120 results about "Cobalt based alloy" patented technology

The invention belongs to the technical field of cobalt-based alloy machining, and particularly relates to high-strength cobalt-based alloy rolling machining equipment which comprises a rack and a cooling system, an upper roller and a lower roller are installed on the rack, one end of the rack is fixedly connected with a first motor, and the first motor is connected with the end of the lower roller through a reduction gearbox; and the other end of the lower roller is mounted on the bearing seat. The device further comprises a thickness acquisition module and a stress acquisition module. The thickness acquisition module and the stress acquisition module are used for monitoring the thickness and rolling pressure fluctuation of a rolled plate in real time, the control module is used for generating a corresponding fluctuation coefficient, and the thickness fluctuation coefficient and the stress fluctuation coefficient are comprehensively analyzed to generate an evaluation coefficient; and the roller spacing, the rolling speed and the working state of a cooling system are dynamically adjusted according to the evaluation result, so that the rolling process can adapt to material characteristics and working condition changes, the thickness uniformity of rolled plates is effectively improved, and the adverse effect caused by abnormal fluctuation of rolling pressure is reduced.

The invention relates to the field of electrochemical polishing of cobalt-based alloys, in particular to an environment-friendly electrochemical polishing solution of a cobalt-chromium-tungsten-nickel alloy and a polishing method of the environment-friendly electrochemical polishing solution. The cobalt-based alloy comprises the following chemical elements in percentage by mass: 15.0-25.0% of Cr; w: 10.0% to 20.0%; 0.0% to 15.0% of Ni; the balance is Co and unavoidable impurity elements such as O, N and H. The environment-friendly polishing solution comprises the following chemical components by mole percent: 0.5-2 mol / L of ChCl; 0.7 to 1.0 L of ethylene glycol; 0 to 0.3 L of ethanol; 0.1 to 0.3 L of glacial acetic acid; and a small amount of citric acid. According to the electrolytic polishing, alloy serves as an anode, a U-shaped titanium plate serves as a cathode, the voltage is 40-60 V, the current density is 0.5-2 A / cm < 2 >, and the polishing temperature is normal temperature. The method has the advantages that the environment-friendly electrolyte is adopted, the surface of the cobalt-chromium-tungsten-nickel alloy can be polished, pollution caused by electrolyte of a traditional chromium oxide system and an acid system is avoided, the follow-up repeated cleaning procedure is reduced, and material precision control is improved.

The invention relates to the technical field of material science, and discloses a slurry valve erosion-resistant multi-layer coating with gradient function design and a preparation method thereof.The coating comprises a bonding layer, a gradient function layer and an erosion-resistant surface layer which are sequentially arranged from inside to outside, the bonding layer is composed of nickel-based alloy or cobalt-based alloy, the thickness of the bonding layer is 50-100 micrometers, and the thickness of the gradient function layer is 50-100 micrometers. The gradient functional layer is made of composite powder of metal and ceramic, the metal is nickel or cobalt, the ceramic is tungsten carbide or chromium carbide, and the components of the gradient functional layer are from the bonding layer side to the erosion-resistant surface layer side; the bonding layer is arranged and forms firm metallurgical bonding with the matrix, the interface stress is reduced, the basic reliability of bonding of the coating and the matrix is guaranteed, meanwhile, the gradient functional layer with the metal and ceramic volume fraction gradually changing continuously is adopted, the problem that the thermal expansion coefficients of the coating and the matrix are not matched is solved, and the service life of the coating is prolonged. And the crack initiation and expansion risk caused by internal stress concentration is reduced, so that the long-term stability of the coating structure is ensured.

