36results about How to "Play a strengthening effect" patented technology

The invention relates to a preparation method of a graphene / metal composite panel. The preparation method comprises the steps of firstly uniformly mixing a monodispersed graphene solution with a polyvinyl alcohol solution to prepare graphene / polyvinyl alcohol mixed slurry, spraying the graphene / polyvinyl alcohol mixed slurry to the upper and lower surfaces of a plurality of metal panels, heating to remove polyvinyl alcohol in a coating, and finally laminating the metal panels to prepare the graphene / metal composite panel in a hot rolling manner. The preparation method has the beneficial effects that by compositing the graphene / polyvinyl alcohol mixed slurry with the metal panels, the dispersity of graphene can be guaranteed; by utilizing a hot rolling process, the graphene can be beneficially dispersed into matrixes of the panels so as to play a strengthening effect; the molecular association between the graphene and the metal panels is realized in the premise of well preserving intrinsic physical properties of the graphene and a metal material; the process is simple, the large-batch and large-size graphene composite panels are easily prepared, the production cost is lowered, and the preparation method has excellent engineering application prospects in the fields of light armor materials, aviation, spaceflight and the like.

The invention discloses a preparation method of a carbon nanotube-alumina composite reinforced magnesium-based composite material, which relates to the manufacture of magnesium-based alloy by using a casting method. The preparation method comprises the steps of: step 1, calcining and reducing raw materials of ferric nitrate nonahydrate and alumina in the ratio of (0.07-1.00):1 to obtain an iron / alumina composite catalyst, and finally, performing catalytic pyrolysis reaction by using the mixed gas of nitrogen gas and ethylene in the volume ratio of (6-12):1 for uniformly dispersing carbon nanotubes on the surface of the alumina, so as to prepare a carbon nanotube-alumina composite reinforced phase; and step 2, adding the carbon nanotube-alumina composite reinforced phase to a molten magnesium base material, and stirring and casting to prepare the carbon nanotube-alumina composite reinforced magnesium-based composite material, wherein the added carbon nanotube-alumina composite reinforced phase accounts for 1-15% of the molten magnesium base material by mass percentage. According to the invention, the defect of a magnesium-based alloy texture in the magnesium-based composite material produced in the prior art is overcome, the excellent enhancing effect of the carbon nanotubes in a magnesium matrix can be brought into full play, and the comprehensive performance of the magnesium-based composite material is ensured to be enhanced.

The invention discloses a preparation method of a graphene alloy nanocomposite and an SLM (Selective Laser Melting) forming process. According to the preparation method, turbid liquid is prepared through the ultrasonic vibration of anhydrous ethanol, so that the graphene is uniformly dispersed in the anhydrous ethanol, the graphene is uniformly dispersed, then after the graphene anhydrous ethanolturbid liquid is mixed with high-temperature alloy in proportion, the graphene and partial residue are distributed in the grain boundary and crystals by participating in the interfacial reaction, so that the strength and toughness of a formed part are improved, and the hot cracking tendency is reduced; the addition of graphene changes the organization form of the material; and in the SLM forming process, the graphene in the graphene high temperature alloy nanocomposite is used as a heterogeneous nucleating agent, and increases the nucleation rate in the solidification crystallization process.The graphene high temperature alloy nanocomposite is prepared by the dielectric barrier discharge plasma-assisted ball milling technique. The plasma enhances the activity of powder, so that columnar crystals preferentially growing change to isometric crystals, grains are refined and the performances are improved.

The invention discloses an instant food containing five red foods and a preparation method, belongs to the technical field of agricultural product deep-processing. Small red beans, red dates without cores, peanuts with red skin, medlar and brown sugar are used as raw materials, wherein the instant food block dry product containing five red foods is obtained by soaking the small red beans, red dates without cores, peanuts with red skin and medlar, boiling, heat-preserving, adding brown sugar, boiling, cooling, applying on mode, quick freezing, and freezing drying in vacuum; and the technical advantage of the vacuum freeze drying technology for maintaining the effective ingredients such as nutrient ingredient, pharmacology effect and color, aroma and taste of each component is sufficiently utilized, each component can sufficiently play the self effect, the obtained product has the food therapeutic effect of tonifying Qi, cultivating blood, beautifying skin, delaying senility if being eaten often. The instant food block dry product containing five red foods produced by the invention is ruddy in color, convenient for carrying, rapid in rehydration, and ready to use by adding warm water or hot water; the color is ruddy and natural after rehydration, the aroma is strong, and the taste is sweet; and the instant food has excellent color, aroma and taste, and is convenient for eating and good in flavor.

