39results about How to "Refined grain structure" patented technology

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 1700MPa-grade hot-formed steel with high cold bending performance and a preparation method and application thereof. The surface layer of the hot-formed steel has a soft-phase ferrite structure, the secondary surface layer of the hot-formed steel has a mixed structure of soft-phase ferrite and martensite, and the core layer of the hot-formed steel has a carbon-poor martensite structure. The preparation method comprises any one or a combination of at least two of the following conditions: (A) the coiling temperature after hot rolling is 650-700 DEG C; (B) the pickling speed is less than or equal to 150m / min; (C) the continuous annealing temperature is 780-830 DEG C; (D) the atmosphere in the furnace is mixed gas of nitrogen and hydrogen; and (E) the dew point temperature is-35 DEG C to-17 DEG C. Through fine component design and process integration, the contradiction between the strength and the toughness of the material is successfully solved, double guarantee of high strength and high toughness is achieved, meanwhile, the requirement for light weight is met, and the competitiveness of an existing product is improved.

The invention relates to the technical field of copper alloy materials, and discloses a preparation method of a high-strength copper-nickel-tin alloy material, which comprises the following steps: S1, raw material preparation, S2, smelting and casting, S3, homogenization treatment, S4, forging processing, S5, solid solution quenching, and S6, aging treatment. The invention further discloses the copper-nickel-tin alloy material prepared by the preparation method. According to the invention, by adding trace elements such as manganese and niobium into the copper-nickel-tin alloy, the internal structure of the crystal is changed, the structure grains are refined, the hardness and tensile strength of the copper-nickel-tin alloy are further improved, and continuous precipitation of discontinuous precipitates in the alloy structure grains is avoided; a forging process combining free forging and small-deformation forging is adopted, and meanwhile, a solution treatment process and an aging treatment process are adopted, so that the elements are fully dissolved in a copper matrix, internal stress generated in the forging process is greatly relieved, and the strength and hardness of the alloy material are further improved.

The invention belongs to the technical field of aluminum alloy material preparation, and particularly relates to a preparation method of an optical aluminum alloy material, which comprises the following steps: heating an aluminum alloy cast ingot to 230-270 DEG C, preserving heat, carrying out hot rolling, cooling to room temperature, carrying out cold rolling, and sequentially carrying out intermediate annealing, solution treatment and aging treatment to obtain the optical aluminum alloy material. According to the method, grains are obviously refined, the surface roughness is reduced, and the surface quality of the optical aluminum alloy material is improved.

The invention relates to the technical field of heat-resistant stainless steel, and particularly discloses martensite heat-resistant steel and a manufacturing method and application thereof. According to the manufacturing method of the martensitic heat-resistant steel, by precisely controlling the technological conditions of the working procedures of smelting, AOD refining, LF refining, VD vacuum refining, forging, annealing and the like, the strength, toughness and plasticity of the prepared martensitic heat-resistant steel are effectively improved, the grain structure of the heat-resistant steel is effectively refined, the grain size ranges from 7.5 grades to 8.5 grades, the sum of inclusions ranges from 3 grades to 4.5 grades, Rp0.2 ranges from 800 MPa to 900 MPa, Rm is smaller than or equal to 1100 MPa, A is larger than or equal to 14%, Z is larger than or equal to 40%, and the yield of the heat-resistant steel is increased. The HBW is 280N / mm < 2 >-305N / mm < 2 >, the KV2 is greater than or equal to 30J, and the Rm (400 DEG C) is greater than or equal to 650 DEG C, so that a solid and reliable material support is provided for the ultra-supercritical steam turbine, and the material is particularly suitable for manufacturing parts such as a wheel disc of the ultra-supercritical steam turbine and the like, and has a relatively high practical value.

