231 results about "Chromium carbide" patented technology

The invention discloses a rare earth oxide modified high-entropy hard alloy and a preparation method thereof. A high-entropy hard phase (high-temperature calcination), a high-entropy binding phase and rare earth oxide are adopted, grinding, pressing and air pressure sintering at the temperature of 1450-1550 DEG C are conducted, and the high-entropy hard phase is prepared from tungsten carbide, titanium carbide, zirconium carbide, yttrium carbide, manganese carbide, chromium carbide and molybdenum carbide; the high-entropy binding phase comprises the following components: cobalt and a CoCrFeNi-series high-entropy alloy; and the component of the rare earth oxide is Y2O3 or Nd2O3. The prepared rare earth oxide modified high-entropy hard alloy has the advantages of high strength, high compactness, high hardness, high wear resistance and the like.

The utility model relates to a supercritical unit drain ball valve structure which comprises a valve body, a valve rod and a valve ball, the valve body is integrally manufactured, a valve cavity is formed in the middle of the valve body, and flange holes are formed in the two ends of the valve body respectively. One side of the valve cavity is communicated with one flange hole, and the other side of the valve cavity is communicated with the other flange hole through a water through hole; a valve rod hole is formed in the middle of the upper end of the valve body, and fixing supports are arranged on the two sides of the upper end of the valve body respectively. The valve body is of an integrated die forging structure, the situation that a split valve is prone to leakage is avoided, the valve body is of a floating ball structure, and the ball body is easier to seal under high pressure; medium chromium carbide is sprayed on the ball body and the valve seat, so that the spraying hardness, the binding rate and the porosity are guaranteed, and the sealing reliability is guaranteed; a compensation disc spring is arranged between the valve seat and the positioning pressing ring, so that the valve seat ensures the mounting reliability and the sealing reliability; the thrust ring is arranged on the valve rod to limit the displacement of the valve rod and prevent the valve rod from being separated from the ball body, and safety and reliability are achieved.

The invention relates to the technical field of flux-cored wires. The preparation method comprises the following steps: weighing the following raw materials in parts by weight: 4-6 parts of chromium carbide powder, 7-9 parts of molybdenum powder, 6-8 parts of nickel powder, 10-15 parts of niobium powder, 15-18 parts of tungsten carbide powder, 7-11 parts of a modified titanium carbide agent, 5-8 parts of a blending agent added based on boron and 2-4 parts of 30-mesh natural graphite; 1-2 parts of sodium fluosilicate; 1-2 parts of aluminum powder; and 70-75 parts of iron powder. The flux-cored wire can adapt to complex service environments of parts such as rollers and continuous casting crystallizers in the metallurgical industry, the service life of the parts subjected to surfacing repair is prolonged, the production efficiency of the parts subjected to surfacing repair is improved, the obtained flux-cored wire achieves balance of high-temperature performance, mechanical performance and low-temperature stability, and the comprehensive applicability of products is improved.

The invention relates to the technical field of powder metallurgy, and particularly discloses an ultra-coarse grain WC-Co hard alloy and a preparation method thereof.The preparation method comprises the following steps that S1, the following raw materials including, by weight, 4.6-9.2 parts of cobalt powder, 96-102 parts of coarse grain tungsten carbide powder, 3.6-5.2 parts of functional gel, 3.4-4.6 parts of modified penetration enhancer, 2.2-2.8 parts of binder and 36-62 parts of organic solvent are prepared; step S2, preparation of a mixture; step S3, carrying out granulation treatment; step S4, compacting; step S5, pressurizing and sintering; the functional gel and the modified penetration enhancer are added, the functional gel contains yttrium oxide, polytannic acid, ultrafine tungsten carbide, tantalum carbide, chromium carbide, silica gel and other components, and the functional gel not only has excellent physical properties, but also can be cross-linked with the modified penetration enhancer to form a more compact silicon dioxide network structure; and the hardness, toughness, impact resistance and wear resistance of the alloy are improved.

