788results about How to "Improve fatigue performance" patented technology

This high-strength steel sheet includes: in terms of percent by mass, 0.03 to 0.10% of C; 0.01 to 1.5% of Si; 1.0 to 2.5% of Mn; 0.1% or less of P; 0.02% or less of S; 0.01 to 1.2% of Al; 0.06 to 0.15% of Ti; and 0.01% or less of N; and contains as the balance, iron and inevitable impurities, wherein a tensile strength is in a range of 590 MPa or more, and a ratio between the tensile strength and a yield strength is in a range of 0.80 or more, a microstructure includes bainite at an area ratio of 40% or more and the balance being either one or both of ferrite and martensite, a density of Ti(C,N) precipitates having sizes of 10 nm or smaller is in a range of 10¹⁰ precipitates/mm³ or more, and a ratio (Hvs/Hvc) of a hardness (Hvs) at a depth of 10 μm from a surface to a hardness (Hvc) at a center of a sheet thickness is in a range of 0.85 or more.

The invention discloses a stainless steel plate type heat exchanger and a processing molding method thereof. The plate type heat exchanger comprises a snakelike flow channel type and honeycomb flow channel type evaporation plate or a cold plate. The plate type heat exchanger adopts a stainless steel plate and consists of a stainless steel upper plate, a stainless steel lower plate, an inlet pipe and an outlet pipe, wherein the two stainless steel plates are overlapped and connected by a special welding method; the inlet pipe and the outlet pipe are inserted in the upper end and the lower end between the two stainless steel plates and are connected with the stainless steel plate type heat exchanger body by using an electric arc welding method; and then the plate type heat exchanger is finally molded through a mould and high-pressure bulging technology.

A method of manufacturing a workpiece involves performing any one of various post-processing part modification steps on a workpiece that has been previously subjected to laser shock processing. In one step, material is removed from the compressive residual stress region of the processed workpiece. Alternately, the workpiece may be provided with oversized dimensions such that the removal process removes an amount of material sufficient to generate a processed workpiece having dimensions substantially conforming to design specifications. Alternately, the material removal process is adapted to establish a penetration depth for material removal that coincides with the depth at which the workpiece exhibits maximum compressive residual stress. Alternately, a first high-intensity laser shock processing treatment is performed on the workpiece, followed by the removal of material from the compressive residual stress region, and then a second low-intensity laser shock processing treatment is performed on the workpiece. Material may be removed from the compressive residual stress region through a workpiece surface different from the laser shock processed surface. Material may also be deposited onto the laser shock processed surface.

The invention relates to a light metal surface laser impact micronano particles injection reinforcing method, comprising the following steps: 1) removing the oxide layer probably existing on the surface of the light metal by a mechanical polishing or chemical corrosion method, then grinding and polishing with sand paper, and finally cleaning the surface of the light metal alloy with acetone or alcohol; 2) precoating the micronano particles on the surface of the light metal with inorganic bonding agent, recoating a layer of black paint on the surface of the micronano particle coating layer to serve as the absorption layer of laser impact after drying, and drying naturally; 3) impacting the absorption layer and the micronano particle layer with high-energy short pulse laser, and utilizing K9 glass or running water as a restriction layer during laser impact; and 4) soaking the micronano particle coating layer processed by acetone, and then removing the absorption layer through washing with running water or ultrasonic washing to obtain the micronano particle injection reinforcing layer. The invention integrates the actions of laser impact reinforcement, nano particle reinforcement and nano particle reinforcement, can dramatically improve hardness, abrasion resistance and fatigue resistance property of light metal surface layer, and has wide application prospect.