A high-alloy steel electroslag ingot and its homogenization method are provided, comprising the following steps: S1, electroslag ingot pretreatment: removing surface oxide scale and crack defects, and grinding to a surface roughness Ra≤6.3μm; S2, staged heating: heating to 800-900℃ at a rate ≤100℃ / h and holding for 2-6h; heating to 1000-1100℃ at a rate ≤100℃ / h and holding for 2-6h; heating to 1200-1300℃ at a rate ≤150℃ / h and holding for 10h. -20h; S3, Stepped cooling: Turn off the heating device and cool with the furnace to 800-1000℃, hold for 2-6h; cool to 500-650℃ at a rate of ≤50℃ / h, hold for 2-6h; open the furnace door and introduce cooling air at a speed of 0.5-3m / s to cool to room temperature, obtaining homogenized high-alloy steel electroslag ingots; S4, Post-homogenization testing: the relative standard deviation of each alloying element is ≤5%; the average grain size is ≤10μm; the Brinell hardness fluctuation range is ≤15HBW. This invention eliminates component segregation, refines grain structure, optimizes process parameters, is highly efficient and energy-saving, easy to promote, and has strong practicality.

The application provides a 1700MPa-grade hot forming steel with high cold bending performance and a preparation method and application thereof. A surface layer of the hot forming steel has soft ferrite structure, a subsurface layer has mixed structure of soft ferrite and martensite, and a core layer has carbon-poor martensite structure. The preparation method comprises any one or a combination of at least two of the following conditions: (A) the coiling temperature after hot rolling is 650-700 DEG C; (B) the pickling speed is less than or equal to 150 m / min; (C) the temperature of continuous annealing is 780-830 DEG C; (D) the atmosphere in the furnace is a mixture of nitrogen and hydrogen; (E) the dew point temperature is-35 DEG C to-17 DEG C. Through fine component design and process integration, the application successfully solves the contradiction between material strength and toughness, realizes double guarantee of high strength and high toughness, simultaneously meets the light weight requirement, and improves the competitiveness of existing products.

The invention discloses a corrosion-resistant and high-performance aluminum alloy cable material as well as a preparation method and application thereof, and relates to the technical field of aluminum alloy preparation. The component formula of the conductor is Al-xMg-ySi-zNi-mCe-nSc-qY, x is larger than or equal to 0.05 and smaller than or equal to 0.3, y is larger than or equal to 0.6 and smaller than or equal to 1.4, z is smaller than or equal to 0.35, m is larger than or equal to 0.01 and smaller than or equal to 0.2, n is larger than or equal to 0.03 and smaller than or equal to 0.2, q is larger than or equal to 0.04 and smaller than or equal to 0.1, iron is a main impurity element in the alloy, and the content of the iron is not larger than 0.1%. The aluminum alloy cable material with excellent mechanical properties (the tensile strength is larger than or equal to 122 MPa, and the elongation is larger than or equal to 14%), electrical properties (the conductivity is larger than or equal to 62% IACS) and corrosion resistance (the maximum IGC depth is smaller than 100 micrometers) is prepared by adopting the technological method of flame direct injection smelting, synchronous water quenching pull casting, cold forming machining and non-isothermal aging synchronous heat treatment, and the aluminum alloy cable material is suitable for aluminum alloy cables. The method is short in technological process, good in cable quality, high in corrosion resistance and wide in application prospect.

The invention belongs to the technical field of casting, and provides an investment casting process of a martensitic stainless steel material part, according to the investment casting process of the martensitic stainless steel material part, through introduction of silicon carbide and metamorphism of a rare earth ferrosilicon alloy, the thermal expansion coefficient of steel is reduced, and the performance of the martensitic stainless steel part is improved. And meanwhile, structure grains in the martensitic stainless steel solidification process are remarkably refined, formation of thick and large matrix structures is reduced, and therefore internal stress generated in the casting solidification stage is reduced. And meanwhile, the plasticity and toughness of the material can be improved through the refined crystal grains, the adaptive capacity of the casting to martensite transformation volume change in the subsequent heat treatment process is enhanced, accumulation of internal stress is relieved, and finally cracks are effectively restrained. Compared with existing schemes such as casting temperature optimization and shell deformability adjustment, the process improves the material performance from the structure level through modification treatment, the anti-cracking capacity of the casting can be fundamentally improved, meanwhile, the size precision and the mechanical property of the casting are considered, and the bottleneck of the prior art is broken through.