The invention discloses a preparation method of a superfine WC-Co hard alloy. 89.8-90% wt of superfine tungsten carbide, 9% wt of superfine Co powder and 1-1.2% wt of composite additive chromium carbide and vanadium carbide are adopted; wherein the weight ratio of chromium carbide to vanadium carbide is 1 / 2; ball-milling the raw materials to obtain a mixture; and the pressed blank is subjected to a specific oscillation pressure and rapid cooling sintering process, the contact form and interface state among particles are improved, the density of the hard alloy is improved, WC grain growth is inhibited, flowing of binding phase Co is promoted, the structure and mechanical properties of the alloy are remarkably improved, and the nanocrystalline WC-Co hard alloy with high strength and high density is obtained.

The invention relates to a preparation method of coarse-grained chromium carbide powder. The preparation method comprises the following steps: firstly, carrying out preliminary stirring, ball milling, pre-drying, low-temperature drying and medium-temperature pyrolysis on chromium sesquioxide powder, a dispersing agent and glycerol, so that the glycerol is pyrolyzed into solid carbon, and coating the surface of chromium sesquioxide with the solid carbon to form first-stage carbon source coated powder; mixing the powder with graphite powder and glycerol, carrying out pre-drying and low-temperature drying and shaping to obtain a two-stage carbonization column, carrying out gradient heating carbonization under a protective atmosphere to enable chromium sesquioxide and carbon to fully react to generate a chromium carbide phase mainly comprising Cr3C2, and then carrying out post-treatment to obtain the coarse-grained chromium carbide powder. According to the invention, glycerol is introduced as a main carbon source in the early stage and microcosmic coating is realized, so that the contact between the carbon source and chromium sesquioxide is more sufficient, and the reaction efficiency is improved; and meanwhile, the graphite powder is subjected to independent ball milling in advance to control the granularity, so that carbon source demolding is avoided, and better granularity control is realized. The method is flexible in process, and the product is coarse, uniform and stable in granularity.

The invention provides a plasma spraying high-temperature-erosion-resistant coating and a coating preparation method, and relates to the technical field of material surface treatment. Comprising the following components in parts by mass: 30-45 parts of tungsten carbide, 15-25 parts of chromium carbide-nickel-chromium alloy, 15-25 parts of yttria-stabilized zirconia, 5-10 parts of aluminum oxide-titanium dioxide composite ceramic, 10-20 parts of nickel-chromium-aluminum-yttrium alloy, 1-3 parts of nano aluminum oxide and 1-3 parts of lanthanum oxide. Multiphase collaborative design is adopted, tungsten carbide and chromium carbide-nickel-chromium alloy form double hard phases, the hardness is higher, aluminum oxide-titanium dioxide composite ceramic fills pores and improves compactness, rare earth and nanometer are adopted to cooperate, lanthanum oxide and nanometer aluminum oxide react to generate a LaAlO3 protective layer, oxidation weight gain is small, oxygen diffusion is inhibited, nanometer aluminum oxide refines grains, and the hardness is higher. In conclusion, the high-temperature oxidation resistance is high, and the erosion rate is low.

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.

The invention relates to the technical field of cutting tools, and discloses a high-strength wear-resistant cutting tool and a preparation method thereof.The high-strength wear-resistant cutting tool is prepared from, by weight, 85-89.5 parts of tungsten carbide nanometer powder, 9-12 parts of cobalt powder, 0.5-1 part of chromium carbide, 1-2 parts of tantalum powder and 0-0.5 part of molybdenum powder, and the particle size range of the tungsten carbide nanometer powder is 50-100 nm. The synergistic effect of the tungsten carbide nano powder and the gradient cobalt content is accurately controlled, breakthrough improvement of the performance of a base material is achieved, the gradient structure design enables the surface layer of the material to obtain high hardness, meanwhile, the core part keeps fracture toughness, and the technical problem that a traditional homogeneous material cannot give consideration to high hardness and high toughness is solved. And the cutting tool can adapt to wider machining working conditions and material types.