The invention relates to a combined high-precision hot stamping plate and a three-channel hot stamping refraction anti-counterfeiting mark, which aims to solve the technical problem of poor anti-counterfeiting effect of the traditional nesting overprinting, including a set of combined high-precision The laser engraving plate and two hot stamping films with different effects and colors, through the combination of the combined hot stamping plate and the hot stamping plate, combined with the structural design characteristics of the hot stamping mold and the hot stamping mold, realize the hot stamping plate and the hot stamping plate The three-channel refraction anti-counterfeiting logo is successively folded and ironed, so that different patterns, characters or lines can be observed from different viewing angles, which solves the technical problem that the folded ironing cannot form refraction anti-counterfeiting at various angles of view in the prior art.

The invention discloses a casting heat-proof magnesium alloy material in the light metal material domain, which comprises the following parts: 5%-10% gadolinium, 0. 5%-1. 0% manganese, 0. 3%-0. 8% scandium and residual magnesium, wherein Gd is main alloy element, which can form stable Mg-Gd compound under high temperature; Mn and Sc can form Mn2Sc in the heat disposing course; the property of alloy possesses dynamic property under normal temperature, which reduces the strength of the alloy slowly under 200-300 deg. c to satisfy aviation and automobile industry.

The invention relates to a 540MPa grade hot-rolled pickled steel plate and a manufacturing method thereof. The hot-rolled pickled steel plate comprises the following chemical components in percentageby mass: 0.15-0.25% of C, 0.01-0.06% of Si, 0.80-1.30% of Mn, 0.01-0.06% of Al, 0.015-0.050% of Nb, and / or 0.30-0.40% of Cr, less than 0.010% of P, less than 0.005% of S, and the balance Fe and inevitable impurities; and the final structure of the hot-rolled pickled steel plate comprises 55-65% by volume of ferrite, 30-40% by volume of pearlite, and 5-15% by volume of bainite. According to the 540MPa grade hot-rolled pickled steel plate, the components are optimized on the basis of the chemical components of a C-Mn series steel; the technical parameters of the rolling process, the cooling process and the pickling process are controlled, and thus the hot-rolled pickled steel plate of which the yield intensity is 440MPa or more, the tensile strength is at540MPa grade or more, and the longitudinal elongation A is not less than 26% can be obtained.

The invention discloses a preparation method of a carbon nanotube-alumina composite reinforced magnesium-based composite material, which relates to the manufacture of magnesium-based alloy by using a casting method. The preparation method comprises the steps of: step 1, calcining and reducing raw materials of ferric nitrate nonahydrate and alumina in the ratio of (0.07-1.00):1 to obtain an iron / alumina composite catalyst, and finally, performing catalytic pyrolysis reaction by using the mixed gas of nitrogen gas and ethylene in the volume ratio of (6-12):1 for uniformly dispersing carbon nanotubes on the surface of the alumina, so as to prepare a carbon nanotube-alumina composite reinforced phase; and step 2, adding the carbon nanotube-alumina composite reinforced phase to a molten magnesium base material, and stirring and casting to prepare the carbon nanotube-alumina composite reinforced magnesium-based composite material, wherein the added carbon nanotube-alumina composite reinforced phase accounts for 1-15% of the molten magnesium base material by mass percentage. According to the invention, the defect of a magnesium-based alloy texture in the magnesium-based composite material produced in the prior art is overcome, the excellent enhancing effect of the carbon nanotubes in a magnesium matrix can be brought into full play, and the comprehensive performance of the magnesium-based composite material is ensured to be enhanced.