A heat treatment technology for markedly raising comprehensive performance of aluminium alloy is accomplished by the adoption of the following scheme: carrying out a solid solution treatment on the aluminium alloy, taking the aluminium alloy out of a furnace and carrying out water quenching, and carrying out a pre-aging treatment, cold deformation and a secondary aging treatment. Nanometer-level aging precipitation strengthening phase is formed by the pre-aging treatment, and dislocation configuration generated from the subsequent cold deformation can be changed, so as to improve the strength, ductility and toughness of the alloy; during the cold deformation, nanometer-level atomic clusters will precipitate out from solute atoms precipitated during the pre-aging treatment, or ''pinning'' air mass is formed around the dislocation structure, thus further raising the strength of the alloy. The precipitated precipitation strengthening phase is nanometer level, thus raising the ductility and toughness of the alloy and markedly enhancing the strength of the alloy on the basis of guaranteeing good plasticity. The technological process provided by the invention is simple, is convenient to operate, can be adopted to markedly raise comprehensive performance such as the strength and plasticity of the aluminium alloy and improve the corrosion resistant performance and fatigue resistant performance of the aluminium alloy, and is suitable for industrial application.

A reinforcing bar splice secures together reinforcing bar ends by utilizing, at both ends, both tapered-thread coupling and coupling involving a filler, such as a grout or an epoxy. The splice may include a central tapered-thread central sleeve or coupler, and a pair of collars that are screwed onto externally-threaded ends of the central sleeve. The central sleeve has a channel therethrough with tapered internal threads at both ends, and a center internal relief. The internal relief is an increased radius center portion that ensures full thread contact between the tapered internal threads and external threaded sections of the rebar ends. The sleeve has externally-threaded ends that are engaged by internally-threaded ends of a pair of collars. Distal to their internally-threaded ends, the collars have filler-material-receiving channels. The channels include plural sloped surfaces for aiding in securing filler material between the collars and the rebar ends.

The invention proposes an added material manufacturing method under a vibration condition. In an arc wire feeding added material manufacturing or laser powder feeding melting added material manufacturing process, mechanical vibration with a certain frequency is synchronously introduced, so that parts are located in a micro vibrating state; and the mechanical vibration acts on a micro liquid-state molten bath formed in the added material manufacturing process to refine grains, so that the structure becomes more uniform, and such phenomenon as air holes, inclusions and incomplete fusion is reduced or even eliminated. Meanwhile, the vibration acts on metal just condensed, so that the stress generated by vibration and residual stress generated in the added material manufacturing process are superposed to generate local plastic deformation to achieve the purpose of reducing residual stress and deformation of added material manufacturing parts, and the added material manufacturing parts under vibration condition are more excellent in performances.

The invention relates to spring steel and a production process thereof, in particular to 55Si2MnVNbN spring steel and a production process thereof. The 55Si2MnVNbN spring steel comprises the following components in percentage by weight: 0.52 to 0.60 percent of C, 1.60 to 1.90 percent of Si, 0.60 to 0.80 percent of Mn, 0.15 to 0.35 percent of Cr, 0.06 to 0.12 percent of V, 0.015 to 0.025 percent of Nb, 0.80 to 1.50 percent of N, less than or equal to 0.0035 of P, less than or equal to 0.0035 percent of S and the balance of Fe and inevitable impurities. The process comprises electric furnace electrosmelting, LF refining, VD furnace vacuum degassing, continuous casting and rolling. The spring steel can meet the requirements of springs on various severe working environments, high strength and long service life and has high tensile strength, high delayed fracture resistance, high corrosion resistance, high fatigue resistance and high elasticity attenuation resistance.

The invention provides a permanent deformation cold resistance nitrile-butadiene rubber composition with low hardness and low compression, which contains nitrile-butadiene rubber, peroxides and auxiliary crosslinking agents; wherein, the auxiliary crosslinking agents are selected from one or a plurality of 1, 3-(citraconic maleimide methyl) benzene, meta phenylene bis maleimide, triallyl cyanurate and triallyl isocyanurate. The nitrile-butadiene rubber which is prepared by the nitrile-butadiene rubber composition has the advantages that peroxide curing system containing the auxiliary crosslinking agents of the invention can improve the cold resistance and has small compression permanent deformation; at the same time, the tensile strength and the elongation at break are large, and the fatigability is good. The advantages are not possessed by the curing systems that singly use peroxides and the combination of the peroxide sulphur and other auxiliary crosslinking agents.

