1000 results about "Chromium carbide" patented technology

The invention discloses an analysis and detection method for impurity elements such as aluminum, calcium, ion, molybdenum, niobium, titanium, tungsten and the like in chromium carbide. The method comprises adding a chromium carbide sample into a dissolving cup, adding hydrofluoric acid, sulphuric acid and nitric acid sequentially, stirring, charging into a sealed high-pressure jar; putting the sealed high-pressure jar into a microwave extinguishing instrument for two times of microwave extinguishment; taking the high-pressure jar out of the microwave extinguishing instrument for cooling, transferring the dissolved chromium carbide liquid sample into a volumeric flask, diluting to a predetermined index, stirring; preparing a chromium substrate matched mixed standard solution series of aluminum, calcium, iron, molybdenum, niobium, titanium and tungsten; measuring element emission power of aluminum, calcium, iron, molybdenum, niobium, titanium, tungsten or the like in a blank liquid sample, a chromium carbide liquid sample and the prepared series mixed standard solution by an inductively coupled plasma atomic emission spectrometer in the same time, obtaining the analysis result by checking a standard working curve or by linear equation calculation. The invention adopts two times of microwave extinguishment using the mixed acid, solves the problem of hardness in chromium carbide decomposition, having a measurement range from 0.010% to 1.00%, which is high in accuracy, and good in precision.

The invention discloses a refractory high-entropy alloy/titanium carbide composite. A refractory high-entropy alloy serves as a matrix phase, and titanium carbide serves as a wild phase; and elements in the refractory high-entropy alloy are selected from at least four kinds of elements of W, Mo, Ta, Nb, V, Ti, Zr, Hf and Cr. A preparation method of the refractory high-entropy alloy/titanium carbide composite comprises the steps that at least four kinds of carbonization metal powder in tungsten carbide, molybdenum carbide, tantalum carbide, niobium carbide, vanadium carbide, the titanium carbide, hafnium carbide, zirconium carbide and chromium carbide are selected and mixed according to the equal molar ratio or the ratio close to the equal molar ratio to form high-entropy matrix powder; and after the high-entropy matrix powder and titanium powder are mixed, alloy mechanization is carried out, then spark plasma sintering or hot-press sintering is carried out, and the refractory high-entropy alloy/titanium carbide composite is obtained. The density and cost of the composite are reduced while the hardness of the composite is improved, excellent high-temperature performance is achieved, and the requirement for manufacturing a high-temperature structural component is met.

The present invention relates to a high-anticracking high-chrome cast iron type hardfacing flux-cored welding wire. Its flux core composition includes (by wt%) 43-70% of chromium carbide, 10-25% of ferrovanadium, 1-5% of 75# ferro-silicon, 3-8% of metal manganese, 1-3% of alumino-magnesium alloy, 2-5% of ferro-boron, 2-6% of ferro-titanium, 1-5% of ferro-niobium and 2-8% of ferro-molybdenum.

The invention provides a high-carbon high-chromium high-niobium cast iron self-protection flux-cored wire. The flux-cored wire has a steel belt as an outer skin. The flux core comprises the following components in weight percentage: 10 to 30 percent of ferroniobium, 20 to 30 percent of high carbon ferrochrome, 0.1 to 3 percent of V, 0.2 to 3 percent of W, 0.6 to 0.8 percent of ferromanganese, 0.2 to 0.8 percent of 75 ferrosilicon, 20 to 30 percent of chromium carbide, 5 to 12 percent of graphite, 1 to 10 percent of aluminum-magnesium alloy, 1 to 5 percent of silicon carbide and 1 to 3 percent of ferroboron; and the percentage of a counter weight is between 46 and 54 percent. The high-carbon high-chromium high-niobium cast iron self-protection flux-cored wire has the advantages of high hardness, good wear resistance, good oxidation resistance and strong shock resistance, and is widely applied to grinding rolls and grinding disks of coal grinding machines in thermal power plants and cement plants, material charging equipment in blast furnaces(material charging slots, receiving cones, material storage areas and sieve plates), slag vertical mills, hammer heads and rollers of crushers and sintering equipment workpieces in steel plants.

