1291results about How to "Grain refinement" patented technology

The invention relates to a hot-rolled V-containing high-strength wire rod for a 1860MPa-grade bridge cable and a manufacturing method thereof.After a C-Si-Mn-Cr-V hypereutectoid component system is adopted for rolling and spinning to form a wire rod, online molten salt isothermal weak tempering treatment is conducted, the wire rod passes through front-section molten salt and is cooled at the cooling speed larger than or equal to 35 DEG C / s, the wire rod enters a sorbite phase region from an austenite state, and then the wire rod is cooled at the cooling speed larger than or equal to 35 DEG C / s; the preparation method comprises the following steps of: forming a structure taking sorbite as the main part, then promoting isothermal tempering and sorbite lamellar fusing of the structure through rear-section molten salt heating, and finally, slowly cooling through a roller way to prepare a microscopic structure which takes tempered sorbite as the main part and is a mixed structure consisting of ferrite and fused sorbite, so that the problems of network carbides and hard and brittle structures can be improved; and the structure uniformity and the strength and plasticity matching of the large-specification wire rod are improved, the tensile strength is 1340-1390 MPa, the percentage reduction of area is 38%-43%, and the steel wire rod can be used for manufacturing 1860 MPa bridge cables and meets the wire manufacturing and twisting requirements.

The invention relates to an annealing-free alloy cold heading steel wire rod for a 12.9-grade bolt and a production method of the annealing-free alloy cold heading steel wire rod. The production process comprises the steps of molten iron pre-removal of P / S, electric furnace or converter smelting, external refining, bloom continuous casting, rolling into an intermediate billet and steel billet finishing, intermediate billet heating, high-pressure water descaling, rough rolling, intermediate rolling, pre-finish rolling, finish rolling, spinning, coil collecting and cooling. The annealing-free alloy cold forging steel wire for the 12.9-grade bolt comprises the following components in percentage by mass: 0.30%-0.35% of C, 0.10%-0.30% of Si, 0.70%-1.20% of Mn, 1.0%-1.5% of Cr, 0.15%-0.30% of Mo, 0.015%-0.030% of Al, 0.0030%-0.0080% of N, 0.01%-0.04% of Nb, less than or equal to 0.30% of Ni, less than or equal to 0.10% of Cu, less than or equal to 0.015% of P, less than or equal to 0.010% of S, less than or equal to 0.012% of (As + Sb + Bi), less than or equal to 0.0010% of O and the balance of Fe and inevitable impurity elements, the niobium-nitrogen product (Nb * N) is greater than On the premise that main alloy components are not reduced, a fine grain structure can be obtained under a certain condition by adding grain refining elements, and the delayed phase change effect the same as that of a low-temperature finish rolling process is achieved by utilizing the delayed phase change characteristic of the fine grain structure.

The invention discloses a high-toughness, low-pinhole-rate and heat-resistant power battery aluminum foil produced in a short process and a preparation method thereof, and belongs to the technical field of power battery materials and processing methods. The invention discloses a high-toughness, low-pinhole-rate and heat-resistant power battery aluminum foil produced through a short process. The power battery aluminum foil comprises the following components: 0.21-0.55% of Fe; 0.15 to 0.35 percent of Si; 0.02% to 0.08% of Cu; ti: 0.01 to 0.04%; less than or equal to 0.02% of Mn; less than or equal to 0.02% of Zn; 0.003% to 0.005% of Y; 0.003% to 0.005% of Er (Erbium); the content of Sc is 0.003 to 0.005 percent; and the balance of Al. In the smelting stage, through composite spiral electromagnetic stirring, the melt uniformity and the alkali, impurity and gas removal effect are improved; and a novel rolling mode assisted by pulse current is introduced, so that the grain refinement degree is increased, and the production efficiency is greatly improved.