According to the intelligent casting device based on the digital boiling cooling channel and the control method of the intelligent casting device, firstly, high-performance low-pressure anti-gravity stable mold filling of metal melt is achieved, and then intelligent and high-cooling-speed metal melt high-performance solidification is achieved based on the digital boiling cooling channel. By means of the method, stable mold filling of low-pressure anti-gravity casting can be achieved, the defects of gas entrapment, oxidation slag inclusion and the like are reduced, sufficient feeding under pressure solidification is ensured, the problems of shrinkage cavities, shrinkage porosity, hot cracks and the like are reduced, and therefore a compact structure is obtained; and intelligent cooling speed enhanced solidification and sequential solidification of castings in any shape in a three-dimensional space can be realized based on a digital boiling cooling channel, a solidification structure with refined grain structure, small secondary dendritic crystal arm spacing and few defects is obtained, and finally, a high-performance high-end complex casting is produced.

The present application relates to the technical field of titanium-based cathode roller, in particular to a large-size titanium-based cathode roller and a processing technology thereof, comprising the following processes: step one, taking a blank to carry out high-temperature blooming upsetting, punching, hole expanding, mandrel drawing, and obtaining a ring blank; step two, taking the ring blank obtained in step one to perform dressing and marking inspection; step three, taking the ring blank obtained in step two to perform turning, and obtaining a ring piece; step four, taking the ring piece obtained in step three to perform post-processing, and obtaining a cathode roller. The present application uses a new technology of forging-rolling combination to successfully produce a whole seamless ring piece at one time, which can effectively meet the requirements of the cathode roller on the morphology and mechanical properties at the microstructure level, and eliminate the occurrence of periodic bright band during the production of copper foil by the customer.

The invention provides a low-segregation aluminum-tin alloy round cast ingot and a preparation method thereof, and belongs to the technical field of aluminum alloy casting forming. The low-segregation aluminum-tin alloy round cast ingot provided by the invention is prepared from the following components in percentage by mass: 5.5 to 7.0 percent of Sn, 0.7 to 1.3 percent of Cu, 0.7 to 1.3 percent of Ni, less than or equal to 0.15 percent of Fe, 0.15 to 0.25 percent of Si, 0.15 to 0.25 percent of Zr, 0.01 to 0.20 percent of Ti, 0.15 to 0.25 percent of Sb, 0.02 to 0.10 percent of P and the balance of Al. By using various elements such as zirconium, titanium, silicon, antimony and phosphorus, a synergistic effect can be achieved, and the uniformity of the tin content of the aluminum-tin alloy is remarkably improved. The result of the embodiment shows that even if the diameter of the low-segregation aluminum-tin alloy round cast ingot is larger than or equal to 250 mm, the low-segregation aluminum-tin alloy round cast ingot cannot crack in the casting process, and meanwhile element distribution uniformity is good.

The invention relates to the technical field of ferrous metallurgy, and discloses welding wire steel for maritime work equipment and a smelting method.The smelting method comprises the steps that an ingot mold and a heat preservation riser are prepared, and drying and heat preservation are conducted in a heating furnace; the method comprises the following steps: preparing materials according to the chemical components of the welding wire steel, polishing the surface, sequentially charging in a smelting furnace, carrying out vacuum induction smelting, starting to carry out power transmission smelting when the vacuum degree is less than or equal to 10Pa, sequentially adding carbon blocks, metal silicon and aluminum in batches when the vacuum degree is less than or equal to 5Pa, filling argon, adding ferrotitanium, metal manganese and metal boron, finally adding rare earth zirconium, regulating the temperature to 1590-1620 DEG C, and tapping, casting in a steel ingot mold; and carrying out heat treatment on the blank to obtain the welding wire steel cast ingot. By adding trace Ti, B and rare earth alloy elements, a bainite structure is obtained in a wide cooling range while grain structures in the steel are refined and inclusions are modified, the toughness of a welding seam is improved, the low-oxygen and low-nitrogen steel for the welding wire is prepared by adopting a vacuum induction process, and the problem of cracking in the cold drawing process of the welding wire steel is solved.