The invention discloses a nickel toughening high-chromium cast iron self-protection overlaying flux-cored wire. The flux-cored wire uses a low-carbon steel strip as a cover, and comprises the following flux-cored components in percentage by mass: 55-65% of high carbon ferrochrome, 16-24% of nickel powder, 0.5-1% of 60-mesh graphite, 1-2% of 200-mesh graphite, 1-5% of 60-mesh ferroboron, 1-3% of 200-mesh ferroboron, 1-2% of 60-mesh aluminum magnesium alloy, 1-2% of 200-mesh aluminum magnesium alloy, 1-2% of 60-mesh manganese powder, 1-3% of 200-mesh manganese powder, and the balance iron powder; and the flux-cored powder is 50-56% of the total weight of the flux-cored wire. The flux-cored components with different particle sizes are added to the flux-cored wire to guarantee excellent welding process performance, and a proper amount of Ni is added in the flux-cored components to urge increment of austenite number in an overlaying alloy high-chromium cast iron hypereutectic structure matrix; and meanwhile, the solid solution strengthening effect of the matrix is obvious, an overlaying alloy is effectively toughened, the crack resistance is greatly improved, the welding process performance is excellent, the cladding efficiency is high, and the multilayer welding needs no slag removal.

The invention discloses a quick-drying type SBR-modified emulsified asphalt sealing layer mixture and a preparation method thereof. The mixture comprises the following components in parts by mass: 100parts of mineral aggregate, 11-13 parts of SBR-modified emulsified asphalt, 3-5 parts of cement, 3-5 parts of carbon fiber powder and 12-14 parts of tap water. The mixture has the advantages of beinghigh in strength, good in crack control effect and capable of being rapidly formed under a humid climate condition. The problems existing in the prior art are solved.

The invention discloses a preparation method and application of a modified SiCf / SiC ceramic-based composite material with SiC nanowires grown in situ. The preparation method comprises the following steps: placing a graphite flake containing a metal coating and a carbon fiber preform into a chemical vapor deposition furnace under a non-contact condition; carrying out chemical vapor deposition to realize in-situ growth of the SiC nanowires on pores and the surface of a carbon fiber preform so as obtain a SiC fiber preform with the SiC nanowires; and carrying out chemical vapor deposition again to obtain a SiC matrix, thereby obtaining the SiC nanowire modified SiCf / SiC ceramic-based composite material. According to the invention, a metal catalyst is indirectly introduced, the metal catalyst is diffused to the surface and internal pores of the SiC fiber preform in a gas phase manner, catalyst distribution is more uniform, and the density of the SiC nanowires grown under catalysis is moderate; and the maximum crushing load of the obtained SiC nanowire-containing SiCf / SiC composite material can reach 1175.0 N, so compared with a SiC nanowire-modified SiCf / SiC ceramic-based composite material in the prior art, the crushing performance of the tubular SiCf / SiC composite material obtained by the preparation method disclosed by the invention is greatly improved.

Provided are molded articles made of a fiber-reinforced material which are lightweight and have superior surface smoothness and mechanical strength, heat-curable resin compositions that are favorably used in the manufacture of said molded articles, and fiber-reinforced molding materials that are used in manufacturing said molded articles and have a superior low-pressure moldability. As a heat-curable resin composition to be used in the fiber-reinforced molding material, that which comprises a heat-curable resin, a hollow filler with packed bulk density of 0.24-0.45 g / cm3, and kaolin clay with packed bulk density of 0.60-1.20 g / cm3 as essential components was used.