The invention discloses a laser-TIG (Tungsten Inert Gas) hybrid welding and method based on ultrasonic-assisted wire powder coaxial conveying, after entering, a laser beam forms a semicircular Bessel beam through a lens, a metal wire passes through an ultrasonic-assisted device and then introduces vibration into a welding pool, and six powder conveying guide pipes are uniformly distributed around the metal wire; according to the wire core six-way powder channel coaxial device, a semi-circular light beam passes through the wire core six-way powder channel coaxial device and enters a laser head, and finally the effect of coaxially melting a wire powder material through laser is achieved. A TIG welding auxiliary device is added to one side of a molten pool, metallurgical reaction is promoted, and compactness of a welding seam is improved. The device mainly comprises an annular laser beam wire core six-way powder channel simultaneous melting system, an automatic wire feeding system, a powder feeding system, an ultrasonic vibration system, a TIG auxiliary welding system and the like. The welding efficiency can be improved through the wire core six-way powder channel coaxial melting technology, the flowing stability of a molten pool can be promoted through the ultrasonic-assisted technology, and the welding seam forming quality can be improved through laser-TIG composite welding.

The invention discloses a preparation method of a high-toughness corrosion-resistant titanium alloy pipe, which comprises the following steps of: 1, sequentially carrying out multi-heating forging deformation and one-time precision forging deformation on a titanium alloy cast ingot to obtain a titanium alloy bar blank; 2, machining the titanium alloy bar blank into an extrusion blank, and carrying out sheath extrusion to obtain an extrusion pipe blank; and thirdly, the extruded pipe blank is subjected to heat treatment, and the high-toughness corrosion-resistant titanium alloy pipe is obtained. According to the method, the titanium alloy cast ingot is prepared into the bar blank through the efficient fine grain forging and precision forging method, then the titanium alloy extrusion blank is machined, the pipe blank is prepared through extrusion, and finally the titanium alloy pipe is obtained through heat treatment, so that it is effectively guaranteed that the titanium alloy pipe has the excellent structure and performance, and the requirements for high toughness and corrosion resistance of the oil and gas exploration service environment are met; and the technological process is simple, and the cost is low.

The invention discloses a die-casting process for a small cover plate of a motor end cover. The die-casting process comprises the following steps: step 1, raw material treatment; step 2, material melting operation; thirdly, die casting is conducted; 4, flushing a water gap; step 5, removing burrs; step 6, heat treatment before preparation; step 7, shape correction; 8, CNC machining is carried out; step 9, cleaning treatment; and step 10, packaging and warehousing. According to the invention, mechanical cleaning and acid pickling are carried out on the raw materials before melting operation is carried out on the cast aluminum, so that the purity of the raw materials is guaranteed, bubbles are prevented from being generated in the melting process, and the quality of the prepared product is improved; a modifier is added in the melting process to refine grains, so that the hardness and the corrosion resistance of the prepared product are improved; after die casting, pre-manufacturing heat treatment is carried out to optimize the machining performance of the plate, the process difficulty of CNC machining is reduced, meanwhile, the internal stress remaining in the plate is removed through the stress relief annealing process, and product deformation caused by the internal stress is prevented.

The invention discloses active brazing filler metal for sealing sapphire and kovar alloy and a preparation method of the active brazing filler metal. The active brazing filler metal comprises 25.0 wt%-27.5 wt% of Cu, 1.0 wt%-6.0 wt% of Ti, 1.0 wt%-5.0 wt% of Al, 0.1 wt%-1.0 wt% of B, 0.1 wt%-0.5 wt% of rare earth element RE, RE is one or more of La, Ce, Sc, Pr, Nd and Er, and the balance is Ag. The preparation method comprises the following steps: preparing silver-based pre-alloying powder by adopting a gas atomization method, mixing the alloy powder with additive element powder in a ball milling manner, sintering by utilizing vacuum pressure to obtain an alloy ingot blank, and carrying out rough rolling, intermediate annealing and finish rolling to obtain an active brazing filler metal strip with the thickness of 0.05-0.2 mm. The active brazing filler metal is well matched with the thermal expansion coefficient of sapphire, direct brazing of sapphire and Kovar alloy can be achieved, the brazing temperature is moderate, and a brazed joint is uniform in structure and free of defects such as air holes and cracks.

