72results about How to "Improve strong plasticity" patented technology

The invention relates to the technical field of alloy steel, and particularly discloses high-strength and high-plasticity 3GPa-grade maraging steel and a preparation method thereof. The invention discloses high-strength and high-plasticity 3GPa-grade maraging steel, which is prepared from the following elements in percentage by weight: 15 to 20 percent of Ni, 0.1 to 2 percent of Al, 3 to 7 percent of Mo, 1.0 to 2.0 percent of Ti, 12 to 16 percent of Co and the balance of Fe and inevitable impurities. According to the maraging type ultrahigh-strength steel, by reasonably adding the elements and the proportion thereof and combining the forging process that the forging ratio and the forging temperature are reasonably adjusted and controlled, the maraging type ultrahigh-strength steel with the tensile strength of 3 GPa or above and the excellent plasticity is obtained.

The invention relates to the technical field of metal materials, and discloses an Al-Zn heat-treatment-free aluminum alloy and a preparation method and application thereof. The Al-Zn series heat treatment-free aluminum alloy is prepared from the following components in percentage by mass: 8.0 percent to 18.0 percent of Zn, 4.0 percent to 9.0 percent of Si, 0.5 percent to 4.0 percent of Cu, 0.3 percent to 1.2 percent of Mn, 0.1 percent to 0.5 percent of Zr, 0.1 percent to 0.9 percent of V, 0.1 percent to 0.4 percent of Er, 0.05 percent to 0.6 percent of Sr, 1.0 percent to 3.0 percent of TiC / TiB2 and the balance of Al and inevitable impurities. The Al-Zn heat-treatment-free aluminum alloy provided by the invention is compact in structure, fine in crystal grain, uniform in solute element distribution and excellent in mechanical property, and can meet the application requirements of the fields of automobiles and spaceflight on aluminum alloy materials.

The invention discloses a large-specification TC4 titanium alloy bar for a large aero-engine fan blisk and a preparation method of the large-specification TC4 titanium alloy bar, a large TC4 titanium alloy cast ingot with the diameter phi of 860-1000 mm is used and subjected to upsetting, drawing and cogging by 2-3 heating numbers, and the deformation amount of each heating number is controlled to be 40-70% for sufficient deformation; the method comprises the following steps of: performing upsetting and drawing for 3-7 heating numbers, controlling the deformation amount of each heating number to be 40-95%, controlling the upsetting and drawing temperature to be performed in a beta-phase region and a two-phase region, and controlling the change of a cooling mode after upsetting and drawing, finally converting the structure form into an equiaxed structure, and increasing the primary alpha-phase content in the structure to 70-90%, thereby obtaining the large-specification TC4 titanium alloy bar with good strength and plasticity. And the diameter phi of the bar is 400-800 mm, and the bar can be directly used for manufacturing the blisk, so that the processing and application potential of the titanium alloy is further widened, and the application field of the titanium alloy is enriched.

The invention relates to a method for improving the strength and plasticity of an additive manufacturing titanium alloy through Si. The method comprises the following steps: (1) mixing silicon source powder and titanium source powder to obtain mixed powder; (2) taking ball-milling mixing as an example: carrying out ball-milling mixing on the prepared mixed powder under the protection of argon; and (3) the mixed powder obtained after ball milling is subjected to a forming process, and a titanium alloy block is obtained. The forming process is additive manufacturing and comprises a direct laser deposition technology, a laser powder bed melting technology and the like. According to the method, the strength and plasticity of the titanium alloy are greatly improved without heat treatment.