Wrought age-hardenable nickel-chromium-cobalt based alloy compositions suitable for use in high temperature gas turbine cases possessing higher mechanical strength, toughness / containment, and thermal stability compared to current commercial alloys and an acceptable containment factor containing in weight percent 16 to 20 wt. % chromium, 8 to 13 wt. % cobalt, 4 to 8.5 wt. % molybdenum, up to 8 wt. % tungsten, 2.1 to 4.1 wt. % aluminum, titanium up to 1.9 wt. %, up to 3.7 wt. % niobium, up to 5 wt. % iron, carbon present up to 0.15 wt. %, up to 0.015 wt. % boron, up to 7.1 wt. % tantalum, up to 0.13 wt. % silicon, up to 1.0 wt. % manganese, and up to 0.06 wt. % zirconium, with a balance of nickel and impurities. The amounts of certain alloying elements must be carefully controlled according to three compositional relationships here disclosed.

The invention relates to the technical field of superhard composite materials, in particular to a manufacturing method of a superfine diamond compact, which is characterized by comprising the following steps: S1, raw material selection and pretreatment: diamond particles: selecting high-purity diamond powder with the particle size of 0.1-1 mu m; a hard alloy, such as a cobalt-based alloy, is adopted as a matrix material; nanoscale ceramic particles such as silicon nitride and aluminum oxide are added to serve as the reinforcing materials, gaps between the base body and the diamond particles are filled, and the compactness of the materials is improved; and S2, diamond particle uniform distribution treatment is conducted, specifically, a mechanical stirring and ultrasonic dispersion combined method is adopted, the diamond particles and the matrix powder are fully mixed, the matrix powder and the diamond particles are stirred at a low speed through mechanical stirring, and the particles are preliminarily dispersed. And the uniformity is improved: mechanical stirring, ultrasonic dispersion and electrostatic dispersion are combined, so that the distribution uniformity of diamond particles in a matrix is remarkably improved.

The invention relates to an oxygen evolution electrode of a nickel-iron-cobalt-based alloy coating and a preparation method of the oxygen evolution electrode, the oxygen evolution electrode is composed of a conductive substrate and an alloy coating which is deposited on the surface and takes Ni, Fe and Co as main metal elements and takes at least one of Mn, Cr, Cu, Mo, W, Ti, Al or Zn as an additional metal element, the preparation method adopts a spraying process, and the nickel-iron-cobalt-based alloy coating is deposited on the conductive substrate. The nickel-iron-cobalt-based alloy coating of the oxygen evolution electrode is well combined with the conductive substrate, the microstructure is controllable, the oxygen evolution electrode is suitable for large-area preparation, the structure formed through element synergy and the spraying process has excellent oxygen evolution catalytic activity and stability, the preparation process is flexible, the cost is low, and large-scale production is easy. And an effective way is provided for development of a high-performance and large-size OER catalyst.

The invention belongs to but not limited to the technical field of dissimilar metal welding, and discloses a method and system for improving the erosion resistance of a laser cladding cobalt-based alloy coating. Carrying out surface pretreatment on the base material; preparing a cobalt-based alloy cladding layer through a laser cladding technology; and the clad material is subjected to stress relief annealing treatment. Through the key step of annealing treatment after laser cladding of the cobalt-based alloy, generation of micro cracks and defects in a cobalt-based alloy cladding layer is effectively reduced, and therefore the coating which is tightly combined with a base body, excellent in mechanical property and remarkably improved in erosion resistance strength is prepared. The invention further provides an effective solution for solving the problem that cracks are easily generated due to improper heating rate and heat dissipation conditions in the laser cladding process of the cobalt-based alloy, and the quality and reliability of a cladding layer are remarkably improved. The technical innovation is of great significance in promoting high-quality development of the manufacturing industry, especially in the aspect of prolonging the service life of key parts and improving the performance of the key parts.

