52results about How to "Improve carburizing efficiency" patented technology

The invention relates to Cr-Mo steel for high-temperature carburizing, a carburizing method of the Cr-Mo steel and a carburizing component. The Cr-Mo steel for high-temperature carburizing comprises the following chemical components of, in percentage by weight, 0.13%-0.25% of C, less than or equal to 0.25% of Si, 0.55%-0.90% of Mn, less than or equal to 0.035% of P, 0.020%-0.040% of S, 0.85%-1.25% of Cr, 0.017%-0.037% of Al, 0.008%-0.015% of Ti, 0.040%-0.060% of Nb, less than or equal to 15ppm of O, 120ppm-170ppm of N, 0.010%-0.030% of Ni, 0.10%-0.20% of Cu, less than or equal to 0.06% of Mo, less than or equal to 0.04% of V, and the balance Fe and inevitable impurities. According to the Cr-Mo steel for high-temperature carburizing, when the carburizing temperature is larger than or equal to 980 DEG C, the grain size of a part is not larger than 7 grades; and according to the continuous furnace high-temperature carburizing method, the three-section preheating type and low-carbon potential diffusion high-temperature carburizing technology is adopted, high-efficiency carburizing of the part is achieved, on the premise that it is guaranteed that the carburizing layer depth of the part is 1.1-1.6 mm, the carburizing heat treatment period can be shortened to 13.2 h, the carburizing time is shortened to 7.2 h, and the carburizing efficiency is improved by 25%-30% relative to the carburizing efficiency at the temperature of 920-930 DEG C.

The invention relates to a pre-oxidation technology for improving wind power gear gas carburizing efficiency. The pre-oxidation technology includes the following steps that carburizing steel is slicedinto a gear-shaped sample; the sample is subjected to thermal refining; the sample is subjected to ultrasonic cleaning and drying after grinding; the sample is placed in a program control box type electric stove and is subjected to the pre-oxidation treatment; and the sample is placed into a gas carburizing multipurpose stove, and is subjected to carburizing, quenching and tempering treatment. The pre-oxidation technology has the beneficial effects that the pre-oxidation treatment is carried out before the gas carburizing, an oxidation film layer is formed on the sample surface, wettability of the sample surface is increased and the pre-oxidation treatment is beneficial for absorbing activated carbon atoms; the oxidation film is preferentially restored during the process of gas carburizing, through the defect of existing a plurality of holes on the sample surface, permeating of the activated carbon atoms into the base body, and a quick channel is provided for diffusing the carbon atoms; and gas carburizing efficiency is greatly improved, carburizing time is greatly shortened in the condition of reaching the same layer depth of the carburizing and the energy is saved.

The invention discloses a vacuum carburizing method for obtaining dispersed fine carbides. The vacuum carburizing method comprises a heating and heat preservation stage, a pulse carburizing stage, a carbide precipitation and spheroidizing stage and a quenching stage. The pulse carburizing stage refers to a high-concentration carburizing process in which carburizing / diffusion is alternated for multiple times, and a required surface carbon concentration gradient is formed; and the carbide precipitation and spheroidizing stage refers to immediately inflating to quickly cool the surface of a workpiece to a certain temperature above an Ac1 line and keeping the temperature for a period of time, so that carbides are precipitated in austenite and form dispersed distribution, and meanwhile, the workpiece reaches the quenching temperature by using the waste heat of the core part. According to the method, the structure performance and the deformation amount are both considered, on one hand, fine carbides which are high in carbon content (1%-1.5%) and are distributed in a dispersed mode are obtained, the effect that the outside is hard and the inside is tough is achieved, and on the other hand, quenching distortion is reduced, and size control is achieved; and the method is short in process time, high in carburizing efficiency, low in equipment operation cost, excellent in product surface performance and small in deformation, and the obdurability of the material is exerted to the maximum extent, so that the service performance of the workpiece is improved.