The invention relates to a method for preparing a dense boron carbide matrix ceramic material by sintering. The method includes fully mixing boron carbide powders and a sintering aid and subjecting the mixture to forming, drying, binder-removing and sintering to obtain the dense boron carbide matrix ceramic material, wherein the sintering aid at least comprises a first sintering aid which is chromium carbide powders.

The invention discloses a high-toughness toughened hard alloy which comprises 10%-30% of Co or Co and Ni serving as a binding phase, 0-1.5% of Cr3C2 serving as an inhibitor, and the balance of hard phase WC, wherein the hard phase consists of WC crystalline grains with coarse, medium and fine grain sizes, the grain size of coarse grains is 9-15 mu m, the grain size of medium grains is 4-7 mu m, the grain size of the fine grains is less than 2 mu m, and the mean grain size of the hard phase WC is 1.6-3.2 mu m. The preparation method of the toughened hard alloy comprises the following steps of: preparing materials including 10%-30% of cobalt powder or cobalt powder and nickel powder, 0-1.5% of chromium carbide powder, and the balance of tungsten carbide powder, wherein Fsss grain size of the coarse grains WC is 9.0-11.0 mu m, the coarse grains WC account for 20%-42% of the prepared powder, the Fsss grain size of the medium grains WC is 4.0-6.0 mu m, the medium grains account for 10%-25% of the prepared powder, the Fsss grain size of the fine grains WC is 1.0-2.0 mu m, and the fine grains account for 20%-40% of the prepared powder; grinding, wherein a liquid paraffin forming agent which accounts for 2% of the prepared materials is added, mixed with absolute ethyl alcohol in a liquid-solid ratio of 300 ml/kg-350ml/kg, wet-ground for 20-28 hours according to the condition that the ratio of grinding media to material is 4:1, and sprayed and dried to obtain mixed materials; pressing; vacuum-sintering and isostatic-pressing and sintering. According to the invention, the toughness is improved on the premise of ensuring the hardness of the alloy, so that the operation field is expanded, special requirements of a cold-heating and cold-punching mould and a holt-rolling hard alloy roller ring are satisfied, and the service life of the high-toughness toughened hard alloy is prolonged.

The invention relates to a solid lubricating high-temperature anti-wearing powder composition and a preparation method of a compound coating of the composition. The powder composition comprises the following components in percentage by mass: 14-17.5% of nickel, 3-3.5% of chromium, 49-52.5% of chromium carbide and 25-30% of tungsten disulfide with a surface coated by an alloy-phosphorus alloy. A solid self-lubricating high-temperature anti-wearing compound coating is prepared by the powder composition through utilizing a laser smelting technology. According to the invention, NiCr-Cr3C2 compound powder is used as a metal substrate and the compound coating is formed by a ceramic anti-wearing phase and a metal toughening phase; WS2 is a solid lubricating phase and one layer of a micron-grade Ni-P alloy is coated on the surface of a WS2 powder grain by utilizing a chemical plating method, so that the thermal stability and the chemical stability of WS2 are increased, the decomposition and evaporation of the WS2 in a laser smelting process are effectively inhibited and the compatibility of the WS2 and the metal substrate is increased; and the compound material coating has the characteristic of high-temperature self-lubricating wearing resistance.

