35results about How to "Improve grain refinement" patented technology

The invention discloses a martensitic steel copious cooling and high-pressure twisting mold and method, and relates to the technical field of high-strength steel fine grain treatment. A mold with a groove formed in a lower mold is adopted, a USIBOR1500 martensitic high-strength steel plate is contained in liquid nitrogen in the groove of the lower mold, an upper mold descends to be pressed on theplate, the groove of the lower mold is filled with liquid nitrogen, then the upper mold and the lower mold are sealed, copious cooling treatment is carried out on a sample, and the treatment time is 20 min or 30 min; after copious cooling treatment, high-pressure twisting is carried out under the pressure being 4 GPa or 5 GPa, and the twisting angle is 360 degrees; and the USIBOR1500 martensitic high-strength steel plate subjected to copious cooling treatment of different processes and high-pressure twisting is subjected to vacuum electric field assisted recrystallization annealing treatment,the temperature is 750 DEG C, the soaking time is 20 min, and air cooling is carried out after heat preservation is finished. Grains of finally-prepared USIBOR1500 martensitic high-strength steel areeven tiny martensitic grains, and the yield strength, tensile strength and ductility of the steel are all improved to a certain degree by being compared with steel before treatment.

The invention discloses a large-diameter moderately-strong heat-resisting magnesium alloy thick-wall barrel-shaped piece forming process. The process includes the steps of large-furnace smelting, semi-continuous casting, homogenizing annealing, varying-temperature multi-direction forging, mechanical punching, ring rolling forming and aging treatment. The varying-temperature multi-direction forging is conducted on an oil press, pressing speed is 200-400mm / min, upsetting reduction in pass is 30-40%, drawing down reduction in pass is 5-10%, blank before ring rolling forming is kept at the temperature of 380-400 DEG C for 4-8 hours, and rolling deformation is 60-80%. The thick-wall barrel-shaped piece 700-1100mm in outer diameter, 50-100mm in wall thickness and 300-700mm in height is manufactured. The thick-wall barrel-shaped piece is high in strength and good in heat resistance and meets size and performance requirements of structural parts in the aerospace field.

The invention belongs to the field of chemical engineering materials and particularly discloses a treatment technique of aluminum alloy profiles for photovoltaic assembly supports. The technique comprises the steps of preparation of alloy raw materials, fused mixing of the alloy raw materials, refining and deslagging of molten aluminum, pouring of the molten aluminum, acid pickling of castings, plating assisting of the castings, and passivating treatment of the surfaces of the castings. According to the treatment technique, aiming at existing aluminum alloy materials, by adding metal elementssuch as Mn, Cu, Si, Mg and Ta and through reasonable formula design, the alloy strength is effectively improved, the grain refinement extent is greatly increased, and the effects on improvement of comprehensive properties such as the tensile strength, the elongation and the anti-corrosion property of aluminum alloys and the firm forming quality of oxidation films are remarkable.

The invention discloses a system and a method for continuous extrusion production of a fine-grain magnesium alloy strip. The system comprises a decoiling emptying device, an on-line straightening device, an on-line heating device, a continuous extrusion device, a cooling device and a winding displacement collection device. Through control of a temperature of a rod, a good extrusion driving force is produced between the rod and an extrusion wheel groove. Through an expansion mold cavity and a flow-blocking mold, magnesium alloy expansion flowing in a width direction is realized. In order to extrude a plate having larger width, the system adopts a two / three rod feeding-type extrusion mode so that joining and intermetallic welding of multiple rods in a corresponding multi-rod mold cavity are realized. The system and the method have the advantages that a process route is short; production efficiency is high; a grain refinement degree of a product microstructure is high; plate formability is good; and a continuous production line provided by the invention is suitable for industrial application.