The invention discloses a method for carburizing the surface of cemented carbide, which is characterized in that it first heats the temperature at 550-700°C for 1-2 hours to form a cemented carbide blank containing carbide-forming elements; 2 o 3 coated TiH 2 Core / shell structure powder with thickness less than 3nm, number of layers less than 3 and specific surface area greater than 250m 2 / g of graphene and two substances are mixed according to the weight percentage of 2:3 to prepare a hydrogen-containing carburizing medium; then the green body is embedded in the hydrogen-containing carburizing medium and compacted under a pressure of 5~15MPa; finally, the liquid phase Sintering to realize carburizing of cemented carbide surface. The invention overcomes the problems of severe crystal grain growth, long carburizing time and low efficiency in the prior art, and realizes carburizing of the hard alloy surface in the sintering process.

The invention discloses a method for preparing surface carburized gradient cemented carbide, which is characterized in that it first heats the temperature at 550-750°C for 2-4 hours to form a cemented carbide product with a porosity of 25%-40% and removes the forming agent. blank; then SiO2-coated TiH2 core / shell structure powder, graphene with a thickness of less than 3nm, a number of layers less than 3 layers and a specific surface area greater than 250m2 / g, and BaCO3 are prepared by mixing 1:2:1 by weight percentage Hydrogen-containing carburizing medium; then the green body is buried in the hydrogen-containing carburizing medium and compacted under a pressure of 5-15MPa; finally, liquid-phase sintering is carried out to prepare a surface-carburized gradient cemented carbide. The invention overcomes the problems of serious grain growth, long carburizing time and low efficiency in the prior art, and prepares surface carburized gradient hard alloy in the sintering process.

The invention discloses a preparing method for a gradient hard alloy with the surface rich in graphite phase. The preparing method is characterized in that firstly, heat preservation is conducted for 2-4 h at the temperature ranging from 550 DEG C to 750 DEG C, and a hard alloy raw blank removing a forming agent is formed, wherein the porosity of the hard alloy raw blank ranges from 25% to 40%; then, the three substances including amorphous Si-C-O wrapping TiH2 core / shell structure powder, a multi-wall carbon nano tube and Na2CO3 are mixed according to the weight percent of 1:2:1, and then a hydrogen-containing carburizing medium is prepared, wherein the outer diameter is smaller than 8 nm, the length is smaller than 30 microns, and the specific surface area is larger than 350 m<2> / g; then, the raw blank is embedded in the hydrogen-containing carburizing medium and is compacted under the pressure of 5-15 MPa; and finally, liquid phase sintering is conducted, and the gradient hard alloy with the surface rich in graphite phase is prepared. The preparing method solves the problems that in the existing technology, grain growth is serious, the carburization time is long, and efficiency is low; and in the sintering process, the gradient hard alloy with the surface rich in graphite phase is prepared in the sintering process.

The invention provides a metal ceramic wear resisting material. The metal ceramic wear resisting material is characterized by comprising the following components in parts by weight: 20-30 parts of boron nitride, 25-35 parts of chromium carbide, 5-10 parts of scandium nitride, 5-10 parts of molybdenum nitride, 8-10 parts of niobium boride, 8-10 parts of titanium silicide, 4-6 parts of boron silicide, 1-3 parts of carbon fiber, 1-4 parts of amido montmorillonoid, 1-5 parts of cerium powder, 1-3 parts of strontium powder, and 3-6 parts of zirconium powder. The invention further discloses a preparation method of the metal ceramic wear resisting material. The metal ceramic wear resisting material is low in preparation cost, high in toughness and wear resistance, excellent in high-temperature resistance and corrosion resistance and long in service life.

The invention provides a rapid carburizing heat treatment process for a driving gear used in an automobile differential, comprising the following steps: 1) heating up; 2) strong infiltration; 3) diffusion; 4) quenching; 5) cleaning; 6) tempering. The carburizing period of the treatment process is obviously shortened, the production efficiency is improved, the output is increased, the energy saving effect is achieved, the carburizing cost is obviously reduced, and the economic benefit is significantly improved.

The invention discloses a preparation method of a gradient cemented carbide with a graphite-rich surface, which is characterized in that it first heats the cemented carbide at 550-750°C for 2-4 hours to form a cemented carbide with a porosity of 25%-40%. Green body; then amorphous Si-C-O-coated TiH2 core / shell structure powder, multi-walled carbon nanotubes with outer diameter less than 8nm, length less than 30μm and specific surface area greater than 350m2 / g, Na2CO3 three kinds of substances by weight The ratio of 1:2:1 is mixed to prepare a hydrogen-containing carburizing medium; then the green body is embedded in the hydrogen-containing carburizing medium and compacted under a pressure of 5~15MPa; finally, liquid phase sintering is carried out to prepare a surface graphite-rich phase gradient cemented carbide. The invention overcomes the problems of severe grain growth, long carburizing time and low efficiency in the prior art, and prepares gradient hard alloy with graphite-rich phase on the surface during the sintering process.