The invention provides a self-lubricating solid composite material, which comprises 15-30 wt% of nickel-chromium alloy, 40-60 wt% of chromium carbide, 10-20 wt% of tungsten disulfide and 10-20 wt% of calcium fluoride. The invention also provides a preparation method of a self-lubricating solid coating. By a laser cladding method, the self-lubricating solid coating is formed on a matrix material. The self-lubricating solid composite material can be firstly coated on the matrix material and forms a coating by laser cladding; and also the matrix material can be firstly irradiated by a laser beam to form a molten pool, and then the self-lubricating solid composite material is sent into the molten pool and is continuously irradiated to form the coating. The prepared self-lubricating solid coating has excellent wear resistance and good lubrication performance within the temperature range of room temperature to 600 DEG C, and can satisfy the usage requirement under severe working conditions.

The invention relates to an abrasion-resisting surfacing flux-cored wire for a coal milling roller, which is composed of high carbon ferro chrome 45-65%, chromium carbide 8-20%, chromium metal 5-15%, flake graphite 3-8%, high carbon ferromanganese 3-6%, 75# ferrosilicon 5-7%, ferroboron 5-15%, aluminum magnesium alloy 2-5% and an agglutinant 2-8%. The diameter of a welding wire is phi 3.2-phi 4.0mm, welding wire metal is a low carbon steel strip, and 49%-53% of cored powder by mass is filled in the formed low carbon steel strip. No protective gas is additionally arranged outside the flux-cored wire, and the manufacturability is good in the self protection open arc welding. During the welding, the arc is stable, the spatter lose rate is low, molten slag is little, the welding can be continuously performed, the welding joint is attractive in forming, the self-protection effect is good, and no air holes is on the surface of the flux-cored wire. The hardness of the abrasion-resisting surfacing flux-cored wire for the coal milling roller reaches above 62 HRC after multilayer surfacing by metal piling, the evenness of the whole hardness is +/-2HRC, and the performance resistant to abrasion of low-stress grinding materials is good.

A cutting element and bit incorporating the cutting element is provided, as well as a method for forming the same. The cutting element includes an ultra hard material layer including chromium and carbon and exhibiting increased abrasion resistance without sacrificing toughness. The method for manufacturing the cutting element includes providing a layer of ultra hard material particles and chromium carbide over the substrate, and then sintering to form the cutting element.

The high hardness high wear resistance self-protecting metal core built-up welding filament used in material processing engineering features the metal core comprising chromium carbide 64-77 wt%, 75# ferrosilicon 4-8 wt%, metal Mg 5-10 wt%, Al-Mg alloy 1-3 wt%, ferroborium 2-5 wt%, ferrotitanium 2-6 wt%, ferrocolumbium 1-5 wt% and ferrovanadium 1-8 wt%. Using the filament in welding needs no added protecting gas and produces no welding slag, and this makes it possible to perform continuous welding. Programming the automatic welding machine can perform automatic welding operation in high built-up welding quality. The present invention is used mainly in built-up welding for repairing coal grinding roller, cement grinding disc, chute, etc.

The invention relates to novel WC-Cr3C2-Ni thermal spraying powder and a preparation process thereof. The WC-Cr3C2-Ni thermal spraying powder consists of the following raw materials in percentage by mass: 73 mass percent of tungsten carbide with two kinds of particle sizes, 19.5 mass percent of chromium carbide, 7 mass percent of nickel, and 0.5 percent of trace titanium carbide served as a grain inhibitor, wherein the tungsten carbide in the raw materials is formed by mixing the following raw materials in percentage by mass: 22 to 51 mass percent of nano tungsten carbide with 0.05 to 0.2 micrometer of particle size and 22 to 51 mass percent of medium-grain tungsten carbide with 2.0 and 8.0 micrometers of particle size in certain proportions. The invention also relates to a corresponding preparation process. According to the WC-Cr3C2-Ni thermal spraying powder and the preparation process, related performance of coatings subjected to the thermal spraying can be improved, and the coatings have high abrasive resistance, high-temperature oxidation resistance and higher toughness.

