2382 results about "Plasticity" patented technology

The invention discloses a steel wire rod for a 2300-2360 MPa grade stress corrosion resistant steel strand, the steel strand and a preparation method. The steel wire rod comprises the following chemical components in percentage by mass: 0.85-0.91% of C, 0.3-1.0% of Si, 0.2-0.8% of Mn, 0.15-0.45% of Cr, 0.02-0.05% of V, less than or equal to 0.008% of S, less than or equal to 0.010% of P, less than or equal to 0.004% of N, less than or equal to 0.0020% of O and the balance of Fe and other inevitable impurities. The steel wire rod has excellent strength and plasticity, the ultrahigh strength of 2300 MPa or above can be obtained through drawing with a small area reduction rate, surface damage and internal defects of the steel wire rod during subsequent drawing machining are reduced, and the stress corrosion index of the steel strand is improved.

The invention discloses a steel wire rod for a 2200-2260 MPa grade ultrahigh stress corrosion resistance prestressed steel strand, the steel strand and a production method of the steel strand, and the steel wire rod comprises the following alloy components in percentage by mass: 0.83-0.89% of C, 0.60-1.40% of Si, 0.20-0.80% of Mn, 0.15-0.50% of Cr, less than 0.30% of Cu, less than 0.30% of Ni, less than 0.30% of Mo, 0.01-0.05% of V, 0.001-0.05% of Nb, less than or equal to 0.008% of S, less than or equal to 0.010% of P, less than or equal to 0.0040% of N, less than or equal to 0.0020% of O and the balance of Fe and other inevitable impurities, through component design and a reasonable after-rolling controlled cooling process, the microstructure is refined, the sorbite rate is improved, high strength and plasticity are obtained with low carbon content, the drawing deformation can be reduced, material damage can be reduced, and the corrosion resistance of the steel strand is improved.

The invention provides a data correction method and system combined with lattice structure additive manufacturing process characteristics, and the method comprises the steps: firstly employing a Newton iteration method, taking the radius of a pillar as a variable, optimizing the relative density of an iteration target and generating a lattice structure geometric model under the condition that a process constraint condition is satisfied, and extracting actual geometric parameters after forming through CT scanning, the elastic modulus is corrected through the pillar diameter deviation and the defect volume fraction, a compression failure mechanism is combined, a density-related failure criterion is introduced, a nonlinear relation with the relative density is constructed through specific energy absorption data, material plasticity parameters are inversely optimized, and a defect coupling evaluation model is constructed according to the surface powder sticking rate and the pillar diameter deviation. And establishing a Gaussian mixture model based on a stress-strain curve to screen out abnormal data, and finally fusing the parameters to construct a data correction model. The dot matrix structure design precision can be improved, and then a high-quality data basis is provided for performance prediction-structure design two-way feedback.

The invention relates to a 1200MPa-grade high-strength tool steel wire rod and a manufacturing method thereof, after V-containing chemical components are designed, rolled and spun into a wire rod, the wire rod is subjected to online molten salt isothermal quenching treatment, and the wire rod is controlled to enter a bainite phase region from a high-temperature austenite state at a cooling speed greater than or equal to 32 DEG C / s; the steel wire rod with a microscopic structure comprising tempered bainite and ferrite is prepared through isothermal tempering, toughening and destressing treatment, carbide precipitation control and roller way cover opening and slow cooling, so that generation of deteriorated structures such as martensite can be avoided, the structure state can be effectively adjusted, strong plasticity matching of the steel wire rod is achieved, and the service life of the steel wire rod is prolonged. And the tensile strength is 1120-110MPa, the percentage reduction of area is 63-67%, and the steel is suitable for the application fields of manufacturing 1200MPa-grade high-strength tool steel and the like, and is favorable for being directly processed into tool parts after being subjected to cold processing molding.