To provide a new multilayer thin film exhibiting a tunnel magnetoresistance effect.SOLUTION: The present invention is a multilayer thin film having an insulating layer and a magnetic layer sandwiching the insulating layer. At least one of the magnetic layers is made of a Co-based alloy containing Al and / or Ga. For example, Co is contained in an amount of 58.5 to 63 at% with respect to the entire Co-based alloy. The Co-based alloy constituting a magnetic layer may be a β phase. The insulating layer is, for example, MgO or MgAl2O4. The magnetic layer on the other side of the insulating layer may be CoFeB (alloy) in addition to CoAl. Each layer is formed by sputtering, and planarization, crystallization, and the like are performed by heat treatment. A magnetic tunnel junction (MTJ) having the multilayer thin film of the present invention exhibits a high magnetoresistance change ratio (MR ratio), and can be applied to a next-generation magnetoresistance memory (MRAM) or the like.SELECTED DRAWING: Figure 3

The invention provides a wear-resistant Stellite6 / WC laser cladding composite coating and a preparation method thereof.The preparation method comprises the following steps that 1, Stellite6 cobalt-based alloy powder and WC powder are weighed to obtain composite powder, and the mass of the WC powder accounts for 2.5-10% of the mass of the composite powder; 2, the surface of a to-be-treated base body is pretreated, and a sample base body is obtained; and step 3, preparing a laser cladding coating on a sample matrix by using the obtained composite powder to obtain the wear-resistant Stellite6 / WC laser cladding composite coating. The wear resistance of the surface of the blade can be effectively improved, the service life of the blade is prolonged, and the requirements of the turbine blade under severe working conditions are met.

The invention discloses cobalt-based alloy powder and application thereof, and belongs to the technical field of metal alloy materials. The cobalt-based alloy powder comprises the following components in percentage by mass: 0.2 to 0.6 percent of C, 2.0 to 3.0 percent of Si, 2.0 to 3.0 percent of Fe, 25.0 to 32.0 percent of Cr, 5.0 to 7.0 percent of Mo, 1.0 to 3.0 percent of Mn, 0.1 to 9.0 percent of W, 2.0 to 12.0 percent of Ni and the balance of Co and inevitable impurities. The cobalt-based alloy powder provided by the invention can be used for repairing a nut column through laser cladding, a cladding layer without cracks, air holes, inclusions and other defects on the surface and the interior can be obtained after cladding under certain laser power, the average Vickers hardness of the cladding layer can reach 434.3 Hv, meanwhile, the cobalt-based alloy powder has excellent wear resistance, and the service life of the cladding layer is prolonged. The method has remarkable advantages in the aspect of improving the material surface performance, and is suitable for various repair scenes needing high hardness and wear resistance.

The utility model discloses a convex pushing cutter for a steel rail welding machine, which solves the problem of short service life of the existing convex pushing cutter. The push protruding cutter is a movable welding push protruding cutter body composed of a cutter body chain-shaped structure and a locking mechanism, the cutter body chain-shaped structure is composed of a left cutter, a top cutter and a right cutter which are sequentially hinged into a whole, and the left cutter, the top cutter and the right cutter are provided with cutting edges matched with the section shape of a steel rail. The cutting edge is a non-magnetic cobalt-based alloy surfacing body fixed on the cutter body, the high point of the cobalt-based alloy surfacing body is at least 3mm higher than the plane of the cutter body, and the distance between the high point of the cobalt-based alloy surfacing body and the surface of the steel rail is not less than 1mm. The wear-resistant surfacing body is additionally arranged at the blade position, so that the service performance and the service life of the bulged cutter body are remarkably improved.

An Fe—Co-based alloy bar and a method for manufacturing same, whereby excellent magnetic properties can be reliably obtained. The Fe—Co-based alloy bar has 20% or more by area ratio of crystal grains having a grain orientation spread (GOS) value of at least 0.5°. The Fe—Co-based alloy bar contains 95% or more of Fe+Co in mass %.

The invention relates to a low-fault-energy micro-twin synergistic deformation cobalt-based alloy and a preparation method thereof, and belongs to the field of cobalt-based high-temperature alloys. According to the alloy, on the basis of Co-Al-W, Ti and Ta which are smaller than or equal to 4 wt% are added according to calculation of a first principle, and the stacking fault energy is controlled to be-95 mJ / m < 2 > to-89 mJ / m < 2 > (0K). Aiming at the defect of insufficient high-temperature plasticity of the gamma '-phase strengthened cobalt-based alloy, an electronic structure is accurately regulated and controlled through a first principle, intrinsic stacking fault energy is designed to reach an optimal negative value interval, a micro-twin mechanism is activated, dislocation slippage and micro-twin coordination is realized, and the problem of sudden plasticity drop caused by single deformation mechanism (dislocation slippage leading) and grain boundary weakening of a traditional alloy is solved; the high-temperature strength and the plasticity are synchronously improved.

