30 results about "CHROMIC OXIDE" patented technology

The invention discloses an enamel ceramic glaze tile with a metal spot bionic effect and a preparation method thereof, and relates to the technical field of ceramics. The enamel porcelain glaze tile comprises a bottom blank, a metal ground glaze layer and a semi-opaque cover glaze layer, the metal ground glaze layer is prepared from a first ground glaze formula or a second ground glaze formula, and the first ground glaze formula comprises, by mass, potassium feldspar, quartz, calcite, kaolin, talc, zinc oxide, ferric oxide and manganese dioxide; the formula of the second ground glaze comprises the following components in percentage by mass: potassium feldspar, quartz, calcite, kaolin, talc, zinc oxide, ferric oxide and chromic oxide; the semi-opaque surface glaze layer is prepared from the following raw materials in percentage by mass: albite, calcite, talc, burnt soil, zircon powder, oriental zirconium, calcined zinc oxide, black clay powder and calcined aluminum oxide. Through a double-layer glaze structure and a black mud powder glaze breaking mechanism, the stereoscopic visual effect that metal spots are randomly generated on an opacifying substrate is achieved, and meanwhile the Moh's hardness of the ceramic tile is improved.

The invention relates to the technical field of thermal insulation materials, and discloses a hollow glass bead as well as a preparation method and application thereof. The hollow glass beads are prepared from the following components in percentage by weight: 40 to 65 percent of silicon dioxide, 5 to 15 percent of boron oxide, 5 to 15 percent of sodium oxide, 2 to 8 percent of cuprous oxide, 1 to 5 percent of barium oxide, 2 to 10 percent of chromic oxide, 3.5 to 7.5 percent of nickel oxide, 1.5 to 3 percent of tin oxide and 1 to 5.5 percent of silicon carbide. Cuprous oxide, barium oxide and chromic oxide have high reflection coefficients, and heat absorption of buildings can be reduced; nickel oxide, tin oxide and silicon carbide have high radiation coefficients, heat can be dissipated into outdoor air in an infrared radiation mode, and therefore the temperature of the outer surface of a building is reduced. Cuprous oxide can significantly improve the surface cleanliness of the coating and enhance the thermal insulation performance of the coating.

The invention relates to the technical field of dyes, in particular to an acid black dye with green light and a preparation method thereof.The preparation method comprises the steps that a front color base I and a front color base II are synthesized firstly, then the front color base I and chromic oxide are complexed to obtain a reaction solution I, then the front color base II is added into the reaction solution I, and the acid black dye with the green light is prepared. The preparation method is simple and environment-friendly, a dye compound A, a dye compound B, a dye compound C and a dye compound D are formed by complexing a front color base I, a front color base II and chromium ions, and then the adding amount proportion of the front color base I, the front color base II and the chromium ions is adjusted; the ratio of the dye compound A to the dye compound B to the dye compound C to the dye compound D is adjusted, the green and full acid black dye is prepared, and the obtained acid black dye with green light is excellent in color fastness.

Provided are a dielectric powder composition for multilayer ceramic capacitors. The dielectric powder composition includes 93 to 98.5 wt % of a main ingredient composed of dielectric base material powder, 1.0 to 5.0 wt % of a first sub-ingredient including glass powder coated on an outer periphery of the dielectric base material powder to form a core-shell structure, and 0.5 to 2.0 wt % of a second sub-ingredient made of a transition metal oxide mixed with the core-shell structure powder, wherein the main ingredient is non-stoichiometrically represented as [(BaxCaySr1-x-y)O]m[(TizZr1-z)O2](where x: 0.22 to 0.42, y: 0.10 to 0.35, z: 0.03 to 0.08, and m ranges from 0.85 to 1.05), the first sub-ingredient includes an alkaline earth metal compound including (Ba, Sr, Ca), SnO2, B2O3 and SiO2, and the second sub-ingredient includes at least two selected from the group consisting of manganese oxide (Mn3O4), tungsten oxide (WO3), and aluminum oxide (Al2O3).

