34 results about "Vanadium carbide" patented technology

This invention relates to the field of metal matrix composite material preparation technology, and discloses a method for preparing a bundled vanadium carbide reinforced steel matrix composite material, comprising: immersing vanadium wire in a pretreatment chemical isolation liquid and drying it to form a precursor solid film on the surface; fabricating a preform from the vanadium wire with the solid film on the surface using a three-dimensional orthogonal weaving process; placing the preform in a vacuum sintering furnace and heating it to complete solid-phase pre-alloying; fixing the preform in a mold and preheating it under a protective atmosphere; melting a high-carbon steel matrix material until it is completely liquefied, injecting it into the mold to immerse the preform, and cooling it to obtain a composite preform block; subjecting the composite preform block to in-situ reaction diffusion heat treatment to obtain the composite material. This invention prevents the thermal loss of vanadium wire during liquid casting and, through in-situ diffusion reaction, allows the generated vanadium carbide to inherit the initial weaving morphology, achieving a three-dimensional bundled uniform distribution of the reinforcing phase within the steel matrix.

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 present invention provides a low-oxygen vanadium carbide and a method for producing the same, which is formed by reducing the oxygen content, mixing vanadium oxide and a carbon compound, then refining the particle size by high-energy milling using a high-energy milling apparatus, followed by vacuum heat treatment and a carbonization reduction reaction.

The invention belongs to the technical field of electro-catalytic hydrogen evolution, and particularly relates to a metal type cobalt-vanadium carbide heterostructure composite material and a preparation method and application thereof. The method comprises the following steps: dissolving Zn (NO3) 2.6 H2O and Co (NO3) 2.6 H2O in methanol, then adding a 2-methylimidazole methanol solution, uniformly stirring, continuously adding a methanol / water mixed solution containing MXene sol, stirring for reaction, washing, drying to obtain a precursor, and finally putting the precursor in a mixed atmosphere for high-temperature pyrolysis and cooling to obtain the composite electrocatalytic material. According to the method, MOF is adopted for in-situ assembly on the surface of two-dimensional V2C MXene, the composition and structure of a precursor can be effectively controlled, uniform dispersion of a cobalt-vanadium carbide heterostructure in the mesoporous carbon sheet is achieved, and the problems that traditional metal nanoparticles are prone to agglomeration, uneven in distribution and the like are solved. In addition, the synthesis process is simple, convenient and controllable, does not need complex post-treatment or multi-step calcination process, and is suitable for large-scale production.

The invention is directed to a wear resistant vanadium alloyed powder metallurgy produced cold work tool steel for knives consisting of in weight % (wt.%): 2.2 - 2.4 C; 0.1 - 0.55 Si; 0.2 - 0.8 Mn; 4.1 - 5.1 Cr; 3.1 - 4.5 Mo; 7.2 - 8.5 V optional components and impurities balance Fe, wherein the cold work tool steel after hardening does not contain more than 1 volume % of carbides larger than 1 pm other than vanadium carbides and wherein at least 25 % of the vanadium carbides have a size of 3 pm and / or wherein the vanadium carbides are near spherical and at least 55 of the number of the vanadium carbides has an aspect ratio ≤ 1.5. The invention is also directed to a method of producing said steel and the use of said steel.

The invention provides a hard alloy material for an optical mold, a preparation method of the hard alloy material and a near-net forming preparation method of the optical mold. The hard alloy material for the optical mold is formed by mixing 90-93 wt.% of tungsten carbide powder, 90-93 wt.% of vanadium carbide powder and 100 wt.% of silicon nitride powder and then carrying out SPS (spark plasma sintering) on the mixture, and the content of the tungsten carbide powder, the vanadium carbide powder and the silicon nitride powder is 100 wt.% of the total weight of the material. The content of the vanadium carbide is 0.95 wt.% to 1.05 wt.%; and the balance being silicon nitride. The hard alloy material has certain hardness and strength, the thermal expansion coefficient can be matched with the mold core material, the eccentricity of the aspheric lens and the lens assembly yield are effectively improved, the problems that materials are wasted and the machining period is prolonged due to a cake material prepared through a traditional spark plasma sintering technology are solved, and the yield of the optical mold is effectively improved.