Wrought age-hardenable nickel-chromium-cobalt based alloy compositions suitable for use in high temperature gas turbine cases possessing higher mechanical strength, toughness / containment, and thermal stability compared to current commercial alloys and an acceptable containment factor containing in weight percent 16 to 20 wt.% chromium, 8 to 13 wt.% cobalt, 4 to 8.5 wt.% molybdenum, up to 8 wt.% tungsten, 2.1 to 4.1 wt.% aluminum, titanium up to 1.9 wt.%, up to 3.7 wt.% niobium, up to 5 wt.% iron, carbon present up to 0.15 wt.%, up to 0.015 wt.% boron, up to 7.1 wt.% tantalum, up to 0.13 wt.% silicon, up to 1.0 wt.% manganese, and up to 0.06 wt.% zirconium, with a balance of nickel and impurities. The amounts of certain alloying elements must be carefully controlled according to three compositional relationships here disclosed.

The invention relates to the technical field of alloys, in particular to a preparation method of a high-wear-resistance hard alloy for geomines. The method comprises the following steps: taking nickel-based corrosion-resistant alloy powder with specific components as a binding phase instead of cobalt, carrying out wet ball-milling mixing, forming, dewaxing and pre-sintering on the binding phase and hard phase powder such as tungsten carbide, and then carrying out vacuum-back pressure pulse treatment on a pre-sintered body by adopting an infiltration solution containing polyacrylic acid, branched polyethyleneimine and dopamine hydrochloride; and carrying out vacuum final sintering and hot isostatic pressing densification treatment to obtain a final product. Through material system innovation and process optimization, the wear resistance, corrosion resistance and toughness of the hard alloy under the underground severe working condition are remarkably improved, and the problems that a traditional cobalt-based alloy binding phase is prone to corrosion, and the service life of a tool is short are effectively solved.

This invention discloses a cobalt-based alloy sand, a method for preparing and optimizing the surface of the damaged area, relating to the field of alloy repair. The cobalt-based alloy sand includes Cr, Ni, Mo, Ti, Ta, B, and Y, with the remainder being Co and / or unavoidable impurity elements. The method for optimizing the surface of the damaged area mainly involves sandblasting the surface of the damaged area twice. This invention can sandblast the damaged area surface to achieve the purpose of surface modification, thereby inhibiting the aggregation of Si-rich and B-rich brittle eutectic phases at the interface during powder metallurgy and improving the interfacial bonding strength of the repair joint.

The invention aims to provide a repair welding method for an investment casting part of a gas turbine, and belongs to the field of welding. Comprising the following steps: (1) eliminating surface defects; (2) the repair welding requirement is limited; (3) welding is carried out; (4) interlayer treatment; and (5) post-welding treatment. The invention encompasses repair welding processes for investment casting nozzle segments, bulkheads, turbine shrouds, and other investment casting stator parts made of cobalt-based alloys and cobalt-based alloys. Repair welding processing is carried out on local cracks, the production period can be greatly shortened, the production cost is saved on a large scale on the premise that the product quality is guaranteed, and the product requirements are met.