The invention discloses a modified silicon carbide special ceramic material and a preparation method thereof, and belongs to the technical field of ceramic materials. The special ceramic material is prepared from the following raw materials in parts by weight: 80-100 parts of silicon carbide powder, 2-5 parts of chromic oxide, 5-10 parts of zirconium oxide, 3-8 parts of nickel oxide, 3-7 parts of boron nitride, 0.2-0.5 part of a binder and 1-4 parts of a lubricant. The special ceramic material prepared by the invention has relatively high hardness, excellent fracture toughness, extremely low density, wear resistance and extremely low thermal expansion coefficient, has a wide application prospect in practice, is simple in preparation method, and can be subjected to large-scale industrial production.

The present invention provides a method for resource recovery of chromium-containing electroplating sludge, including the process steps of pigment preparation and metal recovery. Among them, the ceramic pigment is prepared by a solid-phase method using chromium-containing electroplating sludge and calcium-silicon substances as raw materials. The waste liquid generated during the preparation process realizes the cascade recovery of metals through the methods of adding iron powder to reduce and precipitate copper, hydrogen peroxide to oxidize and precipitate iron, and reduction and flocculation to precipitate chromium. The recovered chromium hydroxide can be returned to the raw material electroplating sludge for secondary utilization. The present invention prepares a ceramic pigment with good color rendering effect and excellent acid and alkali resistance through a simple solid-phase reaction method. Moreover, the purity of the grossularite phase Ca3Cr2(SiO4)3 is relatively high, with stable properties, acid and alkali resistance, and at the same time realizes the cascade recovery of metals. The present invention realizes the resource utilization of chromium-containing sludge, a solid hazardous waste, in the field of ceramic pigments. The process is simple, easy to control, environmentally friendly, and the raw materials are cheap and easily available, greatly reducing the production cost and having good economic and environmental benefits.

The invention relates to the technical field of building materials, and particularly discloses a preparation process of a color stone facing thermal insulation and decoration integrated board, which comprises the following steps: step 1, preparing a color stone raw material which is basalt, and crushing and screening basalt serving as a raw material to obtain basalt particles with the particle size of 1-5mm; in the high-temperature sintering process, basalt particles are placed in a resistance-type sintering furnace and sintered at the temperature of 1100-1300 DEG C, inorganic mineral pigments such as ferric oxide series pigments, chromic oxide series pigments and cobalt oxide series pigments are added, the pigments are evenly added into the high-temperature sintering furnace through an automatic feeding device, and under the high-temperature effect, the inorganic mineral pigments are added into the resistance-type sintering furnace to be sintered at the temperature of 1100-1300 DEG C; the pigment and the basalt particles are fully fused to form the colored stone with uniformly colored surface, the coloring effect is stable, the colored stone is not easy to fade, and the attractive decorative effect can be kept for a long time.

The invention discloses a composite anti-oxidation and corrosion-resistant ceramic glaze for continuous casting of three large pieces. The glaze comprises the following components in terms of weight percentage: 18% to 20% of quartz powder, 21% to 27% of potassium feldspar, 5% to 8% of Suzhou soil, 0% to 3% of barium carbonate, 8% to 12% of glass powder, 8% to 10% of pyrophyllite, 0% to 3% of zinc oxide, 5% to 7% of borax, 0% to 2% of magnesia, 0% to 3% of chromium oxide green, 0% to 3% of cobalt blue powder, 0% to 3% of iron red powder, 0% to 5% of diopside, 0% to 15% of frit, 0% to 5% of wollastonite, 0% to 2% of lead oxide, 0% to 5% of calcite, 0% to 0.2% of sodium humate, 0% to 20% of binder, 0% to 8% of silica sol, 0% to 2% of styrene-acrylic emulsion and 20% to 25% of water. The invention has the beneficial effects of being environmentally friendly, having good oxidation resistance, wear resistance, good adhesion effect, and being able to effectively increase the service life of three major parts of the sprayed product, including continuous casting.

