30results about How to "Achieving grain refinement" patented technology

The invention discloses a compound treatment purifying method of a magnesium alloy melt. The method comprises the following step: carrying out gas blowing stirring treatment while purifying the magnesium alloy melt by a refining flux, wherein the refining flux can purify and remove bigger inclusions of the magnesium alloy melt, and meanwhile, bubbles of inert gases or nitrogen introduced by gas blowing stirring enable the inclusions suspended in the magnesium alloy melt to quickly come up to the surface of the melt, so that inclusions in the magnesium alloy melt are effectively removed, particularly fine inclusions, thereby improving the quality of a magnesium alloy to a great extent. Furthermore, the method further promotes homogenization of magnesium alloy components, improves the yield of a zirconium refiner and controls segregation of zirconium element. Therefore, the method disclosed by the invention has the compound purifying and refining functions, and is short in treatment time, simple and suitable for experimental and industrial applications.

The invention discloses a method for prolonging fatigue life of welded joints, and belongs to the technical field of surface strengthening processing for improving the fatigue performance of metal welds. This method adopts surface spinning strengthening technology to carry out surface strengthening processing on welded joints to obtain metal surface structure with hardness gradient, realize surface strengthening and hardening of metal welded joints, and process smooth surface at the same time, which reduces the level of stress concentration and stress concentration on the surface of welded components. Post-weld residual stress levels. When metal welded components serve under cyclic loads, the initiation of fatigue cracks from the surface of welded joints can be inhibited after spinning, thereby improving the fatigue performance of metal welded joints.

The invention belongs to the field of material welding and particularly relates to a vibration, impact and extrusion method for eliminating weld joint residual stress. According to the vibration, impact and extrusion method, a vibration impact source device which generates vibration impact force is arranged over an extrusion wheel which parallelly moves along weld joints; and when the extrusion wheel parallelly moves along the surfaces of the weld joints, the vibration impact force generated by the vibration impact source device and extrusion force of the extrusion wheel jointly act on the weld joints coaxially in the same direction, so that the weld joints are locally compressed and deformed, and the weld joint residual stress is eliminated. Compared with weld joint residual stress eliminating through an original extrusion method, the application range is wider, the post-welding residual stress of the thin plate weld joints, the middle-thick plate weld joints and the high-strength weld joints can be eliminated, eliminating of the weld joint residual stress or generation of negative stress particularly facilitates long-term storage and safe use of welded structural parts without the harmful stress effect, and significant using value is achieved on welding of ships, vehicles, artilleries and ammunition and stable use of various storage and transport containers for nuclear powerfor decades.

The invention provides a high-toughness plastic die steel and a production method thereof. The die steel comprises the following chemical components in percentage by mass: 0.30-0.42% of C, 0.20-0.50% of Si, 0.75-1.00% of Mn, 1.50-2.00% of Cr, 0.25-0.50% of Mo, at most 0.015% of S, at most0.025% of P, 0.010-0.040% of Als and the balance of Fe and inevitable impurities. According to the production method of the high-toughness plastic die steel, a normalizing-tempering technique is utilized to product the die steel to implement grain refinement, so that the product hardness is up to 28-32 HRC, the uniformity of hardness is favorable, the Charpy V-notch ballistic work is up to higher than 80J, and the product specification can cover 20-120mm.

The invention discloses a rotary deep drawing forming method of a thin-walled cup-shaped part, which includes ① blanking, ② homogenizing heat treatment, ③ heating and heat preservation of the blank and the mold, ④ putting the blank into a V-shaped cavity, and the punch rotates on the top Driven by the hydraulic press, it moves downwards, and first touches the upper surface of the blank, and the punch moves downward at a constant speed, so that the metal on the contact surface flows into the groove on the end face of the punch one after another, and is integrated with the punch, and the punch drives the blank to start torsion and Press down, and at the same time, the peripheral part of the billet is squeezed and flows into the multi-pass arc convex platform. First, one side of the peripheral metal touches the first round arc convex platform, forming a height difference with the other side, and then makes the In the next downward twisting deformation process, the speed difference is formed on both sides, and finally squeezed into the rectangular cavity until it moves to the specified position. This case can improve the formability of steel materials, improve the comprehensive mechanical properties of formed components, and overcome the shortcomings of the large difference in anisotropic strength of thin-walled cup-shaped components formed by traditional thinning and deep drawing.