The application discloses a method for electron beam fuse additive manufacturing of beta titanium alloy components, and belongs to the technical field of additive manufacturing. The application aims to solve the problems of long preparation period, low efficiency, low utilization rate, serious oxidation, significant beta spot and poor strength and toughness of the prior art. The method comprises the following steps: pretreating the printing wire and the substrate; establishing a three-dimensional entity model based on the target beta titanium alloy component, performing slice processing on the three-dimensional entity model to generate multi-layer two-dimensional slice data, and then importing the slice data into an electron beam fuse additive manufacturing equipment, and setting a scanning path, preheating parameters and printing process parameters; starting the equipment and performing vacuumization, printing the beta titanium alloy according to the set printing parameters and procedures, completing all layers, and obtaining the beta titanium alloy component. The beta titanium alloy component prepared by the application has high density, and provides a reliable technical approach for the preparation of high-performance beta titanium alloy components in the fields of aviation and aerospace.

The present invention relates to the technical field of surface grinding devices, and in particular to a large-scale bearing surface grinding device and a grinding quality detection method, which includes an electrical control module and a mechanical module, wherein the mechanical module includes a control cabinet, a tool holder, a long-stroke movable track, a suction cup fixture, a plurality of bolts, a plurality of nuts and a power mechanism, wherein the bottoms of the tool holder and the suction cup fixture are both slidably connected to the top of the long-stroke movable track, the power mechanism is fixedly connected to the top of the tool holder, and the interior of the suction cup fixture is clamped with a bearing ring; the electrical control module includes a controller with a display screen and buttons. The present invention has the function of adjusting the processing intensity of the bearing ring by the power mechanism in real time, and the central part of the connection between the grinding disc and the main shaft is converted into the radial vibration of the grinding disc, and ultrasonic vibration-assisted grinding parallel to the processing surface and perpendicular to the grinding line speed direction can reduce the grinding force between the workpiece and the grinding wheel, and improve the surface quality of the ground workpiece.

The invention discloses an aluminum alloy wire machining method and a machining production line, and belongs to the technical field of power transmission. The aluminum alloy wire machining method comprises the following steps that S1, an extrusion technology is adopted for forming an aluminum alloy rod material into a middle wire; s2, the middle wire obtained after extrusion forming is cooled and subjected to heat preservation; and S3, the middle wire obtained after heat preservation is formed into a finished wire through a drawing process, and the drawing temperature ranges from 100 DEG C to 230 DEG C. According to the aluminum alloy wire processing method, the formed aluminum alloy wire can meet the performance requirements of high strength and high conductivity, the production efficiency can be improved, and the production cost can be reduced. The aluminum alloy wire processing production line can realize continuous extrusion, drawing and heat treatment of the aluminum alloy wire, so that the finished wire meets the performance requirements of high strength and high conductivity, the production efficiency can be improved, and the production cost can be reduced.

According to the composite plating layer electroplating process method, a plating solution comprises, by molar mass, 50%-80% of sodium hydroxide, 2%-3% of ZnO, 3%-7% of nickel sulfate, 2%-9% of triethanolamine, 0.4%-3% of tetraethylenepentamine, 1%-4% of sodium potassium tartrate tetrahydrate, 0.1%-1% of EDTA, 2%-7% of nano silicon dioxide, 0.6%-3% of nano titanium oxide, 12 mL / L of a primary brightener and 12 mL / L of a secondary brightener. By adding the nano silicon oxide and the titanium oxide, a multifunctional composite coating with enhanced surface hardness, self-lubrication, wear resistance and corrosion resistance can be produced, due to the nano size effect, the microstructure of the coating is refined, a finer grain structure is obtained, the compactness of the composite coating is improved, and the corrosion resistance is greatly improved.

The invention relates to the technical field of smelting, in particular to high-impact-toughness low-temperature B-grade steel which comprises the following components in percentage by mass: 0.17%-0.23% of C, 0.3%-0.4% of Si, 1%-1.2% of Mn, less than or equal to 0.03% of S, less than or equal to 0.03% of p, 0.3%-0.4% of Cr, 0.25%-0.3% of Ni, less than or equal to 0.04% of Cu, 0.01%-0.04% of Ti and the balance of Fe and inseparable impurities. The invention further relates to a preparation process of the high-impact-toughness low-temperature B-grade steel. The prepared low-temperature B-grade steel can keep high impact toughness at the low temperature (minus 50 DEG C), wherein the impact toughness is almost unchanged compared with the impact toughness at the normal temperature.