The invention relates to a graphene surface modification method based on a dry method. The method comprises the following steps: S1, adding graphene oxide into a concentrated nitric acid solution, performing ultrasonic dispersion and filtration, repeatedly washing a filter cake with deionized water to be neutral to obtain the roughened graphene oxide; S2, putting the roughened graphene oxide in the S1 into a ball mill to be ball-milled, and then pouring silver acetate into the ball mill to be mixed with graphene oxide and ball-milling the mixture again to obtain a graphene oxide / silver acetate mixture; S3, putting the graphene oxide / silver acetate mixture into a muffle furnace to be heated and introducing a nitrogen atmosphere to obtain Ag particle-loading graphene oxide; and S4, adding the Ag particle-loading graphene oxide after ultrasonic treatment into hydrazine hydrate to be reduced to prepare Ag particles, the grain sizes of which are 30-100nm, and uniformly dispersing the Ag particles to the surface of graphene. The method provided by the invention is simple to operate, can produce on a large scale, and is free of heavy metal pollution.

The invention belongs to the field of composite solder, and particularly relates to a composite reinforced solder and a preparation method thereof. The composite type reinforced solder is composed ofSiC reinforced particles and the balance of matrix alloy; the SiC reinforcing particles are SiC particles modified by silver plating; and the mass fraction of SiC particles in the solder is 0.2-1% ofthe mass of the matrix alloy. The preparation method of the solder comprises the following steps of preparing silver-plated SiC particles; drying, grinding and storing; taking a matrix alloy, and smelting; preparing silver-plated SiC particle slurry; fully mixing the silver-plated sic particle slurry with the matrix alloy; and casting and forming. According to the composite reinforced solder, theyield strength of the welding spots can be obviously improved, the creep resistance and the anti-fatigue performance are improved, the service life of the electronic device is prolonged, and the electronic device can be suitable for large-scale production of enterprises.

The invention discloses a high-toughness carbon nanotube reinforced aluminum-based composite material with a non-uniform structure and a preparation method thereof, and belongs to the technical fieldof composite material preparation. The preparation method comprises the following steps: pre-grinding high-content carbon nanotube / aluminum composite material powder in a ball milling process, addinglow-content carbon nanotube / aluminum composite material powder at set intervals, performing ball milling, and finally adding aluminum alloy powder, so that gradient change of the content of carbon nanotubes is formed in a composite material micro-area under the action of cold welding. In addition, the later added composite material powder is short in ball milling time and small in grain refinementdegree, so that grain size gradient distribution of the micro-area is formed. The powder is subjected to subsequent densification and secondary processing to obtain the final composite material, andthe toughness of the composite material is far higher than that of a composite material with a uniform structure.

The invention relates to a construction method for a soft rock roadbed in a rainy and humid area, construction of a roadbed working area is carried out according to the depth of the roadbed working area obtained in advance, and construction of the roadbed working area comprises the following steps that after the construction of an embankment is completed, a water-resisting layer is paved on a surface of the constructed embankment; a roadbed working area is paved on the waterproof layer, wherein at least two layers of geocells are arranged in the roadbed working area. The method is advantaged in that the overall modulus and rigidity of the roadbed can be remarkably improved, and the requirements for roadbed construction and long-term service performance are met.

The invention provides a road heating mat for melting ice and snow and a pavement construction method thereof. The heating mat is arranged on an interface surface of an upper surface layer and a middle surface layer, is preformed by a heat insulation grid and heating cables, and can be divided into a straight mat and a bend mat according to the set shape of the heat insulation grid; the interlayer overall size occupancy rate and the field pavement power of the heating mat are utilized for synchronously adjusting the set parameters of the heat insulation grid, so that the interlayer stability can be effectively improved; the heating cables are arranged along grid bars of the heat insulation grid, so that the heat utilization ratio of the heating cables can be maximized. According to the construction method provided by the invention, through paving a rail, the heating mat can be effectively prevented from being crushed, pulled to be rolled up or pushed to slide so as to be damaged; through spraying emulsified asphalt for two times, fixing the heating mat through staple bolts, and setting the grinding times according to the interlayer overall size occupancy rate of the heating mat, the interlayer stability of the road requiring melting ice and snow can be effectively improved, the road damage is reduced, and the service life of the road requiring melting ice and snow is prolonged.