The invention provides solid powder for treating formaldehyde-containing wastewater as well as a preparation method and application of the solid powder. The method comprises the following steps: stirring and mixing the waste of the hydrometallurgy device and water to obtain a mixture; performing high-temperature treatment on the mixture in a stirring state to obtain target solid powder; wherein the waste of the hydrometallurgy device comprises cobalt hydroxide, chromium hydroxide, polyaluminum chloride, polyacrylamide, activated carbon powder, phosphate kerosene and calcium hydroxide. Wherein the polyacrylamide is decomposed into ammonia gas under a high-temperature alkaline condition, so that the solid powder is expanded, and the solid surface area of the powder is greatly increased. The solid powder reagent has a good treatment effect on formaldehyde in wastewater of an acrylic acid device, peroxide-containing wastewater is fully utilized as an oxidizing agent to oxidize formaldehyde in the wastewater, the purpose of treating waste with waste is achieved, and the biochemical property of the wastewater is improved.

The utility model discloses roasting equipment for producing chromium sesquioxide from chromium-containing waste, which comprises a support frame, a plurality of support legs arranged at the bottom end of the support frame, a chimney arranged in the middle of the support frame, a roasting furnace arranged at the bottom end of the chimney, a material conveying pipe arranged on one side of the roasting furnace, and a feeding hopper arranged at the other end of the material conveying pipe. A bin door is arranged at one end of the roasting furnace, an observation window is arranged in the middle of the bin door, an ignition gun is arranged on the other side of the roasting furnace, an exhaust port is formed in the top end of the chimney, and a filtering device is arranged at the top end of the exhaust port. An air inlet is formed in one side of the air chamber, a slag discharging opening is formed in the middle of the bottom end of the air chamber, a partition plate is arranged at the top end of the air chamber, and a plurality of filtering holes are formed in the surface of the partition plate. Through the arrangement of the air chamber, the air chamber is fixedly connected to the bottom end of the roasting furnace during use, and then sufficient oxygen is provided for the roasting furnace through the air inlet, so that substances in the roasting furnace are combusted more sufficiently, and the production rate of chromic oxide is further increased.

The invention discloses stuffing sand for a steel ladle and a filling method of the stuffing sand, and belongs to the technical field of steelmaking. The stuffing sand filling mode is that the first stuffing sand, the second stuffing sand and the third stuffing sand are sequentially arranged from the bottom of the steel ladle to the top. The first stuffing sand comprises the following raw materials in percentage by mass: 50-60% of limestone, 10-20% of magnesium oxide and 20-30% of calcium oxide; the second stuffing sand comprises the following raw materials in percentage by mass: less than or equal to 10% of rare earth oxide, 20-30% of magnesium oxide, 20-30% of limestone, 5-10% of carbon powder and 20-30% of silicon dioxide; and the third stuffing sand comprises the following raw materials in percentage by mass: 10%-20% of ferric oxide, 10%-20% of silicon dioxide, 30%-40% of chromic oxide, 10%-20% of aluminum oxide and 10%-20% of calcium oxide. The self-opening rate of the ladle filler sand reaches 100%, meanwhile, the first ladle filler sand can form tiny bubbles and calcium oxide after entering the molten steel, impurities in the molten steel are captured and float upwards to a tundish slag layer, and the molten steel purification effect is achieved.

The invention relates to a composite spinel refractory material and a preparation process thereof, which are characterized in that chromic oxide sand, industrial alumina, magnesia, high titanium slag and zinc oxide powder are adopted as raw materials, and the refractory material is prepared through the procedures of batching, melting in an oxidizing atmosphere, casting, annealing, cold working and the like. The prepared fused and cast composite spinel refractory material has the advantages of being high in density, low in porosity, good in erosion resistance and thermal shock resistance and the like, can be used for seriously eroded parts of kilns such as an oxygen-fuel combustion glass kiln and a copper smelting industrial furnace, and effectively prolongs the service life of the kilns.