The invention provides a continuous casting round billet as well as a preparation method and application thereof. The continuous casting round billet comprises the following components: 0.17 to 0.19 weight percent of C, 0.62 to 0.68 weight percent of Mn, 1.62 to 1.70 weight percent of Cr, 0.29 to 0.31 weight percent of Mo, 1.52 to 1.60 weight percent of Ni, 0.017 to 0.025 weight percent of Nb, 0.020 to 0.030 weight percent of Al, 0.0075 to 0.0110 weight percent of N, 0.20 to 0.28 weight percent of Si, less than or equal to 0.010 weight percent of P, less than or equal to 0.005 weight percent of S and the balance of Fe. The tensile strength of the obtained continuous casting round billet is preferably as high as 1520 MPa or above, the yield strength is preferably as high as 1130 MPa or above, the impact energy at-40 DEG C (KV2) is preferably as high as 50 J or above, and the carbon segregation range of the cross section is preferably as low as 0.033% or below.

The present application introduces a method for processing large unit weight zirconium alloy wire, which relates to the field of wire drawing technology, and the steps are: S1: ingot pretreatment; S2: blank forging; S3: first fire rolling; S4: cutting to size; S5: second fire rolling; S6: coil heat treatment; S7: cold drawing; S8: roller die cold drawing + continuous annealing; S9: surface treatment. The present invention combines blank forging, rolling, roller die cold drawing + continuous annealing and surface treatment, strictly controls the blank forging process, hot rolling temperature, etc., so that the zirconium alloy microstructure is fully refined and uniform, which is conducive to the smooth implementation of the subsequent drawing process; in the subsequent roller die cold drawing process, the drawing pass, deformation, cold drawing rate, etc. are strictly controlled to avoid the occurrence of cracks, defects and even wire breakage, and at the same time break through the bottleneck that the traditional drawing process cannot achieve large unit weight drawing of zirconium alloy, greatly improving the production efficiency and yield rate.

The invention relates to a high-temperature titanium alloy used for a long time in a high-temperature, high-pressure and high-rotating-speed extreme environment, belongs to the technical field of metal materials, and solves the problem that a titanium alloy part in the prior art cannot serve in a high-temperature (650-700 DEG C), high-pressure and high-rotating-speed extreme working environment for a long time. The high-temperature titanium alloy comprises the following chemical components in percentage by weight: 6.0%-8.0% of Al, 2.5%-4.5% of Sn, 2.5%-7.0% of Zr, 0.5%-1.5% of Hf, 0.05%-0.85% of Mo, 0.20%-0.80% of Nb, 1.0%-3.0% of Ta, 0.40%-0.90% of Si, 0.4%-1.0% of W, 0.05%-0.07% of C and the balance of Ti. By regulating and controlling the alloy element composition and the content ratio and combining a processing technology and a heat treatment process, the high-temperature titanium alloy can be prepared into the high-temperature titanium alloy. The titanium alloy has excellent strength, creep resistance and over-rotation fracture resistance at the high temperature of 650-700 DEG C, is suitable for being used for a long time in the extreme environment of high temperature, high pressure and high rotating speed, and meets the requirements of a new generation of aero-engine titanium alloy parts in the extreme high-temperature working state.

This invention belongs to the field of aluminum-based composite material preparation technology, and relates to a continuous casting and rolling method for preparing aluminum-based composite material strips. The method involves preparing a reinforcing preform with a thickness not exceeding the roll gap distance in the aluminum-based composite material strip. Before preparing the aluminum-based composite material strip, the casting rolls are water-cooled and run at a set speed. Molten aluminum is injected into the molten pool, and the liquid level is controlled to a set value. Throughout the preparation process, the molten pool liquid level is maintained at the set value. The molten aluminum cools and solidifies upon contact with the roll surface of the casting rolls. Under the casting action of the two casting rolls, an aluminum alloy strip is formed and continuously output from the lower end of the roll gap. During the preparation process, the reinforcing preform moves from top to bottom at a set speed and is immersed in the molten aluminum pool. The molten aluminum penetrates into and fills the interior of the reinforcing preform. The reinforced preform, filled with molten aluminum, gradually solidifies as it moves to the roll gap until it is completely solidified. Then, under the casting force of the two casting rolls, it undergoes rolling deformation to form the aluminum-based composite material strip.

