30results about How to "Increased creep life" patented technology

A centrifugal compressor including: a casing; at least one impeller supported for rotation in the casing and provided with a hub, a shroud and an impeller eye; an impeller-eye sealing arrangement, for sealing the impeller in the region of said impeller eye. The centrifugal compressor further includes at least one cooling-medium portlocated at the impeller-eye sealing arrangement, arranged for delivering a cooling medium around the impeller eye.

The invention discloses a high Nb-TiAl alloy added with nano yttrium oxide and a preparation method of the high Nb-TiAl alloy, relates to the field of intermetallic compounds and preparation processesthereof, and aims to solve the technical problems of poor high-temperature mechanical property and weak creep resistance of an existing TiAl alloy. The alloy comprises, by mole: Al: 45-48%, Nb: 6-10%, V: 2.5-3.5%, nano yttrium oxide: 0.05-3%, and the balance Ti. The preparation method comprises the steps of briquetting and shaping raw materials; melting alloy block materials, and adding an yttrium oxide prefabricated block for smelting to obtain an alloy ingot; and then carrying out homogenization annealing treatment to finish the preparation. According to the high Nb-TiAl alloy added with the nano yttrium oxide and the preparation method of the high Nb-TiAl alloy, the high-temperature mechanical property and high-temperature creep resistance of the high Nb-TiAl alloy are improved; and the high Nb-TiAl alloy added with the nano yttrium oxide is applied to the field of high-temperature structural materials.

The invention discloses a rhenium-free nickel-based single crystal superalloy and a preparation method thereof. The composition of the rhenium-free nickel-based single crystal superalloy of the present invention is represented by mass percentage as 7.25-7.75% of Cr, 4.8-5.2% of Co, 1.8-2.2% of Mo, 7.8-8.2% of W, and 6.3-6.7% of Ta , 6.0-6.2% Al, 0.12-0.18% Hf, 0.04-0.06% C, 0.003-0.005% B, 0.010-0.030% Y, and the rest is Ni. The preparation of the above-mentioned rhenium-free nickel-based single crystal superalloy comprises the following steps: using a vacuum induction furnace to melt the master alloy, and preparing a cast rod of the master alloy by gravity casting; using the seed crystal method to pass the Bridgeman directional solidification technology at a temperature gradient of 150-250K / cm , the single crystal test bar was prepared at a pulling rate of 5-100 μm / s; the single crystal superalloy was solid solution treated in the range of 1295-1305 °C for 2-4 hours, followed by air cooling, and then in the range of 1090-1310 °C 2-4 hours of high-temperature aging treatment within 2-4 hours, followed by air cooling; then 16-24 hours of low-temperature aging treatment in the range of 850-890 ° C, followed by air cooling.

The invention discloses a thermal treatment method capable of prolonging the long-time service life of welding seams in the magnesium-alloy friction stir welding process. The method comprises the steps that aging treatment and water quenching are conducted on a magnesium alloy subjected to solution treatment for 0.5 h to 72 h at 180 DEG C to 280 DEG C; friction stir welding is conducted at room temperature, wherein the rotating speed ranges from 100 rpm to 1,000 rpm, and the welding speed ranges from 20 mm / min to 120 mm / min; and annealing treatment is conducted on the welded magnesium alloy for 0.5 h to 10 h at 250 DEG C to 350 DEG C, the magnesium alloy is directly cooled to 100 DEG C to 200 DEG C after being annealed, and then aging treatment and water quenching are conducted for 0.5 h to 6 h. According to the thermal treatment method, a precipitated phase is introduced for the magnesium alloy, the lattice distortion degree is increased, and the crystallization rate is increased; andrare earth magnesium alloy or high-alloyed magnesium alloy which is difficult to recrystallize is rapidly crystallized in the friction stir welding process, so that the yield strength of the weldingseams is improved, and synchronous improvement of the long-time service lives in the directions parallel to or perpendicular to the welding seam direction is achieved.