A solid electrolyte (10) of the present invention comprises: Li a A b E c (SO4) d J e X r H h ... (1), where in formula (1) A is at least one element selected from alkaline earth metals and alkali metals other than Li, E is at least one element selected from the group consisting of Al, Ga, In, Sc, Y, Ti, Zr, Hf and lanthanides, J is at least one group selected from the group consisting of OH, BO2, BO3, BO4, B3O6, B4O7, CO3, NO3, AlO2, SiO3, SiO4, Si2O7, Si3O9, Si4O 11 , Si6O 18 , PO3, PO4, P2O7, P3O 10, SO3, SO5, S2O3, S2O4, S2O5, S2O6, S2O7, S2O8, BF4, PF6, BOB, (COO)2, N, AlCl4, CF3SO3, CH3COO, CF3COO, OOC-(CH2)2-COO, OOC-CH2-COO, OOC-CH(OH)-CH(OH)-COO, OOC-CH(OH)-CH2-COO, C6H5SO3, OOC-CH=CH-COO, OOC-CH=CH-COO, C(OH)(CH2COOH)2COO, AsO4, BiO4, CrO4, MnO4, PtF6, PtCl6, PtBr6, PtI6, SbO4, SeO4, TeO4, HCOO, and O, X, where at least one element is selected from the group consisting of F, Cl, Br and I, 0.5 ≤ a < 6, 0 ≤ b < 6, 0 < c < 2, 0.1 < d ≤ 6.0, 0 < e ≤ 6.0, 0 < f ≤ 6.1, and 0 ≤ h ≤ 0.2 are satisfied, and a peak is observed at a diffraction angle 2θ = 22.3 °± 1.0° in an X-ray diffraction pattern in which Cu-Kα is used as the line source.

The application provides a solid powder for treating formaldehyde-containing wastewater and a preparation method and application thereof. The method comprises the following steps: mixing hydrometallurgy device waste and water to obtain a mixture; and treating the mixture at high temperature under stirring to obtain a target solid powder; wherein the hydrometallurgy device waste comprises cobalt hydroxide, chromium hydroxide, polyaluminum chloride, polyacrylamide, activated carbon powder, phosphate ester kerosene and calcium hydroxide; the polyacrylamide is decomposed to generate ammonia gas under high-temperature alkaline conditions, which plays a role of hole expansion on the solid powder, and greatly improves the solid surface area of the powder. The solid powder has a good treatment effect on formaldehyde in acrylic acid device wastewater, and fully utilizes the peroxide-containing wastewater as an oxidizing agent to oxidize formaldehyde in the wastewater, so that the purpose of waste treatment by waste is achieved, and the biochemical property of the wastewater is improved.

The application provides a metallographic structure display method of a gold-based alloy, and the display method comprises the following steps: taking the gold-based alloy as an anode, electrolytic immersion etching the gold-based alloy in an electrolyte composed of hydrochloric acid, nitric acid and anhydrous ethanol, then cleaning the surface of the obtained gold-based alloy to obtain the gold-based alloy after electrolytic immersion etching; soaking the gold-based alloy after electrolytic immersion etching in ammonia water, then cleaning the surface of the obtained gold-based alloy, and obtaining the gold-based alloy after preliminary treatment after the surface is dried; immersing the gold-based alloy after preliminary treatment in a corrosion liquid composed of a saturated aqueous solution of chromium trioxide, hydrochloric acid and distilled water, then cleaning the surface of the obtained gold-based alloy, and completing the display of the metallographic structure of the gold-based alloy after the surface is dried, which greatly facilitates the observation of the metallographic structure of the gold-based alloy and is beneficial to obtaining the gold-based alloy product meeting the performance requirements.