The invention discloses a preparation method of metal ceramic wear resistant material based on carbide forming elements promoting carbon migration. The method is characterized by comprising the following steps: firstly performing heat preservation for 1 to 2 h at 500 to 700 DEG C, so as to form a metal ceramic body containing the carbide forming elements; then mixing core / shell structure powder of Al2O3 coated TiH2, graphene with the thickness being smaller than 3 nm, the number of layers being smaller than 3 and the specific surface area being greater than 250 m<2> / g, and Na2CO3 according to a weight percentage of 3:2:1, so as to prepare a hydrogen-containing carburizing medium; embedding the metal ceramic body into the hydrogen-containing carburizing medium, and performing compaction at 5 to 15 MPa; and finally performing liquid-phase sintering, so as to prepare the metal ceramic wear resistant material based on the carbide forming elements promoting carbon migration. The method overcomes the problems of serious crystal grain growth, long carburizing time and low efficiency in the prior art, and realizes the preparation of the metal ceramic wear resistant material during a sintering process.

The invention discloses an in-situ preparation method of surface carburized hard alloy, which is characterized in that it first heats the temperature at 550-700°C for 1-2 hours to form a hard alloy body containing carbide-forming elements; then wraps Al2O3 TiH2-coated core / shell structure powder, multi-walled carbon nanotubes with an outer diameter of less than 8nm, a length of less than 30μm and a specific surface area greater than 350m2 / g, and BaCO3 are mixed at a weight percentage of 2:3:1 to prepare hydrogen-containing carburizing medium; then embed the green body in a hydrogen-containing carburizing medium and compact it under a pressure of 5-15 MPa; finally, carry out liquid phase sintering to prepare a surface carburized cemented carbide. The invention overcomes the problems of serious crystal grain growth, long carburizing time and low efficiency in the existing technology, and realizes in-situ preparation of surface carburized hard alloy in the sintering process.

The invention discloses a preparation method of a self-lubricating hard alloy. The preparation method of the self-lubricating hard alloy is characterized in that the temperature is kept at 550-750 DEG C for 2-4 hours, so that a forming-agent-free hard alloy green body with the porosity being 25%-40% is formed; core / shell structure powder with Al2O3 covering TiH2, graphene and NaHCO3 are mixed at the weight percentage ratio of 1:2:1 to be prepared into a hydrogenous carburizing medium, wherein the thickness of the graphene is smaller than 3 nm, the number of layers of the graphene is smaller than 3, and the specific surface area of the graphene is larger than 250 m<2> / g; the green body is embedded into the hydrogenous carburizing medium and is compacted at the pressure of 5-15 MPa; and finally, liquid-phase sintering is conducted, and preparation of the self-lubricating hard alloy is achieved in the sintering process. The preparation method of the self-lubricating hard alloy solves the problems that in the prior art, grains grow severely, the carburizing time is long, and efficiency is low, and the self-lubricating hard alloy is prepared in the sintering process.

The invention relates to the field of heat treatment, in particular to an annular component carburizing and quenching technology. The technology comprises the following steps that annular components are thrown into a cleaning pond to be immersed and cleaned, a water-based cleaning agent is added in the cleaning pond, then, clean water is used for flushing the annular components thoroughly, accordingly, surface impurities and oil dirt of the annular components are removed, and the cleaned annular components are classified after being blown dry; the annular components with the high carburizing requirement are placed in material rods in an annular component carburizing furnace; the annular components with the low carburizing requirement are placed on material containing rods, the space in theannular component carburizing furnace can be sufficiently utilized, the carburizing efficiency is improved, the annular component carburizing furnace is subjected to temperature rise, and gas seepageagent methyl alcohol inflation starts after the temperature is increased to the proper temperature. Through changing of the carbon potential and the temperature in a furnace body, the annular component surface carburizing depth and surface hardness are guaranteed, annular component carburizing and quenching are continuously conducted, accordingly, the technology process is shortened, the transferring and heat treatment cost is reduced, and the production efficiency is improved.