The invention discloses a preparation method for spraying a nickel-chromium-chromium carbide coating on the surface of a gas turbine part through high velocity oxy-fuel, and belongs to the technical field of preparation of the nickel-chromium-chromium carbide coating through thermal spraying. The preparation method comprises the following steps that preparation before spraying is conducted, and nickel-chromium-chromium carbide powder for thermal spraying is placed in a drying oven to be dried; cleaning is conducted, specifically, the spraying area and the adjacent area of the part are wiped and cleaned, and impurities such as oil stains are removed; protection before sand blasting is conducted, specifically, the non-sand-blasting surface and a small part of the spraying area of the part are protected through a high-temperature-resistant adhesive tape; a sand blowing machine is provided with a 0-0.6 MPa adjustable air pressure air source and is provided with an oil-water separator; spraying is conducted, specifically, a nickel-chromium-chromium carbide coating is sprayed through hypersonic flame; and cleaning is conducted, specifically, after spraying is completed, the spraying protection clamp and the adhesive tape are removed, and floating ash on the surface of the part is cleaned. The wear-resistant coating is prepared on the surface of the aero-engine and gas turbine part by adopting the process, a nickel-aluminum bottom layer does not need to be sprayed in advance, the quality is stable, and the production cost is reduced.

The invention relates to the technical field of magnesia carbon bricks, in particular to a preparation method of a magnesia carbon brick and a magnesia carbon brick material prepared thereof.The preparation method comprises the following steps that raw materials including, by weight, 65-70 parts of magnesium aluminate spinel, 35-40 parts of fused magnesite, 10-15 parts of carbon, 5-8 parts of an additive for blending chromium carbide, 4-7 parts of a modified zirconium vanadate agent and 3-5 parts of a binding agent are weighed; according to the magnesia carbon brick disclosed by the invention, magnesium aluminate spinel and fused magnesia are matched with carbon and the binding agent, the additive for blending chromium carbide and the modified zirconium vanadate agent are added for mutual blending and synergistic effect, and the raw materials are co-blended and co-blended, so that the obtained magnesia carbon brick product has excellent fracture toughness, compression strength and oxidation resistance; and the product performance can be harmoniously improved, and the product is resistant to different degrees of corrosion stability.

There is provided a cutting device comprising a base comprising bainite, and a multilayered coating present on the base, wherein said multilayered coating comprises several periods comprising at least two coating layers, of which at least one comprises chromium. Layers of pure chromium, chromium carbide or chromium nitride may be present. The coated cutting device has an excellent wear resistance and stay sharp properties. There is also provided a method for manufacturing such the cutting device, comprising the steps of providing a base comprising bainite and / or martensite, and forming a multilayered coating on the surface using PVD.

The invention discloses a wear-resistant flux-cored wire and a manufacturing method thereof, and belongs to the technical field of welding materials, the wear-resistant flux-cored wire is formed by wrapping three layers of flux cores with a low-carbon steel strip, the inner main wear-resistant layer contains chromium carbide, recycled slag, cobalt-based alloy and carbon nanofibers, and the outer main wear-resistant layer contains chromium carbide, recycled slag, cobalt-based alloy and carbon nanofibers; the gradient mixing layer is in gradient transition of inner and outer layer components; and the outer auxiliary wear-resistant layer contains tungsten carbide, ferrovanadium and electrolytic manganese powder. The preparation method comprises the steps of waste residue recovery treatment, ultrasonic dispersion and mixing, layered vibration compaction and cold drawing forming. Through three-layer structure collaboration, nano reinforcement and solid waste recovery, the wear resistance is improved by 20%-30%, the cost is reduced by 15%-20%, and the composite material is suitable for complex working conditions such as mines and metallurgy and has the advantages of being high in bonding strength, resistant to cracks, stable in process and the like.

The invention belongs to the field of coatings, and particularly relates to a preparation method of a wide-temperature-range wear-resistant protective coating of a metal sealing surface and the coating, and the method comprises the following steps: putting a pre-plated substrate into a plating solution with the Co < 2 + > concentration of 125g / L-155g / L, the ceramic particle concentration of chromium carbide particles and / or chromium oxide particles of 5g / L-15g / L and the hBN particle concentration of 1g / L-10 g / L, and electroplating under ultrasonic waves, the Dv50 values of the ceramic particles and the hBN particles are 2-8 [mu] m and 3-15 [mu] m respectively; the composite electroplating is divided into three stages, the ultrasonic frequencies of the three stages are 28-32 KHZ, 38-42 KHZ and 38-42 KHZ correspondingly, and the current densities of the three stages are 0.5-2 A / dm < 2 >, 1.5-3 A / dm < 2 > and 3-4 A / dm < 2 > correspondingly. The coating has significantly improved wear resistance and reduced surface roughness.