The invention relates to the technical field of casting or heat treatment coatings, in particular to an anti-oxidation and anti-decarburization coating, a preparation method thereof and special steel. The coating is prepared from the following raw materials: high-temperature-resistant ceramic powder, sepiolite powder, mullite powder, aluminum oxide, chromic oxide, silicon carbide, a binder and water. The coating is rapid in film formation, smooth in surface after film formation and relatively good in leveling property; a layer of compact firm protective film capable of isolating a matrix from a heating atmosphere is formed on the metal surface during heating, so that the oxidation and decarbonization phenomena of the high-speed steel are quickly reduced, and permeation of other elements can be reduced; the influence on the physical and mechanical properties and chemical properties of the protected high-speed steel is small; after heating, cleaning is convenient, and automatic stripping is achieved; sagging does not occur at high temperature, and no toxic gas is generated; and after being coated, the coating has higher adhesive force, and after being heated, the coating also has better stripping property.

The invention discloses a high-temperature-resistant resistor material and a preparation method thereof, and relates to the technical field of resistor materials. When the high-temperature-resistant resistance material is prepared, antimony trioxide and zinc oxide are mixed, ball-milled, dried and sintered at high temperature to prepare a zinc-antimony pre-synthesized phase; uniformly mixing zinc oxide, bismuth trioxide, cobaltosic oxide, the zinc-antimony pre-synthesized phase, manganese dioxide and chromic oxide, and performing ball milling, drying and sieving to obtain a refined mixture; mixing the refined mixture and paraffin, granulating, and pressing to obtain a green body; and carrying out glue removal, vacuum sintering and oxygen re-oxidation on the green body to prepare the high-temperature-resistant resistance material. The preparation method of the high-temperature-resistant resistor material provided by the invention not only can reduce the sintering temperature of the resistor, but also enables the prepared high-temperature-resistant resistor material to have excellent electrical properties.

The invention relates to the technical field of ceramic products, in particular to anti-slip transparent bluish white glaze, a bluish white ceramic product and a preparation method thereof, and the anti-slip transparent bluish white glaze is prepared from the following raw materials in parts by weight: 15-25 parts of potassium feldspar, 15-20 parts of a modified aluminum oxide agent, 10-15 parts of silicon dioxide, 8-12 parts of a modifier added based on talcum powder, 4-7 parts of barium oxide, 2-5 parts of calcium phosphate and 2-3 parts of chromic oxide. According to the bluish white glaze, the potassium feldspar is matched with the silicon dioxide, the barium oxide and the modified aluminum oxide agent, the modified body added based on the talcum powder, the calcium phosphate and the chromic oxide are used, and the raw materials are blended, matched and jointly synergized, so that the obtained bluish white glaze is harmoniously improved in skid resistance, transparency and bluish white color and luster; and the product has remarkable water-resistant and heat-resistant stability effects.

The invention relates to the technical field of sodium ion electronics, and particularly discloses a sodium chromite preparation device and method based on a mechanochemical method.The sodium chromite preparation device comprises a base, a driving disc is rotationally arranged on the base, a main ball milling tank is rotationally arranged in the middle of the driving disc, and two symmetrically-arranged auxiliary ball milling tanks are rotationally arranged on the driving disc. Through the synergistic effect of the main ball-milling tank and the auxiliary ball-milling tank, argon serving as protective gas serves as a carrier to continuously flow and dynamically carry refined chromic oxide and sodium carbonate in the auxiliary ball-milling tank into the main ball-milling tank, the continuous process of raw material pretreatment and mechanochemical reaction is achieved, material accumulation is avoided, real-time contact of reactants is ensured, and the production efficiency is improved. And the product is the sodium chromite powder under high-energy ball milling, and mechanical crushing and secondary ball milling are not required to be performed on the product, so that the production period can be greatly shortened, and the production efficiency is improved.

The invention belongs to the technical field of ceramic surface treatment, and particularly relates to a ceramic surface protective agent as well as a preparation method and a use method thereof. The ceramic surface protective agent comprises the following components in parts by weight: 79-92 parts of an aggregate, 2-5 parts of an intermediate, 1-3 parts of an emulsifier, 3-8 parts of zirconium sol, 0.5-2 parts of a nano filler and 1-3 parts of a hardening agent, wherein the condensation body is solid paraffin, the intermediate is glycerol or 1, 2-propylene glycol, the nanometer filling body is a mixture of one or more of zirconium oxide, yttrium oxide and chromic oxide, and the hardening agent is polyethylene wax. The invention aims to develop a novel system ceramic protective agent and a preparation method and a use method thereof, the corrosion resistance of a ceramic plate is greatly improved, and meanwhile, the ceramic protective agent has excellent antifouling performance.