The application discloses an alloy material and a preparation method and a mold thereof. The alloy material comprises tungsten carbide, a binder phase, tantalum carbide, chromium, and a carbon compound, wherein the carbon compound comprises at least one of titanium carbide, niobium carbide and vanadium carbide. The mold prepared from the alloy material can be used for preparing lithium battery tabs. The material has good wear resistance, and is not prone to wear, corner collapse, fatigue cracks and the like in high-frequency and high-impact tab stamping operations, so that the service life of the mold is long, and the production continuity and tab forming precision are not affected.

The present application belongs to the technical field of hard alloy material, and particularly relates to a hard alloy for hard rock tooth and a preparation method thereof. The method comprises the following steps: mixing coarse tungsten carbide powder, submicron tungsten carbide powder, cobalt powder, nickel powder, chromium carbide powder, vanadium carbide powder, tantalum carbide powder, niobium carbide powder, dimolybdenum carbide powder, graphite powder, tantalum-niobium-zirconium composite carbide solid solution pinning body and yttrium-doped cerium oxide toughening control body, ball milling, drying, crushing, sieving, granulating, die pressing, cold isostatic pressing, degreasing, vacuum sintering, hot isostatic pressing treatment, grinding, cleaning and drying. The present application can inhibit grain growth by multiple carbides, and can improve the grain boundary and binder phase distribution by using rare earth oxides, so that the obtained hard alloy has good wear resistance, impact resistance and anti-chipping performance, and is suitable for hard rock tooth.

The invention belongs to the field of metal materials, and provides a multi-element hard alloy wear-resisting ball and application of the multi-element hard alloy wear-resisting ball in the heavy industry. Through gradient design of a chromium-rich / molybdenum-rich nano precipitated phase reinforced binding phase, a vanadium carbide and graphite core-shell modified tungsten carbide hard phase, outer-layer low-binding-phase fine grains and inner-core high-binding-phase coarse grains, synergy of high hardness and wear resistance of the outer layer and high toughness and fragmentation resistance of the inner core is realized; the problems that high-hardness wear resistance and low-friction self-lubricating of an existing ball-milling medium are difficult to consider, gradient structure residual stress and interface defect sensitivity are high, and a high-density non-sheath hot isostatic pressing process window is extremely narrow are solved, the wear-resisting ball has the excellent performance that the Vickers hardness HV is 1200-1600, the compressive strength is 4000-6000 MPa, and the density is 14.0-15.3 g / cm < 3 >, and the wear-resisting performance of the wear-resisting ball is greatly improved. The method has wide application value in grinding media of ore ball mills or semi-autogenous mills.

The present invention provides a low-oxygen vanadium carbide and a preparation method therefor, the low-oxygen vanadium carbide having reduced oxygen content and being formed by mixing a vanadium oxide with a carbon compound, and then refining the particle size thereof by means of high-energy milling by using a high-energy milling apparatus, and carbonizing and reducing same by means of a vacuum heat treatment.

The application discloses a kind of corrosion-resistant alloy steel van body and preparation method, belong to van body technical field, first by to van body blank is carried out normalizing, quenching, tempering treatment after obtaining van body semi-finished product, again to van body semi-finished product is sequentially using picosecond laser and nanometer laser and is etched, after anodic oxidation treatment form porous and uniform oxide layer, by laser cladding method uniform vanadium carbide, titanium carbide coating is formed on surface, the porous structure of oxide film can improve the adhesion of subsequent coating, form oxide film plus coating composite protection system, increase the corrosion resistance of corrosion-resistant alloy steel van body, prolong the service life of corrosion-resistant alloy steel van body in slurry pump.

The present application relates to the technical field of alloy, in particular to a kind of hard alloy rod based on regenerated tungsten carbide powder and preparation method thereof.The rod is prepared from carbon shell regenerated tungsten carbide powder, cobalt powder, vanadium carbide powder and tricarbide chromium powder by low-energy mixing, dense mixing extrusion, dewaxing sintering and fine grinding.The carbon shell regenerated tungsten carbide powder is obtained by sequentially forming first polydopamine sublayer containing urea, second polydopamine sublayer and resorcinol-formaldehyde resin outer layer on the surface of regenerated tungsten carbide particles, and then pre-pyrolysis by argon.The hierarchical carbon shell is used to compensate the carbon-oxygen fluctuation on the surface of regenerated tungsten carbide particles during sintering process, so that the obtained rod has fine and uniform tungsten carbide grains, lower hardness dispersion, higher transverse breaking strength and lower micro-drill edge collapse rate.