The invention relates to a turbine rotor device with a cooling compression structure. The device comprises a blade and a wheel disc which are cooperatively connected with each other through a fir-shaped tenon and a mortise, and further comprises the cooling compression device installed in the gap between the end face of the tenon and the bottom of the mortise in an in interference fit mode. The cooling compression device is internally provided with a main cold air channel with the cross sectional area gradually changed, and multiple secondary cold air channels which communicate with the main cold air channel and are symmetrically formed in the two sides, so that the space of the cold air channels and the effective convection area are increased, the temperature of the connecting parts of awheel rim part, the tenon of the blade and the mortise of the wheel disc is reduced, the thermal stress of the tenon of the blade is reduced, and the creep life of the tenon of the blade, the mortisestructure of the wheel disc and the rim of the wheel disc is prolonged.

The invention discloses a heat-resistant flame-retardant magnesium alloy and a thermo-mechanical treatment method thereof. The magnesium alloy comprises the following elements by mass: 3-16% of Gd, 4-8% of Er, 0.2-1% of Ca, 0.02-0.2% of Zn and the balance being Mg, wherein the mass ratio of Ca to Zn is >= 3. Magnesium alloy ingot billets are prepared by semi-continuous casting, and subjected to hot rolling or hot extrusion to form a plate being 5-25 mm in thickness, the plate is subjected to solid solution treatment, aging is performed at 200-260 DEG C, and water quenching is performed; and then, true strain is performed between room temperature and 100 DEG C, then aging is performed at 150-220 DEG C, and water quenching is performed. The alloy prepared in the invention contains a honeycomb microstructure consisting of a prismatic-plane precipitated phase, a prismatic-plane dislocation, a basal-plane precipitated phase and a basal-plane dislocation; the effect of the synchronous improvement on the heat-resistant and flame-retardant properties of the magnesium alloy is significant; simple equipment, low production cost and high efficiency are achieved; and the magnesium alloy is suitable for use in the industries of aeronautics and astronautics, railway trains and automobile lightweight.

The invention relates to a turbine rotor device with a cooling and pressing structure. The turbine rotor device comprises blades and a wheel disc which are matched and connected through a fir-shaped tenon and a mortise, and further comprises the cooling and pressing device which is arranged in a gap between the end surface of the tenon and the bottom of the mortise in an interference manner, the cooling and pressing device is provided with a lower main supporting column and upper branch supporting columns which are symmetrically arranged. According to the turbine rotor device with the coolingand pressing structure, the main supporting column and the branch supporting columns form a plurality of cold air channels with the tenon tooth end face and the mortise respectively, so that the relative positions of the tenon teeth and the mortise are fixed, the effective convection area of cold air is increased, the space of a cold air channel and the effective convection area are increased, thetemperature of the rim part and the temperature of the joint of the blade tenon and the wheel disc mortise are reduced, the thermal stress of the blade tenon is reduced, and the creep life of the blade tenon, the wheel disc mortise structure and the wheel disc rim is prolonged.

The invention discloses a method for prolonging the long-time service life of a magnesium alloy through drying. The magnesium alloy comprises, by mass, 0.1-0.65% of calcium, 0.05-1.2% of zinc and thebalance magnesium, and the mass percentage ratio of calcium to zinc is greater than or equal to 0.4; or comprises, by mass, 0.1-0.65% of calcium, 0.05-0.6 % of silicon and the balance magnesium, and the mass percentage ratio of calcium to silicon is greater than or equal to 0.9. The method comprises the steps of preparing a magnesium alloy ingot blank through a semicontinuous casting method, conducting hot rolling or hot extrusion on the magnesium alloy ingot blank to form a plate with the thickness of 2-20 mm, conducting solution treatment on the plate, conducting cold deformation on the plate at true strain of 0.01-0.07 at indoor temperature, conducting baking on the plate at 150-230 DEG C for 10-120 min and then conducting water quenching. Compared with a magnesium alloy not subjected to baking treatment, the yield strength of the magnesium alloy subjected to baking can be improved by 30% or more, and the fatigue and creep life of the magnesium alloy can be prolonged by at least 5 times under the long-time service conditions.