The invention relates to a hot-rolled H-shaped steel, and application and a production method thereof. The hot-rolled H-shaped steel contains the following components in percentage by weight: 0.08-0.18% of C, 0.20-0.45% of Si, 1.00-1.65% of Mn, 0.005-0.035% of P, at most 0.025% of S, at most 0.10% of V, less than 0.070% of Nb, less than 0.025% of Ti, and the balance of iron and inevitable impurities. The hot-rolled H-shaped steel can be used for semitrailer girders. According to the production method of the hot-rolled H-shaped steel for semitrailer girders comprises, a selective cooling process is adopted after the hot rolling of the H-shaped steel, thereby uniformly cooling the H-shaped steel with higher temperature to a proper temperature within a short time; and the cooling process lowers the waves at the wing edge and web plate due to the nonuniform temperature of the rolled piece. According to the production method, the hot-rolled H-shaped steel with the specification of 491*146*7*11.5 and the yield strength of 345-500 MPa, which is produced under the reasonable control on the production technique, substitutes the welded H-shaped steel and enhances the all-day fatigue property and safety of the semitrailer.

The invention relates to a method for forming bonded iron-based powder by a high velocity compaction technology, and belongs to the technical field of powder metallurgy. Coarse and fine water-atomized iron powder with different particle sizes are matched, and the mass ratio of the coarse powder to the fine powder is 2:1 to 4:1. In accordance with the particle size matching requirement and the iron-based alloy composition ratio, Ni, Cu, C and iron-phosphorus alloy powder are added into the water-atomized iron powder and then are uniformly pre-mixed with the water-atomized iron powder in a planetary ball mill. 0.3 to 0.8wt. % of plasticizer is added into the pre-mixed powder and then is mixed with the pre-mixed powder for 2 to 5 hours to obtain the bonded powder. The bonded powder is heatedto 600 to 950 DEG C by using a multi-stage heating process to be subjected to plasticizing treatment to obtain plasticized iron-based powder. The plasticized iron-based powder is pressed by a high-speed forming press to obtain a high-density compac. The compact is sintered at a temperature of 1100 to 1250 DEG C in a hydrogen atmosphere for 2 to 5 hours to obtain a high-density powder metallurgy iron-based material. The method integrates the advantages of powder modification treatment, die wall lubrication and high-speed pressing, and is more suitable for preparing the high-density powder metallurgy iron-based material.

The invention provides 600 MPa-level thick-specification hot rolling spoke steel and a manufacturing method thereof. The spoke steel comprises the following chemical constituents in mass percent: 0.06-0.12% of C, 0.20-0.60% of Si, 0.80-1.20% of Mn, 0.02-0.06% of Alt, 0.50-1.00% of Cr, 0.03-0.08% of P, smaller than or equal to 0.005% of S, smaller than or equal to 0.006% of N, and the balance of Fe and inevitable impurities. In the manufacturing method of the spoke steel, the billet heating temperature is 1,150-1,250 DEG C, and the finish rolling temperature is 760-840 DEG C; after rolling, a conventional cooling technology is used to cool the steel at a cooling rate of 20-100 DEG C per second to 350 DEG C below, and then the steel is reeled. The steel plate is good in processability and fatigue performance, and free of Nb, V, Mo, Ni and other elements, so as to save the production cost. The steel plate provided by the invention can be widely applied to the spoke production of steel wheels of commercial vehicles.

An arc-ultrasonic welding method for Ti alloy features that an arc-ultrasonic exciting source using electric arc as heat generater and ultrasonic emitter is parallelly connected with the conventional power supply used for arc welding. The ultrasonic waves can act on the molten bath on the workpiece to be welded to improve the smelting and crystallizing procedure of Ti alloy for finer crystal grains and higher welding strength and fatigue resistance.