The invention relates to the technical field of inorganic pigments, and discloses a high-temperature yellowish-brown inorganic pigment and a preparation method, system and application of the high-temperature yellowish-brown inorganic pigment. Iron minerals are enriched through 3.0 T high field intensity magnetic separation, and Fe2O3gt is obtained; 70% of purification powder; mixing the powder with zinc oxide and chromic oxide according to a specific ratio of 60: 25: 15, and calcining at a high temperature of 1180-1200 DEG C to promote generation of stable hue; and finally, carrying out air jet pulverization to obtain a superfine product. The red mud is successfully converted into the high-performance high-temperature yellow-brown inorganic pigment through a combined process of deep dealkalization, high-field-intensity magnetic separation, a specific formula and high-temperature synthesis, the product is pure in color development and excellent in high-temperature stability, and a new way is provided for high-value-added utilization of the red mud.

The preparation method comprises the following steps: (1) smelting calcium-free chromium slag to obtain an iron-chromium alloy, and then spraying powder on the iron-chromium alloy molten at high temperature to prepare iron-chromium powder; (2) performing acid dissolution on the prepared iron-chromium powder, separating and filtering a dissolution solution to obtain an acid dissolution clear solution, and performing oxygen explosion to completely convert divalent chromium and divalent iron in the acid dissolution clear solution into trivalent chromium and trivalent iron; then continuously stirring and adding ammonia water for neutralization and precipitation to obtain a precipitate; and (3) filtering, washing and separating the precipitate to obtain chromic hydroxide and ferric hydroxide precipitate, drying by flash evaporation, feeding into a mixer, adding a regulator, mixing, and finally feeding into a rotary kiln for roasting to obtain the iron-chromium black pigment. According to the method, the beneficial components chromium and iron in the calcium-free chromium slag are comprehensively utilized, the byproduct ferrochrome obtained after waste slag treatment is subjected to powder spraying, then acid dissolution washing, neutralization precipitation and calcination are performed to produce the iron-chromium black pigment, a new way of waste utilization is provided, and the production cost of the iron-chromium black pigment is reduced.

The invention discloses a low resistance temperature coefficient resistance paste for an electrical element printed circuit, which is composed of conductive phase powder, inorganic nonmetal powder and an organic carrier, and the conductive phase powder is an alloy prepared from tungsten powder, molybdenum powder, tantalum powder, niobium powder and manganese powder through a high temperature solid phase method. The inorganic nonmetal powder is prepared by roasting calcium silicate, magnesium oxide, lanthanum oxide, chromic oxide, titanium dioxide and nano silicon dioxide in an air atmosphere at a high temperature. The slurry is stable and does not precipitate after being stored for 6 months at room temperature; the slurry has good thixotropy, is easy to print, does not stick to a net and has high resolution. An electrical element prepared from the paste is small in resistance temperature coefficient (TCR = (0.05-0.1) * 10 <-3 > / DEG C) and fast in temperature rise; electrical elements are high in power and energy-saving at high temperature; the slurry is matched with a ceramic substrate in thermal expansion coefficient, and the thermal shock resistance of an electrical element is good; the slurry is firmly combined with a ceramic substrate through a glass phase and chemical bonds, the adhesive force is good, and the reliability of an electrical element is high.