The invention provides a production method of an invar alloy 4J36 hot-rolled coil, belongs to the technical field of invar alloy 4J36 hot rolling, and solves the problem that the invar alloy 4J36 hot-rolled coil needs to be efficiently produced. The plate blank is preheated and then heated after being ground, and the heated plate blank is subjected to high-pressure water descaling; and the descaled plate blank is rolled into an intermediate blank through seven-pass rough rolling, the intermediate blank is rolled into a black coil through five-pass steckel mill finish rolling, and the black coil is rolled into an invar alloy 4J36 hot-rolled black coil finished product. The method comprises the steps of slab component control, slab preheating and heating, rough rolling to obtain an intermediate slab, steekle mill rolling, coiling and the like, and surface oxidation generated in the heating process is reduced by adjusting the heating process; and through rolling of the steekle mill, dynamic recrystallization is fully carried out, the surface quality of the produced invar alloy 4J36 hot-rolled coil meets the product requirement, and the yield and the production efficiency are both remarkably improved.

The invention discloses a method for improving the high-cycle fatigue performance of a Ti6Al4V titanium alloy, and belongs to the technical field of metal material processing, and the method comprises the following steps: S1, determining shot peening strengthening parameters based on material performance parameters and related standards; according to the method, high-amplitude residual compressive stress is introduced through shot peening strengthening, the stress state of the surface and the depth direction of the material is changed, accordingly, crack extension can be restrained, the fatigue life is prolonged, in addition, a plastic deformation layer is induced to be generated under the surface depth in the shot peening process, the microstructure of the material is improved, and the anti-fatigue performance of the material is improved; through femtosecond laser shock, surface defects can be effectively removed, the surface compactness can be improved, microcracks can be reduced, and a refined grain structure can be generated, so that the strength and toughness of the material are further enhanced, the high-cycle fatigue performance of the material is further improved, the two are combined, the residual stress state is optimized, and the surface integrity is improved. The fatigue performance of the Ti6Al4V titanium alloy is remarkably improved.

The invention relates to high-performance low-cost microalloyed steel for an automobile I-shaped front axle and a preparation method of the microalloyed steel, and belongs to the technical field of materials. The steel comprises the following chemical components in percentage by weight: 0.20 to 0.60 percent of C, 0.2 to 1.0 percent of Mn, 0.1 to 0.5 percent of Si, 0.6 to 1.2 percent of Cr, 0.01 to 0.10 percent of Nb, 0.01 to 0.06 percent of Mo and the balance of Plt, 0.01%, Slt; 0.01%, Olt; 0.0040%, and the balance being iron. According to the invention, the contents of Nb and C key alloy elements in the material are accurately controlled, so that Nb can be completely dissolved into a matrix in the smelting process, and the phenomenon of one-time NbC liquation is avoided. Heat treatment is directly carried out after smelting and casting, and the component control strategy is adopted, so that the precipitation of nano-sized dispersed NbC on an original austenite grain boundary is promoted, austenite grains are effectively pinned, and a microstructure with uniform and fine grain size is obtained; a martensitic structure is obtained through quenching, and uniform dispersion and precipitation of NbC carbide are realized in the martensitic structure through a subsequent tempering process, so that the strength and the toughness of the I-shaped front axle are ensured to reach the best match.

The invention discloses a graphene composite perovskite manganese oxide polycrystalline ceramic and a preparation method and application thereof, and belongs to the technical field of non-refrigeration high-sensitivity infrared detection. The chemical expression of the graphene composite perovskite manganese oxide polycrystalline ceramic is La < 0.81 > (Ca < 0.03 > Sr < 0.16 >) MnO3: Gy, G is graphene, y is the mass fraction of graphene in perovskite manganese oxide composite powder, and y is equal to 0.1-0.2%. The TCR value of the prepared polycrystalline ceramic can reach 30% or above, the Tk value is close to 300K, the polycrystalline ceramic has excellent adaptability to room temperature work and excellent sensitivity to temperature change, and when the polycrystalline ceramic is applied to an uncooled infrared detector, the detection precision of the uncooled infrared detector can be effectively improved.