The invention relates to a 1100MPa-grade high-strength tool steel wire rod and a manufacturing method thereof, the wire rod adopts a middle-carbon Nb-V-containing chemical component design, after a steel billet is rolled and spun into the wire rod according to the spinning temperature of more than or equal to 860 DEG C, online molten salt semi-quenching isothermal treatment is performed, the wire rod is controlled to be subjected to front-section molten salt treatment, and then the steel wire rod is subjected to hot rolling and hot rolling to obtain the 1100MPa-grade high-strength tool steel wire rod. According to the method, the steel wire rod enters a bainite phase region from a high-temperature austenite state at the cooling speed of more than or equal to 30 DEG C / s to form a structure taking quenched bainite as a main component, and then is subjected to rear-section molten salt heating isothermal tempering and toughening destressing treatment, and finally is subjected to roller way slow cooling to prepare the steel wire rod with a microscopic structure comprising tempered bainite and ferrite, so that the material cost can be reduced, and the production efficiency is improved. The method has the advantages that martensite brittle structures are effectively avoided, the structure state of the hot-rolled wire rod is controlled, the plasticity and cold working performance of the wire rod are improved, the tensile strength of the product can reach 980-1030 MPa, the percentage reduction of area is 61%-66%, and the product can be directly machined into tool parts after cold forming.

The invention discloses preheating-free welding maritime work steel with excellent low-temperature toughness and a preparation method of the preheating-free welding maritime work steel, and belongs to the field of steel and iron material preparation. The produced steel plate has good comprehensive mechanical properties through alloy component-secondary rolling-controlled cooling process coupling design, the problem that the strength, plasticity, low-temperature toughness and preheating-free post-welding performance of the steel plate are difficult to match and harmonize is solved, the steel plate has ultrahigh-strength plasticity, excellent low-temperature toughness and excellent Z-direction performance, and room-temperature preheating-free welding can be achieved.

The invention discloses a forging method for improving plasticity of a large invar alloy steel ingot and invar alloy, and the forging method comprises the following steps: smelting molten steel by adopting an electric furnace, and casting to obtain the large invar alloy steel ingot with the weight of 15-25t; the cold-state invar alloy steel ingot is heated to 1000-1200 DEG C for heat preservation, and the heat preservation time is controlled to be longer than or equal to 10 h; the heated invar alloy steel ingot is subjected to three-heating-number upsetting and drawing-out, upsetting is conducted according to the rolling reduction of 15-50% of the total height of the invar alloy steel ingot in each heating number, the invar alloy steel ingot is drawn out to the height of the original invar alloy steel ingot after upsetting, and the invar alloy steel ingot is returned to a heating furnace to be heated and subjected to heat preservation after upsetting and drawing-out in each heating number; the final forging temperature of the last heating number is greater than or equal to 750 DEG C; and the invar alloy steel ingot subjected to heating and heat preservation in the last heating number is forged to the specified size, and then the invar alloy steel ingot is slowly cooled to the room temperature in air to obtain an invar alloy steel forging stock. The thermoplasticity of the large invar alloy steel ingot is improved, and the technical problem that the large invar alloy steel ingot is prone to cracking during forging is solved.

The invention discloses a high-strength high-temperature alloy and a preparation method thereof. The high-strength high-temperature alloy comprises a high-temperature alloy matrix and rare earth oxides dispersed and distributed in the high-temperature alloy matrix. The high-temperature alloy matrix is GH4169, and the high-temperature alloy matrix is made of The rare earth oxide is one or two of La2O3 and Ce2O3, the particle size of the rare earth oxide is 50-500nm, and the total adding amount of the rare earth oxide is 0.02-0.03% of the mass of the alloy; the preparation method of the high-strength high-temperature alloy comprises the following steps: (1) preparing rare earth oxide particles; (2) charging and smelting rare earth oxide particles and alloy raw materials in a vacuum induction furnace, and casting into ingots after the components are qualified; (3) electroslag remelting: adding analytically pure rare earth oxide into a slag system; and (4) the electroslag ingot is subjected to homogenization, forging and solid solution aging treatment, and then the alloy is obtained. According to the method, the strength and plasticity of the high-temperature alloy are improved.