The invention belongs to the technical field of magnesium-lithium alloy plastic processing, and particularly relates to a 400 MPa ultrahigh-strength magnesium-lithium alloy and a preparation method and application thereof. The 400 MPa ultrahigh-strength magnesium-lithium alloy consists of the following components in percentage by mass: 4.0 to 8.0 percent of Li; 4.5 to 7.5 percent of Zn; 1.3%-4.0% of RE (rare earth); 0.2 to 1.0 percent of Zr; 0.1 to 0.5 percent of Bi; and the balance of Mg. The ultrahigh-strength magnesium-lithium alloy is obtained by designing alloy components, controlling the mass ratio of Zn to Y, introducing a W phase, a quasicrystal phase, a magnesium-rare earth phase and a plurality of strong plastic phases and thermal stable phases and carrying out thermomechanical treatment. The preparation method of the ultrahigh-strength magnesium-lithium alloy mainly comprises the working procedures of high-temperature solid solution heat treatment, extrusion-hot rolling / cold rolling composite plastic deformation and the like, the tensile strength of the prepared ultrahigh-strength magnesium-lithium alloy reaches up to 400.5 MPa, the elongation is 9.4%, and a high-strength ultra-light metal structure material can be provided for the fields of aerospace, weaponry and the like; the method is applied to shells, supports, skins, cover plates and the like.

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

The invention provides a composite manufacturing method for improving the integrity of the side face of a 316L part manufactured through selective laser melting additive manufacturing. The composite manufacturing method comprises the following steps that S1, selective laser melting additive manufacturing is conducted on the part; in this step, each layer is divided into a boundary region and a core region, and differentiated scanning strategies are implemented. Specifically, the boundary area adopts a scanning strategy of parallel section contour lines, and the core area adopts a conventional strip or chessboard type scanning strategy, so that the surface quality is optimized; and S2, ultrasonic surface deep rolling post-treatment is conducted on the side face of the part. The method is characterized in that through the combination of partition scanning and post-treatment, the excellent surface integrity, including high surface hardness, high corrosion resistance and low surface roughness, of the side face of the additive manufacturing 316L stainless steel part is achieved. Particularly, the surface roughness reaches the precision grinding level, meanwhile, the thin-wall part manufactured through the method shows extremely high strength and plasticity at the same time, and therefore the requirement for high-performance application is met.

The invention discloses ultrahigh-plasticity hot-rolled austenitic stainless steel and a preparation method thereof, and belongs to the technical field of austenitic stainless steel production and manufacturing. The preparation method comprises the following steps: smelting and pouring according to a certain mass percent of chemical components to obtain a steel billet, homogenizing the steel billet, and forging the steel billet into a square billet; performing multi-pass hot rolling on the square billet to obtain a hot-rolled plate, performing interrupted solution treatment on the hot-rolled plate, and performing water cooling to room temperature; by controlling element selection of C, Cr, Mn, Ni and N and cooperating with a multi-pass hot rolling-solid solution interruption preparation method, an austenite structure after complete recrystallization is regulated and controlled firstly, then part of austenite is recrystallized again through low-temperature solid solution, and high mechanical stability and excellent strong plasticity are obtained based on two recrystallization behaviors.

The invention provides a low-modulus, high-strength and high-plasticity Ti-Zr-Nb-Hf-Ta series biomedical alloy which comprises the following raw materials in atomic percent: 30-45% of titanium, 30-45% of zirconium, 5-15% of niobium, 5-20% of hafnium and 5-20% of tantalum, the # imgabs 0 # value of the biomedical alloy is 2.6-2.75 eV, the # imgabs 1 # value of the biomedical alloy is 2.92-3.06, and the valence electron concentration of the biomedical alloy is 4.1-4.3. The tensile elastic modulus of the biomedical alloy ranges from 54.6 GPa to 57.8 GPa, the yield strength of the biomedical alloy ranges from 885 MPa to 1061 MPa, and the ductility of the biomedical alloy ranges from 14.8% to 25.6%. The preparation method comprises the following steps: mixing titanium, zirconium, niobium, hafnium and tantalum to obtain a mixture; and then carrying out vacuum treatment, gas washing, smelting and cooling to obtain the alloy. The biomedical alloy is low in elasticity modulus and high in yield strength and ductility, and the problems of stress shielding, biological mechanical compatibility and the like can be effectively relieved.