The invention discloses a ZnFeP-particle gradient abrasion-resistant chemical composite coating and a preparation method of the ZnFeP-particle gradient abrasion-resistant chemical composite coating. The ZnFeP-particle gradient abrasion-resistant chemical composite coating is divided into a passivation layer, a low-iron ZnFeP-particle chemical composite coating and a high-iron ZnFeP-particle chemical composite coating from outside to inside, and a gradient coating with the corrosion potential from low to high is formed; the content of iron in the low-iron ZnFeP-particle chemical composite coating ranges from 0.03 wt% to 1.0 wt%, the thickness of the low-iron ZnFeP-particle chemical composite coating ranges from 8 micrometers to 18 micrometers, and the hardness of the low-iron ZnFeP-particle chemical composite coating ranges from 150 HV to 300 HV. The content of iron in the high-iron ZnFeP-particle chemical composite coating ranges from 5 wt% to 30 wt%, the thickness ranges from 8 micrometers to 18 micrometers, and the hardness ranges from 500 HV to 650 HV. By means of the ZnFeP-particle gradient abrasion-resistant chemical composite coating, a metal component can be resistant to abrasion and corrosion, and therefore the service capacity of the metal component such as electric power fittings in the abrasion working condition is obviously improved.

The invention is applicable to the technical field of titanium alloy pipe processing, and particularly relates to a preparation method of a high-plasticity TA15 titanium alloy pipe, which comprises the following steps: step S1, selecting sponge titanium, pure metal and intermediate alloy, preparing according to standard components of TA15 titanium alloy to obtain a prepared raw material, and smelting the prepared raw material for three times by adopting a vacuum consumable smelting furnace to obtain a high-plasticity TA15 titanium alloy pipe; and the TA15 titanium alloy cast ingot with the diameter being 600 mm is obtained. According to the method, the mechanical property and plasticity of the titanium alloy pipe are remarkably improved by accurately controlling the temperature and deformation of each machining step. And three-time upsetting and three-time drawing forging is carried out within the temperature range of T beta or above, coarse grains are effectively crushed, and grain structures are refined. And then, the metallographic structure of the wool rod is gradually optimized by accurately controlling the forging temperature and the deformation amount.

The invention provides low-yield-ratio super-thick maritime work steel with excellent core low-temperature toughness and a manufacturing method of the low-yield-ratio super-thick maritime work steel, and belongs to the field of steel and iron material preparation. The low-yield-ratio super-thick marine steel with the excellent core low-temperature toughness comprises the following chemical components in percentage by mass: 0.10%-0.15% of C, 0.35%-0.45% of Si, 1.20%-1.50% of Mn, 3.00%-3.50% of Ni, 0.30%-0.50% of Mo, 0.15%-0.3% of Cr, 0.01%-0.02% of Ti, 0.030%-0.040% of V, 0.050%-0.060% of Nb, 0.0016%-0.0020% of B, 0.15%-0.25% of Cu, 0.060%-0.070% of Al, less than or equal to 0.010% of P, less than or equal to 0.004% of S, less than or equal to 0.39% of CET and the balance of Fe and inevitable impurities. According to the invention, a component design thought of a low-C, Ni-Nb-Mo-Al-B system is adopted, and a three-section rolling and quenching and tempering heat treatment process is combined. Through strict control of smelting continuous casting, controlled rolling and controlled cooling processes and quenching and tempering heat treatment parameters, the super-thick marine steel with excellent comprehensive mechanical properties is successfully prepared. The steel shows good low-temperature toughness in the core part, and meanwhile, the steel has a relatively low yield ratio. According to the low-yield-ratio super-thick maritime work steel with the excellent core low-temperature toughness, the thickness range is 80-150 mm, the yield strength is larger than or equal to 690 MPa, the tensile strength is larger than or equal to 920 MPa, the percentage elongation after fracture is larger than or equal to 20%, the yield ratio is smaller than or equal to 0.77, and the impact energy KV2 at the temperature of-60 DEG C is larger than or equal to 80 J.