The invention relates to a carbon-carbon composite material loaded vanadium carbide and bismuth vanadate self-supporting photoelectrocatalysis electrode and a method and application, and belongs to the technical field of photoelectrocatalysis materials.The method comprises the steps that vanadium carbide powder and bismuth vanadate powder are dispersed in isopropanol and polyacrylic acid respectively, then elemental iodine is added, the mixture is mixed to be uniform, and a corresponding mixed solution is obtained; a carbon-carbon composite material is used as a substrate, vanadium carbide and bismuth vanadate are sequentially deposited under 5-10 V and then dried, bismuth vanadate and vanadium carbide are deposited, then drying and etching are sequentially conducted, the mass ratio of vanadium carbide to bismuth vanadate is (0.34-1.02): (0.34-1.02), and the vanadium carbide / bismuth vanadate photoelectrocatalytic photo-anode and photo-cathode are obtained. The efficient and stable photoelectrocatalysis full water splitting performance under the neutral condition can be realized.

This application provides a method for toughening high-strength steel based on the synergistic effect of residual ferrite and vanadium carbides, comprising the following steps: S1: vanadium carbide dissolution treatment; S2: multi-morphology carbide formation treatment; S3: sub-temperature austenitizing heating and holding treatment; S4: multi-type bainite controlled cooling treatment; S5: austenite undecomposed tempering treatment. This application, through the synergistic effect of the formation of multi-morphology vanadium carbides in S1, the residual undissolved ferrite in S2, and the formation of multi-morphology bainite in S3, can significantly improve the impact toughness of steel workpieces without reducing or slightly reducing their strength.

This application relates to the technical field of aluminum alloys, and in particular to a high-strength electrical aluminum alloy and its smelting process. The aluminum alloy comprises an aluminum alloy matrix and a grain inhibitor. The amount of grain inhibitor added is 0.08-0.16% of the weight of the aluminum alloy matrix. The weight percentage of each chemical component of the aluminum alloy matrix is ​​as follows: Fe 0.6-0.85%, Mg 0.7-0.9%, Si 0.05-0.09%, Cu 0.3-0.5%, Re 0.12-0.22%, B 0.02-0.06%, with the balance being Al. The grain inhibitor is prepared by treating a metal carbide mixture with a cationic surfactant, loading graphene oxide, and then reducing the graphene oxide with hydrazine hydrate. The metal carbide mixture is a mixture of titanium carbide, vanadium carbide, and tantalum carbide. It has the advantages of improving the electrical conductivity and strength of the electrical aluminum alloy.

A method is provided for densifying a ceramic matrix composite (CMC) preform in which a porous CMC preform is subjected to slurry infiltration wherein metal carbide particulate material is introduced into the spaces between fiber tows of the CMC preform to form an infiltrated CMC preform. Thereafter, molten metal or molten metal alloy is introduced into the infiltrated CMC preform by melt infiltration to react the metal or molten metal alloy with the metal carbide particulate material and create a ceramic matrix within the CMC preform forming a ceramic matrix composite. The metal carbide particulate material is selected from zirconium carbide particles, hafnium carbide particles, tantalum carbide particles, niobium carbide particles, titanium carbide particles, tungsten carbide particles, cobalt carbide particles, vanadium carbide particles, chromium carbide particles, ytterbium carbide particles, yttrium carbide particles, tantalum hafnium carbide particles, and mixtures thereof.

This invention discloses a method for preparing high-density cobalt-free nano-tungsten carbide cemented carbide, belonging to the field of cemented carbide technology. The preparation method includes the following steps: aluminum powder, copper powder, manganese powder, molybdenum powder, and titanium powder are mixed and then subjected to a first ball milling process to obtain high-entropy alloy powder; nano-tungsten carbide powder, high-entropy alloy powder, tantalum carbide powder, vanadium carbide powder, carbon nanotubes, lanthanum oxide, and yttrium oxide are mixed and then subjected to a second ball milling process to obtain composite powder; paraffin wax, stearic acid, ethylene-vinyl acetate copolymer, and low-density polyethylene are mixed to obtain a binder; the composite powder and binder are kneaded to obtain a compound; the compound is extruded to obtain a green body; the green body is subsequently subjected to solvent degreasing and hot degreasing treatments to obtain a degreased green body; the degreased green body is rapidly hot-pressed and sintered to obtain the high-density cobalt-free nano-tungsten carbide cemented carbide. Through the above scheme, this invention prepares a high-density cobalt-free nano-tungsten carbide cemented carbide with good density, hardness, and oxidation resistance.