The invention discloses a frame assembly and an engineering vehicle, and relates to the technical field of engineering machinery. The frame assembly comprises two longitudinal beams arranged in a spaced mode, a first beam set, a second beam set, a gantry beam, a lifting beam set and a rack assembly. The first beam set is arranged at one ends of the longitudinal beams, and the two ends of the first beam set are connected with the two longitudinal beams respectively. The second beam set is arranged at the other ends of the longitudinal beams, and the two ends of the second beam set are connected with the two longitudinal beams respectively. The gantry beam is arranged between the first beam set and the second beam set, the two ends of the gantry beam are connected with the two longitudinal beams respectively, and a steering support is arranged on the gantry beam. The lifting beam set is arranged between the gantry beam and the second beam set, and the two ends of the lifting beam set are connected with the two longitudinal beams respectively. The two ends of the rack assembly are detachably connected with the two longitudinal beams, and a part of the rack assembly is arranged corresponding to the gantry beam. The frame assembly can reduce the stress concentration phenomenon, reduce the production cost and improve the strength, the rigidity and the reliability.

Disclosed is a direct-current boost double-fed switch reluctance generator current conversion system. The direct-current boost double-fed switch reluctance generator current conversion system is composed of a storage battery, a main circuit, a charging and energy feeding circuit, a bidirectional isolator and an output capacitor; the main circuit is composed of phase circuits of respective phase windings, each phase circuit is in parallel connection with each other, the storage battery provides excitation, and each phase circuit can realize the enhancement excitation effect of one time amplification when the excitation voltage is increased during excitation, the voltage of the output side can be obviously higher than that of the storage battery at the input side, and meanwhile, the problemthat continuous output current cannot be obtained at the output side of the excitation stage in the operation of the switched reluctance generator is solved, and the storage battery participates in output in the excitation stage, so that the output side electric energy quality is higher; the charging and energy feeding circuit can automatically charge the storage battery positively, and the electric energy of the storage battery can be reversely output to a load side under the extreme condition, so that the adaptability of the system is improved; and the system is suitable for being applied tomedium-high-speed medium-and-small-sized switched reluctance generator systems under various power drives.

The invention discloses aluminum alloy powder for additive manufacturing and a preparation method and application of the aluminum alloy powder. A small amount of graphene powder, zirconium oxide powder and aluminum alloy powder are mixed, agglomeration of graphene can be prevented by mixing the zirconium oxide powder, the graphene can be subjected to interface reaction on a matrix to generate carbide, the carbide is uniformly dispersed in grain boundaries and grains to generate a pinning effect; the dislocation density is increased through Orowan strength, grains are refined through heterogeneous nucleation, and transfer of more loads from a matrix to graphene is promoted, so that a strengthening effect is achieved, spatial distribution of a double-phase reinforced phase is improved, interface bonding strength is improved, wettability of the reinforced phase and the matrix is improved, powder fluidity is improved, and the quality of the composite powder is improved; and meanwhile, by combining the high-temperature-resistant, wear-resistant and corrosion-resistant reinforcing phases of the graphene and the zirconium oxide powder, about 5% of volume expansion can be generated during conversion from a t phase (tetragonal phase) to an m phase (monoclinic phase), crack propagation in a matrix is hindered, and phase toughening is generated.

The invention relates to a ceiling splicing structure and a splicing method thereof. A first splicing block flush with the upper surface of a first splicing plate is arranged on the side face of the first splicing plate, a second splicing block is arranged in the middle of the side face of a second splicing plate, and the first splicing plate and the second splicing plate are connected through vertical splicing wood pins. The distance between the upper side of the second splicing block and the upper surface of the second splicing plate is consistent with the thickness of the first splicing block, a bonding glue layer is arranged on the contact positions of the first splicing plate and the first splicing block with the second splicing block, and a steel wire net is arranged on the lower surface of the second splicing block. The side face of the steel wire net penetrates into the first splicing plate and the second splicing plate through wire net fixing bolts, and the lower portion of the steel wire net is integrally connected with a concrete layer flush with the lower surfaces of the first splicing plate and the second splicing plate. Through improvement on the structure and splicing mode of the two splicing plates, it can be ensured that the supporting face of the upper portion of the concrete layer is a seamless plane, it is ensured that the structure of the concrete layer isstable for a long time, and the function of wall paint cracking prevention of the ceiling splicing structure is achieved.