The invention discloses a metallurgical-defect-free high-temperature wear-resistant cobalt-based alloy coating and a preparation method and application thereof.The preparation method comprises the following steps that (1) Fe powder, Co powder, Cr powder, Ti powder, Mo powder and Ni powder are accurately weighed according to the stoichiometric equation Co57Fe5Ni5Cr25Ti5Mo3, and (2) the weighed powder is put into a ball milling tank to be subjected to ball milling, so that the powder is evenly mixed, and then drying, sieving and drying storage are conducted; (3) 5NiCrMo hot work die steel is selected as a base material, a sand mill is used for polishing the surface of the base material so as to remove surface oxide skin until a bright surface is exposed, and oil stains on the surface are removed; and (4) a laser directional energy deposition method in laser additive manufacturing is used for continuously depositing the crack-free cobalt-based alloy coating with high temperature resistance, wear resistance and no cracks one by one. The high-temperature wear-resistant alloy shows excellent wear resistance at a high temperature, the alloy has a shallower wear depth and a narrower grinding crack width at the high temperature, and the wear rate at the high temperature of 800 DEG C is reduced from 2.171 * 10 <-4 > mm < 3 > / N.m of a 5CrNiMo base material to 2.45 * 10 < 6 > mm < 3 > / N.m of a coating.

Provided is a mold copper plate with which it is possible to form a solidified shell of a slab in an appropriate state and with which it is possible to prolong the life of a coating layer applied to the mold copper plate. A mold copper plate for a continuous casting mold has a base material layer comprising copper or a copper alloy, and a coating layer provided on the base material layer. The coating layer includes at least one of nickel, cobalt, a nickel-based alloy, a cobalt-based alloy, and a stainless steel alloy as a component element, and includes an alloy including at least one of a metal nitride, a metal carbide, and a metal oxide as another component element. According to the invention, the solidification shell of the slab can be formed in an appropriate state, and the service life of the coating applied to the mold copper plate can be prolonged.

The invention discloses a cobalt-based alloy powder production device for hard alloy and a preparation method of the cobalt-based alloy powder production device, and relates to the technical field of alloy powder production, the cobalt-based alloy powder production device comprises a smelting furnace and a gas atomization reaction furnace connected with the smelting furnace, and further comprises grinding and screening equipment connected with the gas atomization reaction furnace, a rotating groove is formed in the side wall of the box body, a door plate located on the outer side of the rotating groove is fixed to the side wall of the box body, a rotating frame is arranged in the rotating groove, a plurality of device grooves are formed in the inner wall of the rotating frame in a penetrating mode and arranged at equal intervals in the circumferential direction of the rotating frame, and a screening mechanism is arranged on the inner wall of each device groove. The cobalt-based alloy particle circular grinding device can automatically complete circular grinding machining of cobalt-based alloy particles, full grinding can be achieved through the closed-loop circular design, the grinding efficiency is greatly improved, meanwhile, the screening efficiency of the cobalt-based alloy particles can be effectively improved, and meanwhile the problem that a screen plate is prone to being blocked is greatly solved.

This invention relates to the field of circuit material processing technology, and in particular to a high-performance buried resistive copper foil and its preparation method. The buried resistive copper foil is composed of an electrolytic copper foil layer, a barrier layer, a resistance alloy layer, and a cobalt-based alloy seed layer. The cobalt-based alloy seed layer is a cobalt-tantalum-iridium-molybdenum alloy. The resistance alloy layer is an alloy composed of two or more elements selected from nickel, chromium, aluminum, silicon, phosphorus, cobalt, tin, tantalum, iridium, and molybdenum. The barrier layer is an alloy composed of one or two elements selected from nickel, chromium, aluminum, silicon, phosphorus, cobalt, tin, tantalum, iridium, and molybdenum. The preparation method includes the following steps: carrier cleaning, double-sided seed layer preparation, double-sided resistance alloy layer preparation, double-sided barrier layer preparation, hot pressing treatment, and carrier peeling. This invention improves the overall performance of the product through a multi-layer alloy plating structure design; at the same time, it provides an efficient preparation method to achieve simultaneous double-sided preparation and one-time production of two sheets of buried resistive copper foil, significantly improving production efficiency and reducing production costs.