A method is provided for densifying a ceramic matrix composite (CMC) preform in which a porous CMC preform is subjected to slurry infiltration wherein metal carbide particulate material is introduced into the spaces between fiber tows of the CMC preform to form an infiltrated CMC preform. Thereafter, molten metal or molten metal alloy is introduced into the infiltrated CMC preform by melt infiltration to react the metal or molten metal alloy with the metal carbide particulate material and create a ceramic matrix within the CMC preform forming a ceramic matrix composite. The metal carbide particulate material is selected from zirconium carbide particles, hafnium carbide particles, tantalum carbide particles, niobium carbide particles, titanium carbide particles, tungsten carbide particles, cobalt carbide particles, vanadium carbide particles, chromium carbide particles, ytterbium carbide particles, yttrium carbide particles, tantalum hafnium carbide particles, and mixtures thereof.

The present disclosure relates to a cemented carbide valve ball manufacturing method, comprising: S1, batching and mixing: S1.1, batching: selecting main material, hard carbide, binder phase and forming agent by percentage; wherein the main material comprises WC powder; the hard carbide adopts one or any combination of titanium carbide, chromium carbide and vanadium carbide; the binder phase adopts Co powder or Ni powder; the forming agent adopts PEG or paraffin; S1.2, mixing: after mixing the main material, hard carbide, binder phase and forming agent, adding alcohol grinding and spray drying, thereby generating a mixture; S2, pressing forming: pressing the mixture generated in S1 into a near-spherical compact; S3, semi-processing: processing the near-spherical compact into a standard spherical compact through semi-processing equipment; S4, sintering: placing the standard spherical compact on a graphite sintering tool in the shape of a ball, and sintering through a hydrogen PEG removal-low pressure sintering integrated sintering process, finally obtaining a cemented carbide valve ball.

The application discloses a rare earth permanent magnet, a sintered magnet material, a preparation method and application. The sintered magnet material comprises a first component and a second component. The first component comprises R: 29mas% to 33mas%, wherein R is a rare earth element; B: 0.86mas% to 1mas%; Cu: 0 to 0.5mas% and not 0; Ga: 0 to 0.5mas% and not 0; and Fe: 64mas% to 70mas%. The second component comprises an antioxidant and a high-melting-point carbide. The high-melting-point carbide comprises one or more of titanium carbide, zirconium carbide, chromium carbide, niobium carbide, tantalum carbide, molybdenum carbide, tungsten carbide, vanadium carbide and hafnium carbide. The content of the high-melting-point carbide is 0.1 to 0.5mas%, and mas% is the mass percentage of each component in the sintered magnet material. The remanence and coercive force of the sintered magnet can be simultaneously maintained at a high level.

The application discloses a vanadium salt hetero-support and a preparation method and application thereof, and belongs to the field of material preparation and catalysis technology. The vanadium oxide-vanadium carbide hetero-support is prepared by a precursor method, vanadium salt is uniformly mixed with an organic carbon source, stirring and dissolving are conducted, drying and filtering are conducted, and a vanadium oxide-vanadium carbide hetero-support precursor is obtained, and the precursor is calcined in an argon or nitrogen atmosphere to obtain the vanadium salt hetero-support. The raw material used is low in price, the process is simple, no flammable and explosive gas is generated in the calcination process, the safety factor is high, the target product is generated by one-step calcination, impurities are not easily introduced, and the repeatability is high. The method is based on the theory of strong and weak metal carrier interaction, and a two-component vanadium salt hetero-support is used as a catalyst base, the catalyst sintering problem caused by Ostwald ripening, particle aggregation and migration is overcome, and thus a catalyst with good stability and good catalytic performance is obtained.