The invention provides a laser vibration cladding device and a method thereof.The device comprises an annular heating cover and an infrared focal plane detector which are arranged in a working cabin with a laser cladding head, and a plurality of independently-controlled infrared heating units evenly distributed in the circumferential direction of the annular heating cover are arranged on the annular heating cover; a workpiece clamping position is arranged below the circle center of the annular heating cover, and the infrared heating units all point to the workpiece clamping position. A multi-channel coaxial powder feeder is further arranged in the working cabin, a plurality of independently-controlled powder bins are integrated in the multi-channel coaxial powder feeder, a powder feeding pipe of the multi-channel coaxial powder feeder is integrated with the laser cladding head, and powder in all channels is converged before entering the powder feeding pipe and conveyed to the laser cladding head through inert gas flow; and an ultrasonic generator, a piezoelectric transducer and a vibration transmission rod are also arranged in the working cabin.

The invention discloses a method for producing a quenched and tempered bar for a high-temperature gas cooled reactor fastener by using rolling instead of forging. The problem that the mechanical property requirement of a forged piece is difficult to meet in the prior art is solved. The method comprises the following steps: (1) optimally designing chemical components of steel, strictly controlling sulfur, phosphorus and oxygen, and adding a certain content of microalloy vanadium and niobium elements; deoxidation and denitrification are achieved through an LF furnace and VD degassing, and the purity of molten steel is improved; the structure segregation is reduced through the constant-melting-speed electroslag furnace; (2) the compactness and the uniformity of the core structure of the steel are improved through high-temperature and large-rolling-reduction controlled steel airing differential-temperature rolling; (3) through normalizing and tempering pretreatment, the uniformity and consistency of the hardening and tempering performance are ensured; and (4) the pre-straightening treatment before hardening and tempering is carried out, so that the straightening stress after hardening and tempering is effectively reduced. The method has the beneficial effects that the maximum production specification phi is 200mm, and the flaw detection quality is excellent; the purity of the steel is high, and the total amount of inclusions is within the 2.0 level; the mechanical property of the bar is ensured.

The invention discloses an aluminum alloy for preparing a traction beam of an external bogie of a train and a preparation method of the aluminum alloy, and belongs to the technical field of alloys for high-speed trains. The aluminum alloy contains Zn, Mg, Cu, Zr, Ti, Mn, Ni, La and other elements, and lanthanum can refine grains, improve the metallographic structure and form a dispersion strengthening phase, so that the strength and toughness of the alloy are improved; the nickel and the aluminum element can form a solid solution, so that the alloy structure is more compact, and the obtained aluminum alloy shows higher resistance when bearing external force and is not prone to deformation or fracture. According to the method, the aluminum alloy is manufactured through two-step superplastic die forging, after two-step die forging, plastic deformation of the alloy is uniform, the grain size is small and uniform, mechanical properties of the aluminum alloy are improved, the aluminum alloy particularly has good fatigue performance, and the aluminum alloy has good safety and reliability while light weight of the aluminum alloy is guaranteed.

The invention provides neodymium-containing high-corrosion-resistance laser cladding powder for a mining hydraulic oil cylinder and a cladding method, the neodymium-containing high-corrosion-resistance laser cladding powder comprises Nd2O3 powder and alloy powder, the mass percent of the Nd2O3 powder is 0.4%-1.0%, and the balance is the alloy powder; the alloy powder comprises the following components in percentage by mass: 19.2%-20.8% of Cr, 4.0%-8.0% of Ni, 0.3%-0.75% of Mn, 4.5%-8.5% of Mo, 0.04%-0.08% of C, 1.35%-1.52% of Si and the balance of Fe. In an inert atmosphere, the neodymium-containing high-corrosion-resistance laser cladding powder for the mining hydraulic oil cylinder is used for carrying out laser cladding on the outer surface of the mining hydraulic oil cylinder. The cladding method also has the advantages of moderate hardness, good wear resistance, strong purification capability and low hot crack sensitivity on the premise of ensuring that the cladding layer has better corrosion resistance.