The invention discloses an instant food containing five red foods and a preparation method, belongs to the technical field of agricultural product deep-processing. Small red beans, red dates without cores, peanuts with red skin, medlar and brown sugar are used as raw materials, wherein the instant food block dry product containing five red foods is obtained by soaking the small red beans, red dates without cores, peanuts with red skin and medlar, boiling, heat-preserving, adding brown sugar, boiling, cooling, applying on mode, quick freezing, and freezing drying in vacuum; and the technical advantage of the vacuum freeze drying technology for maintaining the effective ingredients such as nutrient ingredient, pharmacology effect and color, aroma and taste of each component is sufficiently utilized, each component can sufficiently play the self effect, the obtained product has the food therapeutic effect of tonifying Qi, cultivating blood, beautifying skin, delaying senility if being eaten often. The instant food block dry product containing five red foods produced by the invention is ruddy in color, convenient for carrying, rapid in rehydration, and ready to use by adding warm water or hot water; the color is ruddy and natural after rehydration, the aroma is strong, and the taste is sweet; and the instant food has excellent color, aroma and taste, and is convenient for eating and good in flavor.

The invention discloses a nickel toughening high-chromium cast iron self-protection overlaying flux-cored wire. The flux-cored wire uses a low-carbon steel strip as a cover, and comprises the following flux-cored components in percentage by mass: 55-65% of high carbon ferrochrome, 16-24% of nickel powder, 0.5-1% of 60-mesh graphite, 1-2% of 200-mesh graphite, 1-5% of 60-mesh ferroboron, 1-3% of 200-mesh ferroboron, 1-2% of 60-mesh aluminum magnesium alloy, 1-2% of 200-mesh aluminum magnesium alloy, 1-2% of 60-mesh manganese powder, 1-3% of 200-mesh manganese powder, and the balance iron powder; and the flux-cored powder is 50-56% of the total weight of the flux-cored wire. The flux-cored components with different particle sizes are added to the flux-cored wire to guarantee excellent welding process performance, and a proper amount of Ni is added in the flux-cored components to urge increment of austenite number in an overlaying alloy high-chromium cast iron hypereutectic structure matrix; and meanwhile, the solid solution strengthening effect of the matrix is obvious, an overlaying alloy is effectively toughened, the crack resistance is greatly improved, the welding process performance is excellent, the cladding efficiency is high, and the multilayer welding needs no slag removal.

A direct-boost double-fed switched reluctance generator converter system, which is composed of a battery, a main circuit, a charging and energy feeding circuit, a bidirectional isolator, and an output capacitor. The main circuit is composed of a phase circuit of each phase winding, and each phase circuit is mutually Parallel connection, the battery provides excitation, each phase circuit can realize the enhanced excitation effect of doubling the excitation voltage during excitation, and can directly realize that the voltage on the output side is significantly higher than the battery voltage on the input side, and at the same time solve the problem of output during the excitation phase of the switched reluctance generator. The problem that the continuous output current cannot be obtained on the side, and the battery participates in the output during the excitation phase, so that the power quality of the output side is higher; the charging and energy feeding circuit can automatically charge the battery in the forward direction, and can also reverse the battery power in extreme cases The output is to the load side, which improves the adaptability of the system; it is suitable for application in medium and high speed medium and small switched reluctance generator systems driven by various powers.

A high volume fraction SiC nanowire-reinforced aluminum matrix composite material densification device and method based on three-dimensional constrained deformation relates to a SiC nanowire / Al composite material densification device and method. The purpose is to solve the high SiC nw SiC nanowire-reinforced Al-matrix composites with high content are prone to cracking after hot extrusion and there are problems of adverse reactions after high-temperature extrusion. The device is composed of a mold, a mold bottom plate, an upper pressing head, a lower pressing head and a constraint body. The constraint body has a cylindrical cavity. METHODS: The device was assembled and the aluminum matrix composite was placed in a cylindrical cavity, preheated and pressure applied. When the method and the mold of the invention are densified, the composite material is under three-dimensional compressive stress, and the cracking of the aluminum-based composite material can be avoided while densifying. The strength, density and elongation of aluminum matrix composites are improved. The invention is suitable for densification of aluminum-based composite materials.