This invention discloses a stainless steel welding wire for repair welding of martensitic stainless steel turbine runners, its preparation method, and its application, belonging to the field of metal welding material preparation technology. The chemical composition of the welding wire provided by this invention, expressed as a percentage by weight, is: C≤0.03%, Si: 0%~0.6%, Mn: 5.0%~8.0%, S≤0.010%, P≤0.020%, Cr: 12.5%~15.5%, Ni: 5.0%~7.0%, Mo: 1.0%~2.0%, with the balance being Fe and impurities. The welding wire provided by this invention is suitable for repair welding of Cr13Ni4~6 type martensitic stainless steel, and post-weld heat treatment is not required. The weld metal produced by this welding wire exhibits good strength, plasticity, and toughness, with a tensile strength ≥750MPa, elongation after fracture ≥35%, and impact absorption energy at -40℃ ≥120J.

The invention provides a 10.9-grade non-quenched and tempered cold heading steel wire rod and a production method thereof. The 10.9-grade non-quenched and tempered cold heading steel wire rod comprises the following chemical components: 0.23-0.27% of C, 0.30-0.50% of Si, 1.45-1.55% of Mn, less than or equal to 0.025% of P, less than or equal to 0.025% of S, 0.40-0.50% of Cr, 0.025-0.050% of Ti, 0.0025-0.0050% of B, less than or equal to 0.0050% of N and more than or equal to 0.015% of [Ti]-3.5 * [N]. According to the invention, on the basis of component design, a controlled rolling process deformation induced phase change, an online salt bath isothermal treatment cooling process and an artificial aging process are matched, so that rapid cooling and isothermal phase change of the wire rod are realized, and the prepared wire rod is uniform in through ring mechanical property, high in yield ratio, good in plasticity and long in fatigue life. The steel wire rod can be used for directly cold-drawing the steel wire without annealing, and the cold-drawn steel wire can meet the performance requirement of a 10.9-grade fastener without quenching and tempering after being formed. According to the production method of the wire rod, the production process can be simplified, the fastener production period is shortened, the cost is reduced, meanwhile, the energy consumption is reduced, and the method conforms to the current green and low-carbon development route.

The invention provides a method for additive forming of a high-performance Ti2AlNb three-period minimal curved surface lattice structure in a nitrogen atmosphere, and belongs to the technical field of additive manufacturing. Comprising the following steps: step 1) modeling an implicit function of a TPMS configuration: designing a CAD model of the TPMS configuration and exporting the CAD model as an STL file; 2, pretreatment of the Ti2AlNb lattice structure formed through L-PBF, wherein an STL file is subjected to slicing treatment, and technological parameters are set; 3, L-PBF forming of the Ti2AlNb lattice structure is conducted, specifically, in the nitrogen-argon mixed atmosphere, the Ti2AlNb lattice structure is formed through the L-PBF technology; and (4) the TPMS configuration Ti2AlNb lattice structure is subjected to surface treatment. According to the method, the Ti2AlNb lattice structure with the TPMS configuration is designed through implicit function modeling, the Ti2AlNb lattice structure with the TPMS configuration is formed through L-PBF in the nitrogen-argon reaction atmosphere, the problems that in traditional particle strengthening, reinforcements are distributed unevenly, and the solid solution strengthening effect is limited are solved, and good matching of the strength, plasticity and toughness of the lattice structure is achieved.

The application discloses a preparation method of high-strength and high-plasticity additive manufacturing nickel-based high-temperature alloy. The application effectively solves the problem of high strength and low plasticity of the nickel-based high-temperature alloy caused by heat treatment of precipitation strengthening, and obtains high-performance nickel-based high-temperature alloy with a tensile strength of 1609 MPa and an elongation rate of 16.6%. The application first uses 1160 DEG C. to 1200 DEG C. solid solution treatment, and then carries out 843 DEG C. / 4 h+760 DEG C. / 8 h two-stage aging heat treatment process, to prepare a multi-scale heterogeneous structure composed of bimodal size distribution grains, nano second phases and nano defects, and the heat-treated product has excellent strength and plasticity. The preparation process is simple, controllable and adjustable, the product has excellent performance, and is convenient for large-scale industrial application.