The invention discloses a vulcanization pipe bending device for rubber sleeve cable extrusion and an operation method of the vulcanization pipe bending device. The vulcanization pipe bending device comprises a heat preservation assembly, a heating conduction assembly, a pipe bending assembly, a vulcanization pipe and a PLC control system. The device can effectively improve the bending uniformity and consistency of each point position of the vulcanized pipe, realizes the accurate bending and shaping effects of the vulcanized pipe, and can measure and calculate the vertical displacement of a plurality of point positions relative to the center line according to the bending angle of the vulcanized pipe, thereby meeting the process requirement of the bending deformation quantity of the vulcanized pipe; compared with a bending mode of a traditional rubber sleeve cable vulcanized pipe, the method adopts a mode of combining hot-state bending and cold-state bending, hot-state processing is firstly performed for preliminary forming, the hardness is reduced by utilizing the plasticity of the rubber sleeve cable vulcanized pipe, then cold-state processing is performed for accurate forming, and therefore the problems of cracks and the like of materials are avoided; by means of the operation method of the device, it is guaranteed that deformation of the vulcanized pipe is uniform in the whole bending deformation process, product quality is guaranteed, and the technological requirement for the bending deformation quantity of the vulcanized pipe is met.

This invention discloses a method for synergistic control of residual stress and microstructure in a pulsed current-assisted metal additive manufacturing process, belonging to the field of metal material additive manufacturing technology. The method includes the following steps: S1, setting the process parameters for metal additive manufacturing and planning the area and timing for synchronously applying pulsed current; S2, during the layer-by-layer deposition process of the component, when a high-energy laser beam, electron beam, or electric arc acts on the deposition area to form a molten pool, a pulsed power supply is triggered by a synchronous control unit to apply a pulsed current with preset parameters to the molten pool and the heat-affected zone; S3, through the synergistic effect of the electroplasticity and Joule heating of the pulsed current, thermal stress relaxation, grain refinement, and microstructure homogenization are simultaneously achieved during the manufacturing process. This invention, by employing the above method and precisely controlling the electrical pulse parameters, simultaneously achieves stress relaxation and solidification microstructure optimization during the manufacturing process, significantly improving the dimensional stability, fatigue life, and mechanical properties of the formed component.

The invention provides a flux-cored wire and a preparation method and application thereof, and particularly relates to the field of welding materials. The flux-cored wire comprises a steel belt and a flux core wrapped in the steel belt, and the flux core comprises, by mass, 33%-35% of micro-carbon ferrochrome, 21%-23% of calcium fluoride, 11%-13% of nickel powder, 12%-14% of rutile, 7%-9% of iron-molybdenum alloy, 3%-5% of manganese powder, 2%-4% of ferrotitanium, 1%-2% of ferrosilicon and the balance iron powder. The flux-cored wire can be suitable for all-position welding, is stable in welding arc, easy in slag removal, smooth in wire feeding and attractive in weld joint forming, has better hardness and excellent impact resistance and crack resistance, has the weld joint hardness up to 68 HRC, is applied to turbine blade repair, and can greatly prolong the service life of turbine blades.

The invention relates to the technical field of nuclear reactors, and discloses a forge piece for a safety end of a reactor pressure vessel and a forging method of the forge piece, the forge piece comprises, by mass, 0.15%-0.20% of C, 0.15%-0.35% of Si, 1.20%-1.50% of Mn, less than or equal to 0.015% of P, less than or equal to 0.010% of S, 0.90%-1.20% of Cr, 0.90%-1.20% of Ni, 0.20%-0.30% of Mo, less than or equal to 0.20% of Cu, 0.02%-0.05% of V, 0.01%-0.03% of Nb, 0.01%-0.03% of Ti and the balance Fe and inevitable impurities, the yield strength of the forge piece is larger than or equal to 400 MPa, the tensile strength is larger than or equal to 550 MPa, by optimizing chemical components and adopting a specific forging process, the strength and toughness of the forge piece are improved, so that the forge piece has excellent mechanical properties, radiation resistance and corrosion resistance, is not easy to deform and crack when bearing high pressure and impact force, refines a grain structure, improves the internal quality of the forge piece, reduces the generation of defects, and improves the production efficiency. And the requirement of long-term stable operation of the nuclear reactor in a severe environment can be met.