A high-plasticity 1500MPa grade ultra-high strength steel and a manufacturing method thereof, wherein the weight percentage of the components is: C 0.35-0.40%, Si 1.0-1.8%, Mn 1.5-2.0%, Cr 0.3-0.6%, Al 0.02-0.05%, Ti 0.02-0.05%, B 0.002-0.02%, and the balance includes Fe and other inevitable impurities; and at the same time, the carbon equivalent C of the peritectic reaction zone is satisfied. eq1 >0.17%, C eq1 =C-0.03Mn-0.06Si-0.222S-0.04P; welding carbon equivalent C eq2 ≤0.56%, C eq2 =C+Mn / 20+Si / 30+2P+4S. The ultra-high strength steel of the present invention has a yield strength of 1000-1300 MPa, a tensile strength of ≥1500 MPa, an elongation at break of ≥18%, and good surface quality, and is particularly suitable for manufacturing vehicle structural parts and safety parts with complex shapes and high requirements on forming performance, such as A / B pillars, door anti-collision bars, longitudinal beams, bumpers, etc.

The invention relates to a high-plasticity GH4141 alloy cold-drawn bar with a uniform structure and a preparation method of the high-plasticity GH4141 alloy cold-drawn bar, belongs to the field of high-temperature alloy materials, and solves at least one of the problems that in the prior art, a GH4141 bar is poor in grain size uniformity, and a fastener is poor in performance stability, low in forming qualification rate and the like due to insufficient plasticity. The preparation method of the high-plasticity GH4141 alloy cold-drawn bar with the uniform structure comprises the steps that a hot-rolled GH4141 alloy bar blank is subjected to solution treatment, and then first-time cold drawing, first-time intermediate annealing treatment, second-time cold drawing, second-time intermediate annealing treatment, finished product cold drawing and finished product annealing treatment are sequentially carried out. According to the method, the plasticity is remarkably improved while the strength of the GH4141 alloy cold-drawn bar is guaranteed, and the upsetting qualification rate of a fastener and the product performance consistency are effectively improved.

The invention discloses a 800MPa-grade steel plate with ultralow cost and excellent weldability and a manufacturing method thereof. The 800MPa-grade steel plate comprises the following components in percentage by weight: 0.050-0.090% of C, less than or equal to 0.10% of Si, 1.60-2.00% of Mn, less than or equal to 0.013% of P, less than or equal to 0.0030% of S, 0.25-0.60% of Cr, 0.030-0.060% of Nb, 0.008-0.016% of Ti, 0.0008-0.0018% of B, 0.030-0.070% of Als, less than or equal to 0.0055% of N, 0.001-0.0040% of Ca and the balance of Fe and inevitable impurities. (% Als) / [(% N)-0.292 (% Ti)] is greater than or equal to 33; (% C) * [0.85 (% Mn) + 1.19 (% Als) + 9.33 (% P) + 12.05 (% S) + (% Si)] < = 0.16; and in Ca treatment, the Ca / S ratio is 1-3, and (% Ca) * (% S) is less than or equal to 1.5 * 10 <-3 >. On the basis that precious alloy elements such as Cu, Ni and Mo are not added, the high strength of 800 MPa is obtained at ultra-low cost, meanwhile, the toughness and weldability of the steel plate are also excellent, preheating is not needed before welding, stress relief heat treatment is not needed after welding, and the steel plate is particularly suitable for large steel structures and equipment such as engineering machinery and coal mine machinery.

This invention belongs to the field of aluminum alloy materials technology, and relates to a high-strength and ductile aluminum alloy and its preparation method. The alloy comprises, by mass fraction: 2-6% Mg, 0.4-0.9% Mn, 0.2-0.6% Si, 0.05-0.15% Sn, Fe≤0.15%, Ti≤0.1%, with the balance being Al. By introducing Sn, a low-melting-point MgSiSn primary phase is formed in the as-cast stage, and transforms from a continuous network to a discontinuous granular structure during homogenization heat treatment, weakening the adverse effects of brittle intermetallic compounds at grain boundaries. Simultaneously, Sn dissolved in the aluminum matrix forms a nanoscale MgSiSn precipitate during homogenization, serving as a heterogeneous nucleation core for the Mn-containing second phase, lowering its nucleation energy barrier, and promoting high-density, fine, and uniform precipitation, thereby achieving a synergistic improvement in the alloy's strength and ductility.