The invention discloses a vacuum melting method of a high-nitrogen high-chromium wear-resistant cobalt-based alloy. The vacuum melting method comprises the following steps: (1) burdening according to target components; (2) carbon powder is placed at the bottom of a crucible, and then cobalt, chromium, molybdenum, nickel and iron are sequentially put into the furnace; (3) heating and raising the temperature until melting down, and carrying out vacuum refining; (4) filling high-purity nitrogen, and carrying out gas-phase nitriding; and (5) after nitriding is completed, hot-line pouring tapping is carried out. The high-nitrogen high-chromium wear-resistant cobalt-based alloy prepared by the method has the advantages of low production cost, simple process, stable nitrogen content and the like, and is suitable for large-scale popularization.

The invention belongs to the technical field of material additive manufacturing and surface engineering, and particularly relates to a process method for preparing an erosion-resistant layer on the surface of a high-speed pump diffuser runner opening. According to the method, a cold metal transition welding technology is adopted, cobalt-based alloy with high corrosion resistance is selected as a surfacing material and applied to the surface of the high-speed pump diffuser runner opening in a surfacing mode, an erosion-resistant surfacing layer which is free of metallurgical defects and high in hardness is constructed, and therefore the service life of a diffuser is effectively prolonged. According to the technological method, through precise welding parameter regulation and control and scientific selection of materials, the erosion resistance of the surface of the diffuser runner opening of the high-speed pump is remarkably improved, an efficient and reliable surface strengthening solution is provided for the industrial field, and the technological method has important technological innovation value and application prospects.

This invention relates to the field of electrochemical polishing of cobalt-based alloys, specifically to an environmentally friendly electrochemical polishing solution and polishing method for a cobalt-chromium-tungsten-nickel alloy. The cobalt-based alloy has the following chemical element mass percentages: Cr: 15.0%–25.0%; W: 10.0%–20.0%; Ni: 0.0%–15.0%; the balance being Co and unavoidable impurities such as O, N, and H. The environmentally friendly polishing solution has the following chemical composition and molar percentages: ChCl: 0.5–2 mol / L; ethylene glycol: 0.7–1.0 L; ethanol: 0–0.3 L; glacial acetic acid: 0.1–0.3 L; and a small amount of citric acid as an additive. The electrochemical polishing uses the alloy as the anode and a U-shaped titanium plate as the cathode, with a voltage of 40–60 V and a current density of 0.5–2 A / cm². 2 The polishing temperature is room temperature. The advantage of this invention is that it uses an environmentally friendly electrolyte, which can polish the surface of cobalt-chromium-tungsten-nickel alloy, avoiding the pollution of traditional chromium oxide system and acidic electrolyte system, reducing the need for repeated cleaning processes, and improving the precision control of materials.

The application discloses an anti-abrasion cobalt-based cladding powder, an ultrafine lamellar eutectic cobalt-based coating and a preparation method, and belongs to the technical field of anti-abrasion and anticorrosion alloy coating. The cladding powder comprises 15.0-20.0% of Ni, 14.0-15.0% of Cr, 22.0-25.0% of Mo, 2.7-2.9% of Si and 0.07% or less of C, and the rest is Co, in percentage by mass. The application utilizes the difference in mixing enthalpy of a specific content of Ni element and other elements in the cobalt-based alloy system, changes the non-equilibrium solidification path in laser cladding, suppresses the excessive precipitation and growth of Laves phase, and forms a Laves phase / (gamma-Co / Ni) lamellar ultrafine eutectic structure with excellent strength and toughness. Compared with the prior art, the application can significantly reduce the crack sensitivity of the coating without sacrificing the comprehensive performance of the coating in abrasion resistance and corrosion resistance.

The invention discloses a wear-resistant and corrosion-resistant metal mold and a preparation process thereof, and relates to the technical field of metal molds. The method specifically comprises the following steps that a die steel base body is taken and ground to be flat through a grinding machine, then cleaned and dried through acetone, nitrided and preheated, a transition layer and a functional surface layer are sequentially prepared on the surface of the die steel base body through laser cladding, and finally the abrasion-resistant and corrosion-resistant metal die is obtained through boriding. The transition layer comprises the following raw materials in parts by mass: 40-60 parts of nickel-based alloy, 20-30 parts of cobalt-based alloy, 10-12 parts of carbide and 5-8 parts of oxide; the functional surface layer comprises the following raw materials in parts by mass: 80-100 parts of cobalt-based alloy, 0.3-1 part of modified carbon nanotubes, 4-8 parts of carbides and 0.8-1 part of oxides.