The invention discloses a super-fine cemented carbide coating powder and process of preparation thereof. Super-fine hard-phase carbonization tungsten in the cemented carbide coating powder and other carbides such as titanium carbide, tantalum carbide, niobium carbide, vanadium carbide and/or chromium carbide are composed around by cobalt-phase ultra-fine powder particles. Karl Fischer's mean particle size of the super-fine cemented carbide coating powder is <=1 mu m. The super-fine tungsten carbide of the invention is put into the liquor of water-soluble metal cobalt-salt after being activated and dispersed with other hard-phase of carbide powder, the super-fine carbide powder and other hard-phase of carbide powder are taken as the core, chemical coprecipitation coating is employed in the reaction, and a uniform cobalt carbonate or cobalt hydroxide inhibitory coating is formed on the surface of the tungsten carbide powder and other hard-phase of carbide powder. The coprecipitation coating powder can be made into the super-fine cemented carbide coating powder by filtering, washing, and drying and low temperature reduction. The invention has the advantages of simple technique and low cost, which can take place the existing cemented carbide wet grinding mixture and the preparation method. High quality super-fine cemented carbide can be prepared by utilizing the powder of the invention.

The invention provides a nanometer carbonized tungsten compound powder, which includes carbonized tungsten, vanadium carbide or/and chrome carbide, and a metallic element without binding phase exists in the compound powder. The preparation method of the nanometer carbonized tungsten compound powder is characterized in that the powdery ammonium tungstate, the carbonaceous reducing agent and the inhibitor are adopted as raw materials, the raw materials are dissolved in deionized water or distilled water and evenly stirred so as to obtain a solution, then the solution is heated and dried, the precursor powder is obtained finally, the precursor powder is put into a high-temperature reaction furnace, under the vacuum, argon or hydrogen atmosphere protection condition and the condition of 1,000 to 1,200 DEG C and 30 to 60 min, the carbonized tungsten compound powder with the average particle diameter less than 100 nm and even particle size distribution is obtained through carbonization. The method has the characteristics of low reaction temperature, short reaction time, low manufacturing cost, simple process and the like, which is suitable for the industrial production and used for the ultrafine hard alloy nanometer carbonized tungsten compound powder.

The invention discloses a smelting preparation method of a high-strength aluminum alloy profile. The smelting preparation method comprises the following operation steps: (1) configuring an aluminum alloy melt: mixing the following raw materials in parts by weight: 55-60 parts of 6063 aluminum ingot, 30-40 parts of waste aluminum product, 5-10 parts of chromium carbide and 5-7 parts of glass slag powder, adding the raw materials into a smelting furnace, heating till a furnace charge is softened and collapses, and scattering a layer of covering agent on the surface of a molten solution for covering; and properly stirring the melt after the furnace charge is completely molten so as to enable the temperature in a melting bath to be uniform and consistent and finally adding a magnesium ingot into the melt. The waste aluminum material is added into the raw materials for mixing so as to be conductive to stabilizing the performances of the aluminum profile and reducing the possibility of affecting the quality of the aluminum profile due to the appearance of the non-detected materials during the smelting of aluminum liquid; the formula is further optimized so as to increase the strength and the hardness of an aluminum alloy and be conductive to improving the comprehensive properties of the aluminum alloy profile; and the surface of the aluminum alloy profile is chromized, so that the anti-corrosion capability of an oxide film on the surface of the aluminum alloy profile and the bonding force between the aluminum alloy profile and a coating are improved.

The invention provides an ultrafine cemented carbide coating blade suitable for a numerical control machining center, the ultrafine cemented carbide coating blade is prepared from the following components by weight: 0.5-2% of tantalum carbide, 0.5-2% of chromium carbide, 0-0.5% of niobium carbide, 6-10% of cobalt and the balance of ultrafine tungsten carbide, and the invention also provides a manufacturing method of the ultrafine cemented carbide coating blade. The manufacturing method of the ultrafine cemented carbide coating blade is low in cost, and the manufactured ultrafine cemented carbide coating blade is excellent in performance, stable in quality, and suitable for the numerical control machining center, satisfies ever-growing market demands of mechanical processing industry of the numerical control machining center, and gradually replaces expensive imported products.