The invention relates to a medium-stress abrasive wear resistant plasma surfacing flux-cored wire and a preparation method thereof. The medium-stress abrasive wear resistant plasma surfacing flux-cored wire comprises an outer skin and a flux core, the flux core is composed of, by weight, 3%-6% of graphite powder, 2%-6% of high-carbon ferrochrome powder, 10%-30% of chromium carbide powder, 3%-6% of ferromolybdenum powder, 45%-65% of ferrovanadium powder, 1%-2% of silicon carbide powder, 1%-3% of electrolytic manganese powder and the balance reduced iron powder. The outer skin is a low-carbon cold-rolled steel strip. The flux-cored wire has the advantages that various alloy elements such as Cr and V are added into the flux core, under the high-temperature effect of plasma surfacing, precipitated carbon elements and other alloy elements form various carbides, M7C3 type carbides distributed in a net shape and dispersed and fine VC carbides are generated, the dispersion strengthening effect is achieved, fine grain strengthening can be achieved, the impact resistance is guaranteed, and meanwhile the flux-cored wire has the good mechanical property. Therefore, the wear resistance of the metal coating is further improved.

The high-temperature-resistant composite wear-resistant plate is characterized in that a chromium carbide alloy layer is welded to the surface of a base plate, the surface of the chromium carbide alloy layer is coated with an electroplated layer, the base plate is prepared through raw material melting, pouring, cooling and tempering, the chromium carbide alloy layer is made of chromium carbide alloy, and the electroplated layer is coated with an electroplated layer. The content of the chromium carbide alloy is 20%-30%; the plate is prevented from being in direct contact with high temperature and other objects, direct consumption of the plate is reduced, the service life of the plate is prolonged, meanwhile, the surface of the base plate is sequentially subjected to acid pickling, surface attachment of chromium carbide alloy and forming of a composite wear-resistant laminate, then electroplating is conducted, the surface strength of the base plate is improved, and the usability of the base plate is improved.

The invention provides a tungsten carbide composite coating as well as a preparation method and application thereof, and belongs to the technical field of surface protection. The preparation method of the tungsten carbide composite coating comprises the following steps that tungsten powder, chromium carbide powder and high-entropy alloy powder are mixed, and mixed raw material powder is obtained; and the mixed raw material powder is laid on the surface of a metal substrate material to form a preset coating, then laser cladding treatment is conducted, and the tungsten carbide composite coating is formed on the surface of the metal substrate material. Tungsten carbide is generated through an in-situ reaction in the laser cladding treatment process, so that the comprehensive performance (such as hardness, frictional wear resistance and corrosion resistance) of the coating is improved by adding the tungsten carbide.

According to the preparation technology of the wide-temperature-range wear-resistant self-lubricating composite coating, a double-ceramic-layer structural system is adopted, the matching performance between the coating and a base body and the matching performance between the coatings are integrally improved, the oxidation resistance and the thermal cycle performance of the coatings are improved, and peeling of the coatings in the using process is reduced; nickel-chromium / chromium carbide is sprayed on the surface of a metal matrix through supersonic speed to serve as a wear-resistant coating bottom layer, lanthanum fluoride-containing nickel-chromium / chromium carbide is sprayed through supersonic speed flame to serve as a wear-resistant self-lubricating surface layer, the friction coefficient is reduced, the friction performance is improved, and it is guaranteed that the coating system has satisfactory coating thermal cycle performance. The method has the advantages that the matching property of the coating and a metal matrix is improved, the oxidation resistance of a wear-resistant coating system is improved, and the coating system is ensured to have good frictional wear performance and satisfactory thermal cycle performance of the coating. The service life of parts can be prolonged by 2-10 times, and the device can also be applied to other power machinery fields and has a very wide market prospect.

