126results about How to "prevent oxidation" patented technology

The invention discloses a preparation and use of raw liquid of ceratin of animal hairs, such as wool, camel hair, bristle, human hair, bird feather and animal hair. The method comprises preparing combination reducing agent by sulfite, carbon amide compound and sodium salt organic matter, reducing the material hairs and producing raw liquid of ceratin of animal hairs. The keratin spinning fluid can be mixed with a plurality of materials, if mixing together with the nano silver series antiseptic material, then producing spinning fluid by grafting with the cellulose graft. The wet processing device and art can produce filament yarn or short fiber.

A package for a drug-device combination product includes an outer package including a first gas impermeable sheet and a second gas impermeable sheet hermetically sealed there to on three sides. A gas permeable header is attached to an unsealed side of the first sheet and sealed to the second sheet on two sides. The first and second gas impermeable sheets and the header form an interior and an opening communicating with the interior. A gas permeable inner package is disposed within the outer package. A product is sealed within the inner package. The inner package is placed within the outer package and a top end of the header is sealed to the second sheet. The outer package is then sealed by sealing the first gas impermeable sheet to the second gas impermeable sheet at a seal point below the point where the header attaches to the first sheet.

The invention relates to a preparation method of zirconium diboride and silicon carbide high-temperature antioxidant coating, belongs to the technical field of thermal spraying and particularly relates to a preparation method of material surface high-temperature antioxidant coating. ZrB2-SiC coated composite powder is prepared by spray-drying, so that volatilization of SiC during spraying is prevented; the SiC helps further improve high-temperature oxidization resistance of the coating. The ZrB2-SiC composite coating is prepared by means of ultralow-pressure plasma spraying, so that oxidization of the ZrB2-SiC composite powder during spraying is avoided effectively, porosity of the coating can be reduced and bonding strength of the coating can be improved. The prepared ZrB2-SiC composite powder is not larger than 45s/50g in mobility and 2-3.0g/cm<3> in apparent density; the prepared coating is 7-10% in porosity and 20MPa in bonding strength.

The invention provides an elastic bonding type Nd-Fe-B magnetic material, which is prepared through the following steps: preparation of raw materials, refinement of the prepared powder mixture, rolling, heat treatment and formation, thereby obtaining the elastic bonding type Nd-Fe-B magnetic material. The raw materials comprise the following components: 10-95 parts by weight of Nd-Fe-B magnetic powder, 1-50 part(s) by weight of ferrite powder selected from strontium ferrite and/or barium ferrite, 2-20 parts by weight of adhesive selected from at least one of CPE plastic, PE plastic and NBR rubber, 0.1-3 part(s) by weight of coupling agent, 0.2-3 part(s) by weight of plasticizer and 0.1-3 part(s) by weight of binder. The preparation of the raw materials comprises the following steps: screening the Nd-Fe-B magnetic powder with a 40-mesh sieve or a sieve with more than 40 meshes, blending the Nd-Fe-B magnetic powder after screening and the coupling agent until the coupling agent is completely dipped in the metal magnetic powder, and adding other raw materials. The invention also provides a manufacturing method of the elastic bonding type Nd-Fe-B magnetic material.

The invention discloses a flame tube head assembly brazing method and belongs to the technical field of aero-engine part manufacturing. In a brazing method of a traditional flame tube head assembly, an assembly substrate at a positioning welding point is oxidized due to the fact that a tube front section and a splash pan are positioned through argon arc welding, so that during brazing, brazing filter metal cannot moisten the substrate at the positioning welding point, the brazing seam is not continuous, and a design requirement of a continuous brazing seam cannot be achieved, and after brazing, a cold air hole is blocked by the brazing filter metal, the brazed rate between a sleeve and a swirler cannot achieve a design requirement of more than 80%. The flame tube head assembly brazing method has the advantages that the assembly substrate at the positioning welding point is avoided from being oxidized due to positioning through energy storage spot welding, enabling the paste brazing filter metal to moisten the substrate at the positioning welding point and guaranteeing the continuous brazing seam design requirement; enabling a to-be-welded position on the internal side of the sleeve to satisfy the brazed rate requirement and avoiding the brazing filter metal blocking the cold air hole during the brazing process due to the fact that check soldering flux pains inside the cold air hole; the operability is strong and production costs are obviously reduced.