The invention relates to the technical field of alloy materials, in particular to a high-strength alloy material based on a rail transit vehicle and a processing technology of the high-strength alloy material. Raw materials are smelted and cast to obtain a cast ingot; the cast ingot is sequentially subjected to solution treatment and aging treatment, and an alloy material is obtained; uniformly mixing the compound, mica powder, a curing agent and an epoxy diluent, adding epoxy resin, a defoaming agent and a flatting agent, and performing ultrasonic treatment to obtain a corrosion-resistant coating; the high-strength alloy material is obtained by sequentially grinding, polishing, cleaning and drying the surface of an alloy material, coating a corrosion-resistant coating, and curing to form a corrosion-resistant coating. The prepared high-strength alloy material has excellent mechanical properties, corrosion resistance and hydrophobicity, and is suitable for application requirements of rail transit vehicles.

The invention discloses high-toughness cold-rolled dual-phase steel, a preparation method thereof and an automobile part, and belongs to the technical field of alloy production. The high-toughness cold-rolled dual-phase steel comprises the following chemical components in percentage by weight: 0.15%-0.35% of C, 0.10%-0.50% of Si, 0.50%-4.00% of Mn, less than or equal to 0.5% of Mo, Nb, Ti and V, and the balance of Fe and impurity elements, the matrix structure of the dual-phase steel is long lath ferrite and martensite. The high-toughness cold-rolled dual-phase steel with the chemical components and the matrix structure has excellent toughness while having ultrahigh strength, the reaming and cold bending properties of the dual-phase steel are effectively improved, and the high-toughness cold-rolled dual-phase steel can be applied as an excellent automobile part. The preparation method of the high-strength and high-toughness cold-rolled dual-phase steel comprises the following step of preparing raw materials according to preset chemical components of the high-strength and high-toughness cold-rolled dual-phase steel. The method is simple, easy to operate and suitable for industrial production.

The invention belongs to the technical field of welding, and discloses a dissimilar metal power modulation galvanometer laser welding method which comprises the following steps: finely cleaning a 6061 aluminum alloy and a 304 stainless steel plate by using acetone, and then airing for more than 20 minutes; the aluminum steel sheet is assembled, pressed and fixed on a welding test platform in a steel-up-aluminum-down mode; the position of the welding test platform is adjusted, argon serves as welding protection gas, and a protection gas nozzle is arranged to be aligned with a welding pool area; laser welding parameters are set, a laser power modulation mode is set to be a gradient power mode, and the gradient power mode is to regulate and control phase point laser power in a circular scanning track in the advancing direction of a welding seam; a welding test is carried out in the mode that a galvanometer laser head is fixed and a welding test platform is moved, and a laser and the welding test platform are synchronously started and stopped; and the protective gas is started 5 seconds before the laser is started, and after the laser is stopped, the protective gas is stopped lagging for 10 seconds so as to continuously protect the welding seam and prevent oxidation.

The invention provides a high-temperature alloy for manufacturing a nickel-copper alloy hot extrusion die, which is characterized by comprising the following components in percentage by weight: 0.02 to 0.08 percent of C, less than or equal to 0.15 percent of Si, less than or equal to 0.15 percent of Mn, less than or equal to 0.01 percent of P, less than or equal to 0.01 percent of S, 14.0 to 17.0 percent of Cr, 7.5 to 9.5 percent of Mo, 2.2 to 2.6 percent of Nb, 1.0 to 1.6 percent of Al, 2.2 to 2.8 percent of Ti, 0.005 to 0.015 percent of B, 0.01 to 0.05 percent of Zr, 21.0 to 24.0 percent of Fe and the balance of Ni. The preparation method of the alloy comprises the following processes: firstly, alloy raw materials are subjected to vacuum induction melting and then cast into ingots, then electroslag ingots are obtained through electroslag remelting, then the electroslag ingots are subjected to multi-heating-number forging, and then heat treatment is carried out. The highest use temperature of the alloy reaches 1000 DEG C, and the oxidation rate at 1000 DEG C is as low as 0.08 g / m < 2 >. H; at the temperature of 650 DEG C, the tensile strength reaches 1000 MPa, the yield strength reaches 850 MPa, the fatigue strength is higher than 400 MPa, and the lasting time of the load of 700 MPa reaches 80 h; the service life of a nickel-copper alloy hot extrusion die made of the alloy can reach 25000 times.