The invention relates to the technical field of metal ceramic layer preparation, and discloses a method for preparing a chromium carbide metal ceramic coating through a thermal spraying technology and the chromium carbide metal ceramic layer.The preparation method comprises the steps that CoCrMo powder and Cr3C2-NiCr powder are mixed and then added into a ball-milling tank, absolute ethyl alcohol and grinding balls are added into the ball-milling tank, and the mixture is stirred to be uniform; sealing the ball-milling tank and placing the ball-milling tank in a ball mill for ball-milling; and after ball milling is completed, a vacuum drying box is used for drying powder slurry in the ball milling tank, a screen is used for screening the dried powder, and therefore Cr3C2-NiCrCoMo composite powder with the uniform particle size distribution is obtained. And the Cr3C2-NiCrCoMo composite powder is sprayed on the surface of a preheated base body through a thermal spraying technology, and the chromium carbide metal ceramic coating is generated. The Cr3C2-NiCrCoMo chromium carbide metal ceramic coating prepared by the method disclosed by the invention has excellent high-temperature oxidation resistance, hardness and wear resistance.

The application discloses a kind of hard alloy cutter materials for deep hole machining, the cutter material is composed of the following weight percentage components: tungsten carbide: 75%~85%, wherein 0.2~0.4 μm superfine tungsten carbide particles account for 60%~80%, 0.4~0.8 μm tungsten carbide particles account for 20%~40%; Cobalt: 10%~15% titanium carbide: 2%~5%; Tantalum carbide: 1%~3%; Niobium carbide: 0.5%~2%; Vanadium carbide: 0.3%~1.0%; Chromium carbide: 0.2%~0.8%; Rare earth element: Y2O3 Or La2O3: 0.1%~0.5%. The application breaks through the bottleneck of high temperature wear, insufficient strength and short service life of traditional hard alloy in deep hole machining through three-dimensional innovation of component design, structure control and surface strengthening, and provides an efficient solution for precision deep hole machining of high hardness materials.

The invention relates to the technical field of hard alloy, in particular to a hard alloy composite coating and a preparation method thereof.The hard alloy composite coating comprises the following layer structures deposited in sequence: a matrix layer, hard alloy composed of, by mass, 8-10% of cobalt, 0.3-0.8% of chromium carbide and the balance tungsten carbide, a transition layer and a titanium nitride layer; plasma enhanced chemical vapor deposition equipment is adopted to deposit on the surface of the base body layer at 870-890 DEG C under the pressure of 200 MPa to form the gradient functional layer and the titanium carbonitride layer, and the carbon-nitrogen atom ratio of the gradient functional layer and the titanium carbonitride layer is changed from 1.2: 1 of the inner layer to 0.6: 1 of the outer layer in a gradient mode. According to the preparation method, through the design of the gradient functional layer, a continuous thermal expansion coefficient transition area is formed in the titanium carbonitride layer, so that the interface thermal stress and the interface crack density are greatly reduced, and the interface bonding strength of the hard alloy composite coating can be remarkably improved; and the layering resistance of the coating in high-speed cutting can be remarkably improved.

The invention discloses a preparation method of carbide-enhanced Ni / Cr composite binding phase Cr3C2-based metal ceramic, and belongs to the field of composite materials. The preparation method is characterized by comprising the following steps: firstly, respectively weighing 0 to 25 weight percent of binder metal powder, 0 to 16 weight percent of second-phase carbide powder, 0 to 1 weight percent of carbon supplementing agent carbon powder and the balance of chromium carbide (Cr3C2) powder; the carbide-enhanced Ni / Cr composite binding phase Cr3C2-based metal ceramic is prepared through traditional powder metallurgy processes such as chromium carbide-second phase carbide pre-ball-milling, mixed material ball-milling, ball-material separation, drying and sieving, glue mixing and granulation, compression molding, vacuum pressureless sintering and the like. The Ni / Cr composite metal powder is used as a binder, the second-phase carbide is used as a modifier, and the carbon powder is used as a carbon supplement agent, so that the problems that the market price of binder metal nickel is relatively high, domestic mineral resources are scarce, a decarburization phase is easily generated in the sintering process of Cr3C2 in industrial production, grains grow abnormally and the like are solved; on the basis of ensuring the wear resistance and corrosion resistance of the chromium carbide-based metal ceramic, certain hardness is improved, and the chromium carbide-based metal ceramic is suitable for the fields of cutting tools, wear-resistant and corrosion-resistant parts and the like.