A method for preparing an isotropic mesh graphene-aluminum composite material relates to a method for preparing a graphene-aluminum composite material. In order to achieve isotropic distribution of graphene in aluminum-based composite materials, and solve the problems of carbon-aluminum interface reaction, low graphene-aluminum bonding strength, and discontinuous graphene layers. The present invention mechanically ball-milled graphene is closely attached to the surface of aluminum metal powder through the strong chemical bonding of the skeleton structure metal, which is conducive to the uniform dispersion of high-content graphene in the preform. The mesh-connected skeleton structure constructed during the sintering process provides a three-dimensional path for the conduction of graphene stress and heat flow, showing macroscopic isotropy; the graphene sheets are bridged by the skeleton structure metal and the infiltrated aluminum metal, which effectively ensures the full conduction of stress between the graphene sheets, relieves material stress concentration, and is conducive to achieving material strain homogenization. The skeleton structure metal effectively improves the interface bonding between the graphene-aluminum metal matrix.

This invention discloses an ultra-high strength and plasticity three-dimensional multi-level hybrid heterogeneous titanium-based composite material and its preparation method. The method includes: 1. performing a flow friction coating treatment on titanium alloy powder and modified amorphous cracked carbon with high active sites; 2. performing a flow friction coating treatment on modified high active and highly dispersed boron source; 3. low-temperature short-time high-pulse current-assisted vacuum hot pressing sintering; 4. multiple non-constant rate hot deformation treatments. This invention uses modified amorphous cracked carbon with high active sites and modified high active and highly dispersed boron source as reinforcing phase precursors to sequentially coat a titanium alloy powder matrix. Combined with sintering and hot deformation treatments, a multi-level, multi-scale, and multi-heterogeneous phase structure is constructed in four dimensions to obtain a three-dimensional multi-level hybrid heterogeneous titanium-based composite material, which exhibits ultra-high strength and plasticity, with a tensile strength of 1430 MPa to 1605 MPa and an elongation of 7.5% to 9%.

The invention discloses a micro-nano hybrid SiCp reinforced aluminum matrix composite cylindrical part and a preparation method thereof, and belongs to the technical field of plastic processing of aluminum alloy materials. According to the preparation method provided by the invention, micron SiCp, nano SiCp and aluminum powder are mixed and then subjected to high-energy ball milling, the mixture and aluminum alloy are subjected to high-temperature dissolution and ultrasonic treatment, then die casting and homogenization treatment are carried out, and then continuous forging, backward extrusion and T6 heat treatment are carried out, so that the micro-nano mixed SiCp reinforced aluminum matrix composite cylindrical part is obtained. According to the micro-nano mixed SiCp reinforced aluminum matrix composite cylindrical part prepared through the preparation method, nanoscale SiCp and micron SiCp can be embedded with aluminum powder, the strength and hardness of crystals are improved, and then the mechanical property of an aluminum matrix composite is improved; by means of continuous forging and backward extrusion thermal deformation, as-cast defects such as shrinkage porosity and air holes can be eliminated, grain refinement is achieved, reinforcement distribution is improved, and therefore the cylindrical part is endowed with excellent mechanical performance.

The application discloses a kind of local reinforcement selected area laser melting deposition high-strength titanium alloy preparation method and system, belong to additive manufacturing technical field.The local reinforcement selected area laser melting deposition high-strength titanium alloy preparation method provided by the application, by establishing target titanium alloy structure three-dimensional model and carrying out finite element limit load simulation analysis, stress distribution and potential dangerous area are identified;Based on the analysis result, the performance requirement is divided, the material enhanced local area is determined, and the laser scanning path and powder feeder movement trajectory are planned;Path file is imported into composite equipment to set process parameters;Titanium-based composite material powder is selectively laid in the enhanced area, and a locally reinforced structure is obtained by selective laser melting.The scheme realizes the spatial selective distribution of powder composition, forms a uniform distribution of high-stress areas, significantly improves the local strength and maintains the overall strength and plasticity matching, effectively solves the problem of insufficient performance matching of titanium alloy components under complex load.