The invention relates to a preparation method of an ultrafine-grain titanium matrix composite material by using a mushy-zone titanium alloy as a matrix. The preparation method comprises the following steps: carrying out hot working of a titanium matrix composite material; cutting to form a blank material, and polishing; simultaneously preheating a sample and a die, and uniformly smearing the surface of the sample and the inner wall of the die with a graphite lubricant; respectively carrying out heating and heat insulation of the die and the sample; putting the sample in a die channel to make the sample completely go through the channel corner of the equal-diameter corner extrusion die, and cooling the sample with water to complete a primary extruding technology; and machining the sample, carrying out 90DEG anticlockwise rotation, beveling the head, and carrying out 2-4 time equal-diameter bending channel extrusion deformation to obtain the ultrafine-grain titanium matrix composite material. The preparation method realizes the strength and plasticity deformation of the titanium matrix composite material, effectively refines the internal crystal grain size, has the advantages of short process flow, easy operation, high efficiency, low cost and strong adaptability, and can be used in the titanium matrix composite material processing field.

The invention discloses an anodic oxidation aluminum alloy. The anodic oxidation aluminum alloy mainly comprises, by weight, 0.6-1.2% of Si, 0-0.2% of Fe, 0.1-0.6% of Cu, 0-0.15% of Mn, 1.0-1.4% of Mg, 0-0.03% of Cr, 0-0.1% of Zn, 0-0.1% of Ti, and the balance Al. According to the anodic oxidation aluminum alloy, an improvement is made on the chemical components of the aluminum alloy; a manufactured and prepared aluminum alloy plate strip has the yield strength of more than 330 MPa, the tensile strength of more than 370 MPa and the Vickers hardness of more 130 HV; grain refinement is achieved,and the grain size is less than 80 microns; the high strength and high uniformity are achieved; the roughness of a plate is controlled within Ra 0.1-0.3 microns. The alloy has excellent anodic oxidation effect and high strength and hardness, has high lustrous surface and can be extensively applied to high-end anodic oxidation products, especially the field of 3C electronic product shells such asmobile phones, tablet computers, notebook computers, all-in-on PCs, routers and game machines. Moreover, the preparation method is simple, easy to grasp and convenient to implement.

The present invention is one kind of RE Inver alloy superior to available Inver alloy, which has low welded joint strength caused by element diffusion in the Inver alloy / hard alloy interface. The RE Inver alloy consists of Ni 30-42 wt%, C 0.6-1 wt%, Mn 3.4 wt%, Nb 3-5 wt%, Y2O3 6-8 wt%, and Fe for the rest. Its production process includes the following steps: 1. compounding materials in the said composition; 2. vacuum induction smelting at 1450 deg.c; 3. casting and naturally cooling; and 4. pressing ingot to form rod of 58 mm diameter.

The invention discloses steel for a damping piston rod for an automobile and a production method of the steel. The steel for the piston rod comprises, by mass percent, 0.34%-0.36% of C, 0.19%-0.24% of Si, 0.67%-0.73% of Mn, not larger than 0.030% of P, 0.025%-0.030% of S, 0.020%-0.040% of Al and the balance Fe and inevitable impurities. The production method comprises the procedures of converter smelting, LF furnace refining, RH furnace refining, continuous casting, cogging, heating furnace treatment, rolling and cooling. According to the produced steel for the damping piston rod, the tensile strength is larger than or equal to 530 MPa, the percentage elongation after fracture is larger than or equal to 20%, the grain size is larger than or equal to the sixth stage, total oxygen in the steel is smaller than or equal to 0.002%, a decarburized layer is smaller than or equal to 1.0%D, and the requirement of the steel for the damper piston rod for the automobile can be effectively met.

The invention relates to a tin plating electrolyte which contains a solvent and the materials with following concentration: 10-20g / L of tin methane sulfonate, 30-60g / L of methanesulfonic acid, 0.4-5g / L of compound additive, and a proper amount of PH regulator; and the compound additive is formed by thiourea, hydroquinone, 2-mercapto benzimidazole and propylene glycol block polyether. For the tin plating electrolyte, by reasonably selecting types and use amount of additives, the problems of instable plating solution and high cost in the methanesulfonic acid system are solved, and by using the tin plating electrolyte, a high-mass plating layer is acquired beneficially.