The invention discloses a method for manufacturing a functionally graded composite material through wire powder composite arc additive manufacturing, which comprises the following steps: firstly, carrying out surface treatment on a base material, enabling the surface of titanium alloy to expose fresh white bright metal luster by adopting a machining mode, and removing surface oil stains by using alcohol and acetone; according to the requirement of materials for the gas atmosphere in the additive manufacturing process, the flexible inert gas cabin is filled with appropriate gas, and the gas atmosphere is kept all the time in the additive manufacturing process. On the basis of the electric arc additive manufacturing technology, electric arc additive manufacturing of the functional gradient metal-based composite material is achieved through a wire powder composite device, and the key technology is that according to different position requirements of parts, the metal-based composite materials with different ceramic particle contents are manufactured in an additive mode; a gradient transition area is manufactured between two areas with large particle content difference, and large stress generated at an interface due to component mutation is reduced.

The invention discloses preparation of a titanium-based composite material continuous core net structure wire material for fuse wire additive manufacturing. Comprising the following steps: taking a titanium belt as an external titanium shell, and taking fine net-shaped titanium-based composite material composite powder as filling powder; and the titanium shell and the filling powder are rolled in a sealed mode, drawing and diameter reducing are conducted, a continuous core net structure wire is formed, and then the in-situ synthesis reinforced titanium-based composite material is prepared through a fuse wire additive manufacturing method. According to the method, the in-situ synthesis reaction of a reinforcement body of the continuous core net structure wire in the melting process is fully played, matrix grains are refined, the organization structure and the size and distribution of the reinforcement body are accurately regulated and controlled, the comprehensive mechanical property of the additive manufacturing titanium-based composite material can be improved, and the method has the advantages of being high in design freedom degree, high in material utilization rate and the like; and a new method is provided for integrated preparation of the difficult-to-deform titanium-based composite material complex component.

The invention relates to a forging heat treatment process for an ultralow-temperature high-strength austenitic stainless steel forge piece. The forging heat treatment process comprises the following steps that S1, raw materials are smelted; s2, performing high-temperature diffusion annealing on the raw materials; step S3, forging: (1) heating for the first time, lightly pressing and rounding a steel ingot at the final forging temperature of more than or equal to 950 DEG C; (2) secondary heating is conducted, the steel ingot is upset and drawn out, and the finish forging temperature is larger than or equal to 900 DEG C; (3) the third heating number is carried out, the steel ingot is upset and drawn out, and the finish forging temperature is larger than or equal to 850 DEG C; s4, heat treatment: (1) water cooling treatment after forging; (2) performing rough machining on the forge piece; (3) carrying out solution treatment, wherein the solution temperature range is 1050-1120 DEG C; the forging method has the advantages that the internal quality of the forge piece is improved, grains are refined, non-uniformity is eliminated, and the overall mechanical performance is improved by improving the components and the structure of the steel ingot and the forging process.

The invention relates to the technical field of titanium strip coils, in particular to a preparation method of a high-strength cold-rolled titanium strip coil for coiled tubing, which comprises the following steps: S1, cold rolling: a hot-rolled pickled coil with the thickness of 5.5-6.5 mm is subjected to cold rolling by adopting 20 rollers, and the hot-rolled pickled coil comprises the following components in percentage by mass: 0.26-0.33% of Fe, 0.27-0.33% of O and the balance of Ti; s2, degreasing is conducted, specifically, the titanium strip coil obtained after cold rolling is subjected to degreasing treatment; s3, annealing is conducted, specifically, a vertical bell-type furnace is filled with argon for protection for annealing treatment, furnace cooling is conducted after annealing is completed, and a titanium strip coil with the thickness being 3-4.5 mm for the coiled tubing is obtained; a cold rolling mode is adopted, the thickness of the titanium strip coil is rolled to 3.0-4.5 mm, a bell-type furnace annealing mode is adopted, an oxide layer is prevented from being generated on the surface, the bending performance of the titanium strip is enhanced, cracks are prevented from being formed on the surface during pipe manufacturing, the compressive strength, the yield strength and the ductility of the product are high, and the bending angle (6T) is large.