The invention realtes to a high-stability recyclable surface-enhanced Raman substrate and a preparation method and belongs to the technical field of trace-amount organic substance detection. In the method, a silver nanorod array thin film is prepared through an inclined growing method and then an amorphous-state titanium oxide thin film is uniformly deposited onto a surface of the silver nanorod array thin film through an atomic layer deposition method to obtain a silver-at-titanium oxide composite nanorod array thin film as the surface-enhanced Raman substrate. By means of the substrate, a surface-enhanced Raman signal is free from being attenuated greatly due to the ultrathin titanium oxide layer. The substrate is excellent in enhancement effect. Meanwhile, the titanium oxide thin film enables silver nanorods to be isolated from external environment so that the silver nanorods are enhanced in anti-oxidizing and anti-vulcanizing performance, thereby greatly enhancing stability of the substrate. The titanium oxide, as a photocatalytic material, can catalytically decomposing organic substances adsorbed on the surface of the substrate with combination of an ultraviolet light. The substrate, after being irradiated by the ultraviolet light, can be recycled as a clean substrate. The substrate has a wide application prospect in the field of the trace-amount organic substance detection.

The invention provides antioxidant salen-metal complexes, compositions of such antioxidant salen-metal complexes having superoxide activity, catalase activity, and/or peroxidase activity, compositions of salen-metal complexes in a form suitable for pharmaceutical administration to treat or prevent a disease associated with cell or tissue damage produced by free radicals such as superoxide, and cosmetic and free radical quenching formulations of salen metal compounds.

The invention provides a distillation apparatus. The distillation apparatus comprises a distillation bottle, a condensation bottle and a backflow bottle as well as a heating device, a condensation system, a control device and a shell, wherein the heating device is corresponding to the distillation bottle, the condensation system is corresponding to the condensation bottle, and a distillation gas inlet, a distillation liquid outlet, a condensate inlet and a condensate outlet are formed in the condensation bottle. The distillation apparatus is characterized in that the distillation bottle is provided with three bottle openings which are respectively a first bottle opening, a second bottle opening and a third bottle opening; and the distillation bottle is communicated with the distillation gas inlet of the condensation bottle through the first bottle opening, is communicated with a nitrogen flushing device through the second distillation bottle and is communicated with a sampling device and an anti-suck-back gas supply device through the third bottle opening. When the heating of the distillation apparatus is stopped, the suck-back cannot occur, the bumping is avoided in the heating process, and a tested material can be prevented from being oxidized in the heating process.

The invention discloses a semiconductor lead frame surface treatment method sequentially comprising ultrasonic degreasing, electrolytic degreasing, washing, sulfuric acid neutralization and activation, washing, electro-coppering, washing, acid neutralization, washing, copper protection, washing, hot washing, and drying. The step of copper protection has the following specific technical requirements: a semiconductor lead frame is guided into and immersed in protection liquid to achieve the purpose of making the semiconductor lead frame coated with a copper protective film, wherein the pH of the protection liquid is 5-7, the temperature is 20-40 DEG C, the immersion time is 10-20S, and the protection liquid contains 9-15g/L alkyl benzimidazole and 1-3g/L acetic acid. An organic protective layer is arranged on a copper surface layer to replace a diaphragm layer, and the protective layer is naturally removed during tin dipping and aluminum wire welding. Thus, protection is achieved without affecting the welding effect.

The invention relates to the technical field of wire annealing, in particular to a wire annealing process and a device thereof, the wire annealing process mainly comprises three working procedures of heating treatment in a high temperature annealing region, cooling treatment in a steam cooling region and liquid water coating and cooling treatment in a liquid water coating and cooling region, wherein steam in the steam cooling region is low-temperature steam generated by a built-in steam generator, thereby realizing high cooling efficiency, having no problem of condensate and being applied in annealing of a variety of wires; furthermore, due to the working procedure of the liquid water coating and cooling treatment, the wire annealing process can not easily complete the wire cooling, but also better complete the tasks of coating of an antioxidant, coating a booster flux, cleaning the booster flux and the like. Therefore, the wire annealing process and the device thereof can avoid the oxidation of annealed wires, improve the performance and the quality stability of the wires after annealing, further realize the perfect coating of the antioxidant and the pretreatment of tin plating, have good energy-saving effect and be applied in the annealing of a variety of wires.