The invention provides a road heating mat for melting ice and snow and a pavement construction method thereof. The heating mat is arranged on an interface surface of an upper surface layer and a middle surface layer, is preformed by a heat insulation grid and heating cables, and can be divided into a straight mat and a bend mat according to the set shape of the heat insulation grid; the interlayer overall size occupancy rate and the field pavement power of the heating mat are utilized for synchronously adjusting the set parameters of the heat insulation grid, so that the interlayer stability can be effectively improved; the heating cables are arranged along grid bars of the heat insulation grid, so that the heat utilization ratio of the heating cables can be maximized. According to the construction method provided by the invention, through paving a rail, the heating mat can be effectively prevented from being crushed, pulled to be rolled up or pushed to slide so as to be damaged; through spraying emulsified asphalt for two times, fixing the heating mat through staple bolts, and setting the grinding times according to the interlayer overall size occupancy rate of the heating mat, the interlayer stability of the road requiring melting ice and snow can be effectively improved, the road damage is reduced, and the service life of the road requiring melting ice and snow is prolonged.

The invention relates to a 540MPa grade hot-rolled pickled steel plate and a manufacturing method thereof. The hot-rolled pickled steel plate comprises the following chemical components in percentageby mass: 0.15-0.25% of C, 0.01-0.06% of Si, 0.80-1.30% of Mn, 0.01-0.06% of Al, 0.015-0.050% of Nb, and / or 0.30-0.40% of Cr, less than 0.010% of P, less than 0.005% of S, and the balance Fe and inevitable impurities; and the final structure of the hot-rolled pickled steel plate comprises 55-65% by volume of ferrite, 30-40% by volume of pearlite, and 5-15% by volume of bainite. According to the 540MPa grade hot-rolled pickled steel plate, the components are optimized on the basis of the chemical components of a C-Mn series steel; the technical parameters of the rolling process, the cooling process and the pickling process are controlled, and thus the hot-rolled pickled steel plate of which the yield intensity is 440MPa or more, the tensile strength is at540MPa grade or more, and the longitudinal elongation A is not less than 26% can be obtained.

The invention discloses a high-strength and tough carbon nanotube-reinforced aluminum-based composite material with a non-uniform structure and a preparation method thereof, belonging to the technical field of composite material preparation. In the process of ball milling, pre-grind high-content carbon nanotube / aluminum composite material powder, then add low-content carbon nanotube / aluminum composite material powder for ball milling at regular intervals, and finally add aluminum alloy powder, thus in the cold Gradient change of carbon nanotube content formed in the micro-area of ​​composite material under welding action. In addition, due to the short ball milling time of the composite material powder added later, the degree of grain refinement is small, thereby forming a grain size gradient distribution of micro-domains. The powder is subjected to subsequent densification and secondary processing to obtain the final composite material, which exhibits much higher strength and toughness than the homogeneous structure composite material.

The invention discloses 600MPa-grade automobile axle housing steel for hot stamping and a production method thereof. The 600MPa-grade automobile axle housing steel comprises the following chemical components in percentage by weight: 0.240%-0.335% of C, 0.08%-0.65% of Si, 1.75%-2.25% of Mn, 0.010%-0.065% of Al, 0.046%-0.085% of Nb, 0.052%-0.102% of Ti, 0.054%-0.102% of V, 0.10%-0.46% of Cr, 0.12%-0.26% of Mo, 0.0014%-0.0035% of B, 0.033%-0.042% of La + Ce, 0.0014%-0.0050% of Ca, less than or equal to 0.010% of P, less than or equal to 0.005% of S and less than or equal to 0.003% of N. The yield strength of the steel plate is not less than 600 MPa, the tensile strength is not less than 780 MPa, and the transverse elongation A50 is not less than 28%.