The present invention discloses a mixed deoxidizer and its application in HDH, belonging to the technical field of inorganic deoxidizers. The components of the mixed deoxidizer are selected from at least three of borides, carbides, hydrides and titanium dichloride, and the deoxidation method is: the mixed deoxidizer and titanium hydride are mixed and kept at 400-850°C for 1-24h; the amount of the mixed deoxidizer does not exceed 0.1% of the mass of high-oxygen titanium hydride. The mixed deoxidizer of the present invention and its application method in HDH can solve the problems of high oxygen content of titanium hydride, powder agglomeration, poor mechanical properties of related molded products, etc., and improve the actual industrial application value of titanium hydride and its processed products.

The invention discloses a manufacturing method of an ultra-large seamless steel pipe with the diameter of 2000 mm, and belongs to the technical field of seamless steel pipe manufacturing in the metallurgical industry. The method comprises the following steps: heating a solid round tube blank, carrying out skew rolling by adopting a micro-expanding process to obtain a pierced billet, manufacturing the pierced billet into a hollow billet with an expanded diameter by utilizing a skew rolling expanding process, further expanding the diameter by using a flattening skew rolling process and simultaneously improving the dimensional precision and the surface quality of the hollow billet, and obtaining a semi-finished steel tube with the diameter of 2000mm by adopting a controlled rolling sizing process. And the semi-finished steel pipe is subjected to heat treatment, flaw detection and finishing procedures to directly obtain the ultra-large seamless steel pipe finished product of 2000 mm According to the method, materials are formed through one-time heating, only pipe blank heating is needed, heat treatment and reheating are not needed, energy is saved, and performance is improved; the on-line structure regulation and control method taking controlled cooling as the core thoroughly turns the passive situation that seamless steel pipes excessively depend on alloying and off-line heat treatment in the past, breaks through the bottleneck of the traditional process, and develops a new process and a new method for high-quality and high-efficiency manufacturing of the steel pipes.

The invention relates to the technical field of preparation of high-thermal-conductivity and high-strength aluminum alloy materials, in particular to a high-thermal-conductivity and high-strength aluminum alloy material and a preparation method thereof. The invention discloses a high-thermal-conductivity and high-strength aluminum alloy material which is composed of the following elements in percentage: 6%-15% of Si, 0.5%-1.0% of Fe, 0.3%-0.5% of Mg, 0.2%-0.5% of Mn and 0.2%-1.8% of Ni. And the balance of Al. The composition proportion of the high-heat-conductivity and high-strength aluminum alloy material is optimized, the hardness and strength of the alloy are remarkably improved by adjusting the adding proportion of Si, and on the basis, the Ni element is further selected to inhibit formation of a needle phase in the aluminum-silicon alloy, so that the strength of the aluminum alloy material is improved, meanwhile, the defect that the heat-conducting property of the aluminum alloy material is degraded is overcome, and the service life of the aluminum alloy material is prolonged. Therefore, the aluminum alloy material meets the requirements of good heat-conducting property and strength property.

The invention discloses a method for improving the grain size and component uniformity of a solidification structure in the smelting process of a titanium alloy EB furnace through ultrasonic treatment, and belongs to the technical field of titanium alloy smelting. In order to solve the problems of non-uniform cast ingot components, serious grain boundary segregation, coarse structure grains and the like in the existing EB furnace smelting process, the invention provides a method for improving the solidification structure grain size and component uniformity in the titanium alloy EB furnace smelting process through ultrasonic treatment, which comprises the following steps: high-temperature titanium alloy melt flows into a crystallizer for solidification and ingot dummy; after ingot dummy is started, an ultrasonic radiation rod is inserted into a titanium alloy melt molten pool on the upper portion of the crystallizer; and when the cast ingot is close to a solidification end point, removing the ultrasonic radiation rod to obtain the titanium alloy cast ingot. According to the method, the ultrasonic radiation rod is inserted, the insertion depth and the ultrasonic frequency are controlled, and ultrasonic vibration and cavitation are utilized, so that grains of a titanium alloy solidification structure are refined, alloy components are uniform, the machining performance of a titanium cast ingot is improved, and efficient production of the high-quality titanium alloy is achieved.