A pressure vessel includes a vessel body and a fiber reinforced plastic layer formed on the surface of the vessel body, wherein the fiber reinforced plastic layer include fiber reinforced plastic in which reinforcing fibers are impregnated with plastic, a strand elastic modulus of the reinforcing fiber is 305 GPa or higher, and a tensile elongation of the reinforcing fiber is 1.45 to 1.70%. A carbon fiber for a pressure vessel has a strand elastic modulus of 305 GPa or higher and a tensile elongation of 1.45 to 1.70%.

A manufacturing method of a carbon fiber metal composite laminated plate relates to a manufacturing method of a fiber metal composite laminated plate. The method aims at solving the problems that no manufacturing methods for manufacturing aircraft structural material with high specific stiffness, high specific strength, tenacity and workability exist in China. The method comprises the following steps of: carrying out surface treatment to three pieces of metal plates; winding a carbon fiber composite material layer which is soaked in liquid cement on one of the metal plates, wherein, the liquid cement is prepared by epoxy resin, a metaphenylene diamine curing agent and an anhydrous alcohol solvent according to the mass ratio of 1:0.1 to 0.18:0.15 to 0.2; fixedly arranging another two metal plates on the upper surface and the lower surface of the carbon fiber composite material layer so as to be integrally put into a mould, and then treated with mould assembling, drying, solidification by adopting the method of gradient temperature increasing, and demoulding. The manufacturing method of the invention is simple and is easy for operation. The carbon fiber metal composite laminated plate manufactured by the method of the invention has the advantages of high specific stiffness, high specific strength, also high tenacity and workability of metal material, good fatigue property, and good damage tolerance capability.

The invention relates to high-performance elastic copper alloy and a preparation and processing method thereof. According to the weight percentage, the high-performance elastic copper alloy comprises the basic components as follows: 1 to 4 percent of Ni, 0.4 to 1 percent of Si, 0.5 to 1.5 percent of Co, and the rest percent of Cu, wherein the components in a copper alloy product need to satisfy the conditions as follows: (a) the content of Ni or Si is larger than or equal to 2.5 percent and smaller than or equal to 5 percent; (b) the content of Ni plus Si is larger than or equal to 1.4 percent and smaller than or equal to 4.0 percent; (c) the content of Ni plus Co is larger than or equal to 1.5 percent and smaller than or equal to 4 percent; and (d) the content of Ni plus Si or the content of C is larger than or equal to 1 percent and smaller than or equal to 5.0 percent. The preparation and processing method of the high-performance elastic copper alloy comprises the step: a, material burdening, material feeding, melting and casting which are conducted according to the weight percent; b, surface milling; c, hot rolling; d, solid solution treatment; e, cold processing; f, primary aging; g, cold processing; h, secondary ageing; i, pickling; and j, finished product annealing. The tensile strength Sigma b of the copper alloy is 780 to 950MPa, the plastic elongation rate Delta of the copper alloy is 4 to 10 percent, and the electric conductivity of the copper alloy is 35 to 55 percent according to an international annealed copper standard (IACS). The copper alloy has the advantages of high elasticity, high strength, high fatigability, good heat resistance and high electric conductivity.

The invention discloses an intravascular stent of a composite structure; the intravascular stent comprises a stent main body, wherein the distal end of the stent is restrained as an adducted form by virtue of a tightening wire, and the tightening wire is degradable magnesium alloy or degradable iron alloy; one or more auxiliary wires are woven on the stent main body; when the stent is applied to blood vessel of brain, the auxiliary wire is pure platinum or alloy thereof, pure gold or alloy thereof, pure tungsten or alloy thereof, or pure tantalum or alloy thereof; and when the stent is applied to peripheral blood vessel, the auxiliary wire is cobalt-chromium alloy or stainless steel or tungsten or tantalum. The stent, when serving as a thrombus removal system for treating cerebral apoplexy, not only can be used for removing thrombus effectively for several times but also can be used for catching small thrombus flowing to distal end so as to prevent distal blood vessels from getting blocked; and the stent can be used for dilating stenosis or blocked brain blood vessel or peripheral blood vessel, so as to take an effect of dredging and reconstructing a blood flow. The stent can be repositioned and released, with high controllability; and the stent can be used for reducing operation difficulty and greatly improving an operation success rate.