The present application relates to the technical field of alloy, in particular to a high-strength, impact-resistant hard alloy cold heading die preparation method. It aims to improve the anti-chipping and anti-radial cracking ability of the die lip and the working zone under high impact cold heading conditions. The die includes an outer working zone surrounding the die cavity and located in the corresponding area of the lip and the working zone, and a core bearing zone located outside the outer working zone, both of which are sintered integrally. The outer working zone adopts a tungsten carbide nano / micro powder compound system, through two-stage cobalt-containing precursor coating, and introduces ionic cerium source and particulate cerium source at different solid contents in sections, and adjusts the grain and binder phase distribution with vanadium carbide; the core bearing zone adopts a tungsten carbide micro powder-cobalt powder system. The die is prepared by partitioning die pressing, dewaxing, liquid phase sintering and argon pressure sintering, and is suitable for high load and high frequency cold heading forming.

The application discloses a laser cladding alloy powder for cast steel brake disc and a method for synthesizing a nickel-based vanadium carbide composite coating, the laser cladding alloy powder comprising A components (Ni powder, coated Ni@C powder and V powder) and B components (TiC powder) in a mass ratio of 100:0.5-2, wherein the carbon content of the coated Ni@C powder in the A components is 0.75-3.75 wt%, the V powder content is 5-15 wt%, and the balance is Ni and inevitable trace impurities. The alloy powder is used to form a cladding coating on the surface of a cast steel brake disc substrate by a laser cladding method. The coating formed by the laser cladding powder is well metallurgically compatible with the cast steel brake disc substrate, the in-situ synthesized small vanadium carbide particles can be uniformly and dispersedly distributed in the formed cladding coating, the wear resistance of the coating is effectively improved, the cladding coating has better toughness and lower crack sensitivity, the service life of the brake disc is improved, and good economic benefits are achieved.

The invention relates to the technical field of single crystal growth, and discloses a semi-insulating compound single crystal and a preparation method thereof.The preparation method comprises the following steps that silicon carbide powder and vanadium carbide powder are mixed, and silicon carbide mixed powder is obtained; placing the silicon carbide mixed powder at the bottom of a graphite crucible, placing the pretreated seed crystal on a graphite crucible cover, placing the pretreated seed crystal on the upper part of the graphite crucible, assembling the pretreated seed crystal, placing the pretreated seed crystal in a single crystal growth furnace, and sealing the single crystal growth furnace to form an assembled single crystal growth furnace; and vacuumizing the assembled single crystal growth furnace, introducing inert gas, carrying out a heating reaction, reducing the pressure, increasing the pressure, and cooling to room temperature to obtain the semi-insulating compound single crystal. According to the present invention, by introducing the specific deep energy level impurity vanadium element, the inevitable impurities in the silicon carbide single crystal are accurately compensated, such that the carrier is frozen, the high resistivity is achieved, the insulating property of the compound single crystal is improved, the lattice distortion caused by the nitrogen element can be compensated, and the crystal dislocation density can be reduced.

The application discloses a vanadium carbide nano material capable of enhancing photothermal therapy and application thereof, and relates to the technical field of biomedical materials. The vanadium carbide nano material comprises vanadium carbide nanosheets and cell membrane vesicles. The vanadium carbide nano material is coated with V2C nanosheets through engineering of tumor cell membrane vesicles, target delivery is realized, and the photothermal therapy effect is significantly enhanced by utilizing the characteristic of vanadium elements to block the HSF1 phase separation process. The vanadium carbide nano material integrates multiple functions such as target delivery, photothermal conversion, oxidative stress induction and HSF1 phase separation inhibition, and effectively overcomes the heat tolerance of tumor cells.

The invention relates to a preparation method of a gradient thermal expansion ring for a hard alloy composite roller. The method comprises the following steps that raw material powder is weighed according to the following weight percentage: 52%-55% of tungsten carbide, 23%-25% of iron, 0.95%-1.10% of carbon, 2.5%-3.2% of nickel, 9%-11% of cobalt, 3.3%-3.65% of manganese, 1.75%-2.05% of molybdenum, 0.2% of vanadium carbide, 0.3% of chromium carbide, less than 1% of yttrium and lt cerium; 1.3%, 0.5-3% of silicon carbide; the raw material powder is mixed and then subjected to ball milling, and slurry obtained through ball milling is dried to form mixed powder; and forming the mixed powder into an annular green body, and sintering the green body to form the gradient thermal expansion ring. The product obtained through the method is uniform in microstructure, high in density and good in strength, toughness and heat stability, and therefore the service life of the composite roller is remarkably prolonged, and the reliability of the composite roller is remarkably improved.