The invention relates to the technical field of material surface engineering and metallurgical equipment, in particular to a composite coating for prolonging the service life of a crystallizer copper plate and a plasma spraying preparation method thereof.The composite coating comprises, by mass, 35%-55% of chromium, 20%-55% of nickel, 5%-10% of titanium diboride, 0.1%-0.3% of niobium and the balance chromium carbide and inevitable trace impurity elements. According to the invention, titanium diboride and chromium carbide are used as main hard reinforcing phases, so that the coating shows excellent wear resistance at normal temperature and high temperature; a hollow graphite electrode is adopted in the spraying process, plasma arc is generated, and meanwhile an ablation product (carbon) provides a carbon source for formation of chromium carbide; the titanium powder and the boron powder are subjected to an in-situ reaction in a plasma arc to generate titanium diboride, and the in-situ synthesis technology enables hard phase particles to be fine and uniformly distributed, and forms a firm interface with a metal binding phase, so that the problems of interface pollution and weak combination caused by the addition of the hard phase are avoided.

The invention provides a preparation method of a high-wear-resistance alloy lining plate, and relates to the technical field of wear-resistance alloys, carbon steel and pig iron are mixed, heated and melted, high-carbon ferromanganese, medium-carbon ferrochrome and ferrosilicon are added, heating refining is carried out, aluminum powder is added, the mixture is put into a mold, cooling and demolding are carried out, heating homogenization, quenching and cooling are carried out, and a mother plate is prepared; mixing bismaleimide, the composite powder and sepiolite fibers, heating and stirring, coating a mother board with the mixture, firstly applying negative pressure, then applying positive pressure, heating and cooling to obtain a substrate layer; and placing the mother board in magnetron sputtering equipment, sputtering on the substrate layer to obtain a chromium nitride functional layer, and cooling to obtain the high-wear-resistance alloy lining board. The composite powder is prepared by mixing and heating chromium carbide powder and a hydrogen peroxide solution, filtering, mixing with an ethanol solution and gamma-aminopropyltriethoxysilane, heating, condensing and refluxing, washing and drying, and mixing and heating with amine-terminated polyether and N, N-dimethylformamide. The wear-resistant stability of the alloy lining plate can be improved.

The invention provides a nano material for a cutter and a preparation method and a product of the nano material, and relates to the technical field of metal materials. The nanometer material is prepared from the following raw material components in parts by weight: 60 to 80 parts of graphene, 10 to 25 parts of nanometer magnesia powder, 10 to 20 parts of nanometer cobalt powder, 5 to 10 parts of lanthanum oxide, 10 to 20 parts of yttrium oxide, 20 to 35 parts of chromium carbide, 20 to 35 parts of a ball milling regulator, 5 to 15 parts of iron powder, 1 to 3 parts of calcium sulfide and 0.5 to 1.5 parts of boron powder. The average particle size of the chromium carbide is 20-50nm. All the components are dispersed and then subjected to intermittent ball milling treatment to obtain the nanometer material, the nanometer material is used for preparing the cutter by controlling the sintering temperature, the heating rate and the time and adopting a gradient heating and gradient cooling method, so that the internal structure of the cutter is more uniform, and the mechanical property is remarkably improved.

The invention discloses a non-stick cooker, a composite film layer structure adopted by the non-stick cooker, target material slurry and a method. The non-stick cooker comprises a base layer, a middle hardening layer and a functional surface layer which sequentially cover a cooker base body from inside to outside. The functional surface layer is a composite film layer formed by codeposition of chromium carbide and carbon fluoride (CFX, x is greater than or equal to 0.75 and less than or equal to 0.95), the mass ratio of the chromium carbide is 50-70%, and the mass ratio of the carbon fluoride is 20-40%. According to the non-stick cooker and the composite film layer structure, the target material slurry and the method adopted by the non-stick cooker, the previous hydrophobic non-stick mode depending on a film layer bionic microstructure is eliminated, and the non-stick purpose is achieved in the mode that extremely low surface energy is formed purely depending on material innovation.