The invention discloses a quaternary precipitation strengthening iron-based high-entropy alloy and a preparation method thereof, the high-entropy alloy comprises the atomic components of Fe, Co, Ni and Al, and the atomic percentage of Fe to Co to Ni to Al is 48%-52%: 23%-27%: 17%-20%: 5%-8%. The preparation process comprises the following steps: preparing four elements of Fe, Co, Ni and Al with the purity higher than 99.95 wt% as alloy elements; the preparation method comprises the following steps: preparing and smelting an as-cast alloy by using a non-consumable vacuum arc melting furnace, then carrying out solid solution treatment by using a heat treatment furnace to obtain a solid solution alloy with a stable single phase, and then carrying out further heat treatment to obtain the high-toughness high-entropy alloy. The high-entropy alloy has fine granular or lamellar B2 phases which are uniformly separated out, precipitates are distributed on a matrix FCC (fluid catalytic cracking) to form precipitation strengthening, and the high-entropy alloy shows excellent comprehensive mechanical properties. Compared with a traditional high-entropy alloy, the high-strength and high-toughness iron-based high-entropy alloy prepared through the method has the excellent comprehensive mechanical property.

The invention provides limit specification hot continuous rolling weathering steel as well as a manufacturing method and application thereof. The component C is 0.05-0.07%; 0.26%-0.35% of Si; 0.8% to 1.2% of Mn; p is less than or equal to 0.090%; s < = 0.002%; 0.5%-0.8% of Cr; 0.05%-0.09% of Ni; 0.15% to 0.20% of Cu; 0.020% to 0.045% of Al < t >; 0.010% to 0.020% of Ti, and 0.020% to 0.060% of Nb; and the balance of Fe and inevitable inclusions. According to the hot continuous rolling weather-resistant steel plate and the preparation method thereof, the hot continuous rolling weather-resistant steel plate which is 20-25.4 mm in thickness, 2000-2130 mm in width, high in low-temperature toughness and high in performance uniformity in limit specification, good in coil shape and surface quality and free of tower shape and coil loosening in the coiling process is obtained through component design in cooperation with process production.

The invention relates to an in-situ generated high-stability nano metal particle dispersion reinforced Mo alloy and a preparation method thereof. The Mo alloy is prepared by pressure sintering through a powder metallurgy method. The Mo alloy is prepared from the following components in percentage by mass: 0.4 to 0.7 weight percent of boride ceramic powder HfB2 and 99.3 to 99.6 weight percent of metal Mo powder, the microstructure of the Mo alloy comprises Mo crystal grains and Hf particles which are evenly distributed in the Mo crystal grains and are of a nano cubic structure. According to the preparation method, a B source is introduced through boride ceramic powder HfB2, the boride ceramic powder HfB2 reacts with impurity O in Mo to generate B2O3 for purifying a grain boundary, Hf particles which are uniformly distributed in Mo crystal grains and have a nano cubic structure are generated through in-situ reaction, and most of the particles are uniformly distributed in the Mo crystal grains, so that the problems that traditional dispersion strengthened Mo alloy particles are easy to agglomerate at the grain boundary and are difficult to agglomerate can be solved; and therefore, the toughness and the strength of the Mo are greatly improved.

This invention discloses a novel ultra-thin strip of 301 stainless steel and its preparation method, belonging to the field of advanced high-strength steel technology. The strip composition by mass percentage is: 0.1–0.2% C, 0.4–0.5% Si, 1–2% Mn, 1–1.5% Al, 15–18% Cr, 8.0–9.0% Ni, 0.1–0.2% Mo, with the balance being Fe and impurities. The preparation method involves: forging the steel ingot at 1100℃–1200℃, followed by low-temperature hot rolling at 600℃–800℃, pickling, and then cold rolling at 150℃–200℃ with a pulsed current, resulting in a reduction of 90%–95%. This invention improves stacking fault energy through compositional regulation, inhibits martensitic phase transformation, and induces twinning deformation; the pulsed current promotes regular dislocation movement; and the Al element grain boundary segregation forms a micro / nano layered structure, achieving a synergistic effect of twin refinement and layered toughening. The resulting ultra-thin strip has a tensile strength of 1100MPa to 1200MPa and an elongation of 40% to 50%, overcoming the contradiction between strength and plasticity, and is suitable for high-performance elastic components in the fields of electronics and aerospace.