The invention discloses a color retention agent and relates to food processing, wherein the color retention agent is composed of the following ingredients: citric acid, phytic acid and calcium chloride. Compared with the prior art, the purple potato flour production method of the color retention agent disclosed by the invention can be used for effectively preventing the oxidization of anthocyanin, reducing the nutritional ingredient loss of the fresh purple potato and improving the reconstitution properties of the product.

The invention provides a melting and iron-smelting device of a heat storage type electric arc furnace, which comprises a furnace body of the electric arc furnace and matched equipment, at least one pair of combustion chambers and at least one pair of heat storage devices, the device is further provided with at least one pair of gasification boxes which are arranged between the furnace body of theelectric arc furnace and the combustion chambers, and at least one layer of coal grid is arranged in each gasification box. Each gasification box is provided with a bypass, and valves are arranged onan outlet, an inlet and the bypass of each gasification box. The device aims at preventing reduced substances at the gas inlet from being oxidized after that circulating gas or air enters the electricarc surface; oxygen-containing gas preheated by the heat storage devices, in particular to the air, firstly enters the combustion chambers to be mixed with fuel sprayed into the combustion chambers for burning before entering the electric arc furnace, and high-temperature flue gas is exhausted from the combustion chambers and then enters the gasification boxes to carry out gasification reaction with coal in the coal grids for generating CO, thereby forming a reducing atmosphere, optimizing the environment of melting, reducing and iron-smelting of the electric arc furnace, being conductive tothe reducing process of the reduced substances, improving the quality of reduced iron products and reducing environmental pollution.

The invention provides a method for preparing a nano-copper/epoxy resin composite material, relates to a preparation method of an epoxy resin composite material, and aims to solve the problem that nano-copper powder in an existing nano-copper/epoxy resin composite material is easy to cluster, and the dispersibility in the epoxy resin is poor, so that a mechanical property of the nano-copper/epoxy resin composite material is poor. The method comprises the following steps: 1, preparing nano-copper powder; 2, dispersing; 3, preparing a composite material. The nano-copper/epoxy resin composite material prepared by the method has the advantages that: 1, the copper powder in the nano-copper/epoxy resin composite material is nanoscale; 2, the oxidation of the nano-copper powder is effectively prevented; 3, an emulsifying machine is used to disperse a nano-copper/epoxy resin system, the method is simple, and the dispersibility is good; 4, the nano-copper/epoxy resin composite material prepared by the invention has the characteristics that the tensile strength is 38-50 MPa, the elastic modulus is 1200-1700 MPa and the hardness is 80-84 degrees. The method can be used to prepare the nano-copper/epoxy resin composite material.

The present invention relates to a method for fabricating a ferroelectric random access memory device. The method includes the steps of: (a) forming a first inter-layer insulation layer on a substrate providing a transistor; (b) etching the first inter-layer insulation layer to form a storage node contact hole exposing a partial portion of the substrate; (c) burying a storage node contact including a plug and a barrier metal layer into the storage node contact hole; (d) forming an adhesion layer on the storage node contact and the first inter-layer insulation layer; (e) inducing a predetermined portion of the adhesion layer to be cracked, the predetermined portion disposed above an upper part of the plug; (f) selectively removing the cracked predetermined portion to expose a surface of the barrier metal layer formed on the plug; and (g) forming a ferroelectric capacitor connected to the plug through the exposed surface of the barrier metal layer.

The invention discloses a household water treatment filter material capable of slowly releasing vitamin C. The household water treatment filter material is prepared from the following components in percentage by weight: 50 to 95 percent of a hydrophilic organic macromolecular polymer, 1 to 20 percent of vitamin C, 0.5 to 5 percent of vitamin E, 2 to 20 percent of an inorganic porous adsorbent, 2 to 5 percent of a foaming agent and 0.1 to 0.4 percent of an antioxidant synergist. The invention further discloses a preparation method of the household water treatment filter material capable of slowly releasing vitamin C. The filter material can control the slow release speed of vitamin C and prolong the dissolving time of vitamin C.