The invention discloses a brazing method for improving the welding strength of a polycrystalline diamond cutter and a hard alloy. The brazing method comprises the following steps that S1, brazing filler metal alloying is conducted; and S2, the PCD tool bit and the hard alloy matrix are subjected to vacuum brazing. According to the brazing filler metal, an Ag-Cu-Co system is adopted, Ag mainly plays a role of a solder matrix and provides plasticity and thermal conductivity, Cu mainly plays a role of forming an eutectic structure with Ag and reducing the melting point, and Co mainly plays a role of wetting the surfaces of PCD and hard alloy. Co infiltration is adopted in the preparation process of the PCD tool bit used in the method, so that a certain amount of Co exists on the PCD surface, and the hard alloy tool body also contains Co, and therefore, a small amount of Co in the brazing filler metal can better wet the welding surface according to the similar intermiscible principle. In the vacuum brazing process, additional pressure does not need to be applied, when the brazing filler metal is molten, the brazing filler metal is evenly laid on the welding face under the action of the pressure of the PCD tool bit on the upper portion and the capillary effect, the redundant brazing filler metal can flow out of the two sides of the mold, and the flatness of the welding surface can be effectively guaranteed.

The invention relates to a reticular biphase heterostructure cast high-entropy alloy as well as preparation and application thereof, and aims to solve the technical problems of high production cost and long period caused by dependence on introduction of high-cost elements or a complex process in the conventional high-entropy alloy. The CrFeNiAlSi series alloy is used as a matrix component, the alloy design is optimized by introducing the Ti element, and the CrFeNiAl0. 28Si0. 12-xTix as-cast high-entropy alloy is prepared by combining the vacuum arc melting and suction casting process. The mechanical property of the alloy is optimized by reasonably adding Ti into the CrFeNiAlSi alloy and regulating and controlling the content of Ti, meanwhile, the adverse effect brought by Ti is overcome or balanced, and the as-cast high-entropy alloy which has a heterogeneous phase structure between battens and has high strength and good plasticity is developed.

The invention belongs to the technical field of metal material preparation, and relates to high-strength and high-plasticity cold-rolled medium manganese steel without a local deformation zone and a preparation method thereof.The preparation method comprises the steps that austenite-ferrite double-phase region annealing is conducted, and a medium manganese steel billet with the microstructure mainly composed of a manganese-rich austenite region and a manganese-poor ferrite region is obtained; carrying out cold rolling treatment on the annealed medium manganese steel billet to obtain a cold-rolled medium manganese steel billet body consisting of martensite and deformed ferrite; the cold-rolled medium manganese steel billet is rapidly heated to the austenite transformation temperature or above, and the medium manganese steel billet with the microstructure mainly composed of austenite with uneven manganese distribution is obtained; and the medium manganese steel billet is quenched to the room temperature, and a medium manganese steel finished product with the microstructure mainly composed of a manganese-rich austenite area and a manganese-poor martensite area is obtained. A martensite matrix and a small amount of metastable austenite in the microstructure ensure good plasticity and strength, a large amount of dislocation inhibits generation of a local deformation zone, and the uniform deformation capacity of the medium manganese steel is ensured.

The invention relates to the technical field of additive manufacturing, in particular to a direct aging treatment process of an SLM molded Ti-6Al-4V alloy and a product thereof, and the direct aging treatment process comprises the following steps: firstly, manufacturing a Ti-6Al-4V alloy sample by adopting an SLM technology, and then putting the SLM molded Ti-6Al-4V alloy sample into a vacuum heat treatment furnace for direct aging treatment, and finally, taking out the sample after furnace cooling or air cooling. According to the method, through direct aging treatment, a natural alpha'martensite structure in the Ti-6Al-4V alloy formed through SLM is decomposed into an alpha + beta double-phase structure, the front solid solution-quenching process in traditional solid solution aging treatment is not needed, and the purposes of optimizing structure uniformity and improving plasticity are achieved. The aging treatment cost and the quenching risk of the SLM titanium alloy are reduced, and the plasticity of the SLM titanium alloy can be remarkably improved while high strength is kept. The method is simple in process, low in cost and suitable for large-scale industrial application.