The invention belongs to the field of material science and engineering, and particularly relates to a magnesium alloy with high strength and plasticity and high creep property in a wide temperature range and a preparation method. According to the method, the requirements of the magnesium alloy for high-strength plasticity and high creep property in a wide temperature range of-180 DEG C to 200 DEG C can be met; the magnesium alloy prepared by the method comprises a multi-scale mixed crystal structure of micron grains and stable ultra-fine grains; the material provided by the method (in a stress interval within 200MPa and a temperature interval below 200DEG C) shows creep resistance far higher than that of magnesium alloys in a common as-cast state, a heat treatment state and a common deformation treatment state, so that the application of the magnesium alloy in a creep-resistant structural member is expanded, and the creep-resistant performance of the magnesium alloy is improved. And meanwhile, the instant mechanical properties at room low temperature (-180 DEG C to room temperature) show good strength and plasticity.

The invention provides a preparation method of a high-strength and high-plasticity AZ31 magnesium alloy sheet with a gradient nanostructure to solve the problem that an existing magnesium alloy sheet is insufficient in strength and plasticity. Commercial as-cast AZ31 magnesium alloy is used as a raw material, a magnesium alloy plate is obtained through rolling, extrusion and other deformation processes firstly, then the plate is further treated through an ultrasonic surface deep rolling technology, and the AZ31 magnesium alloy sheet with the gradient nano structure is prepared, and the strength and plasticity of the AZ31 magnesium alloy sheet are greatly improved compared with as-cast alloy; the comprehensive mechanical property of the magnesium alloy plate is superior to that of a commercial AZ31 magnesium alloy plate, and a high-performance and low-cost lightweight material is provided for intelligent equipment, 3C products and the like.

This invention provides an ultra-high strength, low density Al-Mg-Zn-Sc-Zr-based alloy and its preparation method, belonging to the field of aluminum alloy material technology. The ultra-high strength, low density Al-Mg-Zn-Sc-Zr-based alloy provided by this invention, by mass fraction, has the following chemical composition: Mg 3.0~8.0%, Zn 1.0~5.0%, Cu 0.4~1.0%, Mn 0.1~0.8%, Ag 0.05~0.3%, Sc 0.01%~0.3%, Zr 0.05~0.3%, with the balance being Al. This invention achieves this by precisely controlling the elemental ratios of Mg, Zn, Cu, and Ag, resulting in an alloy that maintains its low density while exhibiting a strong age-hardening effect. Simultaneously, the reasonable addition of trace elements such as Mn, Sc, and Zr enables the alloy to possess a dispersion strengthening effect. Combined with heat treatment and hot deformation processes, this further improves the strength and ductility of the aluminum alloy.

The invention discloses a preparation method for constructing a multistage micro-nano heterostructure based on combination of a laser melting deposition process and a laser shock peening means, which comprises the following steps of: printing by using dry TC4 alloy powder, accumulating a printed TC4 metal printing layer to form a TC4 metal micron layer, performing low-power laser shock peening on part of the TC4 metal micron layer to form a TC4 metal submicron layer, and forming the multistage micro-nano heterostructure. A TC4 metal printing layer is printed on the submicron layer and subjected to high-power laser shock peening to form a TC4 metal nano layer, a TC4 metal printing layer is printed on the nano layer and subjected to low-power laser shock peening to form a TC4 metal submicron layer, printing and cyclic operation are continued on the submicron layer to form a sample, and the sample is obtained through annealing treatment. According to the preparation method disclosed by the invention, a micron layer-nano sandwich composite layer-micron layer multi-stage micro-nano heterostructure is formed, crack propagation is effectively hindered, and the elongation of the material is improved, so that alloy strength and plasticity synergistic strengthening is realized.

The invention provides seawater corrosion resistant H-shaped steel and a preparation method, and relates to the technical field of corrosion resistant low alloy steel. The seawater corrosion resistant H-shaped steel comprises the following chemical components in percentage by mass: 0.05%-0.1% of C, 0.50%-0.90% of Mn, 0.15%-0.35% of Si, 0.15%-0.25% of Ni, 0.6%-1.0% of Cr, 0.2%-0.3% of Cu, 1.0%-1.2% of Cu: Ni, 0.06%-0.15% of Mo, 0.04%-0.09% of Sb, less than 0.10% of Al, 0.41%-0.6% of Ni + Cu + Mo, 0.02%-0.06% of V + Nb + Ti, less than 0.04% of impurity elements P + S + O and the balance of Fe and inevitable elements. The preparation method is high in resource utilization rate, low in production cost, short in process, easy to operate, high in efficiency and beneficial to industrial large-scale production and popularization.