This invention relates to the field of rail manufacturing technology, and proposes a method for producing bainitic rails with fatigue resistance. The method includes: heating and rolling a steel billet with a target composition into a rail, wherein the steel billet with the target composition comprises, by mass percentage: 0.20~0.35% C, 1.4~1.80% Si, 1.50~2.20% Mn, and 0.80~1.50% Cr, and simultaneously contains 0.20~0.70% Ni and 0.03~0.12% Ni. The steel rail comprises % V, 0.0005%~0.637% alloying elements selected from one or more of Mo, Ti, Nb, B, and Al, with the balance being Fe and unavoidable impurities. Controlled cooling after rolling ensures the rail obtains a bainitic structure within the bainitic transformation temperature range. During cooling, deformation treatment is applied to the rail within this range to induce vanadium carbide precipitation and stabilize the structure. Subsequently, cooling to room temperature yields a bainitic rail with fatigue resistance. This invention enables the short-process, high-efficiency industrial production of fatigue-resistant bainitic rails at a relatively economical alloy cost.

The application belongs to the technical field of hard alloy, and particularly relates to a high-cobalt superfine hard alloy and a preparation method thereof. The preparation method comprises the following steps: S1, obtaining tungsten carbide powder, cobalt powder, vanadium carbide powder and chromium carbide powder, performing first ultrasonic cell disruption on the tungsten carbide powder to obtain first mixed material, performing second ultrasonic cell disruption on the vanadium carbide powder to obtain second mixed material, and adding the second mixed material into the first mixed material to perform third ultrasonic cell disruption to obtain third mixed material; performing centrifugal spraying on the third mixed material to obtain WC-VC composite powder; S2, performing first ball milling on the cobalt powder and the chromium carbide powder to obtain first slurry; performing second ball milling on the WC-VC composite powder to obtain second slurry; adding the first slurry into the second slurry to perform third ball milling to obtain third slurry; S3, performing drying, pressing and sintering on the third slurry to obtain the high-cobalt superfine hard alloy. The high-cobalt superfine hard alloy with excellent performance is prepared through VC coating and Cr3C2 pre-solid solution.

The application relates to the technical field of stainless steel pipes, in particular to a corrosion-resistant stainless steel pipe and a preparation method thereof and a stainless steel pipe, the stainless steel pipe comprises the following chemical components in percentage by weight: C: 0.11-0.15%, Si: 0.5-0.7%, Mn: 1.2-1.7%, Ta: 0.3-0.8%, Ce: 0.7-1.2%, Cr: 10.1-13.2%, Ni: 4.5-7.5%, Mo 0.5-1%, Cu 3.5-7.5%, S <=0.02%, P <=0.045%, an inclusion phase regulator 0.5-2%, and the balance is Fe element and inevitable impurities; the inclusion phase regulator is prepared by compounding titanium carbide, vanadium carbide and chromium carbide; the stainless steel pipe has the advantages of improving corrosion resistance.

The invention relates to the field of powder metallurgy materials, and discloses a hot isostatic pressing preparation method of high-density powder metallurgy die steel and a composite powder premix. The premix comprises H13 die steel powder and trace amorphous boron, manganese nitride and vanadium carbide. The preparation method adopts a step-by-step temperature-pressure coupling process: in a low-temperature stage, amorphous boron reacts with surface oxygen to generate liquid-phase wetting particles; in the medium-temperature stage, a liquid-phase channel is used for assisting active nitrogen in replacing a surface refractory oxide film; densification is achieved in the high-temperature stage. According to the method, through the synergistic effect of low-temperature liquid phase induction and medium-temperature diffusion replacement, the continuously-distributed thin-film-shaped oxide is converted into the dispersively-distributed granular carbonitride in situ, and splitting of a matrix by original particle boundaries is eliminated. According to the method, the transverse impact toughness of the die steel is remarkably improved while a fine-grain high-density structure is obtained.