The invention relates to the field of hot rolling molding heat treatment, in particular to a manufacturing method for improving bearing steel ball surface layer performance. The manufacturing method for improving the bearing steel ball surface layer performance comprises the following steps that 1, a steel bar is heated to the temperature higher than the austenitizing temperature, and a first inclined roller is used for one-way rotary hot rolling for forming a steel ball; and 2, when the steel ball in the step 1 is subject to hot rolling to 50%-70% deformation, a steel ball bar is transferredto a second inclined roller to be continuously subject to one-way rotary rolling, metal molding deformation of the steel ball bar generates a reverse macroscopic shear stress strip, and the inclined rolling direction of the second inclined roller is opposite to the inclined rolling direction of the first inclined roller, and the roller dip angles are the same. According to the manufacturing method, shortcomings in the existing technology are overcome, the steel ball surface layer (near surface) grain refinement degree is improved for achieving ultrafine grains, and molding damage is reduced.

The invention relates to a preparation method for a foam metal thickness difference sheet metal part. The preparation method for the foam metal thickness difference sheet metal part is characterized in that 1, firstly, at least two metal plates are stacked, and a foaming agent is sprayed on the contact face of the two metal plates; 2, then the two metal plates are rolled for the first time through rolling equipment to obtain once rolled metal plates each with an area to be foamed; 3, each once rolled metal plate is partitioned into two blocks from the area to be foamed; 4, the two once rolled metal plates are stacked to be rolled for the second time to obtain a foam metal plate with an area to be foamed; 5, the foam metal plate is placed in a heating furnace to be preheated to obtain a foam metal plate with a foaming area; 6, the preheated foam metal plate is placed in a stamping die to be heated until the foaming area reaches a foaming temperature; 7, the foam metal plate reaching the foaming temperature is subjected to hot stamping forming through the stamping die, meanwhile, pressure maintaining is performed to complete the secondary foaming of the foaming area, and then the foam metal thickness difference sheet metal part is obtained. The prepared foam metal thickness difference sheet metal part prepared by the preparation method for the foam metal thickness difference sheet metal part can meet performance requirements of parts of different portions, and the impacting energy absorption effect of the sheet metal part is improved by more than 40%.

The invention discloses a preparation method of a large-scale fine-grained tungsten rod and a large-scale fine-grained tungsten rod prepared by using the same. The preparation method of the large-scale fine-grained tungsten rod includes the steps of: powder preparation step: selecting tungsten powder, and Sieve to obtain tungsten powder; press forming step: press and form the tungsten powder to obtain a tungsten compact; sintering step: sinter the tungsten compact to obtain a tungsten sintered compact; two-roll rolling step: The tungsten sintered billet is continuously rolled by two rolls to obtain a tungsten rod; the swaging and shaping step: the tungsten rod is cleaned and polished, and then swaged into a circle to obtain a pure tungsten rod; annealing step: the pure tungsten rod is obtained Tungsten rods are annealed to obtain fine-grained tungsten rods. The preparation method of the large-scale fine-grained tungsten rod of the present invention has the advantages of high production efficiency, large amount of deformation, high degree of grain refinement, few human factors, stable product quality and small fluctuations, and the like.

The invention relates to a molten soup forging method and a molten soup forging die. The molten soup forging method and the molten soup forging die comprise an upper die, a lower die and side dies, to-be-produced wheel-shaped die cavity is formed among the upper die, the lower die and the side dies, wherein the molten soup forging method and the molten soup forging die are characterized in that a lower die assembly formed by coaxially enclosing the plurality of side dies and the lower die is coaxially embedded in a pressure bearing die sleeve, and a hydraulic pressure lifting mechanism which is vertically upward and used for lifting products is coaxially arranged at the lower end of the lower die. The molten soup forging method and the molten soup forging die have the advantages of improving product quality, reducing molten soup dosage, improving inner structure refined grain of metals, improving product mechanical property, tensile property and other overall properties, shortening product production time, reducing equipment maintenance cost, increasing output, improving production efficiency and prolonging die service life.