The invention provides a titanium-niobium composite microalloying nitrogen-controlled 82B wire rod and a preparation method, and relates to the technical field of high-carbon hard wire production. The diameter of the 82B wire rod ranges from 11 mm to 12.5 mm, and the 82B wire rod is prepared from, by mass, 0.80%-0.85% of C, 0.60%-0.90% of Mn, 0.12%-0.32% of Si, 0.010%-0.015% of N, 0.020%-0.030% of Ti, 0.010%-0.015% of Nb, smaller than or equal to 0.025% of S, smaller than or equal to 0.025% of P, smaller than or equal to 0.20% of Cu and smaller than or equal to 0.20% of Ni. And the balance of Fe and inevitable impurities. The titanium-niobium composite microalloying nitrogen-controlled 82B wire rod is prepared by reasonably selecting Ti and Nb to be compositely added, continuously casting to form a blank and performing temperature-controlled cold rolling; the method is simple and easy to operate, wide in application range and beneficial to industrial large-scale production and popularization.

This application belongs to the field of metal composite plate preparation, specifically relating to a 304 stainless steel-high manganese steel composite plate and its preparation method. The preparation method includes the following steps: S1, obtaining 304 stainless steel slabs and high manganese steel slabs, stacking and welding the 304 stainless steel slabs and high manganese steel slabs to obtain a first composite slab; S2, heating the first composite slab to obtain a second composite slab; S3, rolling the second composite slab to obtain the 304 stainless steel-high manganese steel composite plate. This application solves the problem of "excessive thinning of the soft phase" caused by the hardness difference in "soft / hard" composite plates during rolling by introducing a thickness ratio compensation formula in the billet assembly stage. This significantly improves the thickness ratio accuracy of the final product. By dynamically adjusting the speed ratio, the rolling effect generated by "variable speed rolling" effectively offsets the internal bending moment caused by uncoordinated deformation, significantly reducing the warping and buckling phenomenon of the composite plate.

The invention provides a contact prepressing type additive manufacturing device and application thereof. Metal powder of different thicknesses is flatly laid on an additive substrate and compacted, a contact type pressing head is used for conducting secondary pressurization on a metal powder layer, then pulse current treatment is conducted, and generated joule heat enables the metal powder between the contact type pressing head and the additive substrate to be rapidly sintered. And then the steps are repeated on the next area so that continuous additive forming can be achieved. In the additive forming process, the pressure head exerts pressure on the metal powder so that the powder can be automatically filled into the pore positions, formation of the pores is reduced to a great extent, and the compactness of the materials and the bonding strength between all layers of materials are improved. Due to the pressure action at high temperature, additive manufacturing and micro-zone forging are synchronously carried out, dynamic and static recrystallization of a forming layer is promoted, thick columnar crystals are eliminated, the grain size is effectively refined, and the comprehensive mechanical property of an additive forming material is improved.

The invention discloses a wire rod for a fastener, which comprises Fe, inevitable impurities, and the following chemical elements in percentage by mass: 0.30 to 0.50 percent of C (carbon), 0.30 to 1.50 percent of Mn (manganese), 0.40 to 0.80 percent of Ni (nickel), 0.80 to 1.40 percent of Cr (chromium), 0.80 to 1.40 percent of Mo (molybdenum), 0.05 to 0.20 percent of Ti (titanium), 0.50 to 1.30 percent of Cu (copper), 0.50 to 1.50 percent of Co (cobalt) and 0.002 to 0.010 percent of Ca (calcium). Correspondingly, the invention further discloses a manufacturing method of the wire rod, a fastener manufactured through the wire rod and a manufacturing method of the fastener. By adopting the method, the ultrahigh-strength fastener with low yield ratio can be obtained.