The invention provides an array substrate, a manufacturing method thereof and a display device. The manufacturing method comprises the steps of forming a first conducting layer and a second conductinglayer in a first area and a second area of a substrate, binding pins which are located in the first area and used for being electrically connected with a driving chip are formed, the second conducting layer is located on the side, away from the substrate, of the first conducting layer, and the first area and the second area are spaced; removing the second conductive layer in the second region, and forming a conductive electrode which is located in the second region and is used for being electrically connected with the light-emitting element through a connecting piece; wherein the adhesive force between the first conducting layer and the connecting piece is larger than that between the second conducting layer and the connecting piece, and the second conducting layer is used for preventingthe first conducting layer from being oxidized. The manufacturing method has the advantages that the manufacturing process is simplified, the oxidation resistance of the binding pin is improved, and the adhesive force between the connecting piece and the conductive electrode is improved, so that the light-emitting element is firmly fixed on the array substrate.

The invention discloses a preparation method for a low oxygen content and high alloying nickel-based mother alloy and powder and belongs to the field of powder metallurgy. The technological process of the preparation method includes the steps that firstly, a pure mother alloy ingot is prepared by means of duplex processes of vacuum smelting and electroslag remelting. In the process of vacuum smelting, a calcium oxide crucible is adopted, raw materials are pre-treated, carbon blocks are added in a refining stage for deoxidization, elements prone to the burning loss are supplemented at the end stage of smelting, and the mother alloy ingot in designed components is obtained. In the process of the electroslag smelting, by adjusting the shape, the depth, the viscosity and other parameters of a slag pond, the float-up condition of the nonmetallic inclusion is created, and the mother alloy is further purified. After the mother alloy ingot subjected to electroslag remelting is subjected to scaling, the mother alloy ingot is subjected to high-speed disk grinding breakage under the protective atmosphere, and the ultra-thin mother alloy powder is obtained. The particle size of the K418 mother alloy powder prepared through the method is smaller than 20 microns, the oxygen content is lower than 200 ppm, the sulfur content is lower than 20 ppm, after the alloy podwer is mixed with carbonyl nickel powder, sintering compacting at low temperature can be achieved, and the production cost and the process energy consumption of a high temperature alloy of the powder are greatly reduced.

A method for fabricating a semiconductor device includes the steps of forming an oxide film on a silicon carbide substrate; forming a gate electrode layer on the oxide film thereafter to pattern the gate electrode layer so as to form a gate electrode, comprising: and performing a thermal treatment to the gate electrode layer or the gate electrode in a mixed gas atmosphere of an oxidized gas and an inert gas.

A flip chip package includes a substrate and a semiconductor chip. The substrate includes a substrate body, a metal wiring having a terminal part some of which is disposed in the substrate body, a solder resist pattern formed on the substrate body with an opening for exposing the terminal part, and an organic anti-oxidation layer for covering the terminal part. The semiconductor chip has a bump formed through (e.g., penetrates) the organic anti-oxidation layer and is electrically connected to the terminal part. The present invention prevents oxidation of the terminal part and allows easy coupling of a bump of a semiconductor chip and the terminal part of the substrate, since an anti-oxidation layer including an organic matter is formed over a surface of a terminal part including copper which is easily oxidized.

The invention discloses an extraction separation device for biopharmaceutical and belongs to the technical field of biopharmaceutical. The extraction separation device comprises a liquid allocation cabinet, a waste gas purification mechanism, a centrifugal mixing mechanism and a solid-liquid separation mechanism, wherein a discharge funnel communicating with the interior of the liquid allocation cabinet is arranged at the bottom of the liquid allocation cabinet; a discharge pipeline communicating with the interior of the discharge funnel is arranged on the discharge funnel; a liquid inlet pipeline is arranged at the upper section of the liquid allocation cabinet; a filtering net is arranged inside the liquid allocation cabinet; the solid-liquid separation mechanism comprises a push plate,a moving strip, an anti-plugging component and a discharge component; and the push plate is horizontally arranged at the bottom of the moving strip. The extraction separation device has the beneficialeffects that through the solid-liquid separation mechanism, solid-liquid separation can be achieved, mesh holes of a filtering net can be prevented from being blocked, an extraction liquid and a liquid can be sufficiently mixed through the centrifugal mixing mechanism, a gas can be conveyed into a purification cylinder through the waste gas purification mechanism under the action of a fan, and centralized treatment on the gas can be achieved.