The invention relates to the technical field of high-speed tool steel, in particular to cobalt-containing high-speed tool steel and a preparation method thereof.The preparation method comprises the following steps that raw materials including, by weight, 55-60 parts of Fe, 2-5 parts of Mo, 2-4 parts of W, 0.5-0.8 part of V, 0.2-0.5 part of Co, 0.1-0.2 part of C and 0.1-0.2 part of rare earth elements are weighed; according to the cobalt-containing high-speed tool steel, through precise control over the content of alloy elements such as C, Mo, W, V and Co, ideal technical indexes of metallographic structures and machining performance are achieved, so that it is guaranteed that after heat treatment, ideal wear resistance and hardness are achieved, the wear resistance, impact resistance and hardness of a product are improved in a balanced and coordinated mode, and the effects of corrosion resistance and cold and heat resistance stability of the product are remarkable.

The invention provides a high-strength pure titanium rod wire and a preparation method thereof, and relates to the technical field of biomedical metal materials, and the preparation method comprises the following steps: preparing materials according to industrial pure titanium components, carrying out vacuum consumable smelting to obtain a titanium ingot blank, and carrying out cogging forging and continuous rolling on the titanium ingot blank to obtain a coiled rod blank; the coiled bar blank is subjected to hot drawing to obtain a pure titanium bar, and the pure titanium bar subjected to hot drawing is sequentially subjected to scaling treatment, heat treatment, cold drawing, sliding block straightening, stress relief annealing and centerless grinding to obtain a finished product of the high-strength pure titanium bar wire. According to the method, the surface reduction rate is controlled through cold drawing, the performance of the rod wire is adjusted through a reasonable heat treatment system, metastable structures in the alloy are obviously deformed and close to each other through cold drawing, the deformation amount of cold drawing is continuously increased, grain boundaries and dendritic grain boundaries are close to each other, the interface distance is gradually reduced, grains and the metastable structures are refined, and the yield of the rod wire is increased. Due to the increase of dislocation density and grain refinement, the yield strength and tensile strength of the cold-drawn pure titanium rod wire are improved.

The invention provides a neodymium iron boron sintered magnet and a preparation method and application thereof. The neodymium iron boron sintered magnet comprises the following components: R, wherein the mass content of R is 28-33wt%; r comprises Nd and Ce, and optionally comprises or does not comprise at least one of Pr, Dy, Tb, Ho and Gd; m, wherein the mass content of the M is 1.5-2.5 wt%; b, the mass content of the B is 0.95 to 1.05 wt%; the mass content of the Ti ranges from 0.1 wt% to 0.25 wt%; fe is the balance; in the neodymium iron boron sintered magnet, the mass content of Ce is 0.3-5 wt%. By accurately controlling the main alloy element components, the generation of a soft magnetic phase in main phase grains is avoided; and meanwhile, the element components of the auxiliary alloy are optimized, and the dosage ratio of the main alloy to the auxiliary alloy is adjusted, so that main phase grains are refined, a fine titanium-rich phase which is dispersed and distributed is formed in a grain boundary phase, and the magnetic performance of the product is improved.

The invention belongs to the technical field of 3-series aluminum alloys, and particularly relates to a 3xxx aluminum alloy and a preparation method and application thereof. By optimizing the content of Mn, Fe and other elements and combining the high-temperature homogenizing annealing process, the aluminum alloy material has high strength and machinability, meanwhile, the size of coarse intermetallic compounds is reduced through high-temperature rolling, distribution is more uniform, grains and textures are refined through the continuous intermediate annealing process, and the yield of the aluminum alloy material is improved. The alloy plasticity is improved, the anisotropy of the plate is reduced, and the battery shell yield is higher. Moreover, high-temperature homogenization and hot continuous rolling are integrated, so that the production time is shortened, and the production efficiency is improved. According to the method, a high-temperature short-time intermediate annealing process is adopted, the grain size in the 3xxx aluminum alloy plate strip is regulated and controlled to be 25-35 microns, the texture proportion of Cube is 2-3.5%, and the texture proportion of Goss is 3-5%, the alloy plasticity is improved, the anisotropy of the plate is reduced, and the surface quality of a battery shell can be effectively improved.