The invention relates to 500MPa-grade preheating-free welding structural steel and a preparation method thereof, belongs to the technical field of structural steel, and solves the problems that in the prior art, traditional structural steel is poor in welding performance, high in carbon equivalent, high in cold crack sensitivity and difficult to consider both high strength and good plasticity. The structural steel comprises the following chemical components in percentage by weight: less than 0.002% of C, less than 0.02% of Si, less than 0.03% of Mn, 1.5-2.0% of Ni, 1.5-2.0% of Cu, less than 0.0008% of S, less than 0.006% of P and the balance of Fe and inevitable impurities, wherein the carbon equivalent Ceq is less than or equal to 0.27. The combination of high strength (the yield strength is larger than or equal to 550 MPa, and the tensile strength is larger than or equal to 650 MPa), excellent welding performance (Pcm is smaller than or equal to 0.14), good plasticity (the percentage elongation after fracture is larger than or equal to 25%, and excellent low-temperature toughness (the impact energy at the temperature of-20 DEG C is larger than or equal to 200 J) is achieved, and the steel is suitable for the structural fields of ships, bridges, buildings and the like with strict requirements for welding performance and mechanical performance.

The invention relates to the technical field of metal powder injection molding, in particular to an MIM titanium alloy binder and application of the MIM titanium alloy binder to preparation of high-plasticity TC4 parts. The MIM titanium alloy binder comprises polyformaldehyde, aluminum stearate, polyethylene, queen bee wax and high-density polyethylene. According to the MIM titanium alloy binder, polyformaldehyde serves as a main component, high-melting-point bee wax and aluminum stearate are introduced, the bee wax can improve the thermal stability of a lubricant, aluminum stearate can inhibit volatilization of Al element, the rheological property and sintering behavior of feeding are remarkably optimized, the number of titanium alloy feeding cycles and the density after sintering can be increased, and the O content can be reduced.

The invention relates to a 1300 MPa-grade high-strength tool steel wire rod and a manufacturing method thereof, after a Cr-Nb-V medium carbon component design is adopted for rolling and spinning to form a wire rod, the wire rod is subjected to online molten salt micro-quenching tempering treatment, the wire rod is controlled to enter a lower bainite phase region from a high-temperature austenite state at a cooling speed greater than or equal to 31 DEG C / s, and a quenching structure mainly comprising quenching bainite is formed; the steel wire rod with a microscopic structure comprising tempered bainite and ferrite is prepared by carrying out isothermal tempering and toughening destressing treatment on a quenched structure and finally carrying out roller way slow cooling, so that the material cost can be properly controlled, the strength and plasticity matching of the steel wire rod is improved, the tensile strength is 1255-1305MPa, and the percentage reduction of area is 58-63%, so that the steel wire rod can be directly processed into a part after being subjected to cold processing molding, and the service life of the steel wire rod is prolonged. And tool steel production energy consumption, cost reduction and efficiency improvement are facilitated.

The invention provides a Fe-containing Ti-Al-Mo series high-strength, high-plasticity and low-cost titanium alloy. The titanium alloy comprises the following components in percentage by mass: 6.0%-7.5% of Al, 0.5%-2.5% of Fe, 1.0%-2.5% of Mo, 0.5%-2.0% of V, 1.5%-3.5% of Zr and 0%-2.0% of Sn. And the balance of Ti and inevitable impurities. The microscopic structure of the titanium alloy is a first tissue structure or a second tissue structure, the first tissue structure comprises an equiaxed primary alpha phase and a secondary alpha phase, and the second tissue structure comprises an equiaxed primary alpha phase, a lamellar primary alpha phase and a secondary alpha phase; wherein the equiaxial primary alpha phase is uniformly distributed in the beta matrix, the lamellar primary alpha phase is distributed in the beta matrix along the deformation direction, and the secondary alpha phase is uniformly dispersed and distributed in the beta matrix. A performance foundation is laid through component design and element matching, directional regulation and control of an alloy microstructure are achieved by combining precise forging and heat treatment processes, excellent matching of high strength and high plasticity is finally obtained, and meanwhile the production cost is remarkably reduced.