The invention discloses a household intelligent wine making machine, which comprises a cover body equipped fermentation tank, a measuring instrument for measuring relevant parameters in the fermentation tank, a motor for controlling the motion state of a connecting rod extending to the inside of the fermentation tank, a control cabinet for controlling the measuring instrument and the motor, a peel residue receiving device and a filter screen bag arranged at the middle-lower part of the fermentation tank in order, a storage tank detachably connected to the fermentation tank and used for receiving and storing wine, a first valve and a filter core arranged on a communicating pipe between the fermentation tank and the storage tank, a second valve located at the lower part of the storage tank, and a cooling device cladding the storage tank and is in connection with the control cabinet. In the fermentation process, the liquid can be taken out to test the degree of fermentation, sundry bacteria cannot be introduced into the fermentation tank in the whole process, and the fermentation quality cannot be affected. At the end of fermentation, the well fermented wine can be filtered and transferred into the storage tank to undergo later fermentation, and sundry bacteria cannot be introduced as well, thus ensuring the wine quality.

The invention relates to a method for modifying an anode active material of a lithium ion battery, comprising the following steps of: stirring and mixing hydrolysis liquid of salt compounds containing metal elements with the anode active material for over one hour, and adjusting the pH value of a mixture to be 2-10; then removing a solution by centrifugation in a centrifugal machine and flushing the anode active material with a water-soluble liquid until the pH value of the flushing liquid is between 1 and 7; drying and sintering the flushed anode active material in the presence protective gases; removing an excessive solution and hydrolysate of metal ions by centrifugal treatment to avoid metallic oxide from being locally deposited on the surface of the active material and uniformly redistribute the metal oxide on the surface of the active material; and flushing the active material with a hydrophilic substance, thereby avoiding other materials from being resided on the surface of theactive material, further avoiding the side effect of the lithium ion battery and improving the overall performance of the lithium ion battery.

The invention discloses a preparation method of a fucoxanthin microcapsule, which belongs to the technical field of food processing. The preparation method comprises the following steps: (1) uniformly mixing palm stearin and fucoxanthin to be used as a core material, and ultrasonically dispersing the core material in a gelatin solution to form uniform emulsion; (2) adding an Arabic gum solution containing a surfactant into the emulsion of the step (1), stirring for 5 to 15 min at constant temperature, adjusting PH to be 3.8 to 4.2 by utilizing acetic acid, and carrying out complex coacervation; (3) lowering the temperature of a system of step (2) to be lower than 10 DEG C, adding a tannic acid solution, and curing microcapsules; and (4) after the microcapsules are precipitated, adding deionized water to wash the microcapsules, repeating for multiple times, and freeze drying to obtain microcapsule powder. The fucoxanthin microcapsule prepared by the invention is uniform in particle size, stable in structure, and unlikely to have the situation such as breaking and leakage of core materials, so that the storage and application of the fucoxanthin can be facilitated.

The invention belongs to the technical field of metal-based composite materials, and particularly relates to an online melting carbon fiber reinforced aluminum-magnesium composite plate cast rolling molding device and method. The technical problems that in an existing continuous fiber reinforced aluminum-magnesium composite plate technology, the technology is complex, molten metal is prone to being oxidized, the interfacial bonding strength is low, and the composite plate quality is poor are solved. The online melting carbon fiber reinforced aluminum-magnesium composite plate cast rolling molding device comprises a rolling mill system, an online heating system, a gas protecting system, a leather plate, a core plate and a reinforced carbon fiber cloth. The online melting carbon fiber reinforced aluminum-magnesium composite plate cast rolling molding device has the advantages that the process of preparing the fiber material reinforced metal-based composite plate through the cast rollingtechnology is short, and the interfacial bonding strength is high; the smelting and pouring links in a traditional cast rolling technology are replaced with online melting, and therefore oxidization caused by metal liquid transferring is avoided; and the structure is compact, the technology is stable, the temperature is easy to control, and the composite plate size precision is high.

The invention discloses a broadband chiral terahertz emitting source and an emitting method thereof. The emitting source comprises a base and a magnetic field generator. One side of the base is covered with at least one layer of non-magnetic topological semi-metal nano-film layer. Each non-magnetic topological semi-metal nano-film layer is covered with a ferromagnetic metal film layer. The adjacent non-magnetic topological semi-metal nano-film layer and the ferromagnetic metal film layer form a double-layer heterojunction. The double-layer heterojunction is located in a magnetic field generated by the magnetic field generator. The outermost ferromagnetic metal film layer is covered with a covering layer. A polarization regulator is arranged outside the covering layer. The femtosecond pulselaser light source is used as an excitation light source, and the intensity and the chirality of the generated terahertz are adjusted by changing the direction of the external magnetic field and thepolarization of the excitation light so that the broadband chiral terahertz with high power and adjustable polarization can be obtained.