The invention discloses a preparation method of a nano-structure WC-Co composite powder, and belongs to the field of an alloy preparation method. The method comprises the following steps in sequence: adding a carbonic powder material which is excessive to tungsten, vanadium and chromium carbides into water-soluble saturated mixed aqueous solution of tungsten-containing compound, cobalt-containing compound, chromium-containing compound and vanadium-containing compound to adsorb the saturated composite salt solution; dehydrating and drying to form a nano-scale composite salt thin layer on the surface of the carbonic powder material; removing crystal water out of the composite salt at the temperature below 500 DEG C under a condition of isolating air, and decomposing the composite salt into composite oxide of tungsten oxide, chromium hemitrioxide, vanadium oxide and cobalt oxide, further heating, and reducing and carbonizing the composite oxide on the surface of the carbonic powder material to generate the WC-Co nano-structure composite powder at the temperature below 850 DEG C. The preparation is a simpler and more reliable novel preparation method of the nano WC-Co composite powder by a direct carbonization method.

The invention discloses a hard alloy, which comprises a hard alloy matrix and further comprises a coating, wherein the hard alloy matrix is composed of metal carbide powder and a metal binder; the coating is coated on the hard alloy matrix; the metal carbide powder mainly comprises the following components in mass percentage: 40-50% of tungsten carbide, 5-10% of vanadium carbide, 3-8% of chromium carbide, 5-9% of titanium carbide, 6-11% of tantalum carbide, and 2-5% of niobium carbide, wherein the metal binder is cobalt the content of which is 12-18%. By means of the manner, the hard alloy disclosed by the invention has the characteristics of being low in cost, high in hardness, intensity, toughness and abrasive resistance, low in wear rate while cutting at high speed, and good in oxidation resistance, heat resistance and chemical stability and is applied to manufacturing cutter materials for high precision processing; in addition, the service life of cutters can be prolonged.

A welding material composition, which is a nickel based super alloy having gamma' phase and chromium carbides precipitated. The composition comprising 18 to 25% by weight of Co, 15 to 20% by weight of Cr, 1.5 to 5.5% by weight of Al, 5 to 14% by weight of W, 0.05 to 0.15% by weight of C, 0 to 0.02% by weight of B, 0 to 1% by weight of at least one of Ta, Nb, Ti, Mo, Re and Fe, 0 to 0.5% by weight of at least one of V, Zr, rare earth elements and Y, 0 to 1% by weight of Mn, 0 to 0.5% by weight of Si, and the balance being Ni.

The invention relates to a nonmagnetic hard alloy material and a preparation method thereof. The alloy comprises (wt %) tungsten carbide 75-90, nickel powder 8-20, chromium carbide 0.5-3.0, and vanadium carbide 0.3-2.5. The preparation method comprises compounding, wet grinding, drying, pressing, sintering and checking, wherein in the wet grinding step, a nonmagnetic alloy lining board wet grinder is used, alcohol or acetone is added as grinding medium, nonmagnetic hard alloy balls is used as grinding material, the ratio of grinding medium to material is 5:1, the solid-to-liquid ratio is 350ml/Kg, and the wet grinding time is 48-56 hours; and pressure sintering is adopted. In the inventive nonmagnetic hard alloy material, fine-particle tungsten carbide powder (1.0-1.5 mum) is used as hard phase, so as to improve the hardness and abrasion resistance of the alloy. The nickel is used as binder, and a small amount of chromium carbide and vanadium carbide are added as tungsten carbide grain growth inhibitor, so as to refine tungsten carbide crystal grains, and further improve the hardness and abrasion resistance of the alloy. The pressure sintering technique accelerates densification speed during sintering process, effectively reduces porosity of the alloy, and remarkably improves the strength of the alloy.