. Comprising the following steps: acquiring EBSD data of a to-be-detected metal-based composite material; identifying a metal matrix phase and a reinforced fiber phase according to the EBSD data; carrying out texture analysis on the to-be-detected metal matrix composite material, and determining grain orientation data; according to the grain orientation data, establishing a finite element model of the to-be-tested metal matrix composite material, and generating a geometric grid; identifying a metal matrix phase and a reinforced fiber phase in the finite element model, and endowing each phase with parameters; according to the crystal plasticity constitutive model, determining the strain of the to-be-measured metal-based composite material; and original crystal plasticity parameters are corrected according to the actually-measured strain and strain, and the metal-based composite material model is obtained. The metal matrix composite model can obtain the grain plastic strain in the plastic deformation process.

The application belongs to the technical field of metal materials, and particularly relates to a kind of multi-element micro-alloyed Al-Zn series magnesium alloy for semi-solid injection and a preparation method thereof, which comprises the following steps: raw materials and pretreatment; vacuum induction melting and purification are carried out on the raw materials to obtain a melt containing multi-element micro-alloyed Al-Zn series; the melt is rapidly solidified and powdered to obtain petal-shaped magnesium alloy granules; the magnesium alloy granules are subjected to semi-solid injection molding to obtain a magnesium alloy molded part; the magnesium alloy molded part is subjected to special gradient heat treatment to obtain a magnesium alloy heat-treated part; and finishing treatment is carried out on the surface of the magnesium alloy heat-treated part. In addition, the application also prepares a multi-element micro-alloyed Al-Zn series magnesium alloy by using the above preparation method. The application realizes the synergistic improvement of strength-plasticity-corrosion resistance by constructing a unique grain boundary dispersed micro-tube core-shell structure and combining semi-solid injection molding and special heat treatment process.

The application relates to a high-temperature high-strength plastic ferrite martensite steel and a preparation method thereof, the preparation method comprises the following steps: (1) obtaining original ferrite martensite steel through heat treatment of a steel ingot; (2) performing cold plastic deformation processing on the original ferrite martensite steel obtained in the step (1) at a temperature of not higher than 50 DEG C to obtain nanocrystalline or ultrafine-grain ferrite martensite steel; and (3) performing annealing treatment on the nanocrystalline or ultrafine-grain ferrite martensite steel obtained in the step (2) to obtain high-temperature high-strength plastic ferrite martensite steel. The ferrite martensite steel prepared by the application can have high strength and plasticity at a high temperature of 550 DEG C, so that the application prospect of the ferrite martensite steel in engineering application is further improved.