The invention discloses a preparation method of an Nb3AL superconducting wire split conductor precursor. The preparation method comprises the following steps: preparing a complex bar, preparing an Nb3AL superconducting wire single core precursor and preparing an Nb3AL superconducting wire split conductor precursor. The preparation method of the Nb3AL superconducting wire split conductor precursor solves the problem that an existing preparation method has rigor requirements on manufacturing equipment and hardly removes the oxide layer on the surfaces of AL particles, and meanwhile a manufactured Nb3AL superconducting wire split conductor precursor is even in ingredients and good in performance, effectively reduces cost and is beneficial for mass production.

The invention provides a welding mechanism of a vacuum welding furnace, belonging to the technical field of vacuum welding. The mechanism is characterized by comprising a welding chamber (18), and a furnace cover which is arranged at the upper side of the welding chamber (18), wherein a welding cavity is arranged between the furnace cover (4) and the welding chamber (18); a welding platform (20) is arranged at the lower part of the welding chamber (18); a heating area is arranged at one side, close to the feeding end, of the welding platform (20); a cooling area is arranged at one side, closeto the discharging end, of the welding platform (20); a negative pressure pumping module (9) is arranged at the upper side of one end, close to the cooling area, of the heating area; the negative pressure pumping module (9) is mounted on the furnace cover (4) by lifting, and the bottom part of the negative pressure pumping module (9) encircles a closed negative pressure chamber with the heating area; a protecting gas inlet pipe is arranged on the welding chamber (18) or the furnace cover (4). With the adoption of the mechanism, sheets can be quickly welded in the negative pressure cavity and are prevented from reacting with oxygen during heating.

The invention discloses an online solid solution heat treatment process for a high-performance copper alloy strip. The online solid solution heat treatment process for the high-performance copper alloy strip is based on an online solid solution heat treatment device for the copper alloy strip. The copper alloy strip is unrolled from a coiled material and is heated, and then the heat preservation,the air cooling, the strip profile correction and other technological operations are performed, so that the continuous online solid solution treatment of the copper alloy strip is realized. The onlinesolid solution heat treatment process has the following five advantages: one. the feed-in speed of the copper alloy strip is synchronized with the rotating speeds of a synchronous roller sealing doorand a rewinding synchronous tensioning wheel to prevent the surface of the copper alloy strip from being scratched; two. the reducing gas protection is adopted to prevent oxidation of the surface ofthe strip; three. the strip is heated by stage, the temperature rises gradually and is uniform, the surface of the strip is free during cooling treatment, and therefore, the residual internal stress is small; four. the profile of the copper alloy strip is corrected by adopting a furnace front S-roller device, multiple sets of middle pinch rolls and a furnace rear S-roller device, so that the stripprofile of the finished product is flat; and five. the process has the characteristics of uniform cooling and fast speed, and the finished copper alloy strip has extremely high mechanical propertiesand consistency.

Disclosed are cover gas compositions comprising fluoroolefins for impeding the oxidation of molten nonferrous metals and alloys, such as magnesium. The cover gas compositions can include at least one fluoroolefin and a carrier gas.

The invention discloses a preparation method of a tantalum 2.5 tungsten alloy plate. The preparation method comprises the following steps: (1) a tantalum 2.5 tungsten alloy ingot is cold forged, and is annealed in vacuum to obtain a forged thick plate blank; and (2) the forged thick plate blank is cold rolled by 1-N times (N not smaller than 1) to obtain a rolled plate blank; and the vacuum annealing is performed after each time of cold rolling to finally obtain a tantalum 2.5 tungsten alloy finished plate. The cold forging process is adopted to prevent oxidation in the heating process of thetantalum 2.5 tungsten alloy ingot; the process is simplified; the raw material cost and the machining cost are effectively reduced; the tantalum 2.5 tungsten alloy plate obtained by multiple times ofvacuum annealing and multiple times of rolling is fine in grain; the average grain size is not more than 35 microns; and the mechanical performances of Vickers hardness, tensile strength, yield strength, ductility and the like are obviously improved.