The invention belongs to the technical field of industrial detection, and provides a low-temperature fatigue crack propagation life prediction method and system based on a steel bridge deck, and the method comprises the steps: judging whether the crack direction deflection risk assessment needs to be started or not through the sharp reduction of steel plasticity and the non-uniform analysis of local stress gradient; if yes, the crack direction deflection risk of the steel bridge deck is evaluated by analyzing the grain orientation difference and the strengthening phase of the welding seam and the HAZ area; if the risk is high, a stress gradient gentle area is determined through a weld toe stress gradient cloud picture, a resistance-gradient coupling equation is established according to the minimum resistance principle and in combination with the stress gradient, and a crack deflection path is determined; dividing the crack crossing area according to the crack deflection path, calculating the actual propagation rate of the crack by combining the path proportion and stress gradient distribution of each stress gradient area after division, and correcting the life prediction output result, thereby improving the crack propagation path prediction precision and the fatigue life prediction evaluation precision.

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 a heat treatment method for improving structure uniformity and performance of a double-state Ti2AlNb-based alloy, the problems of poor plasticity, uneven structure, serious segregation and the like of the Ti2AlNb-based alloy are solved through heat treatment of a primary solid solution process, a secondary solid solution process and an aging process, and the structure uniformity and performance of the double-state Ti2AlNb-based alloy are improved through a heat treatment method of double-solid-solution coordinated regulation and graded aging strengthening. Matching of different mechanical properties can be achieved by regulating and controlling the size of B2 / beta matrix crystal grains and the size, morphology and volume fraction of alpha 2 and O phases, so that the alloy structure is homogenized, and the mechanical properties are remarkably improved.

The invention relates to the field of high-temperature alloy material processing, in particular to a nickel-based high-temperature alloy GH3536 and an SLM preparation and heat treatment process thereof. Through the synergistic effect of ILR and HT, the core pain points of carbide precipitation imbalance and high-temperature instability coarsening in the GH3536 alloy formed through SLM are solved. A high-density subboundary created by the ILR drives short-distance diffusion of carbides at an HT stage to form a uniform spherical nano chain-shaped precipitated phase, so that the strength-plasticity inversion contradiction of a traditional process is broken through, and the strong-plasticity synergistic improvement of the tensile strength and the ductility is realized; the method comprises the steps that in-situ layer-by-layer laser remelting is conducted through the same technological parameters in the SLM process, and then the GH3536 high-temperature alloy is subjected to heat preservation in a vacuum furnace and cooled along with the furnace. The GH3536 high-temperature alloy prepared through the method has excellent performance, the plasticity of the GH3536 high-temperature alloy is equivalent to that of a forged piece, the strength of the GH3536 high-temperature alloy is higher than that of the forged piece, and the GH3536 high-temperature alloy has good industrial application

The invention belongs to the technical field of high-temperature alloy production, and relates to a large-size GH4141 high-temperature alloy fine-grain bar and a preparation method thereof.By means of the forging technology of high-temperature cogging forging, low-temperature forging and medium-temperature finished product forging, the plasticity of a cast ingot is improved through upsetting and drawing-out in the high-temperature stage, and an as-cast structure is fully broken; grains are refined through low-temperature stage upsetting and drawing deformation, and distortion energy is accumulated; through the synergistic effect of dynamic recrystallization and static recrystallization, the bar structure is further refined, and the structure uniformity is improved.

The invention relates to a high-plasticity wire rod for a hand tool and a manufacturing method of the high-plasticity wire rod, and the manufacturing method comprises the following steps: carrying out rolling, spinning, on-line molten salt isothermal toughening and roller way slow cooling treatment on a steel billet to prepare the wire rod with a microscopic structure comprising tempered bainite and ferrite, phase change and isothermal toughening treatment of the wire rod in a ferrite and bainite mixed phase region are controlled through online molten salt isothermal toughening, the wire rod adopts Cr-V chemical component design, the content of alloy elements such as Mn and V is relatively low, the online molten salt isothermal toughening technology is combined, the material cost and the mechanical property fluctuation of the wire rod can be reduced, the plasticity and cold machining performance of the wire rod are effectively improved, and the service life of the wire rod is prolonged. The tensile strength of the wire rod is 910-960 MPa, the percentage reduction of area is 58%-65%, extra heat treatment before cold machining of a hand tool is omitted, the cracking risk of direct cold machining of the wire rod is reduced, and the machining cost of the hand tool is reduced.