The present invention discloses an environmentally friendly waterborne corrosion-resistant metal baking paint and a preparation method thereof, belonging to the technical field of metal baking paints. The method comprises the following steps: mixing dipropylene glycol methyl ether and dipropylene glycol butyl ether, stirring, adding them into a waterborne acrylic-amino resin emulsion, mixing, adding N,N-dimethylethanolamine, adding a curing agent, mixing, adding deionized water, mixing, adding a silver discharge aid, and mixing to obtain a varnish; taking aluminum powder and ethylene glycol butyl ether to prepare a pre-dispersed slurry, and mixing it with the varnish to obtain an aluminum paint; taking 2-(p-dodecyloxyphenyl)pyrazine-5-carboxylic acid, chromium hydroxide, and sulfuric acid solution, heating and stirring, adding potassium chromate and deionized water, ultrasonically dispersing, and spraying it on the surface of the aluminum paint to obtain the environmentally friendly waterborne metal baking paint with excellent corrosion resistance.

The invention discloses a process method for a high-density ceramic coating of a chemical fiber spinning winding head forming plate. The method comprises the following steps that firstly, a formed plate base body is subjected to multiple times of abrasive belt polishing, and surface defects are removed; then sequentially carrying out ultrasonic cleaning with a dilute sulfuric acid solution, washing with tap water, rinsing with deionized water and drying with hot air; then nickel plating treatment is conducted, sand blasting is conducted through white corundum sand after nickel plating, and ultrasonic cleaning is conducted through acetone after sand blasting; mixing pure chromic oxide with specific granularity with titanium oxide powder to prepare spraying powder, and spraying with a plasma spray gun of which the rated power is greater than or equal to 40kW; stress is eliminated through stepped heating annealing after spraying; and finally, numerical control equipment and an electroplated diamond abrasive belt are used for polishing. According to the method, the porosity of the coating is smaller than or equal to 2.0%, the microhardness is larger than or equal to HV1000, the wear resistance of the formed plate is effectively improved, and the service life of the formed plate is effectively prolonged.

This disclosure proposes a hydrophobic / chromium-rich corrosion-resistant composite coating and a method for manufacturing and using the same, and belongs to the technical field of material surface coatings. The manufacturing method includes the steps of: preheating a workpiece; applying a coating slurry to the surface of the preheated workpiece, baking to cure, and sintering to obtain a chromium-rich corrosion-resistant coating on the surface of the workpiece, wherein the coating slurry comprises a solid phase component and a liquid phase component, the solid phase component comprising chromium powder, nickel powder, iron powder, and rare earth compounds, and the liquid phase component comprising Al(H2PO4)3, water glass, ammonium halide, polyvinyl alcohol, and Cr2O3; and spray-coating a superhydrophobic material in one layer onto the surface of the chromium-rich corrosion-resistant coating and curing to obtain a hydrophobic / chromium-rich corrosion-resistant composite coating. This disclosure describes how applying chromizing and superhydrophobic treatments to a workpiece imparts corrosion resistance, wear resistance, and hydrophobic properties to the workpiece, preventing water vapor inside the pipe from remaining on the inner wall of the pipe, thereby avoiding corrosion of the inner wall of the pipe, improving the overall properties of the pipe, and extending its service life.

The invention discloses a high-temperature protection technology, particularly provides a composite coating capable of improving the high-temperature sodium salt corrosion resistance of stainless steel and a preparation method of the composite coating, and belongs to the technical field of material surface treatment and modification. The composite coating comprises a metal oxide coating on the inner layer and an enamel coating and ceramic particles on the outer layer, the metal oxide coating can be a titanium dioxide coating, a chromic oxide coating and a nickel oxide coating, and the composite coating on the outer layer is composed of 68-88% of enamel glaze and 12-32% of aluminum oxide ceramic particles. Wherein the formula of the enamel glaze comprises 55-63% of silicon dioxide, 3-8% of aluminum oxide, 5-14% of zinc oxide, 2-6% of calcium oxide, 3-7% of zirconium dioxide, 1-5% of titanium dioxide, 2-8% of diboron trioxide, 1-6% of sodium oxide and 5-10% of potassium oxide. According to the invention, the high-temperature oxidation resistance and sodium salt corrosion resistance of the coating are improved by adjusting the formula of the enamel glaze, strengthening the ceramic particles and playing a role of a diffusion barrier of the metal oxide coating, so that the composite coating has the characteristics of simple process, low cost, excellent thermal corrosion resistance and the like.