The invention discloses a preparation method of self-lubricating surface Ti (C, N)-based metal ceramic based on a metal hydride. The method is characterized by comprising the following steps: firstly performing heat preservation for 1 to 2 h at 500 to 700 DEG C, so as to form a metal ceramic body containing carbide forming elements; and then mixing core / shell structure powder of Al2O3 coated TiH2, a multiwalled carbon nanotube with the external diameter being smaller than 8 nm, the length being smaller than 30 micrometers and the specific surface area being greater than 350 m<2> / g, and NaHCO3 according to a weight percentage of 3:2:1, so as to prepare a hydrogen-containing carburizing medium; embedding the metal ceramic body into the hydrogen-containing carburizing medium, and performing compaction at 5 to 15 MPa; and finally performing liquid-phase sintering, so as to prepare the self-lubricating surface Ti (C, N)-based metal ceramic. The method overcomes the problems of serious crystal grain growth, long carburizing time and low efficiency in the prior art, and realizes the preparation of the self-lubricating surface Ti (C, N)-based metal ceramic during a sintering process.

The invention discloses an in-situ preparation method of a hard alloy achieving surface self-lubrication. The in-situ preparation method of the hard alloy achieving surface self-lubrication is characterized in that forming-agent-free hard alloy green bodies with the porosity being 25%-40% are formed under the condition that the temperature of 550-750 DEG C is kept for 2-4 h; core / shell structure powder with Al2O3 covering TiH2 and nanometer graphite with the thickness granularity being 30-50 nm are mixed at the weight percentage ratio of 1:2 so as to prepare a carburizing medium containing hydrogen; the green bodies are embedded into the carburizing medium containing hydrogen and are compacted at the pressure of 5-15 MPa; and finally, liquid-phase sintering is conducted, and in-situ preparation of the hard alloy achieving surface self-lubrication is achieved based on carbon migration. The in-situ preparation method of the hard alloy achieving surface self-lubrication overcomes the problems that in the prior art, grains grow severely, the carburizing time is long and efficiency is low, and in-situ preparation of the hard alloy achieving surface self-lubrication is achieved in the sintering process.

The invention discloses a method for preparing cemented carbide with a graphite-rich surface, which is characterized in that it first heats at 550-700°C for 1-2 hours to form a cemented carbide body containing carbide-forming elements; then amorphous Si-C ‑O core / shell structure powder coated with TiH2, graphene with a thickness of less than 3nm, a layer number of less than 3 layers and a specific surface area greater than 250m2 / g, and NaHCO3 are mixed according to weight percentage 2:3:1 to prepare a hydrogen permeable carbon medium; then embed the green body in a hydrogen-containing carburizing medium and compact it under a pressure of 5-15MPa; finally carry out liquid phase sintering to prepare a cemented carbide with a graphite-rich surface. The invention overcomes the problems of serious crystal grain growth, long carburizing time and low efficiency in the existing technology, and realizes the preparation of hard alloy with graphite-rich surface in the sintering process.

The invention discloses a preparation method of a self-lubricating surface type Ti(C, N)-based cermet wear-proof material. The preparation method of the self-lubricating surface type Ti(C, N)-based cermet wear-proof material is characterized in that the temperature is kept at 500-650 DEG C for 2-4 h, so that a forming-agent-free cermet green body with the porosity being 25%-40% is formed; core / shell structure powder with Al2O3 covering TiH2 and graphene are mixed at the weight percentage ratio of 2:1 to be prepared into a hydrogenous carburizing medium, wherein the thickness of the graphene is smaller than 3 nm, the number of layers of the graphene is smaller than 3, and the specific surface area of the graphene is larger than 250 m<2> / g; the green body is embedded into the hydrogenous carburizing medium and is compacted at the pressure of 5-15 MPa; and finally, liquid-phase sintering is conducted, and preparation of the self-lubricating surface type Ti(C, N)-based cermet wear-proof material is achieved. The preparation method of the self-lubricating surface type Ti(C, N)-based cermet wear-proof material solves the problems that in the prior art, grains grow severely, the carburizing time is long, and efficiency is low, and the self-lubricating surface type Ti(C, N)-based cermet wear-proof material is prepared in the sintering process.