The invention discloses blast furnace stemming and a preparation method thereof. The invention discloses a high-temperature-resistant wear-resistant coating which is characterized by comprising the following components in parts by weight: 380-420 parts of brown aluminum oxide, 70-90 parts of a carburant, 50-70 parts of Guangxi white mud, 110-150 parts of silicon carbide, 15-30 parts of asphalt powder, 5-30 parts of vanadium carbide or chromium carbide or a mixture of vanadium carbide and chromium carbide or pore-forming vanadium chromium carbide and 50-100 parts of liquid resin. The blast furnace stemming disclosed by the invention has relatively high high-temperature breaking strength, normal-temperature compression strength and normal-temperature breaking strength, and excellent slag and molten iron erosion resistance and molten iron scouring resistance.

The application belongs to the field of detection and analysis, and particularly relates to a method for detecting free carbon in cemented carbide mixture based on pretreatment, which comprises the following steps: S1, obtaining cemented carbide mixture, the components of the cemented carbide mixture including at least one of chromium carbide, silicon carbide and boron carbide, and grinding the cemented carbide mixture into cemented carbide mixture powder; S2, mixing, stirring and centrifugally separating the cemented carbide mixture powder and heavy liquid to obtain a mixture; taking out the upper layer liquid containing elemental carbon of the mixture and washing and solid-liquid separating to obtain an initial sample to be detected; S3, rinsing and drying the initial sample to be detected to obtain a final sample to be detected, and detecting the final sample to be detected to obtain the content of free carbon. Through the improved pretreatment detection method of free carbon in cemented carbide mixture, the accuracy and efficiency of detection are improved, the range of detection of free carbon in cemented carbide is expanded, and the method is suitable for more kinds of carbides.

The invention discloses a metal powder type flux-cored wire suitable for 1500MPa-grade hot-formed steel, which is characterized by comprising a carbon steel sheath and a welding wire flux core wrapped in the carbon steel sheath, and the welding wire flux core comprises the following components in percentage by weight: 6-12% of electrolytic manganese, 6-12% of silicon carbide, 6-12% of silicon carbide, 6-12% of silicon carbide, 5-10% of silicon carbide and the balance of iron. 6%-10% of high-carbon ferromanganese; 3%-6% of chromium carbide; 18%-28% of nickel powder; 0.5%-1.5% of silicon carbide; 0.4% to 0.8% of high-purity ferrotitanium; 0.5%-1.5% of rare earth ferrosilicon; 2%-5% of ferrosilicon powder; 6%-10% of molybdenum powder; 0.2% to 0.5% of lithium fluoride; 0.1%-0.3% of titanium-boron alloy and the balance of gas atomization iron powder. The welding wire has the advantages of being good in weldability, high in tensile strength, good in crack resistance and the like. According to the mechanical properties of deposited metal, the tensile strength is larger than or equal to 1040 MPa, the yield strength is larger than or equal to 960 MPa, AKV2 at-40 DEG C is larger than or equal to 27 J, and the ductility is larger than or equal to 13%. The tensile strength of a welded joint obtained by welding 1500MPa hot-formed steel through a lap joint test is greater than or equal to 950MPa, and a fracture position is a heat affected zone of a base metal part.

The invention relates to an electrical connector (1), especially an electrical plug connector, comprising a connecting part (1a) and a coupling part (1b) which each have a metallic contact region (2, 2'), wherein the connecting part (1a) is electrically conductively connectable to the coupling part (1b) via the metallic contact regions (2, 2'), and wherein at least one of the metallic contact regions (2, 2') at least partially comprises a layer system (3) applied by a PVD process. The layer system (3) comprises a first layer (3a) of titanium or chromium arranged in the metallic contact region (2, 2') and an at least one second layer (3b) arranged on the first layer (3a) and formed either from carbon-doped titanium and / or chromium or alternatively formed from a carbide comprising titanium carbide and / or chromium carbide, and at least one third layer (3c) arranged on the at least one second layer (3b) and composed of a hydrogen-free tetrahedral amorphous carbon having an sp3 content of greater than 50% as bonding type, undoped or doped with at least one element from the group comprising copper, tungsten, molybdenum, chromium, silver, titanium, iridium, gold, silicon in a concentration in the range from 2 to 30 at%.