The invention relates to the technical field of metal material manufacturing, and discloses a manufacturing process of a super-strong wear-resistant tire protection chain, which comprises the following steps of: forming a chain link blank by adopting high-silicon high-manganese bainite steel through hot rolling and hot die forging; the core of the method is an integrated heat treatment step, specifically, surface functionalization co-permeation of copper and cerium elements is synchronously carried out in the austenitizing stage, then bainite isothermal quenching is carried out, and a composite structure of bainite and stable retained austenite is obtained in a matrix; the process further comprises the steps that a special high-toughness welding wire is adopted for welding, and local tempering treatment is conducted on a welding seam; by means of the scheme, the chain link is endowed with excellent obdurability and fatigue resistance through the phase transformation induced plasticity effect of the base body, the abrasion resistance is remarkably improved through the surface functionalization co-cementation layer, and the reliability of a joint area is ensured through accurate welding and postweld treatment. The technical problems that wear resistance and toughness of a traditional protection chain are difficult to consider at the same time, and a welding joint is prone to failure are systematically solved.

The invention discloses a method for regulating and controlling the strength and plasticity of a FeMnCrCo-series high-entropy alloy based on pre-introduction of multi-dimensional crystallography defects, and relates to the technical field of high-entropy alloy materials. Cleaning in the vacuum induction furnace; performing vacuum melting; casting is conducted; carrying out homogenization treatment; forging treatment; carrying out six-pass hot rolling treatment; first-pass cold rolling treatment; first low-temperature annealing treatment; performing second-pass cold rolling treatment; carrying out secondary low-temperature annealing treatment; third-pass cold rolling treatment; and annealing treatment. Inter-pass annealing treatment is introduced into a cold rolling link of a traditional plate preparation process, and water-cooling quenching is assisted. According to the method, the multi-dimensional crystallographic defects generated in the cold rolling process are reserved in an initial microstructure of the alloy before a mechanical property test, the crystallographic defect type, density and spatial distribution in the initial microstructure of the alloy are regulated and controlled, a multi-dimensional defect strengthening mechanism is constructed, and good strength and plasticity matching of the alloy is achieved.

The invention relates to the technical field of alloys, and discloses 2400MPa-grade ultrahigh-strength steel and a preparation method thereof. The 2400 MPa grade ultrahigh-strength steel comprises the following chemical components in percentage by mass: 0.3%-0.5% of C, 1.0%-2.5% of Si, 3.5%-5% of Mn, 0.2%-0.3% of V, 1%-3% of Ni, 0.02%-0.05% of Nb, 0.3%-0.5% of Mo, 0.5%-2% of Cr and the balance of Fe and inevitable impurities. The microstructure of the 2400 MPa grade ultra-high strength steel comprises martensite and austenite, the average grain size of the martensite ranges from 0.4 micrometer to 2.0 micrometers, and the ratio of the grain length axis to the grain length axis of the martensite is smaller than or equal to 1.6. The strength, plasticity and toughness of the 2400MPa-grade ultra-high-strength steel are improved, and the 2400MPa-grade ultra-high-strength steel has high strength, high plasticity and high toughness.

The invention provides a friction-resistant high-entropy alloy composite coating and a preparation method thereof, and belongs to the technical field of metal surface modification. A FeCoCrNiMox (x is greater than or equal to 0.18 and less than or equal to 0.25) high-entropy alloy is taken as a main component of composite powder, graphene is taken as an additive phase, and the FeCoCrNiMox high-entropy alloy composite coating is prepared on the surface of a matrix by adopting a laser cladding method. The graphene added in the composite powder can generate carbides in situ under the action of laser cladding, and second phase strengthening, solid solution strengthening and fine grain strengthening are generated, so that the friction resistance of the surface of the matrix is remarkably improved. The preparation method is easy to operate and low in cost, the prepared composite coating is high in bonding strength, good in toughness and plasticity and excellent in friction resistance, the surface performance of equipment can be effectively improved, safe and stable operation of the equipment is guaranteed, the service life of the equipment is prolonged, and maintenance expenditure is reduced.