The present application belongs to the technical field of cobalt-based alloy material processing, and relates to a preparation method of high-strength cobalt-based alloy wire, in particular to a cold processing method of high-strength cobalt-based alloy wire. The present application realizes the whole-process cold drawing of cobalt-based alloy wire φ3.0mm-φ0.2mm by controlling the pass deformation amount to be 8%-16%, the heat deformation amount to be 35%-60%, and cooperating with specific heat treatment mode and cold drawing die, the drawing speed reaches 10-35m / min, the prepared cobalt-based alloy wire has high strength, good metallographic structure, high uniformity, and the yield is up to more than 60%. The cold drawing production process of the present application overcomes the problems of poor plasticity and difficult deformation of cobalt-based high-temperature alloy, and the γ phase is transformed into ε phase during the drawing process, thereby improving the strength of the cobalt-based high-temperature alloy.

The valve rod sealing structure under the ultralow-temperature working condition comprises a valve deck and a valve rod, a through hole is formed in the valve deck, the valve rod is in rotating fit with the through hole of the valve deck, a graphite packing set is arranged between the valve deck and the valve rod, and the valve rod sealing structure further comprises a lip-shaped ring. The lip-shaped ring comprises cobalt-based alloy and PTFE, the cobalt-based alloy is coated with the PTFE, the lip-shaped ring is arranged between the valve cover and the valve rod, the valve cover is arranged on the valve body, one end of the valve rod is located in the valve body, the lip-shaped ring is located between the valve body and the graphite packing set, the valve cover is made of austenitic stainless steel, and the graphite packing set is arranged between the valve cover and the valve rod. The valve rod is made of austenitic stainless steel, and the valve body is made of austenitic stainless steel. The utility model further discloses a valve using the valve rod sealing structure under the ultralow-temperature working condition.

The invention relates to a cobalt-based alloy, alloy powder and a manufacturing method thereof, and belongs to the field of cobalt-based alloys, and the cobalt-based alloy comprises the following components in percentage by weight (wt%): 1-40% of Cr, 1-40% of Mo, 1-5% of Si, 0-0.1% of C and the balance of Co. According to the cobalt-based alloy, by reducing the carbon content, a large number of brittle carbides are prevented from being formed, and the material is not prone to cracking when bearing impact loads; the cobalt-based alloy is low in carbon content and slight in decarburization, so that the mechanical property and the strength of a cobalt-based alloy powder product are not worsened; the matrix Co is subjected to solid solution strengthening through the molybdenum with the extremely high content, the intermetallic compounds Cr and Si are supplemented, solid solution strengthening and intermetallic compound strengthening are more stable than carbide strengthening of Co and Mo at the high temperature, overaging is not prone to occurring, and the cobalt-based alloy still has the excellent mechanical property, strength and abrasion resistance at the high temperature.

The application provides a steam turbine blade ultrahigh-temperature coating and a preparation method thereof, and relates to the technical field of material surface treatment, and comprises the following components in mass ratio: yttrium stabilized zirconium 20-30 parts, titanium aluminum nitride 15-20 parts, lanthanum magnesium aluminum spinel 10-15 parts, nano cerium oxide 5-10 parts, cobalt-based alloy 10-15 parts, rare earth element mixture 1-5 parts, hexagonal boron nitride 5-10 parts, SiC nano particles 5-10 parts, and chromium carbide 2-5 parts. The synergistic effect of the lanthanum magnesium aluminum spinel and the rare earth element mixture greatly reduces the grain growth rate of the coating at high temperature, thereby improving the stability at extreme temperature. The protective layer formed by the decomposition of the chromium carbide and the SiC nano particles jointly inhibit the sulfur corrosion, further improve the stability, and ensure the performance of the coating under high temperature conditions.