The invention relates to a metallurgical technology, and specifically relates to 700MPa-grade high-strength hot-rolled H-shaped steel and a preparation method thereof. The 700MPa-grade high-strength hot-rolled H-shaped steel comprises the following chemical components in percentage by weight: 0.05-0.10% of C, 0.20-0.50% of Si, 1.30-1.60% of Mn, not greater than 0.020% of P, not greater than 0.008% of S, 0.32-0.50% of Cu, 0.70-0.90% of Cr, 0.32-0.50% of Ni, 0.20-0.30% of Nb, 0.45-0.60% of V and the balance iron and trace impurities. According to the 700MPa-grade high-strength hot-rolled H-shaped steel and the preparation method thereof, heating and rolling are mainly controlled in a combination manner through a component design; and meanwhile, production for the 700MPa-grade high-strength hot-rolled H-shaped steel is realized by virtue of rapid cooling. The product disclosed by the invention is high in mechanical property, and has a yield strength of greater than 700MPa and a tensile strength of greater than 800MPa. Compared with a preparation method for traditional high-strength steel, the preparation method disclosed by the invention has few production procedures and is low in production cost due to no need of online heat treatment and heat treatment after rolling during a production process.

The invention belongs to the field of biomedical materials and particularly relates to an absorbable orthopedic implanted magnesium alloy. The absorbable orthopedic implanted magnesium alloy comprises, by mass, 4.0-8.0% of Zn, 0.8-2.0% of Y, 0.6-2.0% of Nd, 0.2-0.4% of Sc, and the balance Mg. The invention further discloses a preparation method of the absorbable orthopedic implanted magnesium alloy. According to the method, the absorbable orthopedic implanted magnesium alloy is formed by melting magnesium ingots, zinc ingots, a Mg-Y intermediate alloy, a Mg-Nd intermediate alloy and a Mg-Sc intermediate alloy as furnace burden. High-content Zn is added to pure magnesium to serve as a main strengthening element; the high requirement for the strength of the orthopedic implanted material is achieved through solution strengthening and dispersion strengthening; a few rare earth elements Y, Nd and Sc are added compositely to improve the mechanical performance and the corrosion resistance ofthe alloy and achieve the purposes of structure and grain refinement. Through combination of multiple passes of extrusion processing at the big extrusion ratio and annealing heat treatment after extrusion, the superfine-grained magnesium alloy with second phases finely dispersed and distributed in a base body, and the mechanical performance and corrosion resistance of the absorbable orthopedic implanted magnesium alloy are greatly improved.

The invention discloses a rotary deep-drawing forming die for a thin-walled cup-shaped part, which includes a punch, a forming die and a lower template, the forming die is coaxially provided with a compound cavity for inserting a blank, and the end face of the punch and the blank is in contact It is a conical boss mold surface; the composite cavity is composed of a V-shaped cavity on the upper part and a rectangular cavity on the lower part. There are multiple channels in contact with the blank on both sides of the connection between the V-shaped cavity and the rectangular cavity. The sub-arc convex table, the multi-pass sub-arc convex table is composed of several convex tables arranged in sequence from top to bottom, and the arc radius becomes larger in turn; the number of arc convex tables on one side is larger than that on the other side There is one more arc-convex platform, so that the forming die is an asymmetrical annular body of revolution, and the extra arc-convex platform is arranged at the highest point of the side. This case can effectively improve the formability of steel materials, improve the comprehensive mechanical properties of formed components, and overcome the shortcomings of the large difference in anisotropic strength of thin-walled cup-shaped components formed by traditional thinning and deep drawing.

The invention provides a preparation method of powder metallurgy austenitic stainless steel, comprising the following steps: mixing austenitic stainless steel powder, yttrium oxide powder and lubricant to obtain a mixed powder, and then sequentially pressing and sintering to obtain powder metallurgy Austenitic stainless steel; the mass of the yttrium oxide powder is 0.2-0.4% of the mass of the mixed powder. The invention uses austenitic stainless steel powder and yttrium oxide powder as raw materials, and by adding a certain amount of yttrium oxide powder as a stabilizer, the precipitated phase can be reduced under high temperature conditions, and at the same time, it can be dispersed and distributed in the matrix to achieve matrix grain refinement , thereby reducing porosity, improving the shape and size of inclusions, reducing the number of inclusions in steel, and effectively reducing the number of pitting sources; at the same time, rare earth oxides in steel can effectively desulfurize and reduce inclusions in steel and modify the inclusions, thereby enhancing the corrosion resistance of the steel matrix.